Figure 5:

Cholinergic receptor antagonists infused into the hippocampus decrease the effect of DREADD-mediated stimulation of hippocampal ChAT-Cre-expressing neurons. The effects of local infusion of cholinergic antagonists into the hippocampus were evaluated in BAC-ChAT-Cre male mice during Cre-dependent Gq-DREADD stimulation of the hippocampus with CNO (10 mg/kg), at baseline (+CSF), with mecamylamine (1 ng) or scopolamine (0.5 ng). Mice were infused with AAV2-Gq-DREADD into the hippocampus through a canula. After 3 weeks recovery, to allow for expression of the DREADD construct, animals were infused with either mecamylamine or scopolamine through the same guide canula 15 min before testing (A), allowing for activation of ChAT-positive neurons of the hippocampus by the DREADD construct and infusion of cholinergic antagonists into the same hippocampal area (B). Time spent in the light side of the light-dark box (A). Time spent immobile in the tail suspension (C) or forced swim test (D). Results are expressed as Mean +/− SEM. *: p < 0.05; **: p < 0.01. Control, n = 9; Gq+CSF, n = 10; Gq+MEC, n = 9; Gq+SCOP, n = 11. Red dots represent data from mistargeted animals (provided for reference and not included in calculation of means or SEM).