Figure 6. PV and SOM Neurons Receive Inputs from Distinct Brain Regions.

(A) Experimental design. SOM-Cre or PV-Cre mice were injected in the middle nRT (1.3 mm posterior to Bregma) with AAV expressing TVA-mCherry and rabies glycoprotein (RG) in a Cre-dependent manner at Day 0, and then with monosynaptic rabies virus (EnvA) containing eGFP that only infects cells expressing TVA and spreads retrogradely to presynaptic cells at day 21. Mice were perfused, and presynaptic populations were labeled with eGFP at day 28.

(B) Presynaptic projections at 0.8 mm posterior to Bregma onto SOM cells (left) and PV cells (right) at the anterior nuclei (AN) and somatosensory cortex (S1). Data are represented as mean ± SEM.

(C) Top panels show composite images of coronal sections at −0.46mm (left) and −1.2mm (middle) and −1.8mm posterior to Bregma show presynaptic projections onto nRT PV cells in S1: somatosensory cortex, VPM: ventroposteromedial relay thalamus, GPe: globus pallidus, nRT, and CeA: central amygdala. Bottom panels show individual high-magnification images from these sections; scale 200 μm.

(D) Top panels show composite images of coronal sections at −0.46mm (left) and and −1.4mm posterior to Bregma show presynaptic projections onto nRT SOM cells in GPe, nRT, and CeA. Bottom panels show individual high-magnification images from these sections; scale 200 μm. These results were observed consistently in three SOM-Cre and five PV-Cre mice. See also Figure S5.