Elimination of cholinergic interneurons in lesioned striatum of ChAT-Cre mice. A, Abundant coexpression of EYFP immunolabeling (green) in striatal ChAT-positive (red) neurons of mice injected with AAV-EYFP, while the majority of ChAT neurons are ablated following injection of AAV-DT-A-mCherry (referred to in the text as AAV-DT-A). B, Repeated treatment of lesioned mice with l-DOPA results in ERK activation (pERK, red) mainly in ChAT-positive cells (green) of AAV-EYFP-injected mice, but this is not observed with AAV-DT-A-mediated cell ablation. Scale bar, 100 μm.