The aim of this work was to analyze the effect of carbamazepine (CBZ) on sleep patterns and on "head and body shakes" and to determine the role of serotonin (5-HT) in a model of kainic-induced seizures. Thirty male Wistar rats (280-300 g) were used for polygraphic sleep recording. After a basal recording, the rats were allocated into three groups: kainic acid-treated animals (KA; 10 mg/kg; n=10), carbamazepine-treated animals (CBZ; 30 mg/kg; n=10) and animals injected with KA 30 min after pretreatment with CBZ (CBZ+KA; n=10). Polygraphic recordings were performed for 10 h for 3 days, with the exception of the CBZ group, which were observed for 1 day. In order to measure the head and body shakes that occurred over that time, a behavioral assessment was performed in two additional groups of KA (n=10) and CBZ+KA (n=10) animals. After 10 h of behavioral assessment, the rats were sacrificed, and the levels of 5-HT and 5-hydroxy-indol-acetic acid (5-HIAA) were analyzed. We compared these findings with the results from a group of rats without pharmacological intervention (n=10). All of the recordings were performed from 08:00 to 18:00 h.
Data analysis: the electrographic parameters, head and body shake counting and monoamine concentrations were analyzed by an ANOVA test. Differences of *p < or = 0.01 and **p < or = 0.001 were considered statistically significant. Our results showed that CBZ exerted a protective effect on sleep pattern alterations induced by KA, which when administered alone caused a complete inhibition of sleep for the first 10 h after administration. Although there was a reduction in the amount of sleep after the administration of KA in CBZ-pretreated animals, sleep inhibition was incomplete. In addition, CBZ decreased the frequency of head and body shakes by 60% as compared to KA. The 5-HT and 5-HIAA levels in the pons were increased in the KA and KA+CBZ groups. Our conclusion is that in addition to decreasing seizure intensity, CBZ facilitates the partial recovery of sleep. These results suggest that CBZ provides neuro-protective effects on sleep and against seizures.