Abstracts

Rationale: Memory dysfunction is common in temporal lobe epilepsy. We have demonstrated that low frequency stimulation (LFS) of the anterior piriform cortex (APC) has antiepileptic properties in the kainic acid model. The purpose of this study is to assess the safety of LFS of the APC as regards memory function in rats. Methods: Adult male Sprague-Dawley rats were implanted with a tripolar electrode in APC and unipolar electrodes bilaterally in the hippocampi. We tested 3 different groups experimental (N=7), control (N=3) and sham (N=3) groups. The experimental and control groups were injected with kainic acid intraperitoneally and the sham group received saline injections. Two weeks after emergence of spontaneouse seizures, we started APC-LFS in both the experimental as well as the sham group. LFS was applied 60-min on, 15-min off, for two weeks with 1 Hz biphasic square waves, 0.1 ms per phase, at 200 µA. Two to three weeks after LFS all three groups were tested in the Radial Arm Maze (RAM). All animals received two sessions of habituation before conducting the test in eight-arm maze for eight consecutive days.  Results: The unpaired t-test was used for analyzing differences in RAM performance between each two groups. Groups were compared in latency and percentage of errors. There were no significant differences between performance of experimental and sham groups in latency (p =0.139) and percentage of errors categories (p=0.9312). There were near significant differences between experimental and control groups in latency (p =0.0597) and percentage of errors (p=0.0625). Although there was a near significant difference in percentage of errors between control and sham groups (p=0.072), we didn’t find a significant difference in latency between control and sham groups (p=0.765). Accurate placement of electrodes was confirmed histologically in 13 rats. Conclusions: As preliminary results, our data suggest that APC-LFS may prevent memory decline that is commonly seen in the kainic acid model. Larger experiments are currently being done to confirm these results.  Funding: This study was made possible by the startup funds from the George Washington University for MZK.