GFAP and Anxiety: We have also tested optogenetic activation of other cell types within the DMS such as astrocytes (using Cre-dependent channelrhodopsin (Ai32) and GFAP-Cre for optogenetic activation) without detecting any observable behaviors, (i.e., grooming, Supplementary Fig. 24 and anxiety as reflected by freezing, Supplementary Fig. 25).