Linear feedback control of acetylcholine level in the presynaptic terminal.
A dynamic analysis of acetylcholine (ACh) level during nervous signal transmission was performed by means of computer simulation. The rate equation expressed in a system of non-linear ordinary differential equations represents the dynamic aspects of the fundamental metabolic processes in the chemical transmission at the synapse in terms of the relevant metabolite fluxes and the reactions of choline acetyltransferase, ACh receptor and acetylcholinesterase functioning in two putative homogeneous and open compartments. After a transmitter release, the ACh level in the presynaptic terminal cannot be restored by supplying the substrates of acetyl-CoA (AcCoA) and choline (Ch) at constant influx rates for ACh synthesis. A simple regulatory mechanism of linear feedback of the ACh level for variation of the substrate influx rates can accomplish the desired replenishment of ACh, in which the influx rate of AcCoA characterizes the response speed and its ratio to that of Ch governs the maintenance of the ACh level. The CoA level is ineffective for this regulatory mechanism.
Sakamoto
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N
Institute of Information Sciences and Electronics, University of Tsukuba, Ibaraki, Japan.
D000109:Acetylcholine / Q000378:metabolism*; D003198:Computer Simulation; D005246:Feedback; D007700:Kinetics; D008959:Models, Neurological; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology
D000109:Acetylcholine