Pre-training blocks the improving effect of tetrahydroaminoacridine and D-cycloserine on spatial navigation performance in aged rats

We investigated the effect of pre-training on the improvement of spatial na vigation performance provided by a cholinesterase inhibitor, tetrahydroamin oacridine (3 mg/kg, i.p.), and a positive modulator of NMDA receptor, D-cyc loserine (10 mg/kg, i.p.), or their combination in aged rats. Pre-training consisted of spatial or non-spatial conditions and took place in either the same or a separate room. We found that any kind of pre-training was able t o eliminate the enhancing effect of tetrahydroaminoacridine and D-cycloseri ne on spatial navigation. However, none of these pre-training conditions wa s able to block the age-related deficit in spatial navigation. These result s indicate that tetrahydroaminoacridine and D-cycloserine, separately or in combination, do not themselves alleviate the age-related spatial memory de ficit, but may enhance procedural aspects of water maze learning in aged ra ts. (C) 2000 Elsevier Science B.V. All rights reserved.