Cerebral Circulation

It is a common opinion among physiologists that the cerebral blood vessels do not possess effective vasomotor nerve control. The strongest evidence on which this opinion rests has been brought forward by a number of English physiologists, notably Roy and Sherrington,1Bayliss and Leonard Hill,2Hill and Macleod3and Florey.4Several Germans5have also contributed evidence pointing toward the same conclusion. On the other hand, many important observations which are difficult to reconcile with this point of view have been reported by investigators from Germany,6from France,7from the United States,8and elsewhere.9Our own experiments bring new evidence in favor of the functional activity of vasomotor fibers in the blood vessels of the pia mater. The question whether or not the cerebral vessels possess a vasomotor control is not merely of academic interest, for many clinical conditions such as convulsions