Abstract
Morphine, tubocurarine and veratrine are known to cause motor excitement, hypertension and tachypnea, when they are applied into the cerebrospinal fluid (1-3). Since these drugs have completely different chemical structures, it appears rather strange to elicit analogous excitatory actions on the central nervous system. The facts that morphine and tubocurarine are histamine liberators (4), and that intraventricular histamine elicits hypertension (5), suggest the possibility that histamine might be the common mediator of the central excitatory action of these drugs. The present investigation was carried out on the attempt to verify this assumption.
