CEREBRAL CIRCULATION

Abstract

In a previous paper¹it was shown that dilation of arteries in the pia following stimulation of certain "depressor" nerves was due to the fall in blood pressure and retarded blood flow through the brain brought about by the stimulation. There still remained the possibility that true dilator fibers might reach the pial arteries by some pathway other than that of the vagus and "depressor" nerves. Such a route had been indicated by the physiologic work of Penfield and of Cobb and Finesinger²and the anatomic work of Chorobski and Penfield.³A nerve pathway was traced by the last-mentioned authors (in monkeys) from the facial nerve through the geniculate ganglion to the great superficial petrosal nerve and thence to the internal carotid nerve. Stimulation of the facial nerve near its exit from the medulla (after section of the nerve proximally) or stimulation of the superficial petrosal nerve