Figure 3.

Comparison of the spatial learning ability of chronically epileptic rats at 4-months after status epilepticus (SE) with age-matched naive rats using a WMT. Note that, in comparison to intact rats, the average latency (in seconds) to reach the platform were much greater in rats exhibiting chronic epilepsy at all training sessions (A). Naïve rats learn quickly to locate the hidden platform using spatial cues. Epileptic rats are clearly slow learners and overnight forgetting is common in this group. However, these rats are able to find the platform within the ceiling time (90 sec) in most learning sessions. Thus, learning impairment in chronically epileptic rats is revealed mainly by the greater latency values to reach the platform in all training sessions in comparison to naïve rats. B and C show the results of a probe test conducted one-day after the learning paradigm. Naïve rats appear to exhibit robust memory retention, as they reach the platform quadrant faster (B) and spend most of their probe test time searching for the platform in the platform quadrant (C). In contrast, chronically epileptic rats explore all quadrants of the maze and hence their dwell time in the platform quadrant is much less than that of naïve rats (C). Thus, chronically epileptic rats exhibit memory dysfunction.