INTRACEREBROVENTRICULAR BUT NOT INTRAPERITONEAL ADMINISTRATION OF ALUMINUM ATTENUATES VASOPRESSIN-ENHANCED RETRIEVAL OF A PASSIVE-AVOIDANCETASK IN RATS

We studied the influence of single intracerebroventricular (ICV) and i ntraperitoneal (IF) injections of the neurotoxin aluminum on the retri eval of a passive avoidance task in rats and on the vasopressin-evoked improvement of the recall of the task. It was found that ICV administ ration of the metal alone strongly decreases the retention time of a p assive avoidance task, whereas IP application of aluminum prolongs it. Vasopressin given ICV and IP leads to an enhancement of retrieval (pr olongation of the retention time). Vasopressin in combination with alu minum does not improve the recall of the task when both substances are given ICV. Intraperitoneal injection of the neuropeptide together wit h the metal improves the recall of the task. Our data point to the cru cial importance of the route of application of aluminum for behavioral studies.