Continuous estrone treatment impairs spatial memory and does not impact number of basal forebrain cholinergic neurons in the surgically menopausal middle-aged rat

► Estrone treatment given to middle-aged, surgically menopausal rats was evaluated. ► Estrone increased uterine weights and induced positive vaginal smears. ► Estrone impaired spatial working memory during acquisition and after a delay. ► Estrone did not impact basal forebrain cholinergic neuron number.