---
res:
  bibo_abstract:
  - GABAB 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 at the presynaptic
    active zone (AZ). Strikingly, tonic and phasic release exhibit distinct coupling
    distances and are selectively affected by deletion of synaptoporin (SPO) and Ca2+-dependent
    activator protein for secretion 2 (CAPS2), respectively. SPO modulates augmentation,
    the short-term plasticity associated with tonic release, and CAPS2 retains the
    increased RRP for initial responses in phasic response trains. Double pre-embedding
    immunolabeling confirmed the co-localization of CAPS2 and SPO inside the same
    terminal. The cytosolic protein CAPS2 showed a synaptic vesicle (SV)-associated
    distribution similar to the vesicular transmembrane protein SPO. A newly developed
    “Flash and Freeze-fracture” method revealed the release of SPO-associated vesicles
    in both tonic and phasic modes and activity-dependent recruitment of CAPS2 to
    the AZ during phasic release, which lasted several minutes. Overall, these results
    indicate that GBR activation translocates CAPS2 to the AZ along with the fusion
    of CAPS2-associated SVs, contributing to a persistent RRP increase. Thus, we discovered
    structural and molecular mechanisms underlying tonic and phasic neurotransmitter
    release and their transition by GBR activation in MHb terminals.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Ryuichi
      foaf_name: Shigemoto, Ryuichi
      foaf_surname: Shigemoto
      foaf_workInfoHomepage: http://www.librecat.org/personId=499F3ABC-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0001-8761-9444
  bibo_doi: 10.15479/AT:ISTA:13173
  dct_date: 2023^xs_gYear
  dct_publisher: Institute of Science and Technology Austria@
  dct_subject:
  - medial habenula
  - GABAB receptor
  - vesicle release
  - Flash and Freeze
  - Flash and Freeze-fracture
  dct_title: Transition from tonic to phasic neurotransmitter release by presynaptic
    GABAB receptor activation in medial habenula terminals@
...