Abstract

Introduction: There are many evidence to indicate the role of serotoninergic system and serotoninergic activation in seizure attacks. Given the role of serotonin 5-HT1A receptors in synaptic activity and seizure models, and, the similarity of the mechanisms involved in causing seizures and long term potentiation (LTP), the purpose of this study was to investigate the role of this receptor in pentylenetetrazol (PTZ)-induced synaptic strengthening. Materials and Methods: 24 Male Wistar rats (n=20, 220-320 g) were divided into 6 groups; Group1 (control); without any interference after surgery stereotoxic placement of stimulation electrode, Local Field Potential (LFP) was recorded for 20min.Then; the LTP was induced with tetanic stimulation. Group2: All experimental procedures were similar to the group 1, the difference was that the one-month period before the surgery, the animals kindled with PTZ injection. Groups 3-5: All experimental procedures were similar to the group 2, the difference was that the serotonin receptor antagonist (WAY-100635; at a concentration 12.5, 25 and 50nM) was injected intraventricularly. Group 6 received WAY-100635 only. Results: The results showed that groups 1 and 2 were different responded from one another after LTP induction of LTP with tetanic pulse (p<0.001). Field Excitatory Post-synaptic Potential (fEPSP) and Population Spike (PS) decreased significantly in groups of 3-5 compared to group 2(p<0.001). Also, administration of WAY-100635 reduce fEPSP and PS. Conclusion: The results showed that 5HT1A receptor antagonist attenuated the induction of LTP in kindled animals. It seems that serotonin agonist that enhances LTP induction and thus may be useful in enhancing learning and memory in people with epilepsy. © 2017, Semnan University of Medical Sciences. All rights reserved.