Anticonvulsant effects of focal and intracerebroventricular adenosine on penicillin-induced epileptiform activity in rats

Adenosine has potent anticonvulsant effects on various models of experimental epilepsy. In the present study, we examined the effects of focal and intracerebroventricular (i.c.v.) adenosine on penicillin-induced epileptiform activity in Wistar rats. The effects of theophylline, a non-selective adenosine receptor antagonist, were also researched. The recordings of electrocorticogram (ECoG) were carried out by using a data acquisition system, under urethane anesthesia. Adenosine was given in doses of 1, 10 and 100 μg/rat via focal and i.c.v. 30 min after penicillin administration. Theophylline was injected in doses of 1, 10 and 100 μg/rat by i.c.v. too. Adenosine administration significantly decreased the spike frequency while theophylline increased. Focal adenosine is more effective than i.c.v. adenosine. 100 μg adenosine is an effective dose that causes a decrease in epileptiform activity during experiments. We also demonstrated that 100 μg theophylline significantly increased epileptiform activity. Our findings suggest that focal adenosine is more effective than i.c.v. adenosine on epileptiform activity.