Differential effects of dentate kindling on working and reference spatial memory in the rat.

An 8-arm radial maze was used to examine the effects of dentate kindling on the performance of a task which requires both working (short-term) and reference (long-term) memory. During the 4-week post-operative training period, control and experimental rats performed both components of the task equally well. Performance of the reference memory component, but not the working memory component of the task was significantly impaired during kindling stimulation. The impairment in reference memory appeared to be primarily due to the elicitation of afterdischarges, since the disruption in maze performance was evident in the pre-convulsive stages of kindling. Following the cessation of kindling stimulation, a gradual recovery in reference memory performance was observed. Dentate kindling may provide a useful model for the study of long-term memory deficits associated with temporal lobe epilepsy.