Nucleus accumbens neuronal ensembles vary with cocaine reinforcement in male and female rats

Abstract

AbstractNeuronal ensembles in the medial prefrontal cortex mediate cocaine self‐administration via projections to the nucleus accumbens. We have recently shown that neuronal ensembles in the prelimbic cortex form rapidly to mediate cocaine self‐administration. However, the role of neuronal ensembles within the nucleus accumbens in initial cocaine‐seeking behaviour remains unknown. Here, we sought to expand the current literature by testing the necessity of the cocaine self‐administration ensemble in the nucleus accumbens core (NAcCore) 1 day after male and female rats acquire cocaine self‐administration by using the Daun02 inactivation procedure. We found that disrupting the NAcCore ensembles after a no‐cocaine reward‐seeking test increased subsequent cocaine seeking, while disrupting NAcCore ensembles following a cocaine self‐administration session decreased subsequent cocaine seeking. We then characterized neuronal cell type in the NAcCore using RNAscope in situ hybridization. In the no‐cocaine session, we saw reduced dopamine D1 type neuronal activation, while in the cocaine self‐administration session, we found preferential dopamine D1 type neuronal activity in the NAcCore.