Description:

Ben Yang, PhD: Work-in-Progress Seminar Abstract

Executing appropriate behavioral responses to stimuli in the environment is essential to the survival of all species. In vertebrates, the basal ganglia are crucial for learning stimulus-motor responses. Specifically, dopamine release is thought to promote movement by activating direct pathway spiny-projection neurons (dSPNs) and inhibiting indirect pathway neurons (iSPNs) in the striatum. However, in vivo recordings showing that dSPNs and iSPNs co-activate in spatially overlapped clusters during spontaneous movement challenge this basic model. These results suggest that iSPNs constrain, rather than suppress movement, but they fail to explain dopamine’s modulatory role in how the striatum encodes learned movement. Here we performed in vivo two-photon imaging of GCaMP Ca2+ activity in dSPNs and iSPNs simultaneously while the mice were trained in an active avoidance behavior task. We found that the dynamics with which dSPNs and iSPNs encode movement differed over the course of learning. To understand these differences, we are currently analyzing simultaneous recordings of dopamine transmission and dSPN or iSPN activity in mice learning the same task. Our results suggest that although dSPNs and iSPNs are simultaneously activated during motion onset, dopamine release may differentially modulate these dynamic to promote stimulus-response motor learning