title: [(3)H]Choline uptake and metabolism in nonsynaptic regions of a crustacean sensory nerve.
abstract: The posterior stomach nerve (PSN) is a crustacean sensory nerve containing about 60 cholinergic neurons, which are devoid of synaptic interactions. Kinetic analysis shows that the PSN takes up [(3)H]choline by both low-affinity (K(m) = 163 micron) and high-affinity (Na(¿dependent) (K(m) - 1 micron) processes. The capacity of the high-affinity system is only about 1% that of the low-affinity system. The high-affinity system is not tightly coupled to acetylcholine (ACh) synthesis, and it appears that both ACh and phosphorylcholine are formed from an intracellular pool of choline, which is fed by both uptake systems. There are differences in the rates of [(3)H]choline uptake and (3)H metabolite accumulation between regions of the PSN that contain neuronal cell bodies and those that do not. These differences may arise from differences in the relative proportion of neuronal to nonneuronal tissue in each nerve region.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001369:Axons / Q000378:metabolism; D003386:Brachyura / Q000378:metabolism*; D002794:Choline / Q000378:metabolism*; D003712:Dendrites / Q000378:metabolism; D006426:Hemicholinium 3 / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D009474:Neurons / Q000378:metabolism*; D010767:Phosphorylcholine / Q000378:metabolism; D012679:Sense Organs / Q000294:innervation; D013270:Stomach / Q000294:innervation
chemical_list: D010767:Phosphorylcholine; D006426:Hemicholinium 3; D002794:Choline; D000109:Acetylcholine