Chemogenetic selective manipulation of nucleus accumbens medium spiny neurons bidirectionally controls alcohol intake in male and female rats

Sci Rep. 2020 Nov 5;10(1):19178. doi: 10.1038/s41598-020-76183-2.

Abstract

The nucleus accumbens (NAc), considered the hub of reward circuitry, is comprised of two medium spiny neuron (MSN) subtypes that are classified by their enrichment of dopamine 1 (D1) or 2 (D2) receptors. While reports indicate that alcohol increases excitatory neurotransmission exclusively on NAc D1-MSNs in male rats, it remains unknown how NAc MSNs control alcohol intake in either sex. Therefore, this study investigated how NAc MSNs mediate alcohol intake by using Drd1a-iCre and Drd2-iCre transgenic rats of both sexes. Intra-NAc infusions of Cre-inducible viral vectors containing stimulatory (hM3Dq) or inhibitory (hM4Di) designer receptors exclusively activated by designer drugs (DREADDs) were delivered after 4-weeks of alcohol intake, and clozapine-N-oxide (CNO) was administered to selectively manipulate NAc MSNs. Our results show that activation of NAc D1-MSNs increased alcohol intake 1-, 4-, and 24-h after the start of drinking while inhibition decreased it 1-h after the start of drinking, with no sex differences observed at any time point. Activation of NAc D2-MSNs had no impact on alcohol intake while inhibition increased alcohol intake in Drd2-iCre rats for 1-h in males and 4-h in females. These findings suggest opposing roles for how NAc D1- and D2-MSNs modulate alcohol intake in rats of both sexes.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alcohol Drinking / genetics*
  • Alcohol Drinking / metabolism
  • Animals
  • Clozapine / analogs & derivatives*
  • Clozapine / pharmacology
  • Female
  • Male
  • Neurons / drug effects*
  • Neurons / metabolism
  • Nucleus Accumbens / drug effects*
  • Nucleus Accumbens / metabolism
  • Rats
  • Rats, Transgenic
  • Receptors, Dopamine D1 / genetics*
  • Receptors, Dopamine D1 / metabolism
  • Reward*

Substances

  • Receptors, Dopamine D1
  • Clozapine
  • clozapine N-oxide