Neuropeptide co-release with GABA may explain functional non-monotonic uncertainty responses in dopamine neurons.
Co-release of the inhibitory neurotransmitter GABA and the neuropeptide substance-P (SP) from single axons is a conspicuous feature of the basal ganglia, yet its computational role, if any, has not been resolved. In a new learning model, co-release of GABA and SP from axons of striatal projection neurons emerges as a highly efficient way to compute the uncertainty responses that are exhibited by dopamine (DA) neurons when animals adapt to probabilistic contingencies between rewards and the stimuli that predict their delivery. Such uncertainty-related dopamine release appears to be an adaptive phenotype, because it promotes behavioral switching at opportune times. Understanding the computational linkages between SP and DA in the basal ganglia is important, because Huntington's disease is characterized by massive SP depletion, whereas Parkinson's disease is characterized by massive DA depletion.
Cognitive and Neural Systems Department, Boston University, 677 Beacon Street, Boston, MA 02215, USA.
Can Ozan
CO
Tan
Daniel
D
Bullock
D000818:Animals; D003198:Computer Simulation; D003342:Corpus Striatum / Q000378:metabolism* / Q000503:physiopathology; D004298:Dopamine / Q000378:metabolism*; D006801:Humans; D015233:Models, Statistical; D009434:Neural Pathways / Q000378:metabolism / Q000503:physiopathology; D009474:Neurons / Q000378:metabolism*; D011336:Probability; D013373:Substance P / Q000378:metabolism*; D013378:Substantia Nigra / Q000378:metabolism* / Q000503:physiopathology; D013569:Synapses / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology; D035501:Uncertainty; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D013373:Substance P; D005680:gamma-Aminobutyric Acid; D004298:Dopamine