Synaptic glutamate release

Synaptic glutamate release is the fundamental neurobiological process where glutamate, the brain's primary excitatory neurotransmitter, is secreted from presynaptic neurons into the synaptic cleft. This process involves the active transport of glutamate into synaptic vesicles by vesicular glutamate transporters (VGLUTs) and the subsequent calcium-dependent fusion of these vesicles with the presynaptic membrane, a mechanism facilitated by the SNARE complex. While essential for normal brain function, including learning and memory, excessive or dysregulated glutamate release is a primary driver of excitotoxicity, a pathological state where overstimulation of postsynaptic receptors leads to neuronal damage and cell death. Excitotoxicity is a hallmark of several neurological conditions, such as amyotrophic lateral sclerosis (ALS), stroke, epilepsy, and Alzheimer's disease. Therapeutic intervention strategies aim to reduce excessive release using agents like Riluzole and Lamotrigine, which primarily inhibit the voltage-gated ion channels that trigger the release, or by activating presynaptic metabotropic glutamate receptors (mGluR2/3) that provide inhibitory feedback to the terminal.

Other names

Glutamate exocytosisVesicular glutamate releasePresynaptic glutamate releaseGlutamatergic neurotransmission (presynaptic)

Drugs modulate this process by inhibiting the presynaptic machinery, primarily through the blockade of voltage-gated sodium or calcium channels, activation of inhibitory presynaptic metabotropic glutamate receptors (e.g., mGluR2/3), or interference with the vesicular glutamate transporters (VGLUTs) and the SNARE-mediated fusion complex.