Next-generation sequencing of anterior cingulate cortex neurons in a social problem setting in rats
We studied the brain mechanisms of 'social problem' where a worker's credit is exploited in a group setting. A stable 'worker-parasite' relationship developed when three individually operant-conditioned rats were placed together in a Skinner box equipped with response lever and food dispenser on opposite sides. Specifically, one rat, the 'worker,' engaged in lever-pressing while the other 'parasitic' rats profited by crowding the feeder in anticipation. c-Fos expression in the anterior cingulate cortex (ACC) was significantly higher in worker rats than in parasite rats. ACC inactivation suppressed the worker's lever-press behavior under the social dilemma settings. Importantly, our RNA sequencing and the differential expression analysis showed that GABA- and potassium channel-related mRNA expressions decreased in the worker's ACC. In contrast, network disinhibition induced-activity responsive genes such as Cyr61, Arc, and Klf are upregulated. These results suggest that downregulation and upregulation of network inhibitory and excitatory factors, respectively, in the ACC of the worker compared to parasite rats. Overall design: RNA profiles of anterior cingulate cortex neurons in the worker versus parasite rats in a social problem setting