Further confirmation of serotonin reduction in the neostriatum during hyperthermia-induced convulsions: a quantitative immunohistochemical study.

Changes occurring in serotonin neurons during hyperthermia and hyperthermia-induced convulsions were examined by quantitative immunohistochemistry. A marked increase in serotonin immunoreactivity was observed at the rostral and intermediate levels of the neostriatum of mice kept at high temperatures with no convulsions, and a significant reduction in serotonin immunoreactivity was verified throughout the neostriatum of mice which had hyperthermia-induced seizures. These results suggest that serotonin neurons change significantly during thermal stress and seizures, and that regional analysis is essential for an understanding of the role of serotonin neurons.