HCN2 in cholinergic interneurons of the nucleus accumbens mediates reward response

Abstract

Cholinergic interneurons (ChIs) of the nucleus accumbens (NAc) are important for mediating the behavioral response to rewarding stimuli. A major role for these cells is to regulate dopamine (DA) transmission by activating cholinergic receptors at local DAergic nerve terminals. However, the mechanisms that enable cholinergic neurons to enhance DA release in response to reward remain unknown. Here we report that the hyperpolarization-activated cyclic nucleotide-gated channel 2 (HCN2) in NAc ChIs mediates an enhancement in DA signaling in response to rewarding stimuli. The HCN current in NAc ChIs and its modulation by DA, as well as the increase in cholinergic efflux by local cocaine infusion were impaired in mice with deletion of HCN2 in cholinergic cells. Enhancement in the DA efflux and signaling in the NAc in response to rewarding stimuli, as well as cocaine conditioning were also dependent on HCN2 in ChIs. These results provide a mechanistic link between the activity of NAc ChIs and reward encoding.

Developmental regulation of thalamus-driven pauses in striatal cholinergic interneurons

“…Temporally specific recruitment and/or inactivation of I h would provide parsimonious resolution of the pause mechanism, as HCN channel activity can be potently regulated by D2R signaling ( Deng et al., 2007 ; Lee et al., 2021 ; Wainger et al., 2001 ). However, the directionality of I h effects on pause-related membrane dynamics is unclear, with hypotheses that I h inactivation causes pause-related hyperpolarizations ( Oswald et al., 2009 ) or instead that these effects were an artifact of chronic hyperpolarization caused by I h blockade ( Zhang et al., 2018 ).…”