scholarly journals Adaptation of short-term plasticity parameters via error-driven learning may explain the correlation between activity-dependent synaptic properties, connectivity motifs and target specificity

2015 ◽  
Vol 8 ◽  
Author(s):  
Umberto Esposito ◽  
Michele Giugliano ◽  
Eleni Vasilaki
Keyword(s):  
Target Specificity ◽  
Short Term ◽  
Short Term Plasticity ◽  
Activity Dependent

scholarly journals Ca2+/Calmodulin and Presynaptic Short-Term Plasticity

2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Sumiko Mochida
Keyword(s):  
Transmitter Release ◽  
Presynaptic Terminal ◽  
Neuronal Firing ◽  
Firing Activity ◽  
Short Term ◽  
Short Term Plasticity ◽  
Readily Releasable Pool ◽  
Ef Hand ◽  
Sensor Protein ◽  
Activity Dependent

Synaptic efficacy is remodeled by neuronal firing activity at the presynaptic terminal. Presynaptic activity-dependent changes in transmitter release induce postsynaptic plasticity, including morphological change in spine, gene transcription, and protein synthesis and trafficking. The presynaptic transmitter release is triggered and regulated by Ca2+, which enters through voltage-gated Ca2+ (CaV) channels and diffuses into the presynaptic terminal accompanying action potential firings. Residual Ca2+ is sensed by Ca2+-binding proteins, among other potential actions, it mediates time- and space-dependent synaptic facilitation and depression via effects on CaV2 channel gating and vesicle replenishment in the readily releasable pool (RRP). Calmodulin, a Ca2+-sensor protein with an EF-hand motif that binds Ca2+, interacts with CaV2 channels and autoreceptors in modulation of SNARE-mediated exocytosis.

Activity-Dependent Increase of the AHP Amplitude in T Sensory Neurons of the Leech

2002 ◽  
Vol 88 (5) ◽  
pp. 2490-2500 ◽  
Author(s):  
Rossana Scuri ◽  
Riccardo Mozzachiodi ◽  
Marcello Brunelli
Keyword(s):  
Sensory Neurons ◽  
Time Window ◽  
Training Session ◽  
Repetitive Stimulation ◽  
Short Term ◽  
Pharmacological Agents ◽  
Stimulus Interval ◽  
Short Term Plasticity ◽  
Intracellular Stimulation ◽  
Activity Dependent

We identified a new form of activity-dependent modulation of the afterhyperpolarization (AHP) in tactile (T) sensory neurons of the leech Hirudo medicinalis. Repetitive intracellular stimulation with 30 trains of depolarizing impulses at 15-s inter-stimulus interval (ISI) led to an increase of the AHP amplitude (∼60% of the control). The enhancement of AHP lasted for ≥15 min. The AHP increase was also elicited when a T neuron was activated by repetitive stimulation of its receptive field. The ISI was a critical parameter for the induction and maintenance of AHP enhancement. ISI duration had to fit within a time window with the upper limit of 20 s to make the training effective to induce an enhancement of the AHP amplitude. After recovery from potentiation, AHP amplitude could be enhanced once again by delivering another training session. The increase of AHP amplitude persisted in high Mg2+ saline, suggesting an intrinsic cellular mechanism for its induction. Previous investigations reported that AHP of leech T neurons was mainly due to the activity of the Na+/K+ ATPase and to a Ca2+-dependent K+ current ( I K/Ca). In addition, it has been demonstrated that serotonin (5HT) reduces AHP amplitude through the inhibition of the Na+/K+ATPase. By blocking the I K/Ca with pharmacological agents, such as cadmium and apamin, we still observed an increase of the AHP amplitude after repetitive stimulation, whereas 5HT application completely inhibited the AHP increment. These data indicate that the Na+/K+ATPase is involved in the induction and maintenance of the AHP increase after repetitive stimulation. Moreover, the AHP increase was affected by the level of serotonin in the CNS. Finally, the increase of the AHP amplitude produced a lasting depression of the synaptic connection between two T neurons, suggesting that this activity-dependent phenomenon might be involved in short-term plasticity associated with learning processes.

scholarly journals Rapid regulation of vesicle priming explains synaptic facilitation despite heterogeneous vesicle:Ca2+ channel distances

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Janus RL Kobbersmed ◽  
Andreas T Grasskamp ◽  
Meida Jusyte ◽  
Mathias A Böhme ◽  
Susanne Ditlevsen ◽  
...  
Keyword(s):  
Super Resolution ◽  
Release Site ◽  
Stochastic Simulations ◽  
Short Term ◽  
Short Term Plasticity ◽  
Release Probability ◽  
Vesicular Release ◽  
Dependent Inhibition ◽  
Super Resolution Microscopy ◽  
Activity Dependent

Chemical synaptic transmission relies on the Ca2+-induced fusion of transmitter-laden vesicles whose coupling distance to Ca2+ channels determines synaptic release probability and short-term plasticity, the facilitation or depression of repetitive responses. Here, using electron- and super-resolution microscopy at the Drosophila neuromuscular junction we quantitatively map vesicle:Ca2+ channel coupling distances. These are very heterogeneous, resulting in a broad spectrum of vesicular release probabilities within synapses. Stochastic simulations of transmitter release from vesicles placed according to this distribution revealed strong constraints on short-term plasticity; particularly facilitation was difficult to achieve. We show that postulated facilitation mechanisms operating via activity-dependent changes of vesicular release probability (e.g. by a facilitation fusion sensor) generate too little facilitation and too much variance. In contrast, Ca2+-dependent mechanisms rapidly increasing the number of releasable vesicles reliably reproduce short-term plasticity and variance of synaptic responses. We propose activity-dependent inhibition of vesicle un-priming or release site activation as novel facilitation mechanisms.

scholarly journals Subcortical short‐term plasticity elicited by deep brain stimulation

2021 ◽  
Author(s):  
Mohammad Z. Awad ◽  
Ryan J. Vaden ◽  
Zachary T. Irwin ◽  
Christopher L. Gonzalez ◽  
Sarah Black ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Short Term ◽  
Short Term Plasticity ◽  
Deep Brain

scholarly journals Author Correction: Presynaptic endoplasmic reticulum regulates short-term plasticity in hippocampal synapses

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nishant Singh ◽  
Thomas Bartol ◽  
Herbert Levine ◽  
Terrence Sejnowski ◽  
Suhita Nadkarni
Keyword(s):  
Endoplasmic Reticulum ◽  
Short Term ◽  
Short Term Plasticity ◽  
Hippocampal Synapses
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