Chapter 12.5, Problem 8AYLO

Summary Introduction

To discuss:

Three ways in which synaptic transmission is ended.

Introduction:

Turning off the stimulus on time is as important as stimulating a postsynaptic cell, or else the post synaptic neuron will fire indefinitely, leading to a physiological coordination breakdown.  The neurotransmitter molecule binds to the receptor for just 1 ms or so, then it dissociates from the receptor. If a presynaptic cell releases the neurotransmitter continuously, one molecule is rapidly replaced by another neurotransmitter molecule and the postsynaptic neuron is re-stimulated. This is one of the ways of stopping synaptic transmission - this terminates the addition of a new neurotransmitter molecule and getting rid of which is there already. The first step is attained by a signal cessation in the presynaptic neuron. The second step is achieved by three modes that are explained below.