Sara Abedi1, Narges Zeinalzadeh2, Leila Mehdizadeh3, Yousef Panahi4   1, 2, 3- Department of Animal Sciences, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran.

4- Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran.

Background: This study aimed to compare the number of spikes induced by acute and chronic intraperitoneal injection of pentylenetetrazol in adult male rats.

Methods: In this study, 22 adults male Wistar rats (200-250 g) were used in the control (n=6), acute (n=6) and chronic group (n=10). After anesthesia with the combination of ketamine (80 mg/kg) – xylazine (eight mg/kg), the animal’s head was held fixed using a stereotaxic device and after longitudinal incision in the scalp and wiping the tissue and determining the Bregman point, the intracranial recording electrode was inserted into the CA1 hippocampal striatum layer and seizure activity was induced by intraperitoneal injection of pentylenetetrazol (80 mg/kg). After digestion, the recording electrode was inserted into the CA1 hippocampal striatum layer and seizure activity was induced by intraperitoneal injection of pentylenetetrazole (80mg/kg). Animals were anesthetized with the combination of ketamine (80 mg/kg) – xylazine (eight mg/kg) and after fixation using a stereotaxic apparatus, followed by longitudinal incisions in the scalp and wiping the tissues on the skull, intracranial recording electrodes were placed in the CA1 hippocampal striatum layer, and seizure activity were induced by intraperitoneal injection of pentylenetetrazol (80 mg/kg). In the control group, after recording the activity in basal condition, normal saline and in the acute, group were injected intraperitoneally with pentylenetetrazole and the number of spikes was evaluated by eTrace software. However, whereas in the chronic group for eight weeks on Saturday, Monday and Wednesday, 30 mg/kg pentylenetetrazole were injected intraperitoneally and after the end of this epileptic activity period, similar to the grave group. Diazepam 10 mg/kg was used to suppress epileptic activity induced by pentylenetetrazol.

Results: The results of the present study showed that no spike activity was recorded in the control group and the number of spikes in the acute group compared to the chronic group did not show a significant difference, although the number of spikes in the chronic group in compared with the acute group had been decreased. Data were analyzed by SPSS software version 22 using one-way ANOVA Tukey post hoc test. P <0.05 were considered significant.

Conclusion: The decrease in the number of spikes in animals that are chronically affected by epilepsy is likely to reflect the role of specific biological pathways in the pathophysiology of epilepsy, which requires further study to identify these pathways.

Keywords: Acute, Chronic, Rat, Epilepsy, and Pentylenetetrazol