The Presynaptic Neuron II: Neurotransmitters

Abstract

In the previous chapter the squid giant fibre synapse and the vertebrate neuromuscular junction were considered as the archetypal chemical synapses. The transmitter at both of these synapses is acetylcholine (ACh). In the present chapter transmitters in general are considered, in particular the criteria needed to identify a transmitter, the way in which different transmitters can be classified, the metabolic pathways for synthesis of some transmitters, the ways in which the neurons synthesize and package transmitters for release at their terminals, and the locations in the nervous system of neurons utilising particular transmitters. In the next chapter the actions that follow from combination of the transmitter with its specific receptor molecules on the postsynaptic cell are discussed.