Assesment of Superior Colliculus With a Stereological Method in Audiogenic Epilepsy-Prone Wistar Rats

Abstract

Objectives: Audiogenic seizures are generated in the brainstem and involve inferior and superior colliculi in their expression. The aim of the present study was to assess total number of neurons in the right and left superior colliculi in genetically audiogenic epilepsy-prone Wistar rats using stereological method. Methods: Ten female Wistar rats, weighing 180 to 220 g each, were divided into 2 groups: control (n=5) and audiogenic epilepsy (n=5) groups. Subjects were anesthetized with urethane (1.25 g/kg; intraperitoneal) and perfused through the left cardiac ventricle with 10% formalin. Total number of neurons was estimated in the right and left superior colliculi in both groups using Optical Fractionator stereological method. Results: Total number of neurons in the superior colliculi was statistically lower in the right side of group with epilepsy compared with control group (p<0.05). There was significant difference between right and left sides in groups with epilepsy (p<0.05). Conclusion: It has been determined that cellular mechanisms have significant role in audiogenic epilepsy. The fact that number of neurons was significantly less in right superior colliculus of epilepsy group compared with control group suggests that this area is likely to be influential in triggering onset of seizure activity.