[Postsynaptic potentiation of end plate currents in the rat diaphragm at different levels of synaptic acetylcholinesterase activity].

Nerve-evoked end-plate currents were recorded intracellularly in rat diaphragm when acetylcholinesterase (AChE) was intact or in the presence of galanthamine which reduces AChE activity up to 50% or 75%. Coefficient of correlation of the dependence between half-decay time and amplitude of end-plate currents during short tetanic stimulation pulse (20, 50 and 100 impulses per second) of motor nerve and the slope of this dependence were used to estimate the postsynaptic potentiation. Our results indicate that postsynaptic potentiation shows up clearly when AChE is fully active and grows significantly when AChE activity is slightly reduced. It is proposed that the modulation of the synaptic transmission can be performed by means of postsynaptic potentiation and synaptic AChE can take part in such way of modulation when varying its own activity under the influence of any endogenous factors.