EFFECTS OF A SINGLE INTRASEPTAL INJECTION OF NGF ON SPATIAL-LEARNING IN THE WATER MAZE

Male Sprague-Dawley rats given electrolytic lesions of the septum foll owed by a single intraseptal injection of 5 mu g of NGF were trained o n a water maze task that assessed their ability to learn the location of a visible platform and the location of platform when it was submerg ed. Rats with damage to the septum acquired the visible platform versi on of the task but were significantly impaired in locating the submerg ed platform. Administration of NGF, however, produced an intermediate ameliorative effect on the measure of latency to find the hidden platf orm during these trials. In order to determine the relative strength o f the place and cue responses learned during the Visible and hidden pl atform training trials, a probe trial was given on the final test day in which the visible platform was moved to a new location. Control rat s swam either to the new platform location br the old platform locatio n indicating the use of both a place and cue response. However, both r ats with septal damage alone and rats with septal lesions treated with NGF swam directly to the new platform location indicating the relativ e strength of the cue response. These results support previous finding s indicating that a single injection of NGF can produce improvements o n a cognitive task, but it may not be doing so by restoring lost spati al functions following septohippocampal damage. (C) 1997 Elsevier Scie nce Inc.