gms | German Medical Science

Melatonin has a pivotal role in the circadian regulation of many physiological functions. As a potent antioxidant it has been shown to suppress seizures and epileptogenic process The aim of this study was to asses the influence of treatment with this hormone during epileptogenesis in kainate model of temporal lobe epilepsy (TLE) on hippocampus-associated spatial working and reference memory in rats. In kainate model of TLE long-term melatonin treatment started simultaneously with status epilepticus (SE). The development of chronic epileptic stage was confirmed by the presence of spontaneous motor seizures (SMS) detected by video monitoring (24 h/3–5 month after SE). Epileptic Wistar rats treated with saline exhibited circadian fluctuations in the frequency of the SMS with a prevalence of seizures during the light phase, melatonin-treated rats did not show circadian rhythms of seizures at 3th and 4th month after SE. During training for 18 days in an eight-arm radial arm maze melatonin interacts with days to selectively enhance both working and double working and reference memory in rats. However, in epileptic rats melatonin partially alleviates deleterious consequences on spatial working memory at selected time points. Melatonin did not improve the reference memory performance neither in controls nor in epileptic rats. Taken together, it is suggested that melatonin is a potent antioxidant and is able to prevent some of deleterious consequences of epileptogenesis in Wistar rats.