Abstract
To clarify the mechanism of cerebral blood flow (CBF) regulation in the functioning brains, we compared the activity-induced change in a vessel diameter between the cortical surface arteries and penetrating arterioles, where those vessels have a different role in controlling a spatial distribution of blood flow supply. The measurements were conducted with two-photon microscopy in the anesthetized rat cerebral cortex, while electrical stimulation to nucleus basalis of Meynert (NBM) or forepaw (FP) of the animals was applied with and without pharmacological load. We observed that stimulation to the NBM induced vasodilatation of the penetrating arterioles, but not the surface arteries, whereas the FP stimulation induced a dilation of the both arteries. The results were consistent with our previous reports studied in the anesthetized mouse cortex. Furthermore, a pharmacological inhibition of the acetylcholine receptor activity suppressed the responses of the both arteries to the stimuli. These observations support the notion that the vasodilation mechanisms driven by activity of the NBM partly participate in the CBF response to the sensory stimulation.
