A02Visualization of striatal cell type-specific neuronal activity during stimulus discrimination operant learning

 In trial-and-error learning of goal-directed behavior corresponding to stimulus conditions in the environment (stimulus discrimination learning), neural circuits including the striatum plays an important role. We have employed uniquely developed cell targeting methods and genetically modified animals to clarify the functional roles of the striatal projection neurons (direct- and indirect-pathway neurons) and afferent circuits in the control of stimulus discrimination performance and the behavioral switching accompanying learning rule change. However, the functions of two types of striatal projection neurons in the acquisition phase of stimulus discrimination remain unclear. We recently developed transgenic rats that express Cre recombinase specifically to each of these two types of striatal neurons (Tac1-Cre and Drd2-Cre rats). This project utilizes these animals to visualize the activity of striatal projection neurons in each learning phase (acquisition, execution, extinction, and rule change) by calcium imaging, and seeks to elucidate their behavioral functions.