Studies of learning and memory processes in adult rats in conditions of intracerebral administration of caspase inhibitors.

The effects of caspase inhibitors on different types of learning and memory were studied in adult rats on administration into the cerebral ventricles and application to the vermis of the cerebellum. The wide-spectrum caspase inhibitor z-VAD-fmk, given into the lateral ventricles of adult rats, facilitated the formation of long-term spatial memory in a water maze and increased the ability to rearrange the habit at the early stages of acquisition of this skill. Application of the specific caspase 3 inhibitor z-DEVD-CHO to the cerebellar vermis stimulated the extinction of an acoustic startle reaction but had no effect on its retention or reproduction. These results indicate that caspases may be involved in the mechanisms of learning and memory both via indirect influences on the linked processes of neurogenesis and apoptosis in the adult brain and by regulating synaptic efficiency.