Effects of P2, a peptide derived from a homophilic binding site in the neural cell adhesion molecule on learning and memory in rats
The neural cell adhesion molecule (NCAM) plays a pivotal role in neural development, regeneration, synaptic plasticity, and memory processes. P2 is a 12-amino-acid peptide derived from the second immunoglobulin-like (Ig) module of NCAM mediating cis-homophilic interactions between NCAM molecules present on the same cell. P2 is a potent NCAM agonist, capable of promoting neuronal differentiation and survival in vitro. The aim of this study was to assess the effect of P2 on learning and memory. Rats treated with P2 intracerebroventricularly (1 h prior to test) performed significantly better than controls in the reinforced T-maze, a test of spatial working memory. Further, rats treated with P2 exhibited decreased anxiety-like behavior while learning the T-maze task. In the social recognition test, both intracerebroventricular (1 h prior to test) and systemic (1 and 24 h prior to test) P2 treatment enhanced short-term social memory and counteracted (administration 24 h prior test) scopolamine-induced social memory impairment. In contrast, P2 (1 h prior to test) did not significantly improve long-term (24 h) retention of social memory, nor did it have any significant effects on long-term memory evaluated by the Morris water maze (administration between 2 days before training and 5.5 h posttraining). In the open field test, P2 (1 h prior to test) decreased general locomotion and rearing, but did not influence any other anxiety-related behaviors, indicating only a minimal influence on baseline anxiety levels. Taken together, these data indicate that in vivo P2 enhances short-term memory and protects against the amnestic effects of scopolamine, while modulating emotional behavior in a learning or novelty-related task
Keywords: Amnesia/chemically induced ; Analysis of Variance ; Animals ; Behavior ; Animal/drug effects ; Drug Administration Routes ; Exploratory Behavior/drug effects ; Male ; Maze Learning/*drug effects ; Memory ; Short-Term/*drug effects ; Myelin Proteins/*administration & dosage ; Rats ; Rats ; Wistar ; Reinforcement (Psychology) ; Scopolamine ; Statistics ; Nonparametric ; Time Factors ; Rats
Author address: Department of Neuroscience and Pharmacology, Faculty of Health Sciences, Panum Institute, University of Copenhagen, Blegdamsvej 3C, Building 6.2, DK-2200 Copenhagen N, Denmark.
Record created on 2008-07-24, modified on 2016-08-08