Amygdalofugal pathway The amygdalofugal pathway (Latin for "fleeing from the amygdala") is one of the three principal pathways by which fibers leave the amygdala, a limbic structure in the medial temporal lobe of the brain. The other main efferent pathways from the amygdala are the stria terminalis and anterior commissure. The targets of the amygdalofugal pathway mirror those of the stria terminalis and include the septal nuclei, nucleus accumbens, and hypothalamus. Anterolateral system In the nervous system, the anterolateral system is an ascending pathway that conveys pain, temperature (protopathic sensation), and crude touch from the periphery to the brain. It comprises three main pathways:
Arcuate fasciculus The arcuate fasciculus (Latin, curved bundle) is the neural pathway connecting the posterior part of the temporoparietal junction with the frontal cortex in the brain and is now considered as part of the Superior longitudinal fasciculus. In the dominant hemisphere (usually the left), this pathway is thought to connect Wernicke's area and Broca's area. The function of the arcuate fasciculus of the nondominant hemisphere is very little studied. It is thought to connect areas of the brain involved in the generation and understanding of language.  Corticobulbar tract The corticobulbar (or corticonuclear) tract is a white matter pathway connecting the cerebral cortex to the brainstem (the term "bulbar" referring to the brainstem). The 'bulb' is an archaic term for the medulla oblongata. In clinical usage, it includes the pons as well. The muscles of the face, head and neck are controlled by the corticobulbar system, which terminates on motor neurons within brainstem motor nuclei. This is in contrast to the corticospinal tract, which connects the cerebral cortex to spinal motor neurons, and controls movement of the torso, upper and lower limbs. The corticobulbar tract runs through the genu of the internal capsule and a few fibers in the posterior limb of the internal capsule, as it passes from the motor cortex down through to the brainstem. The corticobulbar tract innervates cranial motor nuclei bilaterally with the exception of the lower facial nucleus which are innervated only contralaterally (bilateral cortical representation, where in unilateral upper motor neuron lesions (UMNL) the frontalis and orbicularis oculi muscles are spared). Among those nuclei that are bilaterally innervated a slightly stronger connection contralaterally than ipisilaterally is observed.  Corticospinal tract Dissociated sensory loss Dopaminergic pathways Dopaminergic pathways are neural pathways in the brain which transmit the neurotransmitter dopamine from one region of the brain to another. There are eight dopaminergic pathways, but the four major ones are: The mesolimbic pathway transmits dopamine from the ventral tegmental area (VTA) to the nucleus accumbens. The VTA is located in the midbrain, and the nucleus accumbens in the limbic system. The "meso-" prefix in the word "mesolimbic" refers to the midbrain, or "middle brain", since "meso" means "middle" in Greek. The mesocortical pathway transmits dopamine from the VTA to the frontal cortex. The "meso-" prefix in "mesocortical" refers to the VTA which is located in the midbrain, and "cortical" refers to the cortex. Malfunctions of the mesocortical pathway are associated with schizophrenia. The nigrostriatal pathway transmits dopamine from the substantia nigra to the striatum. This pathway is associated with motor control, and degeneration of this pathway is related to Parkinson's disease. The tuberoinfundibular pathway transmits dopamine from the hypothalamus to the pituitary gland. This pathway influences the secretion of certain hormones, including prolactin. "Infundibular" in the word "tuberoinfundibular" refers to the infundibulum out of which the pituitary gland develops. The neurons of the dopaminergic pathways have axons which run the entire length of the pathway. The neuron's soma produces the dopamine, which is then transmitted via the projecting axons to their synaptic destinations. Dorsal spinocerebellar tract Frontostriatal circuit Internal capsule Mesocortical pathway Mesolimbic pathway Mossy fiber Nigrostriatal pathway Posterior column-medial lemniscus pathway Rubrospinal tract Spinothalamic tract Tectospinal tract Tuberoinfundibular pathway Ventral spinocerebellar tract Vestibulospinal tract |