Figure 2.

Distinct populations of GABAergic interneurons in the NAc. A, Schematic of potential feedforward inhibitory circuitry in the NAc, with PV+ and/or SOM+ neurons receiving vHPC inputs and inhibiting D1+ MSNs to evoke disynaptic inhibition. B, Injection of AAV-FLEX-EGFP into the NAc of PV-Cre × Ai14 tdTomato reporter mice, with coronal slices of the NAc showing lack of Cre-dependent cell labeling. C, Injection of AAV-FLEX-EGFP into the NAc of PV-2A-Cre × D1-tdTomato mice to label PV+ neurons. EGFP+ cells stain positively for antibodies against PV but not SOM, and show little overlap with D1+ MSNs. D, Similar for injection of AAV-FLEX-EGFP into NAc of SOM-Cre × D1-tdTomato mice to label SOM+ neurons. EGFP+ cells stain positively for antibodies against SOM but not PV, and show little overlap with D1+ MSNs. For C and D, quantification is mean ± SEM for six slices from three animals per condition. Scale bars: B, 300 μm; C, D, left, 300 μm; right, 20 μm.