MEDICAL PHYSIOLOGY

Detailed explanation-1: -neurotransmitter release, discharge of chemical substances known as neurotransmitters from a neuron in response to a given stimulus. Neurotransmitter release occurs at synapses, which are the sites of transmission of electric nerve impulses between two neurons or between a neuron and a gland or muscle cell.

Detailed explanation-2: -At a chemical synapse, an action potential triggers the presynaptic neuron to release neurotransmitters. These molecules bind to receptors on the postsynaptic cell and make it more or less likely to fire an action potential.

Detailed explanation-3: -When the neurotransmitter has been secreted into the synaptic cleft, it binds to specific receptors on the postsynaptic cell, thereby generating a postsynaptic electrical signal, as described in much more detail in Chapter 7.

Detailed explanation-4: -At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis.