Cognitive effects of Colostral-Val nonapeptide in aged rats

Colostrinin, a complex of polypeptides derived from sheep colostrum retards the progress of Alzheimer's disease and facilitates acquisition and retrieval of spatial memory in aged rats. Here we investigated the cognitive effects of colostrinin-derived nonapeptide (Colostral-Val nonapeptide, CVNP) in aged rats that demonstrated learning deficits. Administered for 14 days, CVNP did not affect the acquisition of spatial learning or memory retrieval in the Morris water maze. As a result of reversal learning, placebo treated rats shifted searching behavior and swam less in the area of original platform position and more in the area of recent platform position, suggesting formation of the new spatial map. CVNP treated rats did not change the searching pattern and still investigated the area that contained "original" escape platform, suggesting that CVNP treatment delays the extinction of spatial memory. In another experiment, CVNP administered for 8 days did not influence the acquisition of the active avoidance task, but significantly delayed its extinction. The present findings indicate that colostrinin-derived nonapeptide may delay the extinction of long-term memories.