GABA_B receptors induce phasic release from medial habenula terminals through activity-dependent recruitment of release-ready vesicles.

ABSTRACT: GABA_B receptor (GBR) activation inhibits neurotransmitter release in axon terminals in the brain, except in medial habenula (MHb) terminals, which show robust potentiation. However, mechanisms underlying this enigmatic potentiation remain elusive. Here, we report that GBR activation on MHb terminals induces an activity-dependent transition from a facilitating, tonic to a depressing, phasic neurotransmitter release mode. This transition is accompanied by a 4.1-fold increase in readily releasable vesicle pool (RRP) size and a 3.5-fold increase of docked synaptic vesicles (SVs) at the presynaptic active zone (AZ). Strikingly, the depressing phasic release exhibits looser coupling distance than the tonic release. Furthermore, the tonic and phasic release are selectively affected by

SUBMITTER: Koppensteiner P 

PROVIDER: S-EPMC10895368 | biostudies-literature | 2024 Feb

REPOSITORIES: biostudies-literature