Figure 5. Inhibition of parvalbumin-expressing interneurons within the IC blunts the expression of ethanol-CTA in male mice.

(A) Experimental design. PV-Cre mice received bilateral intra-insular injections of Cre-dependent mCherry or hM4di constructs, allowing for expression of either mCherry (controls) or Gi DREADDs three weeks prior to undergoing ethanol-CTA. Mice were given a .1mg/kg i.p. injection of DCZ 30 min prior to retrieval on Day 3. (B) Representative image of AAV-hSyn-DIO-hM4Gi confined largely within the IC. (C) Electrophysiological validation of DREADD function. Bath application of 300nM DCZ resulted in a significant hyperpolarization of membrane potential in Gi-expressing cells, but not mCherry-expressing cells. (D) A significant effect of DREADD condition and a significant interaction between sex and DREADD condition indicated that male, but not female mice expressing the hM4Gi construct drank significantly less saccharin during retrieval relative to mCherry-expressing controls following a.1 mg/kg i.p. injection of DCZ. (*p < 0.05 male mCherry vs male Gi, data expressed as % change from conditioning).