High resolution

Module 10: Figure dendritic GABA release

Dendritic γ-aminobutyric acid (GABA) release from thalamic interneurons.

5-Hydroxytryptamine (5-HT) neurons from the dorsal raphe nucleus innervate the dorsal lateral geniculate nucleus in the thalamus, where they act on the dendrites of the thalamic neurons to stimulate the release of γ-aminobutyric acid (GABA). This synaptic region thus displays the two main forms of transmitter release. Firstly, there is the classical form of axonal transmitter release responsible for releasing 5-HT. Secondly, 5-HT acts on metabotropic 5-HT2 receptors coupled to the inositol lipid-signalling pathway. Some messenger, as yet unidentified, activates the canonical transient receptor potential 4 (TRPC4) channels, and the entry of Ca2+ triggers GABA release. (Information taken from Munsch et al. 2003.)