D3 dopamine receptors implicate a striatal neuronal subtype in the aversive effects of the antipsychotic drug quetiapine.

Second generation antipsychotics (SGAs) are widely used clinical tools; yet, they often cause negative side effects and take weeks to become effective, leading to poor patient compliance. The effect/side effect profile of individual SGAs is highly variable, and the mechanisms that underlie this variability are not well understood. Here, we identify a role of type 3 dopamine receptor (D3R) neurons in the Nucleus Accumbens (NAc) that mimics the aversive effects of quetiapine. Using single-nucleus RNA sequencing, we show that D3R is expressed in a subpopulation of D1R neurons and defines a distinct NAc cell type. We found that both clozapine and quetiapine cause acute conditioned place aversion in mice, but aversion subsides only after 21 days of treatment with quetiapine, a drug characterized as an arrestin-biased agonist at D3R. We provide evidence at both the cellular and population level that quetiapine inhibits D3R-expressing neurons in the lateral shell (LatSh) of the NAc. We also demonstrate that local injection of quetiapine into LatSh NAc is sufficient to cause place aversion. Selective optogenetic inhibition of D3R-neurons in the LatSh produces real time place aversion in mice, correlating this cell type to the aversive effects of quetiapine. These findings suggest a cell-type-specific mechanism underlying quetiapine-induced aversion and its potential attenuation with chronic treatment, offering insight into the cell types and circuitry that shape the quetiapine side effect profile.