Objectives:

Audiogenic seizures are generated in the brainstem and involve the inferior and superior colliculi in their expression. Aim of the present study was to estimate 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 10% formalin was perfused through the left cardiac ventricle. 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 same side of control group (p<0.05). There was also a significant difference between right and left sides in the epilepsy group (p<0.05).

Conclusion:

It has been determined that cellular mechanisms have a significant role in audiogenic epilepsy. The fact that there were significantly fewer neurons in right superior colliculus of epilepsy group compared with control group suggests that this area is likely to be influential on triggering the onset of seizure activity.

Keywords: Audiogenic seizure, epilepsy, stereological method, superior colliculus