Perfusion of cerebral ventricles: effects of drugs on outflow from the cisterna and the aqueduct

In cats under chloralose anaesthesia the cerebral ventricles were perfused with Locke solution at a rate of 0.1 ml./min. from an indwelling cannula in the lateral ventricle. The effluent was collected from a cannula either inserted into the cisterna magna or pushed into the aqueduct. When collection was from the cisterna the perfusion included relatively large areas of the subarachnoidal spaces since in cats the foramina of Luschka form the only outlet from the fourth ventricle. Tubocurarine, histamine, and adrenaline injected intravenously caused great variations in outflow from the cisterna, but these changes did not occur when the collection was from the aqueduct. The changes in outflow from the cisterna were similar whether the injection produced a fall of arterial blood pressure as after tubocurarine and histamine, or a rise, as after adrenaline.