LINOPIRDINE (DUP-996-AVIVA) - ITS EFFECTS IN THE MORRIS WATER ESCAPE TASK AND ON RETENTION OF AN INCOMPLETELY ACQUIRED BAR-PRESS RESPONSE IN RODENTS

The present study assessed the effects of linopirdine, a putative cogn ition-enhancing drug, on the acquisition and retention of a bar-press response [continous reinforcement schedule (CRF)] in young Wistar rats . It was also investigated whether this substance influenced the acqui sition and retention of a standard Morris water escape task by young N MRI mice and by young and old Wistar rats. Linopirdine was given subcu taneously (0.03, 0.1, 0.3, 1.0, or 3.0 mg/kg body wt.), 30 min before the first trial of a session and in one experiment immediately after t he last trial of each session. A probe trial was given after the last acquisition session. In the CRF task, linopirdine did not affect the r esponse latency and the 24-h retention of young rats. None of the para meters investigated in the Morris maze, including the escape latency ( the time the animals need to find the platform), was affected by linop irdine in the rat and mouse experiments. This was also true for perfor mance in the probe trial: linopirdine treatment did not affect the bia s of the animals for the quadrant in which the platform had been posit ioned during acquisition. Thus, we found no experimental evidence for the hypothesized action of linopirdine as a cognition enhancer.