PMID- 38262726
OWN - NLM
STAT- MEDLINE
DCOM- 20240301
LR  - 20240325
IS  - 1529-2401 (Electronic)
IS  - 0270-6474 (Print)
IS  - 0270-6474 (Linking)
VI  - 44
IP  - 9
DP  - 2024 Feb 28
TI  - Synaptotagmin 7 Sculpts Short-Term Plasticity at a High Probability Synapse.
LID - 10.1523/JNEUROSCI.1756-23.2023 [doi]
LID - e1756232023
AB  - Synapses with high release probability (P(r) ) tend to exhibit short-term 
      synaptic depression. According to the prevailing model, this reflects the 
      temporary depletion of release-ready vesicles after an initial action potential 
      (AP). At the high-P(r) layer 4 to layer 2/3 (L4-L2/3) synapse in rodent 
      somatosensory cortex, short-term plasticity appears to contradict the depletion 
      model: depression is absent at interstimulus intervals (ISIs) <50 ms and develops 
      to a maximum at  approximately 200 ms. To understand the mechanism(s) underlying the biphasic 
      time course of short-term plasticity at this synapse, we used whole-cell 
      electrophysiology and two-photon calcium imaging in acute slices from male and 
      female juvenile mice. We tested several candidate mechanisms including 
      neuromodulation, postsynaptic receptor desensitization, and use-dependent changes 
      in presynaptic AP-evoked calcium. We found that, at single L4-L2/3 synapses, P(r) 
      varies as a function of ISI, giving rise to the distinctive short-term plasticity 
      time course. Furthermore, the higher-than-expected P(r) at short ISIs depends on 
      expression of synaptotagmin 7 (Syt7). Our results show that two distinct vesicle 
      release processes summate to give rise to short-term plasticity at this synapse: 
      (1) a basal, high-P(r) release mechanism that undergoes rapid depression and 
      recovers slowly (tau =  approximately 3 s) and (2) a Syt7-dependent mechanism that leads to a 
      transient increase in P(r) (tau =  approximately 100 ms) after the initial AP. We thus reveal how 
      these synapses can maintain a very high probability of neurotransmission for 
      multiple APs within a short time frame. Key words : depression; facilitation; 
      short-term plasticity; synaptotagmin 7.
CI  - Copyright (c) 2024 Chiu and Carter.
FAU - Chiu, Delia N
AU  - Chiu DN
AUID- ORCID: 0000-0002-7343-7962
AD  - European Neuroscience Institute Gottingen - A Joint Initiative of the University 
      Medical Center Gottingen and the Max Planck Society, 37077 Gottingen, Germany.
FAU - Carter, Brett C
AU  - Carter BC
AUID- ORCID: 0000-0001-6474-6571
AD  - European Neuroscience Institute Gottingen - A Joint Initiative of the University 
      Medical Center Gottingen and the Max Planck Society, 37077 Gottingen, Germany 
      b.carter@eni-g.de.
LA  - eng
PT  - Journal Article
DEP - 20240228
PL  - United States
TA  - J Neurosci
JT  - The Journal of neuroscience : the official journal of the Society for 
      Neuroscience
JID - 8102140
RN  - SY7Q814VUP (Calcium)
RN  - 134193-27-4 (Synaptotagmins)
RN  - 0 (Syt7 protein, mouse)
SB  - IM
MH  - Animals
MH  - Female
MH  - Male
MH  - Mice
MH  - *Calcium/metabolism
MH  - *Neuronal Plasticity/physiology
MH  - Synapses/physiology
MH  - Synaptic Transmission/physiology
MH  - Synaptotagmins/genetics/metabolism
PMC - PMC10904093
COIS- The authors declare no competing financial interests.
EDAT- 2024/01/24 00:42
MHDA- 2024/03/01 06:44
PMCR- 2024/02/28
CRDT- 2024/01/23 21:13
PHST- 2023/09/20 00:00 [received]
PHST- 2023/11/20 00:00 [revised]
PHST- 2023/12/15 00:00 [accepted]
PHST- 2024/03/01 06:44 [medline]
PHST- 2024/01/24 00:42 [pubmed]
PHST- 2024/01/23 21:13 [entrez]
PHST- 2024/02/28 00:00 [pmc-release]
AID - JNEUROSCI.1756-23.2023 [pii]
AID - JN-RM-1756-23 [pii]
AID - 10.1523/JNEUROSCI.1756-23.2023 [doi]
PST - epublish
SO  - J Neurosci. 2024 Feb 28;44(9):e1756232023. doi: 10.1523/JNEUROSCI.1756-23.2023.