While testing the hypothesis that augmenting TrkA-cholinergic signaling could be of relevance to treating PTSD-like behavior, we also found that pharmacological augmentation of cholinergic signaling using donepezil, a cognition enhancing drug that promotes brain cholinergic signaling, accelerated fear extinction in an animal model of PTSD-like behavior. The gene discussed is NTRK1; the disease is post-traumatic stress disorder.