Cerebellar Efferent Pathways

Cross references:      Cerebellum   Deep Cerebellar Nuclei  
Cerebellum Tonic Inhibition   
 
Cerebellar Afferent Pathways 
Posterior Horn of the Spinal Cord      

    From:  Cerebellum
"The cerebellum ... receives input from sensory systems and from other parts of the brain and spinal cord, and integrates these inputs to fine tune motor activity.[2]"
    "...
almost all of its output is directed to a set of small Deep Cerebellar Nuclei lying in the interior of the cerebellum."   
My comment

  
  Maybe I should look more closely at the " Deep Cerebellar Nuclei  ". 


Searching Google for "Cerebellar Efferent Pathways"  revealed 109,000 claimed references: 
https://www.google.com/search?q=Cerebellar+Efferent+Pathways&ie=utf-8&oe=utf-8  


Searching PubMed for "Cerebellar Efferent Pathways"  revealed, first 1214, then 1217, claimed references:
http://www.ncbi.nlm.nih.gov/pubmed/?term=Cerebellar+Efferent+Pathways  


1977   966<1214
An experimental study of the efferent connections of the superior cerebellar peduncle in the rhesus monkey.
   
    "
Unilateral electrolytic lesions were made in the right superior cerebellar peduncle immediately lateral of its decussation or in the dentate nucleus of 6 monkeys. The course of the contralateral ascending and descending degenerated fibers and sites of preterminal degenerated fibers were studied in material stained by Fink-Heimer, Nissl and Weil methods.
    Major thalamic sites of preterminal degeneration were in the rostral part of VPLo, and in VPI, VLo, VApc, CL and PCn. In other thalamic nuclei or subdivisions, no preterminal was observed or was questionable. No degenerated fibers entered the internal capsule or corpus striatum. There was abundant preterminal degeneration in the rostral part of the nucleus ruber and adjacent reticular formation. The descending degenerated fibers of the superior cerebellar peduncle led to massive preterminal degeneration in the central part of the nucleus reticularis tegmentalis and in nuclei raphe pontis and magnus. The most caudal site of preterminal degeneration (minimal) was in the nucleus reticularis gigantocellularis adjacent to the median longitudinal fasciculus."  
    My summary and comments
1.  " Major thalamic sites of preterminal degeneration were in the rostral part of VPLo, and in VPI, VLo, VApc, CL and PCn.
2.  "
No degenerated fibers entered the internal capsule or corpus striatum."   
3.  "
The descending degenerated fibers of the superior cerebellar peduncle led to massive preterminal degeneration in the central part of the nucleus reticularis tegmentalis and in nuclei raphe pontis and magnus."  
4.  No indication of whether the "preterminal fibers" led to excitatory or inhibitory synapses. 


1978   943<1214
Cerebellar cortical efferent fibers of the paraflocculus of tree shrew (Tupaia glis).
   
    "
Efferent projections from the paraflocculus of the tree shrew (Tupaia glis) were studied utilizing the Fink and Heimer ('67) method.  
    Cerebellar corticonuclear fibers of both dorsal (Dpf) and ventral (Vpf) divisions of the paraflocculus terminate in the lateral cerebellar nucelus (NL) and in the posterior interposed nucleus (NIP). These fibers are ipsilateral, topographically organized and arranged into at least two zones.  
    Following injury to either the Dpf or Vpf, degenerated axons are found in lateral and caudal regions of the NIP respectively. Consequently, these two portions of the paraflocculus have relatively exclusive terminal fields with overlap only at the periphery. Preterminal debris is seen in basically similar areas of the NL (caudolateral, caudal, ventral) after damage to either the Dpf or Vpf.  This observation leads to the conclusion that the terminal fields for these areas of parafloccular cortex are largely coextensive in the NL. 
     In addition to the topographical representation of the Dpf and Vpf in both the NL and NIP, there is evidence that these corticonuclear fibers are also organized into the general zonal pattern hypothesized by Voogd ('69). Persistent and numerous degenerated axons from both the Dpf and Vpf end in lateral and caudal NIP, respectively, corroborating the presence of a relatively wide zone C2 in both divisions of the paraflocculus.  
    The Dpf and Vpf also project into the NL to a terminal field that appears to consist of two portions. One part located in caudal, ventral and/or caudoventral areas of the NL and a second at slightly more rostral and rostrolateral areas. The presence of a cortical region which is affiliated with two areas of the NL substantiates not only the existence of zone D in the paraflocculus, but gives experimental evidence that it may consist of two parts as previously suggested (Voogd, '69).  
    From the Dpf many fibers enter the NL while few are seen in this nucleus after damage to the Vpf. This suggests that zone D is wider in the Dpf and narrower in the Vpf. The results of this study do not support previous suggestions that the paraflocculus projects to either only the NL or to most of, or all of, the ipsilateral cerebellar nuclei. No projections to any contralateral cerebellar nuclei are seen. There is also no conclusive proof that the parafloccular cortex of Tupaia projects into the vestibular complex or to any other brainstem relay nuclei."   
    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.   


1979   923<1214
Thalamic relay nuclei for cerebellar and certain related fiber systems in the cat.
   
    "
Anterograde labeling techniques were used to define the terminal distributions in the thalamus of afferents arising in the deep cerebellar nuclei, entopeduncular nucleus and substantia nigra. Anterograde and retrograde labeling methods were then used to determine the extent of the cortical projections of the cerebellar relay nuclei. 
    The cerebellar projection to the contralateral ventral nuclei of the thalamus terminates in a zone which is separate from that receiving pallido- and nigrothalamic fibers. None of the zones of termination of these fiber systems corresponds to commonly recognized cytoarchitectonic divisions. Instead, they include parts of the ventroanterior (VA), ventrolateral (VL) and principal ventromedial (VMp) nuclei. 
     Some cells within the zone of termination of cerebellar afferents project to parietal cortex (areas 5 and 7). A further, distinct group of cells in this zone projects to motor cortex (area 4). But projections to area 4 also arise from small groups of cells: (a) in the zone receiving nigro- and pallidothalamic fibers; (b) in the part of VL, distinct from the cerebellar terminal zone, in which spinothalamic fibers terminate. Cerebellar, nigral, and entopeduncular fibers also terminate in the intralaminar nuclei. These projections are far greater in extent than those arising in the spinal cord. Some parts of the intralaminar nuclei are dominated by a particular afferent system, while others show substantial overlap of the terminal zone of several afferent systems."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1981    898<1214
Projections of the cerebellar and dorsal column nuclei upon the thalamus of the rhesus monkey.
       
    "
Projections from the cerebellar and dorsal column nuclei to the midbrain and thalamus of the rhesus monkey were traced with anterograde autoradiographic techniques, or, in a few cases, with the Fink-Heimer method.  
    The cerebellar nuclei give rise to a massive projection to the contralateral midbrain and thalamus via the ascending limb of the superior cerebellar peduncle.
    Cerebellar efferent fibers terminate contralaterally in both divisions of the red nucleus, and bilaterally in the interstitial nucleus of Cajal, the nucleus of Darkschewitsch, the oculomotor nucleus, and the central gray. All the deep cerebellar nuclei project upon a broad area of the contralateral ventral thalamus as well as certain intralaminar nuclei. Corresponding ipsilateral thalamic terminations are sparse.  
    The topographic organization of cerebellothalamic fibers does not correspond to individual cerebellar nuclei or to cytoarchitectonic divisions of the ventral thalamic nuclei. Rather there are longitudinally oriented strips of terminal labeling which extend through all divisions of the ventral lateral nucleus, i.e., the VLps, the VLc, the VLo, as well as nucleus X, the oral division of the ventral posterolateral nucleus (VPLo), the central lateral nucleus (CL), and the most caudal region of the ventral anterior nucleus (VA).  
    The topography of the cerebellothalamic fibers is arranged in a mediolateral pattern with fibers originating from anterior zones of the dentate and interpositus ending most laterally and those from posterior dentate and interpositus terminating most medially. The fastigial contribution is relatively sparse. The longitudinal strips of terminal labeling in the ventral thalamic nuclei are made up of still smaller terminal units consisting of disk-like aggregates of silver grains separated from one another by grain-free spaces.
    The dorsal column nuclei terminate primarily in the contralateral caudal division of the VPL (VPLc) and never extend rostrally into VPLo. These results demonstrate a segregation of cerebellar and dorsal columnar inputs to motor and sensory regions of the thalamus, respectively. Since these regions are separate and discrete in their cortical associations as well (Kalil, '76), it seems unlikely that fast afferent pathways relaying to motor cortex (Lemon and Porter, '76) could arise from the dorsal column nuclei."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1981   896<1214
Divergent collaterals from deep cerebellar neurons to thalamus and tectum, and to medulla oblongata and spinal cord: retrograde fluorescent and electrophysiological studies.
   
    "
In cat the existence of collaterals from deep cerebellar neurons, which project to mesencephalon and thalamus has been investigated anatomically by means of the multiple retrograde fluorescent tracer technique as well as electrophysiologically by means of conventional antidromic techniques.  
    Both sets of data indicate that several neurons in the medial nucleus, which project to mesencephalon and thalamus, also distribute collaterals to medulla oblongata and spinal cord. These branching neurons were principally located in the caudal and intermediate portions of the medial nucleus. The electrophysiological data in addition indicate that the branching point of the neurons in the medial nucleus is located relatively close to the cell soma. The anatomical findings show a further group of branching neurons in the lateral nucleus at the border with the interpositus nuclei. The majority of these latter neurons distribute collaterals to medulla oblongata but some distribute collaterals to spinal cord. However, it could not be decided as yet whether the collaterals to the medulla oblongata terminate either in medullary medial reticular formation or in inferior olive or in both."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1981    889<1214
Anatomical evidence for direct fiber projections from the cerebellar nucleus interpositus to rubrospinal neurons. A quantitative EM study in the rat combining anterograde and retrograde intra-axonal tracing methods.
   
    "
A quantitative electron microscopic (EM) study combining the anterograde intra-axonal transport of radioactive amino acids and the retrograde intra-axonal transport of the enzyme horseradish peroxidase (HRP) was performed in the magnocellular red nucleus of the rat to obtain anatomical evidence as to whether there is a direct projection from the cerebellar nucleus interpositus to the cells in the red nucleus that give rise to the rubrospinal tract.  
    Large asymmetrical synaptic terminals were radioactively labeled in the magnocellular red nucleus following injections of [3H]leucine into the cerebellar nucleus interpositus. In these same animals, the postsynaptic target neurons were labeled with HRP granules after injection of this substance in the rubrospinal tract.  
    A quantitative analysis showed that more than 85% of the large and giant neurons in the magnocellular red nucleus were labeled with HRP granules and also received synaptic contacts from radioactively-labeled terminals. Thus, it can be concluded that in the rat, afferents from the cerebellar nucleus interpositus establish asymmetrical synaptic contacts with large and giant rubrospinal neurons, thus confirming and extending the previous physiological evidence of such direct monosynaptic connections." 

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1981   885<1214
Cerebellothalamic projections in the rat: an autoradiographic and degeneration study.
   
    "
The purpose of this study was to determine the topographical organization of cerebellothalamic projections in the rat.  
    Following stereotaxic injections of 3H-leucine or electrolytic lesions in the cerebellar nuclei, efferent fibers were observed to emerge from the cerebellum through two discrete routes.  
    Fibers from the fastigial nucleus decussated within the cerebellum, formed the crossed ascending limb of the uncinate fasciculus, ascended in the dorsal part of the midbrain tegmentum, and entered the thalamus.  
    Cerebellothalamic fibers from the interpositus and dentate nuclei coursed in the ipsilateral brachium conjunctivum, decussated in the caudal midbrain, and ascended to the thalamus via the crossed ascending limb of the brachium conjunctivum.  
    Cerebellar terminations were observed in the intralaminar, lateral, and ventral tier thalamic nuclei as well as in the medial dorsal nucleus. Projections to the intralaminar nuclei were more pronounced from the dentate and posterior interpositus than from the anterior interpositus and fastigial nuclei. The lateral thalamic nuclei received a projection from the dentate and posterior interpositus nuclei while the fastigial nucleus projected to the medial dorsal nucleus.  
    Within the rostral ventral tier nuclei fastigiothalamic terminations were localized in the medial parts of the ventral medial and ventral lateral nuclei, whereas dentatothalamic projections were concentrated in the lateral parts of the ventral medial nucleus and the medial half of the ventral lateral nucleus. Terminations from the posterior interpositus nucleus were observed ventrally and laterally within the caudal two-thirds of the ventral medial nucleus and throughout the ventral lateral nucleus, where they were densest in the lateral part of its lateral wing and within the central part of its cap. The anterior interpositus nucleus also projected to the central and lateral parts of the ventral lateral nucleus, but these terminations were considerably less dense than those from the posterior interpositus. A few fibers from the interpositus nuclei terminated in the medial part of the rostral pole of the ventral posterior nucleus. A prominent recrossing of cerebellothalamic fibers from the fastigial, posterior interpositus, and dentate nuclei occurred through the central medial nucleus of the internal medullary lamina. These terminated within the ipsilateral ventral lateral and intralaminar nuclei.  
    These results show that each of the cerebellar nuclei project to the thalamus and that their terminations are topographically organized in the rostral ventral tier nuclei. The clustering of autoradiographic silver grains or terminal degeneration observed in the thalamic nuclei suggests a medial-to-lateral organization of this cerebellothalamic system."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1981   881<1214
Axonal branches of the same cerebellar neurons terminate bilaterally in the thalamus.   
    "
The efferent projections of the deep cerebellar nuclei which terminate bilaterally in the thalamus were investigated in the rat by means of the retrograde fluorescent double-labeling technique. After injection of True Blue or Fast Blue in the thalamus on one side and Nuclear Yellow on the other, the deep cerebellar nuclei on both sides contained many cells single-labeled from the contralateral thalamic injection and some cells double-labeled from both thalamic injections.  
    Double-labeled cells were more numerous in the caudal part of the medial nucleus than in the other cerebellar nuclei. The present results indicate that some cerebellar cells give origin to bilateral thalamic projections by means of axon collaterals."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1981   880<1214
An autoradiographic study on the terminal distribution of cerebellothalamic fibers in the cat.
   
    "
Distribution of cerebellothalamic fibers was studied in the cat by the anterograde tracing method. The vast majority of cerebellothalamic fibers were distributed contralaterally.  
    The fastigial fibers arose mostly from the caudal half of the nucleus. These ended moderately in the VM and the most ventromedial regions of the VA-VL complex, and sparsely in the ventral portions of the CL, Pc and NCM; a few also ended in the CM and ZI.  
    The dentate fibers ended moderately in the median and rostrodorsal VA-VL regions, and sparsely in the VM, CL, NCM, CM, LP and MD. The existence of the dentatopulvinar fibers was also confirmed.  
    The posterior interpositus fibers ended heavily in the central VA-VL regions, moderately in the subparafascicular nucleus and ZI, and sparsely in the CM and the ventral lateral geniculate nucleus. The anterior interpositus fibers ended mainly in the ventrolateral VA-VL regions, and additionally in the CL and CM. The ipsilateral cerebellothalamic fibers arose mainly from the fastigial nucleus, and additionally from the dentate nucleus; those arising from the interpositus nuclei were very sparse."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1981   870<1214
Demonstration of zonal projections from the cerebellar flocculus to vestibular nuclei in monkeys (Macaca fuscata).
   
    "
Purkinje cells in the flocculus of macaque monkeys were labeled by retrograde axonal transport of horseradish peroxidase from the vestibular nuclei. These neurons are organized in three adjacent, narrow bands which span all folia of the ipsilateral flocculus. The central band, 500-750 micrometer wide, projects to the medial vestibular nucleus, while the two adjacent bands, each 300-500 micrometer wide, innervate the superior vestibular nucleus. These three bands cover about one-half of the total area of the Purkinje cell layer of flocculus. Thus, the pattern of zonal projections in monkeys is the same as reported in rabbits and cats."  
    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1982    855<1214
Divergent axon collaterals from rat cerebellar nuclei to diencephalon, mesencephalon, medulla oblongata and cervical cord. A fluorescent double retrograde labeling study.
   
    "
The existence of divergent axon collaterals of neurons in the deep cerebellar nuclei has been investigated in rat by means of the fluorescent retrograde double labeling technique. The results have led to the following conclusions.  
    A. Many of the neurons in the lateral, the interpositus as well as the caudal half of the medial nucleus project to the diencephalon. Some of these neurons distribute divergent axon collaterals to the superior colliculus, but few neurons project only to the latter structure.  
    B. Some of the deep cerebellar neurons located laterally, i.e. in the dorsomedial part of the lateral nucleus, as well as some others located medially, i.e. in the medial part of the interpositus nucleus and the adjoining part of the medial nucleus, distribute divergent axon collaterals to the diencephalon and the spinal cord.  
    C. Deep cerebellar neurons located laterally: in the cell group of the dorsolateral hump (Dlh) and in the adjoining lateral part of the interpositus nucleus, as well as some other located medially, i.e. in the dorsolateral part of the median nucleus (Mdlp), distribute divergent axon collaterals to the diencephalon and to the medulla oblongata, probably primarily its medial reticular formation. However, only few of the neurons, which distribute descending collaterals to the spinal cord or the medulla oblongata, distribute ascending collaterals to the superior colliculus.  
    D. After injections in the medulla oblongata a population of small sized single labeled neurons was encountered especially in the lateral and interpositus nuclei. On the basis of other findings in rat they were assumed to represent cerebello-olivary neurons."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented.


1982     837<1214
The cerebellar projections to the superior colliculus and pretectum in the cat: an autoradiographic and horseradish peroxidase study.
   
    "
Efferent projections from the cerebellar nuclei to the superior colliculus and the pretectum have been studied using both retrograde and orthograde labeling techniques in the cat. In order to identify what parts of the cerebellar nuclei project to the superior colliculus and the pretectum, the retrograde horseradish labeling technique was employed. In another set of experiments, tritiated amino acids were injected into each of the cerebellar regions from which the cerebello-tectal and cerebello-pretectal projections arise, and the laminar and spatial distributions of orthograde labeling in the superior colliculus and the pretectum were compared.  
    The results showed that the cerebello-tectal projections arise from two different regions of the cerebellar nuclei: the caudal half of the medial nucleus and the ventrolateral part of the posterior interposed nucleus. Fibers arising from the medial nucleus distribute bilaterally in the superficial zone of the intermediate gray layer in the superior colliculus, while those originating from the posterior interposed nucleus terminate contralaterally in the deeper aspect of the intermediate gray layer and in the deep gray and white layers. 
    Although the lateral nucleus does not contribute to the cerebello-tectal projection, it projects profusely to the pretectum contralaterally. The origin of the cerebello-pretectal projection lies in the parvicellular part of the lateral nucleus. Among several pretectal nuclei, the posterior pretectal, the medial pretectal nucleus and the reticular part of the anterior pretectal nucleus receive the cerebellar afferents.  
    The findings of the differential projections from the cerebellum to the superior colliculus and the pretectum suggest that the cerebellum exerts a regulatory influence on visuo-motor and somato-motor transfer in these midbrain structures by differential circuits."  

    My comment
No indication of the identity of the neurotransmitters.  Perhaps the necessary technologies had not yet been invented. 
   

N
one of the references I had reviewed so far specied the neurotransmitters employed by the tracts the references consider.  Perhaps the necessary technologies had not yet been invented.    So, one possible next step is to look at more recent references.  I'll be looking for references that mention neurotransmitters in their title. 


1982   830<1214
Convergent inputs from the dentate and the interpositus nuclei to pyramidal tract neurons in the motor cortex.
     
    No mention neurotransmitters in the title. 


1983    
822<1214
Electrophysiologic studies on the pallido- and cerebellothalamic projections in squirrel monkeys (Saimiri sciureus).
   

    No mention neurotransmitters in the title. 


1983   
808<1214
Anatomical evidence for segregated focal groupings of efferent cells and their terminal ramifications in the cerebellothalamic pathway of the monkey.
   

    No mention neurotransmitters in the title. 


1983   
800<1214 
The cerebellar nucleo-cortical projection in the rat studied by the retrograde fluorescent double-labelling method.
   

    No mention neurotransmitters in the title. 


1984   
780<1214   
Cerebellar connections in Xenopus laevis. An HRP study.
   

    No mention neurotransmitters in the title. 


1984   
770<1214   
Electrophysiological and morphological studies on thalamic neurons receiving entopedunculo- and cerebello-thalamic projections in the cat.
   

    No mention neurotransmitters in the title. 


1984   
764<1214 
Cerebellar cortical efferent fibers in the North American opossum, Didelphis virginiana. I. The anterior lobe. 

    No mention neurotransmitters in the title. 


1984   
763<1214   
Cerebellar cortical efferent fibers in the North American opossum, Didelphis virginiana. II. The posterior vermis.  

    No mention neurotransmitters in the title. 


1984   
758<1214 
Cerebellar efferents in the lizard Varanus exanthematicus. I. Corticonuclear projections.
   

    No mention neurotransmitters in the title. 


1984   
755<1214  
An HRP study of hypothalamo-cerebellar and cerebello-hypothalamic connections in squirrel monkey (Saimiri sciureus).
 

    No mention neurotransmitters in the title. 


1984   
753<1214 
Cerebellar efferents in the lizard Varanus exanthematicus. II. Projections of the cerebellar nuclei. 

    No mention neurotransmitters in the title. 


1984   
745<1214   
Bidirectional neuronal connections between the cerebellar interpositus nucleus and the brainstem (an autoradiographic study).  

    No mention neurotransmitters in the title. 


1985   
744<1214
Synaptic organization of the cerebello-thalamo-cerebral pathway in the cat. I. Projection of individual cerebellar nuclei to single pyramidal tract neurons in areas 4 and 6.
 

    No mention neurotransmitters in the title. 


1985   
716<1214 
The cerebellar and vestibular nuclear complexes in the turtle. II. Projections to the prosencephalon.
 

    No mention neurotransmitters in the title. 


1985   
715<1214 
The cerebellar and vestibular nuclear complexes in the turtle. I. Projections to mesencephalon, rhombencephalon, and spinal cord.
  

    No mention neurotransmitters in the title. 


1986    701<1214 
Cerebellar corticonuclear and corticovestibular fibers from the posterior lobe of the albino rat, with comments on zones.
 

    No mention neurotransmitters in the title. 


1986   
694<1214 
Fastigial nucleus projections in the midbrain and thalamus in dogs.
 

    No mention neurotransmitters in the title. 


1986   
684<1214 
Role of the cerebellum in the visual guidance of movement.
 

    No mention neurotransmitters in the title. 


1987   
671<1214 
Collateralization of cerebellar efferent projections to the paraoculomotor region, superior colliculus, and medial pontine reticular formation in the rat: a fluorescent double-labeling study.
  

    No mention neurotransmitters in the title. 


1987   
655<1214   
Origin and trajectory of the cerebello-olivary projection: an experimental study with radioactive and fluorescent tracers in the cat.
  

    No mention neurotransmitters in the title. 


1987   
649<1214 
Afferent and efferent connections of the oculomotor cerebellar vermis in the macaque monkey.
  

    No mention neurotransmitters in the title. 


1987   
646<1214 
The interposito-rubrospinal system. Anatomical tracing of a motor control pathway in the rat.
 

    No mention neurotransmitters in the title. 


1988   
632<1214 
Projections of the vestibular and cerebellar nuclei in Rana pipiens.
  

    No mention neurotransmitters in the title. 


1988  
629<1214 
The cerebellar nucleocortical projections in the rat. A retrograde labelling study using horseradish peroxidase combined to a lectin.
 

    No mention neurotransmitters in the title. 


1988   
627<1214 
Origin of cerebellar projections to the region of the oculomotor complex, medial pontine reticular formation, and superior colliculus in New World monkeys: a retrograde horseradish peroxidase study.
  

    No mention neurotransmitters in the title. 


1988   
616<1214 
Connections of the paraflocculus of the cerebellum with the superior colliculus in the rat brain.  

    No mention neurotransmitters in the title. 


1988   
612<1214 
Observations on the development of certain ascending inputs to the thalamus in rats. I. Postnatal development.
 

    No mention neurotransmitters in the title. 


1989   
601<1214 
The cerebellar nuclear afferent and efferent connections with the lateral reticular nucleus in the cat as studied with retrograde transport of WGA-HRP.  

    No mention neurotransmitters in the title. 


1989    594<1214 
Afferent and efferent connections of the cholinoceptive medial pontine reticular formation (region of the ventral tegmental nucleus) in the cat.   
https://www.ncbi.nlm.nih.gov/pubmed/2736395   
    My comment
This is the first reference in the search which mentions a neurotransmitter in its title.  However, the Abstract makes no mention of any neurotransmitter. 


1991    560<1214 
Distribution of glutamine-like immunoreactivity in the cerebellum of rat and baboon (Papio anubis) with reference to the issue of metabolic compart.   
https://www.ncbi.nlm.nih.gov/pubmed/1686533   
    My comment
This is only the second reference to mention a neurotransmitter in its title. 


1991    546<1214 
Transplantation of a temperature-sensitive, nerve growth factor-secreting, neuroblastoma cell line into adult rats with fimbria-fornix lesions rescues cholinergic septal neurons.     
https://www.ncbi.nlm.nih.gov/pubmed/2033646   
    My comment
This reference was a bit over my head.  It did mention a neurotransmitter in the title, but I didn't understand it. 


1992    529<1214 
Cerebellar nuclei and the nucleocortical projections in the rat: retrograde tracing coupled to GABA and glutamate immunohistochemistry.  
https://www.ncbi.nlm.nih.gov/pubmed/1371781   
    "
The amino acids GABA and glutamate (Glu) are thought to be the principal substances in the central nervous system responsible for neuronal inhibition and excitation. Their distributions among the different neurons in a defined pathway may thus be indicative of the contributions of the cells to pathway function. Examples of such neurons are those of the cerebellar nuclei which, while regulating output from the Purkinje cells of the cerebellar cortex, are also found to project back to the cerebellar cortex. 
    Immunohistochemical experiments were done to identify GABA and glutamate (Glu) containing cells in the adult rat cerebellar nuclei. Consecutive semithin and serial vibratome sections were incubated with antisera raised in rabbit against GABA and Glu. In semithin sections, only small neurons were intensely GABA immunoreactive (GABA-IR) (31.7%), and the majority (80.5%) were Glu immunoreactive (Glu-IR) of different sizes. Consistent with Glu being a metabolic precursor for GABA, 75.4% of the GABA-IR population colocalized Glu.  
    In vibratome sections GABA-IR neurons showed some local differences in number, whereas the Glu-IR were uniformly distributed in the three nuclei studied. Measured mean diameters for these neurons showed a distinct size difference for the GABA- and Glu-IR with little overlap.  
    Cerebellar
nuclei neurons projecting to the cortex (nucleocortical neurons, NCN) were identified by locally preinjecting the retrograde transported WGA-apoHRP-colloidal gold complex in the cerebellar cortex. Vibratome sections of these cerebellar were silver intensified for the retrograde tracer and double labeled for GABA and Glu. Of the total number of identified NCN, 8.7% were GABA-IR (10 animals) and 47.7% Glu-IR (5 animals). Many retrograde labeled NCN in the core of the thick sections were immunonegative for both amino acids due to poor antibody penetration, thus underestimating the proportions of cells containing GABA and Glu. The size distributions for the GABA-IR and Glu-IR NCN were similar to those measured in non-retrograde labeled nuclei in thick sections.  
    The conclusions reached are that GABA-IR neurons of the cerebellar nuclei, including the NCN, use GABA as the presumed inhibitory neurotransmitter and that Glu-IR neurons may use Glu or another excitatory neurotransmitter."  
    My comment
Although this reference provides a clear discussion of GABA and Glu as cerebellar neurotransmitters, I don't have a clear understanding whether either of them are efferent from the cerebellum to other parts of the nervous system.   


1992    522<1214 
Secondary vestibular cholinergic projection to the cerebellum of rabbit and rat as revealed by choline acetyltransferase immunohistochemistry,
retrograde and orthograde tracers.   
https://www.ncbi.nlm.nih.gov/pubmed/1577999  
    See:  Cerebellar Afferent Pathways 


1992    517<1214 
Efferent projections from the flocculus in the albino rat as revealed by an autoradiographic orthograde tracing method. 
https://www.ncbi.nlm.nih.gov/pubmed/1324779   
    "
The terminal sites of floccular efferent fibers were investigated in the albino rat by an autoradiographic orthograde method. The corticonuclear fibers terminated in the caudoventral part of the lateral cerebellar nucleus and in the caudoventral region of the lateral part of the posterior interpositus nucleus. A few fibers from the rostral flocculus terminated in the granular cell layer of the basolateral part of the nodulus and uvula as mossy fiber type terminals. The projection to the nodulus and uvula was confirmed, by an additional retrograde HRP study, to originate from scattered spindle-shaped cells in the floccular stalk.  
    The corticovestibular fibers terminated massively in the subnucleus y. The fibers passing through the subnucleus y divided into two bundles; one bundle coursed rostrally to terminate in the lateral and ventral parts of the superior vestibular nucleus, while the other bundle passed through the lateral and then ventral parts of the lateral vestibular nucleus, supplying a few terminals to these regions, to terminate sparsely in the rostral to intermediate part of the medial vestibular nucleus and the rostroventral part of the spinal vestibular nucleus.  
     Some fibers passing through the lateral vestibular nucleus coursed rostrally to terminate in the medial part of the superior vestibular nucleus. Sparse terminals derived from the rostral flocculus were found in the prepositus hypoglossal nucleus. No definitive differential efferent projections were demonstrated in the rat flocculus."  
    My comment
The only pathways I see leaving the cerebellum terminate in the vestibular and hypoglossal nuclei.   


1992    512<1214   
Patterns of termination of cerebellar and basal ganglia efferents in the rat thalamus. Strictly segregated and partly overlapping projections. 
https://www.ncbi.nlm.nih.gov/pubmed/1279485   
    "
There is a widely held view that the cerebellum and basal ganglia act via separate subcortical channels. In rodent, however, electrophysiological evidence suggests that the output of these two systems is partly sent to a common set of thalamic neurons.  
    In this study, the pattern of thalamic innervations provided by the deep cerebellar nuclei, the entopeduncular nucleus, and the substantia nigra pars reticulata was reinvestigated in the rat using the anterograde tracers Phaseolus vulgaris leucoagglutinin and wheat germ agglutinin.  
    Although the results confirm the existence of some overlap in the cerebellar and basal ganglia projection fields, they also show that in such convergent areas the cerebellar innervation is modest and consists of sparsely distributed fibers of thin diameter that provide a few scattered terminal boutons.  
    These observations are consistent with the view that, in rodent as in higher mammalian species, the cerebellum and the basal ganglia act mainly via distinct thalamo-cortical channels."  
    My comment
No mention of neurotransmitters. 



1994    469<1214 
Cerebellar terminations in the red nucleus of Macaca fascicularis: an electron-microscopic study utilizing the anterograde transport of WGA:HRP. 
https://www.ncbi.nlm.nih.gov/pubmed/7526581        
    "
The red nucleus (RN) of the macaque monkey is divided into a rostral two-thirds, the parvicellularis (RNp), which projects to the cerebellum by way of the inferior olivary nucleus, and a caudal third, the magnocellularis (RNm), which projects to the spinal cord via the rubrospinal tract.  
    The RNp and RNm receive afferents from two principal sources: the cerebral motor cortices and the deep cerebellar nuclei. The terminations of these two afferent projections tend to be spatially segregated on rubral neurons, in that most corticorubral afferents terminate on more distal dendrites, and those from the deep cerebellar nuclei terminate more proximally.  
    The present electron-microscopic analysis of the cerebellar terminations in the macaque RN provides anatomical evidence for the presence of labeled afferents in both divisions of this motor nucleus, following injection of wheatgerm agglutinin conjugated to horseradish peroxidase (WGA:HRP) into the deep cerebellar nuclei and the anterograde transport of the tracer to the RN. The cerebellar terminal afferents are large; contain numerous mitochondria and primarily rounded synaptic vesicles; and form asymmetric synaptic contacts with rubral neurons. Unlike other terminals in the nucleus, they possess an electron-lucent cytoplasmic matrix and less densely packed synaptic vesicles. They are termed "large, round, pale" (LRP) terminals because of the morphological characteristics that distinguish them from other afferent terminal types found in RN. Labeled cerebellar afferents in RNp and RNm contact primarily neuronal somata, proximal dendrites emerging from the cell body, large-diameter dendrites, and the spines of rubral neurons that arise from somata and proximal dendrites"  
    My comment
A clear connection between the cerebellum and the red nucleus, but, unfortunately, no mention of neurotransmitters. 


1994    458<1214   
Topography of Purkinje cell compartments and mossy fiber terminal fields in lobules II and III of the rat cerebellar cortex: spinocerebellar and
cuneocerebellar projections.    
https://www.ncbi.nlm.nih.gov/pubmed/7530818   
    See:  Cerebellar Afferent Pathways


1994    450<1214   
Projections from the lateral and interposed cerebellar nuclei to the thalamus of the rat: a light and electron microscopic study using single and
double anterograde labelling   
https://www.ncbi.nlm.nih.gov/pubmed/7860776  
    "
The lateral and interposed cerebellar nuclei may have different functions in the control of movement. Efferent fibres from both nuclei project predominantly to areas of the thalamus, which in turn project to the motor cortex.  
    In this study, single and double anterograde-tracing techniques have been used to examine and compare the pathways from the lateral and interposed nuclei to the thalamus in the rat by using both light and electron microscopy to look for evidence of organisational or structural features that may underlie the proposed functional differences between these nuclei.  
    Terminals from the lateral nucleus were found to be located most medially in the thalamus, predominantly in the ventral lateral nucleus and the rostral pole of the posterior nuclear group.  
    Terminals from the posterior interposed nucleus were located slightly rostral and lateral to those from the lateral nucleus, mainly around the border between the ventral lateral nucleus and the ventral posterior medial nucleus.  
    Terminals from the anterior interposed nucleus were located slightly rostral and lateral to those from the posterior interposed nucleus, predominantly in the rostral pole of the ventral posterior lateral nucleus.  
    Terminals from the lateral and interposed nuclei were also found in double anterograde-tracing experiments to be nonoverlapping in the regions between these main areas of termination.  
    The structure of terminals from the lateral and interposed nuclei, however, as well as their synaptic relationship with thalamic neurones, were found to be similar. The terminals are large and form synapses with proximal dendrites of thalamic neurones. They contained round vesicles and formed multiple synaptic contacts with dendritic shafts, as well as dendritic spines. The findings indicate that information from the lateral and interposed nuclei is processed in separate regions of the thalamus but that the mode of synaptic transfer to thalamic neurones is likely to be similar for the two projections."  
    My comment:   
No mention of neurotransmitters. 


1997    396<1214   
Location of efferent terminals of the primate flocculus and ventral paraflocculus revealed by anterograde axonal transport methods. 
https://www.ncbi.nlm.nih.gov/pubmed/9129184  
    "
Efferents of the flocculus (FL) and ventral paraflocculus (VP) were examined in seven anesthetized Macaca fuscata by anterograde axonal transport method using wheat germ agglutinin-conjugated horseradish peroxidase or phaseolus vulgaris leucoagglutinin.  
    Several major foci of axon terminals were found in the vestibular nuclear complex and cerebellar nuclei. A difference was seen in the location of efferent terminals between the FL and VP.  
    When the tracer covered the FL, labeled axon terminals were located within the medial and ventrolateral parts of the medial vestibular nucleus, superior vestibular nucleus and y-group.  
    When the tracer covered the VP, labeled axon terminals were located within the caudo-ventral part of posterior interpositus and dentate nuclei, in addition to the medial and ventrolateral parts of the medial vestibular nucleus, superior vestibular nucleus and y-group. Labeled terminals were virtually absent in the basal interstitial nucleus of the cerebellum.  
    On the points of neo- or paleo-cerebellar cortex fiber connections, these results correspond to our previous anatomical observations that the FL received mossy fiber afferents mainly from the vestibular system and nucleus reticularis tegmenti pontis and very little from the pontine nuclei, whereas the VP received mossy afferents mainly from the nucleus reticularis tegmenti pontis and pontine nuclei and very little from the vestibular system.  
    These anatomical observations are consistent with a hypothesis in our previous anatomical and physiological study that the primate FL and VP mediate rather different functional roles in the oculomotor control."  
    My comment:   
Very good discussion of connections, but no mention of neurotransmitters. 


    Note:  at this point PubMed added 2 additional references to this search bringing the total number to 1216. 


1998    121<170 
Postsynaptic current mediated by metabotropic glutamate receptors in cerebellar Purkinje cells.  
https://www.ncbi.nlm.nih.gov/pubmed/9705447   
    "In rat cerebellar slices, repetitive parallel fiber stimulation evokes an inward, postsynaptic current in Purkinje cells with a fast component mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors and a slower component mediated by metabotropic glutamate receptors (mGluR).  
    The mGluR-mediated excitatory postsynaptic current (mGluR-EPSC) is evoked selectively by parallel fiber stimulation; climbing fiber stimulation is ineffective. The mGluR-EPSC is elicited most effectively with increasing frequencies of parallel fiber stimulation, from a threshold of 10 Hz to a maximum response at approximately 100 Hz. The amplitude of the mGluR-EPSC is a linear function of the number of stimulus pulses without any apparent saturation, even with >10 pulses. Thus mGluRs at the parallel fiber-Purkinje cell synapse can function as linear detectors of the number of spikes in a burst of activity in parallel fibers.  
    The mGluR-EPSC is present from postnatal day 15 and persists into adulthood. It is inhibited by the generic mGluR antagonist (RS)-a-methyl-4-carboxyphenylglycine and by the group I mGluR antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid at a concentration selective for mGluR1. Although the intracellular transduction pathway involves a G protein, the putative mediators of mGluR1 (phospholipase C and protein kinase C) are not directly involved, indicating that the mGluR-EPSC studied here is mediated by a different and still unidentified second-messenger pathway. Heparin, a nonselective antagonist of inositol-trisphosphate (IP3) receptors, has no significant effect on the mGluR-EPSC, suggesting that also IP3 might be not required for the response. Buffering intracellular Ca2+ with a high concentration of bis-(o-aminophenoxy)-N,N,N', N'-tetraacetic acid partially inhibits the mGluR-EPSC, indicating that Ca2+ is not directly responsible for the response but that resting Ca2+ levels exert a tonic potentiating effect on the mGluR-EPSC."   
    My comment
1.  "... 
postsynaptic current in Purkinje cells with a fast component mediated by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptors and a slower component mediated by metabotropic glutamate receptors (mGluR).   
2.  "... resting Ca2+ levels exert a tonic potentiating effect on the mGluR-EPSC."    
    Free full text   
http://jn.physiology.org/content/80/2/520.long   


2000    335<1216 
Zonal organization of flocculo-vestibular connections in rats. 
https://www.ncbi.nlm.nih.gov/pubmed/10974430   
    "
Anatomical and electrophysiological evidence has contributed to the hypothesis that microzones in the mammalian flocculus are organized to reflect control of eye movements in the planes of semicircular canals.  
     Adult male Long-Evans rats received iontophoretic injections of FluoroGold and/or tetramethylrhodamine dextran amine (10,000 molecular weight, "FluoroRuby") into the vestibular nuclei. The distribution of retrogradely labeled Purkinje cells revealed that efferent projections from the dorsal surface of the flocculus and the ventral paraflocculus to the superior vestibular nucleus, rostral medial vestibular nucleus, ventral lateral vestibular nucleus, and caudal aspect of the vestibular nuclear complex (caudal medial vestibular nucleus, inferior vestibular nucleus and nucleus prepositus hypoglossi) tended to correspond to previously identified climbing fiber zones  in a manner consistent with other mammals. 
     However, vestibular nucleus projections from the ventral surface of the flocculus did not appear to respect climbing fiber zonal boundaries. Rather, climbing fiber zones each contained interdigitated groups of Purkinje cells that project to different vestibular nuclear regions. It is suggested that this pattern of flocculus efferent organization is a specialization for controlling the activity of primary and accessory extraocular muscle pairs to confine vestibulo-ocular reflexes within semicircular canal planes when the "center of regard" is located at different eccentricities."  
    My comments:   
1.  Makes it sound as though the flocculus projects heavily and only to the vestibular complex. 
2.  No mention of neurotransmitters. 


    Note:  at this point PubMed added yet another additional reference to this search bringing the total number to 1217. 


2002    299<1217 
The relationship between MI and SMA afferents and cerebellar and pallidal efferents in the macaque monkey. 
https://www.ncbi.nlm.nih.gov/pubmed/12088388   
    "
The purpose of the present study was to determine the interrelationship between the thalamic afferents arising from the cerebellum (Cb) and the internal segment of the globus pallidus (GPi) with the neurons projecting to the primary motor cortex (MI) and to the supplementary motor area (SMA). 
     We combined fluorescent retrograde tracers with a double anterograde labeling technique. Multiple injections of a combination of Diamidino Yellow and Fast Blue were made into either the MI or SMA hand/arm representation as determined by intracortical microstimulation. In the same animal, biotinylated dextran amine was injected into the GPi and horseradish peroxidase conjugated to wheat germ agglutinin was injected into the contralateral cerebellar nuclei.  
    The results revealed that the cerebellar and pallidal thalamic territories are largely separate. The ventral anterior nucleus (VA) and the ventral lateral nucleus pars oralis (VLo) contained a greater density of pallidal labeling while a greater density of cerebellar label was observed more caudally in the ventral posterior lateral nucleus pars oralis (VPLo) as well as in nucleus X (X). Moreover, we observed that the greatest coincidence of retrograde cell labeling was within the pallidal thalamic territory following the SMA injections and within the cerebellar thalamic territory following the MI injections. However, interdigitating foci of pallidal and cerebellar label were also observed particularly in the ventral lateral nucleus pars oralis (VLo) and the ventral lateral nucleus pars caudalis (VLc). In both VLo and VLc, we additionally observed coincidence between the cerebellar labeling and SMA projection neurons as well as between pallidal labeling and MI projection neurons. These data suggest that while MI primarily receives inputs originating from Cb and SMA primarily receives inputs originating from GPi, it also appears that MI and SMA receive secondary afferents arising from GPi and Cb, respectively."  
    My comments
The cerebellum projects to both the cerebral cortex and the thalamus: 
1.  "... thalamic afferents arising from the cerebellum (Cb) ...
2.  "... 
cerebellar label was observed more caudally in the ventral posterior lateral nucleus pars oralis (VPLo) ..." 
3.   "...
MI primarily receives inputs originating from Cb ..." 


2002    294<1217   
Efferent connections of the cerebellum of the goldfish, Carassius auratus.
https://www.ncbi.nlm.nih.gov/pubmed/12239469   
    "
Efferent fiber connections of the corpus and valvula cerebelli in the goldfish, Carassius auratus, were studied using an anterograde neural fiber tracing technique. 
     Efferent targets of the corpus cerebelli are: 
        the posterior parvocellular preoptic nucleus, the ventromedial and ventrolateral thalamic nucleus, dorsal posterior
        thalamic nucleus, periventricular nucleus of posterior tuberculum, dorsal periventricular pretectal nucleus, inferior
        lobe, optic tectum, torus semicircularis, nucleus of the medial longitudinal fascicle, nucleus ruber, dorsal tegmental
        nucleus, nucleus lateralis valvulae, reticular formation, torus longitudinalis, and the medial and lateral lobe of the
        valvula cerebelli.
Projections to the posterior parvocellular preoptic nucleus and the periventricular nucleus of posterior tuberculum are not reported in previous studies. Efferent targets of the medial lobe of the valvula cerebelli are similar to that of the corpus cerebelli except for lacking a projection to the inferior lobe and torus longitudinalis, but showing one to the corpus cerebelli. On the other hand, the lateral lobe of the valvula cerebelli projects only to the dorsal zone of the periventricular hypothalamus, the diffuse nucleus of the inferior lobe, corpus mamillare, vagal lobe and the corpus cerebelli. There are topographical projections from the lateral valvula to the inferior lobe. These results suggest that the function of the corpus and medial lobe of the valvula cerebelli include not only motor control but also functions similar to the mammalian higher cerebellum. This study also suggests that there are obvious functional divisions between the medial and lateral lobes of the valvula cerebelli."  
    My comments
1.  The cerebellum clearly projects to many parts of the brain. 
2.  Unfortunately, there was no mention of neurotransmitters.   


2004    250<1217   
Spinal axonal injury induces brief downregulation of ionotropic glutamate receptors and no stripping of synapses in cord-projection central neurons. 
https://www.ncbi.nlm.nih.gov/pubmed/15684654   
    "
Spinal cord injury often damages the axons of cord-projecting central neurons. To determine whether their excitatory inputs are altered following axonal injury, we used rat rubrospinal neurons as a model and examined their excitatory input following upper cervical axotomy.  
    Anterograde tracing showed that the primary afferents from the cerebellum terminated in a pattern similar to that of control animals. Ultrastructurally, neurons in the injured nucleus were contacted by excitatory synapses of normal appearance, with no sign of glial stripping.  
    Since cerebellar fibers are glutamatergic, we examined the expression of ionotropic receptor subunits GluR1-4 and NR1 for AMPA and NMDA receptors, respectively, in control and injured neurons using immunolabeling methods. In control neurons, GluR2 appeared to be low as compared to GluR1, GluR3, and GluR4, while NR1 labeling was intense. Following unilateral tractotomy, the levels of expression of each subunit in axotomized neurons appeared to be normal, with the exception that they were lower than those of control neurons of the nonlesioned side at 2-6 days postinjury.  
    These findings suggest that axotomized neurons are only temporarily protected from excitotoxicity. This is in sharp contrast to the responses of central neurons that innervate peripheral targets, in which both synaptic stripping and reduction of their ionotropic glutamate receptor subunits persist following axotomy.  
    The absence of an injury-induced trimming of afferents and stripping of synapses and the lack of a persistent downregulation of postsynaptic receptors might enable injured cord-projection neurons to continue to control their supraspinal targets during most of their postinjury survival. Although this may support neurons by providing trophic influences, it nevertheless may subject them to excitotoxicity and ultimately lead to their degenerative fate."  
    My comment
    "... cerebellar fibers are glutamatergic 
    This is a very important statement since very few of the references in this search specify the neurotransmitter. 


2005    237<1217 
Postural control in man: the phylogenetic perspective.  
https://www.ncbi.nlm.nih.gov/pubmed/16097476   
    "
Erect posture in man is a recent affordance from an evolutionary perspective.  
    About eight million years ago, the stock from which modern humans derived split off from the ape family, and from around sixty-thousand years ago, modern man developed.  
    Upright gait and manipulations while standing pose intricate cybernetic problems for postural control. The trunk, having an older evolutionary history than the extremities, is innervated by medially descending motor systems and extremity muscles by the more recent, laterally descending systems. Movements obviously require concerted actions from both systems. Research in rats has demonstrated the interdependencies between postural control and the development of fluent walking. Only 15 days after birth, adult-like fluent locomotion emerges and is critically dependent upon postural development. Vesttibular deprivation induces a retardation in postural development and, consequently, a retarded development of adult-like locomotion. The cerebellum obviously has an important role in mutual adjustments in postural control and extremity movements, or, in coupling the phylogenetic older and newer structures. In the human, the cerebellum develops partly after birth and therefore is vulnerable to adverse perinatal influences. Such vulnerability seems to justify focusing our scientific research efforts onto the development of this structure."  
    My comment:   
    I'm very interested in evolution. 
    "About eight million years ago, the stock from which modern humans derived split off from the ape family, and from around sixty-thousand years ago, modern man developed.  
    Upright gait and manipulations while standing pose intricate cybernetic problems for postural control. The trunk, having an older evolutionary history than the extremities, is innervated by medially descending motor systems and extremity muscles by the more recent, laterally descending systems.
"  
    "
The cerebellum obviously has an important role in mutual adjustments in postural control and extremity movements, or, in coupling the phylogenetic older and newer structures."  
   
Free PMC Article  


2006    208<1217    
   
Motor learning in man: a review of functional and clinical studies 
   
https://www.ncbi.nlm.nih.gov/pubmed/16730432   
See:   Human Asymmetry 


2006    206<1217   
Afferent and efferent connections of the cerebellum of a salmonid, the rainbow trout (Oncorhynchus mykiss): a tract-tracing study.
https://www.ncbi.nlm.nih.gov/pubmed/16739164  
    "
The connections of the cerebellum of the rainbow trout were studied by experimental methods.
    The pretectal paracommissural nucleus has reciprocal connections with the cerebellum. Three additional pretectal nuclei project to both the corpus and valvula cerebelli, and seem to receive cerebellar afferents. 
     A large number of cells of the lateral nucleus of the valvula project to wide regions of the cerebellum, including the valvula, the corpus, the granular eminences, and the caudal lobe, whereas the contralateral inferior olive and scattered reticular cells project only to the corpus and valvula cerebelli. Afferents to the corpus were also observed from the ventral tegmental nucleus, the "paraisthmic nucleus," the perilemniscal nucleus, the central gray, and the octavolateral area. Valvular afferents were also observed from the torus semicircularis and the midbrain tegmental areas. 
     In most cases of cerebellar application, labeled fibers were seen in the thalamus, the pretectum, the torus longitudinalis and torus semicircularis, the nucleus of the medial longitudinal fascicle, and midbrain and rhombencephalic reticular areas. From the corpus cerebelli some fibers also project to the posterior tubercle and the hypothalamus. Moreover, the granular eminences project to the cerebellar crest.  
    DiI application to most of the areas showing labeled fibers after cerebellar tracer application led to the labeling of characteristic eurydendroid cells, mainly in the valvula cerebelli and the caudal lobe. A few putative eurydendroid cells were labeled from the octavolateralis regions. These results in a teleost with a generalized brain indicate several differences with respect to the cerebellar connections reported in other teleost fishes that have specialized brains."  
    My comment
Tract tracing revealed many connections from the cerebellum to other parts of the brain, but no mention of neurotransmitters. 


2007    198<1217   
Morphological and electrophysiological properties of GABAergic and non-GABAergic cells in the deep cerebellar nuclei. 
https://www.ncbi.nlm.nih.gov/pubmed/17093116   
    "
The deep cerebellar nuclei (DCN) integrate inputs from the brain stem, the inferior olive, and the spinal cord with Purkinje cell output from cerebellar cortex and provide the major output of the cerebellum.  
     Despite their crucial function in motor control and learning, the various populations of neurons in the DCN are poorly defined and characterized. Importantly, differences in electrophysiological properties between glutamatergic and GABAergic cells of the DCN have been largely elusive.  
    Here, we used glutamate decarboxylase (GAD) 67-green fluorescent protein (GFP) knock-in mice to unambiguously identify GABAergic (GAD-positive) and non-GABAergic (GAD-negative, most likely glutamatergic) neurons of the DCN. Morphological analysis of DCN neurons patch-clamped with biocytin-containing electrodes revealed a significant overlap in the distributions of the soma sizes of GAD-positive and GAD-negative cells. Compared with GAD-negative DCN neurons, GAD-positive DCN neurons fire broader action potentials, display stronger frequency accommodation, and do not reach as high firing frequencies during depolarizing current injections. Furthermore, GAD-positive cells display slower spontaneous firing rates and have a more shallow frequency-to-current relationship than the GAD-negative cells but exhibit a longer-lasting rebound depolarization and associated spiking after a transient hyperpolarization. In contrast to the rather homogeneous population of GAD-positive cells, the GAD-negative cells were found to consist of two distinct populations as defined by cell size and electrophysiological features.  
    We conclude that GABAergic DCN neurons are specialized to convey phasic spike rate information, whereas tonic spike rate is more faithfully relayed by the large non-GABAergic cells."   
    My comment
Fairly detailed discussion of Glu and GABA neurons, but does not specify which type are efferent from the cerebellum. 


2006    196<1217 
Cerebellar efferent neurons in teleost fish. 
https://www.ncbi.nlm.nih.gov/pubmed/17134989   
    "
In tetrapods, cerebellar efferent systems are mainly mediated via the cerebellar nuclei. In teleosts, the cerebellum lacks cerebellar nuclei. Instead, the cerebellar efferent neurons, termed eurydendroid cells, are arrayed within and below the ganglionic layer.  
    Tracer injections outside of the cerebellum, which retrogradely label eurydendroid cells demonstrate that most eurydendroid cells possess two or more primary dendrites which extend broadly into the molecular layer. Some eurydendroid cells mostly situated in caudal portions of the cerebellum have only one primary dendrite. The eurydendroid cells receive inputs from the Purkinje cells and parallel fibers, but apparently do not receive inputs from the climbing fibers.  
    Eurydendroid cells of the corpus cerebelli and medial valvula project to many brain regions, from the diencephalon to the caudal medulla. A few eurydendroid cells in the valvula project directly to the telencephalon.  
    About half of the eurydendroid cells are aspartate immunopositive.  
    Anti-GABA and anti-zebrin II antibodies that are known as markers for the Purkinje cells in mammals also recognize the Purkinje cells in the teleost cerebellum, but do not recognize the eurydendroid cells. These results suggest that the eurydendroid cells receive GABAergic inputs from the Purkinje cells. This relationship between the eurydendroid and Purkinje cells is similar to that between the cerebellar nuclei and Purkinje cells in mammals. The eurydendroid cells of teleost have both dissimilar as well as similar features compared to neurons of the cerebellar nuclei in tetrapods."  
    My comment
Discusses neurotransmitters, but no clear statement of which are efferent from the cerebellum. 


2011    103<1217 
The mysterious microcircuitry of the cerebellar nuclei. 
https://www.ncbi.nlm.nih.gov/pubmed/21521761   
    "
The microcircuitry of cerebellar cortex and, in particular, the physiology of its main element, the Purkinje neuron, has been extensively investigated and described. However, activity in Purkinje neurons, either as single cells or populations, does not directly mediate the cerebellar effects on the motor effector systems. Rather, the result of the entire cerebellar cortical computation is passed to the relatively small cerebellar nuclei that act as the final, integrative processing unit in the cerebellar circuitry. The nuclei ultimately control the temporal and spatial features of the cerebellar output.  
    Given this key role, it is striking that the internal organization and the connectivity with afferent and efferent pathways in the cerebellar nuclei are rather poorly known. In the present review, we discuss some of the many critical shortcomings in the understanding of cerebellar nuclei microcircuitry: the extent of convergence and divergence of the cerebellar cortical pathway to the various cerebellar nuclei neurons and subareas, the possible (lack of) conservation of the finely-divided topographical organization in the cerebellar cortex at the level of the nuclei, as well as the absence of knowledge of the synaptic circuitry within the cerebellar nuclei. All these issues are important for predicting the pattern-extraction and encoding capabilities of the cerebellar nuclei and, until resolved, theories and models of cerebellar motor control and learning may err considerably."  
   
Free PMC Article   
    "
In classic theory, the role of CN has been thought to be limited to assigning opposite ‘signs’ to the cerebellar output: inhibitory GABAergic signalling to the IO (the nucleo-olivary pathway, NO);  excitatory glutamatergic signalling to the forebrain motor areas, with the cerebellar subnuclei targeting different systems."      


2014    58<1217   
Glutamate dysfunction associated with developmental cerebellar damage: relevance to autism spectrum disorders. 
https://www.ncbi.nlm.nih.gov/pubmed/24307139   
    "
Neural abnormalities commonly associated with autism spectrum disorders include prefrontal cortex (PFC) dysfunction and cerebellar pathology in the form of Purkinje cell loss and cerebellar hypoplasia. It has been reported that loss of cerebellar Purkinje cells results in aberrant dopamine neurotransmission in the PFC which occurs via dysregulation of multisynaptic efferents from the cerebellum to the PFC.  
    Using a mouse model, we investigated the possibility that developmental cerebellar Purkinje cell loss could disrupt glutamatergic cerebellar projections to the PFC that ultimately modulate DA release. We measured glutamate release evoked by local electrical stimulation using fixed-potential amperometry in combination with glutamate selective enzyme-based recording probes in urethane-anesthetized Lurcher mutant and wildtype mice. Target sites included the mediodorsal and ventrolateral thalamic nuclei, reticulotegmental nuclei, pedunculopontine nuclei, and ventral tegmental area.  
    With the exception of the ventral tegmental area, the results indicated that in comparison to wildtype mice, evoked glutamate release was reduced in Lurcher mutants by between 9 and 72% at all stimulated sites. These results are consistent with the notion that developmental loss of cerebellar Purkinje cells drives reductions in evoked glutamate release in cerebellar efferent pathways that ultimately influence PFC dopamine release. Possible mechanisms whereby reductions in glutamate release could occur are discussed."  
    My comment
Specifically discusses both glutamate and dopamine, but comes to no clear conclusions. 
   




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