Synaptic transmission: Spillover in the spotlight
نویسنده
چکیده
In the mammalian brain, excitatory and inhibitory neurotransmission are mediated by the transmitters glutamate and γ-aminobutyric acid (GABA), respectively. Fast signaling between neurons occurs at specialized synaptic contacts formed between the axons of presynaptic cells and the soma or dendrites of postsynaptic target neurons. The narrow width of the synaptic cleft (~50 nm) ensures that transmitters reach receptors quickly and at high concentrations. The lifetime of transmitter action at excitatory and inhibitory synapses is governed by a combination of diffusion of transmitter molecules away from receptors in the postsynaptic region, and uptake of transmitter molecules by specific transporters in neuronal and glial membranes. This anatomical arrangement is optimal for rapid, point-topoint signaling that occurs on the millisecond timescale. However, several recent studies [1–3] have now provided evidence that both GABA and glutamate mediate diffuse signaling at sites that are remote from synaptic contacts.
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Synaptic transmission: Spillover at central synapses
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عنوان ژورنال:
- Current Biology
دوره 10 شماره
صفحات -
تاریخ انتشار 2000