Non-uniform response of regional cerebral blood flow to stimulation of cervical sympathetic nerve.

Regional cerebral blood flow (CBF) was measured by an autoradiographic method in nine adult cats, using antipyrine-(14)C as a diffusible indicator. In seven of the cats, CBF measurements were made during stimulation of a cervical sympathetic trunk. Stimulation caused minor regional decreases of CBF in at least five of these seven cats. The decreases were non-uniform and occurred almost exclusively in cortical structures. Although constriction of cervical arteries probably accounts for some of the effects of sympathetic stimulation, the present study indicates that there is also an effect on cerebral regulatory arterioles. However, there is no convincing evidence that function of the autonomic nervous system is necessary for the normal regulation of the cerebral circulation.