Synaptic clearance antagonists

Synaptic Clearance Antagonists. By preventing the removal of naturally-released transmitter from the region of its receptors, the effect of the neuromesssenger on the receiving cell will be prolonged and intensified. There are three principal routes by which neuromessengers are removed from the synaptic cleft (i) enzymatic destruction of the transmitter (e.g., acetylcholine (ACh) which is hydrolyzed in the synaptic cleft by acetylcholinesterase) (ii) uptake into pre- and post- synaptic cells by membrane-associated pumps that have substantial specificty for molecules they will carry (iii) diffusion away from the cleft. 

The classical synaptic clearance antagonist is the cholinesterase inhibitor physostigmine, from the calabar bean, Physostigma... 

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