Summary: Purpose: Several results support the conclusion that the cannabinoid system has a role in generation and cessation of epileptic seizures. The aim of this study was to evaluate the effects of intracerebroventricular AM‐251 [N‐(piperidin‐1‐yl)‐5‐(4‐iodophenyl)‐1‐(2,4‐dichlorophenyl)‐4‐methyl‐1H‐pyrazole‐3‐carboxamide], a CB1‐receptor antagonist, and ACEA (arachidonyl‐2‐chloroethylamide), a CB1‐receptor agonist, on penicillin‐induced epileptiform activity in rats.Methods: In the first set of experiments, 30 min after penicillin injection, AM‐251, at doses of 0.125, 0.25, 0.5, and 1 μg, was administered intracerebroventricularly (i.c.v.). In the second set of experiments, 30 min after penicillin injection, ACEA, at doses of 2.5, 5, 7.5, and 15 μg (i.c.v.), was administered. In the third set of experiments, AM‐251, at doses of 0.125 and 0.25 μg (i.c.v.), was administered 10 min before ACEA (7.5 μg, i.c.v.) injection.Results: ACEA, at a dose of 7.5 μg, significantly decreased the frequency of penicillin‐induced epileptiform activity without changing the amplitude. ACEA, at doses of 2.5, 5, and 15 μg, had no impact on either frequency or amplitude of epileptiform activity. AM‐251, at doses of 0.25 and 0.50 μg, significantly increased the frequency of epileptiform activity. AM‐251, at a dose of 0.25 μg (i.c.v.), was the most effective in changing the frequency of penicillin‐induced epileptiform activity, and it also caused status epilepticus–like activity. AM‐251, at doses of 0.125 and 0.25 μg, 10 min before ACEA (7.5 μg), reversed the anticonvulsant action of ACEA.Discussion: The results of the present study provide electrophysiologic evidence for the role of CB1 receptors in regulating the frequency of epileptiform activity in the model of penicillin‐induced epilepsy. To elucidate the precise mechanism of cannabinoid action in the brain during seizure, more advanced electrophysiologic and neurochemical studies are required.

THE effects of ethanol consumption on the levels of lipid peroxidation (TBARS) and reduced glutathione (GSH) in the brain stem of male rats were investigated. The rats randomly divided into eight groups: control, 10%, 25%, 35% ethanol-consuming groups and four groups given vitamin E. Brain stem GSH levels were significantly decreased by 39.74%, 61.57%, 78.23% in rats consuming 10%, 25% and 35% ethanol, respectively. The level of TBARS was increased six-fold, 12-fold and 17-fold in these groups when compared with the control group. The administration of vitamin E (100 mg/kg/day, i.p) to ethanol-consuming rats for 20 days caused a significant increase in glutathione levels and a significant decrease in lipid peroxidation.

THE effect of sodium nitroprusside (SNP) on epileptiform activity elicited by administration of penicillin (500 units) into the somatomotor cortex was studied in anaesthetized rats. No epileptiform activity was observed after intracortical microinjection of SNP (5 and 20 nM). Microinjection of penicillin into the somatomotor cortex induced epileptiform activity in electrocorticograms (ECoG). Epileptiform discharges elicited by penicillin were significantly decreased by SNP. The effect of SNP appeared within 1 min of application and lasted for 2–5 min. The inhibitory effect of SNP on epileptiform activity could be prevented by pretreatment with methylene blue (20 nM), a soluble guanylate cyclase inhibitor. Prior injection of haemoglobin (5 μl), a nitric oxide (NO) scavenger, prevented the anticonvulsant effect of SNP. These results suggest that NO may be an endogenous anticonvulsant substance.

In this study, the right sciatic nerves of 40 rats were used to determine whether a nerve graft within a vein graft might accelerate and facilitate axonal regeneration, compared with a nerve graft alone. The animals were separated into four groups, as follows: group 1, sham control; group 2 (control), segmental nerve resection and no repair; group 3, segmental nerve resection and nerve grafting; group 4, segmental nerve resection and reconstruction with a nerve graft within a vein conduit graft. For all groups, sciatic functional indices were calculated before the operation and on postoperative days 7 and 90. On postoperative day 90, the sciatic nerves were reexposed and nerve conduction velocities were recorded. The sciatic nerves were harvested from all groups for counting of the myelinated axons with a stereological method. No statistically significant differences with respect to return of gait function, axon count, or nerve conduction were noted between groups 3 and 4 (p > 0.05). However, functional recovery in group 4 on postoperative day 90 was significant, compared with group 2 (p < 0.05); the recovery difference between groups 2 and 3 was not significant (p > 0.05). This study was not able to demonstrate any functional benefits with the use of a nerve graft within a vein graft, compared with standard nerve grafting.