Figure 3.

PV+ and SOM+ interneurons inhibit D1+ and D1− MSNs in the NAc. A, Left, Schematic of AAV-DIO-ChR2 injection into the NAc of PV-2A-Cre × D1-tdTomato mice to allow for optogenetic activation of PV+ interneurons. Right, Current-clamp recording of light-evoked firing of a ChR2+ PV+ cell from resting membrane potential, showing five overlapping traces. B, Left, Average PV+-evoked IPSCs at pairs of D1+ and D1− MSNs held at +20 mV in the presence of AMPAR antagonist NBQX and NMDAR antagonist CPP. Middle, IPSC amplitudes in D1+ and D1− MSNs, shown as means ± SEM with pairs linked by lines. Right, Responses normalized to the D1+ MSN. C, D, Same as in A and B, but using SOM-Cre × D1-tdTomato mice to stimulate SOM+ interneurons. n.s., Not significant.