B04 Spatial range of neurotransmitter action
The central nervous system is a highly organized system in which millions of neurons communicate using diffusible transmitters at synaptic connections. Powerful transmitter uptake and diffusional dilution principally limit the spread of transmitter to neighbouring synapses and permit a point-to-point communication between two individual neurons despite an extremely high density of synapses in the neuropil. However, activation of high affinity receptors by transmitter from remote sources may also play important roles in the activity of synaptic micro-networks. These remote sources can influence synaptic plasticity, presynaptic release probability and postsynaptic excitability. Understanding remote neurotransmitter actions will be highly relevant for our understanding of synaptic integration and network excitability.