A mechanism for discharge of charged excitatory neurotransmitter.
Excitatory neurotransmitter is charged, so that emptying of a transmitter-containing vesicle (discharge) would seem to require considerable energy. Even if the energy problem is surmounted and discharge thereby made possible, there is still a problem of making the discharge fast enough (considerably less than 1 ms). Proposed here is a mechanism wherein discharge of charged transmitter is accompanied by the influx of cocharged ions or coefflux of counter-charged particles (ion interchange). It is shown theoretically that ion interchange obviates the necessity for a separate energy source and can provide the observed rapid vesicle discharge.
Khanin
R
R
Department of Applied Mathematics and Computer Science, Weizmann Institute of Science, Rehovot, Israel.
Parnas
H
H
Segel
L
L
D000109:Acetylcholine / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002712:Chlorides / Q000378:metabolism; D004594:Electrophysiology; D004734:Energy Metabolism; D005089:Exocytosis / Q000502:physiology; D007477:Ions; D007700:Kinetics; D008433:Mathematics; D008561:Membrane Fusion; D008564:Membrane Potentials / Q000502:physiology; D008959:Models, Neurological; D018377:Neurotransmitter Agents / Q000378:metabolism*; D015221:Potassium Channels / Q000502:physiology; D012964:Sodium / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology; D013572:Synaptic Vesicles / Q000378:metabolism*; D014101:Torpedo
D002712:Chlorides; D007477:Ions; D018377:Neurotransmitter Agents; D015221:Potassium Channels; D000255:Adenosine Triphosphate; D012964:Sodium; D000109:Acetylcholine