Chronic administration of cyclosporine A does not impair memory retention in rats

Cyclosporine A (CsA) is the treatment of choice for patients undergoing organ as well as neural transplantation. CsA immunosuppression is associated with neurological and motor alterations in transplant recipients as well as in normal or hemiparkinsonian rats. We investigated possible impairments of memory retention in CsA-treated rats to determine direct effects of CsA on the dementing illness inherent in most neurodegenerative disorders. Rats receiving chronic treatment with CsA at a dose of 10 mg kg-1, i.p., daily for 26 days, as used in neural transplants for animal models of neurodegenerative disorders did not significantly differ from vehicle-treated rats, and even appeared slightly improved, in retention of a passive avoidance task. This present observation parallels recent studies demonstrating 'neuroprotective' effects of CsA in addition to its immunosuppressive effects.