[Histochemical and image-analytic study of the rat locus coeruleus during status epilepticus]

Twenty-four adult male Wistar rats were used in this study. Status epilepticus was provoked in 10 rats by embedding coriaria lactone particle into the left cerebral motor cortex. In the controls were embedded particles without coriaria lactone. After 6 h of continuous seizure, the locus coeruleus was studied with the noradrenaline (NA) fluorescence histochemical technique and enzyme histochemical test for monoamine oxidase (MAO). The intensity of NA fluorescence was detected with fluorescent microscope autoexposuremeter and analysed with MIAS-200 Image Analyser. The study group showed a parallel increase of NA fluorescence as compared with that of the control group by both measurements. NA plays an inhibitory role in the cortex. Our data suggest that the increase of NA in locus coeruleus may be due to the reduction of NA release from axon terminal. Reduction in inhibition could be one of the mechanisms of seizure activity. The intensity of MAO was detected with MIAS-200 Image Analyser. The regulation of monoamine metabolism by MAO in the central nervous system and the increase of MAO activity in the continuous seizure group may be induced by the accumulation of NA in the locus coeruleus soma.