Fig. 1.

Endothelial nitric oxide synthase (eNOS) contributes to neurovascular coupling. A: increases in cerebral blood flow (CBF; expressed as percentage of baseline) measured above the barrel field of the primary somatosensory cortex in response to whisker stimulation in control mice in the presence and absence of the nitric oxide synthase inhibitor N^ω-nitro-l-arginine methyl ester (l-NAME) and in mice with genetic depletion of eNOS (eNOS^−/−). Data are means ± SE (n = 8, *P < 0.05 vs. control, #P < 0.5 vs. control + l-NAME). Inset: representative traces of CBF measured with a laser Doppler probe above the whisker barrel cortex during contralateral whisker stimulation (5 Hz) in control and eNOS^−/− mice. 1 AU corresponds to ∼5% increase in CBF from baseline. B: CBF responses elicited by topical administration of acetylcholine (ACh, 10⁻⁵ mol/l) to the barrel field of control and eNOS^−/− mice (n = 5 in each group, *P < 0.05 vs. control). Data are means ± SE.