PRN COMMAND-LIKE NEURON

PRN (Pattern Reversing Neuron) is a neuron located on the ventral surface of the buccal ganglia. It has projections down both the ipsi- and contralateral cerebrobuccal connectives. PRN is an egestion command-like interneuron. Aversive stimuli which trigger egestion behaviours strongly drive activity in PRN. During egestion cycles, PRN is active during the protraction phase and inhibited during the rasp phase. PRN has a strong monosynaptic excitatory connection with the phase-switching buccal motoneuron, B11. During ingestion, PRN drives B11 activity exclusively in the protraction phase. It also indirectly prevents co-activation of ingestion command-like interneurons (such as CV1a) via its strong excitatory connection with buccal to cerebral projecting interneuron, PS1, which in turn inhibits the ingestion driving circuit. PRN is dopaminergic.

References

Crossley, M., Benjamin, P.R., Kemenes, G., Staras, K., Kemenes, I., 2023. A circuit mechanism linking past and future learning through shifts in perception. Sci Adv 9, eadd3403. https://doi.org/10.1126/sciadv.add3403

Crossley, M., Staras, K., Kemenes, G., 2018. A central control circuit for encoding perceived food value. Sci Adv 4, eaau9180. https://doi.org/10.1126/sciadv.aau9180

Crossley, M., Simon, A., Marathe, S., Rau, C., Roth, A., Marra, V., Staras, K., 2025. Functional mapping of the molluscan brain guided by synchrotron X-ray tomography. PNAS.