Fig. 1

Schematic diagram showing the aging effects of α4β2-like nAChR-mediated neocortical vasodilation (A) and potentiation of vasodilation in the olfactory bulb (B). A Neocortical vasodilation induced by intravenous bolus injection of nicotine at a dose of 30 μg/kg was schematically illustrated [18]. B Vasodilation of the olfactory bulb induced by olfactory nerve stimulation before (black line) and after (red line) intravenous injection of nicotine at a dose of 30 μg/kg was schematically illustrated [54]. nAChR nicotinic acetylcholine receptor