title: Uptake of serotonin by intrinsic neurons of the myenteric plexus grown in organotypic tissue culture.
abstract: The myenteric plexus contains axons, not found elsewhere in the peripheral nervous system, which are distinguished by a specific, high affinity transport system for serotinin (5-HT). This study was undertaken to determine the location of the cell bodies of origin of these axons. Vagotomy decreased uptake of [3H]5-HT and tritiated norepinephrine ([3H]NE) by the myenteric plexus. However, while examination by histofluorescence revealed the presence of descending vagal adrenergic fibers, no evidence was found for the presence or accumulation of 5-HT above a vagal ligature. Vagus nerves thus contain adrenergic but not serotonergic axons. The gut was also denervated of all extrinsic axons by growth of intestinal explants in organotypic tissue culture for 3 weeks. Uptake of [3H]5-HT persisted while uptake of [3H]NE was lost. Light and quantitative electron microscopic radioautography revealed that, as in intact gut, the elements of the cultures responsible for uptake of [3H]5-HT were axons distinguished by varicosities containing large dense cored vesicles. In conclusion, these experiments establish that the mammalian gut contains intrinsic neurons which selectively take up 5-HT. The capacity of these neurons for 5-HT uptake may be influenced by the vagus nerves.
mesh_terms: D000818:Animals; D001369:Axons / Q000648:ultrastructure; D006168:Guinea Pigs; D008297:Male; D009197:Myenteric Plexus / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D009474:Neurons / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D009924:Organ Culture Techniques; D012701:Serotonin / Q000378:metabolism*; D014630:Vagus Nerve / Q000378:metabolism
chemical_list: D012701:Serotonin; D009638:Norepinephrine