ENHANCEMENT OF SEROTONERGIC IMMUNOREACTIVITY IN SYMPATHETIC CEREBROVASCULAR NERVE-FIBERS AFTER EXPERIMENTAL EMBOLIC STROKE

We examined 5-hydroxytryptamine-like immunoreactive cerebrovascular ne rve fibers in rats after experimental thromboembolic stroke. Although there were no visible 5-hydroxytryptamine-like immunoreactive nerve fi bers in normal animals, we found many of these fibers near the clot em boli 30 min after the stroke, and the number of fibers increased sligh tly with lime. In immunohistochemical double staining, these fibers co rresponded to neuropeptide Y-like immunoreactive nerve fibers. And the y were not observed in animals after superior cervical ganglionectomy. These findings suggest that the sympathetic nerves take up serotonin released from intraluminal aggregating platelets.