Abstracts

Rationale: The objective of this study was to find out if comorbidities of Epilepsy such as depression can be detected in the latent period of the rodent model of epilepsy. Methods: To test for depression in the latent period of post status rodents, 39 Wistar rats were injected systemically with PILO. In the two following weeks of the latent period (before the rats developed chronic seizures), they were tested for depression with two behavioral tests. These tests were the forced swimming test (FST) which was administered for a duration of 5 minutes and the saccharin taste preference test (STPT), which measures anhedonia- a symptom of depression. Behavioral tests were statistically analyzed. Rats were subjected to 24 hour video-monitoring for 4 months to detect which of them developed recurrent spontaneous seizures and which not. The analysis of behavioral results and video-monitoring were performed blindly by different people. The results were open only after the completion of the analysis. Results: Out of the 39 rats used, 17 developed seizures eventually, 15 did not, and 7 had complications after the PILO injection and were discontinued from further study. The group of rats that later developed (SZ-group) and the group of rats that did not develop epilepsy (nSZ-group) responded differently on both behavioral tests. There were no significant differences between the nSZ-group and the na ve group in both behavioral tests. On average rats from the SZ-group swam longer (4:17 - 0:27 minutes), than the naive and nSZ-group (respectively 3:38 -0:26, and 2:43 -0:47 minutes) out of 5 minutes (p<0.0001). On the other hand, SZ-group did show signs of anhedonia in the STPT, by having less preference for saccharin during the latent period than the naive rats. The ratio of saccharine/water consumed by the SZ-group rats was much lower (1,8 -1.6) than in naive and nSZ-group rats (3.6 -1.5 and 3.5 -2.5 respectively) (p<0.01).