AUTHOR=Kim Taegyo , Capps Robert A. , Hamade Khaldoun C. , Barnett William H. , Todorov Dmitrii I. , Latash Elizaveta M. , Markin Sergey N. , Rybak Ilya A. , Molkov Yaroslav I. TITLE=The Functional Role of Striatal Cholinergic Interneurons in Reinforcement Learning From Computational Perspective JOURNAL=Frontiers in Neural Circuits VOLUME=13 YEAR=2019 URL=https://www.frontiersin.org/journals/neural-circuits/articles/10.3389/fncir.2019.00010 DOI=10.3389/fncir.2019.00010 ISSN=1662-5110 ABSTRACT=

In this study, we explore the functional role of striatal cholinergic interneurons, hereinafter referred to as tonically active neurons (TANs), via computational modeling; specifically, we investigate the mechanistic relationship between TAN activity and dopamine variations and how changes in this relationship affect reinforcement learning in the striatum. TANs pause their tonic firing activity after excitatory stimuli from thalamic and cortical neurons in response to a sensory event or reward information. During the pause striatal dopamine concentration excursions are observed. However, functional interactions between the TAN pause and striatal dopamine release are poorly understood. Here we propose a TAN activity-dopamine relationship model and demonstrate that the TAN pause is likely a time window to gate phasic dopamine release and dopamine variations reciprocally modulate the TAN pause duration. Furthermore, this model is integrated into our previously published model of reward-based motor adaptation to demonstrate how phasic dopamine release is gated by the TAN pause to deliver reward information for reinforcement learning in a timely manner. We also show how TAN-dopamine interactions are affected by striatal dopamine deficiency to produce poor performance of motor adaptation.