Brain Monoamines in Seizure Mechanism (Review)

SUMMARY A majority of experimental studies have strongly suggested that catecholamine and/or 5-HT play an important role for regulating the seizure susceptibility. As mentioned previously, however, the relative significance of individual monoamine has not yet been fully clarified. Since it is well known that the interaction between cate-cholaminergic and serotonergic neuronal activity is quite complex, a causal relationship between each monoamine and seizure susceptibility cannot be easily established if results are obtained from the whole brain study on pharmacologic manipulation of experimental seizures. The extensive study, including the monoamine turnover rates and concentrations in specific brain regions, may help to delineate such a correlation in the future. Further, when an object of study is concerned in excitability of the central nervous system, it should be necessary to elucidate the mutual relationship of mono-amines to the other putative neurotrans-mitters (e.g., acetylcholine, amino acid). Does there exist an abnormal metabolism of monoamines in the brain of epileptic patients? If so, how is it related to the elaboration or maintenance of epileptic seizures? Unfortunately, we have no sufficient information on the monoamine metabolism of epileptic patients.