Activation-flow coupling with forepaw stimulation in female and male rats

Activation-flow coupling (AFC), the coupling of changes in cerebral blood flow (CBF) with neuronal function, is the basis for many functional neuroimaging techniques. Prior studies have shown that females have higher cerebral blood flow levels than males and that estrogen may affect the mediators involved in AFC. No studies have compared AFC responses between males and females. We assessed the AFC responses to forepaw stimulation using signal-averaged laser Doppler (LD) measurements of CBF in α-chloralose anesthetized female and male rats. Results for various stimulus parameters were similar for both sexes except at 2 Hz where females had a higher blood flow response. These results suggest that the AFC responses in males and females are similar, but require further validation in humans.