localized D2Rs regulate synthesis and release of DA as the main autoreceptor of the dopaminergic system [29, 30].
(10) Although the mechanism of action of gabapentin is not completely understood, the drug likely binds to the [alpha]2[delta] subunit of voltage-gated calcium channels that then act presynaptically
to decrease the release of excitatory neurotransmitters.
The eCB-mediated LTD is just one form of presynaptically
expressed LTD that is initiated by the activation of Gi/o-coupled receptors (Atwood et al.
(19) Activation of muscarinic receptors presynaptically
inhibits the amplitude of GABAergic synaptic currents.
They found that, similarly to DSI, DSE was induced by postsynaptic [Ca.sup.2+] elevation, expressed presynaptically
, and mediated by retrograde endocannabinoid signaling.
[alpha]2 receptor activation by clonidine inhibits the release of Substance P from afferent fibres within the dorsal horn.
5-HT1A receptors are located both presynaptically
in the raphe nuclei and postsynaptically in discrete brain regions, including the cortex, amydale, and the hippocampus .
Pregabalin works presynaptically
on overactive calcium channels and can reduce the symptoms of neuropathic pain.
Moreover, in different brain regions, sst1 is also localized presynaptically
, controlling SST release from somatostatinergic neurons .
Both groups are generally located presynaptically
and inhibit neurotransmitter release primarily through modulation of calcium and potassium ion channels.
These receptors are situated presynaptically
on the endings of the parasympathetic cholinergic innervation of the intestinal smooth muscle which exerts a facilitatory effect on smooth muscle contractility .
The neurotoxins act presynaptically
, initially releasing acetylcholine, followed by an interference with or blockade of its release.