Functional dissociations between striatal subregions: Activation of direct pathway neurons increases motor output in the dorsomedial, but not ventral, striatum
Friday, September 18, 2015 — Poster Session V
- KP Nguyen
- KH LeBlanc
- AV Kravitz
The striatum is composed of distinct functional subregions, each of which is implicated in separate processes related to movement and reinforcement. However, recent evidence suggests there is more functional overlap than previously thought. Surprisingly, there is little research providing a cogent comparison of output behaviors between two main striatal substructures: dorsomedial (DMS) and ventral (VS) striatum. We therefore sought to investigate the role of the DMS and VS and the role that each region plays in mediating motor and reinforcement behaviors in rodents. Transgenic male and female Drd1-cre mice (n=18) were infused with channelrhodopsin, directly followed by a bilateral fiber optic implant in either the dorsal (n=7) or ventral (n=4) striatum. Unilateral activation of D1-expressing direct pathway neurons increased contralateral rotations only in the DMS. Additional experiments will investigate the role of DMS and VS optogenetic stimulation on reinforcement behaviors. Collectively, these data suggest that although both striatal substructures have overlapping neural circuitry, DMS stimulation has a more pronounced effect on motor output.