Age dependent learning and memory deficit in Pentylenetetrazol kindled mice

Epilepsy is a chronic neurological disorder and well documented to induce cognitive impairment. Further onset of epilepsy at different age levels have different effect on cognitive function. Kindling has been used to model clinical epilepsy to study different psychiatric and neurological changes associated with it. Only one study has been reported for age dependent learning deficit in kindled rats but till date no such study is available for mice. Therefore this study was envisaged to find out the correlation of age of mice with feasibility for induction and resistance to kindling and learning and memory deficits. In this study, kindling was induced by administration of subconvulsive dose of pentylenetetrazol (35 mg/kg; i.p.) on alternate days in mice of different age group (2, 6 and 12 month old). For the evaluation of short term, long term spatial and contextual fear memory Elevated Plus Maze and Passive Shock Avoidance Paradigm were used respectively. Induction of kindling significantly impaired learning and memory in different age group of mice as compared to their naïve. Kindling also affected the working and reference spatial memory, with function of age in kindled mice, and contextual fear memory in kindled mice, however not in age dependent manner. Thus the present study validated the existence of age dependent differences in learning and memory deficit and induction of kindling in mice. Results suggested suitability of 6 month old mice for long term neuropharmacological studies pertaining to epilepsy associated cognitive deficit with adequate memory deficit and insignificant resistance to kindling and mortality.