title: A histochemical and ultrastructural study of serotonin-containing nerves in cerebral blood vessels of the lamprey.
abstract: Lamprey, Entosphenus japonicus, cerebral blood vessel autonomic nerve supply was studied with fluorescence and cholinesterase histochemistry and electron microscopy. Nerve fibers emitting a yellow fluorescence characteristic of serotonin (Exc./Em. max.; 380/530 nm) were found on the major cerebral and pial arteries, but not acetylcholinesterase (AChE)-positive ones. Single ganglion cells also emitting a strong yellow fluorescence were seen in the artery adventitia. On rare occasions these cells were observed in pairs. Terminal varicosities of central catecholamine-containing nerves (Exc./Em. max.; 410/475 nm) were observed on parenchymal capillaries, but not central AChE-positive nerve terminals. In ganglion cells, dense cored vesicles (ca. 130 nm in average diameter; DCV) were abundant in the Golgi area, suggesting their formation at this site. Two types of DCV were observed; one with a homogeneous dense core and the other with a granular core. DCV were numerous in axons as well, axons in which many small clear vesicles (40--60 nm in diameter) as well as DCV were occasionally observed. The question of whether the small clear vesicles or the DCV contained serotonin could not be resolved.
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D001341:Autonomic Nervous System / Q000032:analysis / Q000648:ultrastructure*; D002536:Cerebral Arteries / Q000294:innervation*; D005399:Fishes / Q000033:anatomy & histology*; D006651:Histocytochemistry; D007798:Lampreys / Q000033:anatomy & histology*; D008854:Microscopy, Electron; D012701:Serotonin / Q000032:analysis*; D013050:Spectrometry, Fluorescence
chemical_list: D012701:Serotonin; D000110:Acetylcholinesterase