08.02 Neural signalling

The nervous system produces nerve signals in the form of electrical impulses (action potentials) that are transmitted along special nerve cells or neurons. Neurotransmitters are chemical messengers released by neurons to allow for communication at the synapses or junctions between neurons or between neurons and target cells (they respond to the neuron e.g. a skeletal muscle cell may contract when receiving a messagefrom a motor neuron) (Figure 8.1).

Figure 8.1 A diagram showing 2 neurons communicating at the synapse (Copyright QUT)

Neurotransmitters are released from the terminals of the axon (single arm-like process) of the presynaptic neuron; they cross the synaptic gap and bind to receptors on adjacent, postsynaptic neurons or targetcells (Figure 8.2). Transmission of nerve impulses along the neuron is in the form of electrical signals, whilst the neurotransmitters are chemical signals.

Figure 8.2 A more detailed view of a synapse (Copyright QUT)