Distinct forms of short-term plasticity at excitatory synapses of hippocampus and neocortex

Paired-pulse depression (PPD) is a form of short-term plasticity that plays a central role in processing of synaptic activity and is manifest as a decrease in the size of the response to the second of two closely timed stimuli. Despite mounting evidence to the contrary, PPD is still commonly thought to reflect depletion of the pool of synaptic vesicles available for release in response to the second stimulus. Here it is shown that PPD cannot be accounted for by depletion at excitatory synapses made by hippocampal neurons because PPD is unaffected by changes in the fraction of the readily releasable pool (RRP) released by the first of a pair of pulses.

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A Quantitative Description of Short-Term Plasticity at Excitatory Synapses in Layer 2/3 of Rat Primary Visual Cortex

Journal of Neuroscience ◽

10.1523/jneurosci.17-20-07926.1997 ◽

1997 ◽

Vol 17 (20) ◽

pp. 7926-7940 ◽

Cited By ~ 338

Author(s):

Juan A. Varela ◽

Kamal Sen ◽

Jay Gibson ◽

Joshua Fost ◽

L. F. Abbott ◽

...

Keyword(s):

Visual Cortex ◽

Primary Visual Cortex ◽

Quantitative Description ◽

Excitatory Synapses ◽

Short Term ◽

Short Term Plasticity ◽

Layer 2

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Plasticity in prefrontal cortex induced by coordinated nucleus reuniens and hippocampal synaptic transmission

10.1101/2020.07.11.197798 ◽

2020 ◽

Cited By ~ 1

Author(s):

Paul J Banks ◽

E Clea Warburton ◽

Zafar I Bashir

Keyword(s):

Prefrontal Cortex ◽

Pyramidal Neurons ◽

Ex Vivo ◽

Excitatory Synapses ◽

Short Term ◽

Nucleus Reuniens ◽

Short Term Plasticity ◽

Physiological Properties ◽

Theta Frequency ◽

Afferent Inputs

AbstractThe nucleus reuniens of the thalamus (NRe) is reciprocally connected to a range of higher order cortices including hippocampus (HPC) and medial prefrontal cortex (mPFC). The physiological function of NRe is well predicted by requirement for interactions between mPFC and HPC, including associative recognition memory, spatial navigation and working memory. Although anatomical and electrophysiological evidence suggests NRe makes excitatory synapses in mPFC there is little data on the physiological properties of these projections, or whether NRe and HPC target overlapping cell populations and, if so, how they interact. We demonstrate in ex vivo mPFC slices that NRe and HPC afferent inputs converge onto more than two-thirds of layer 5 pyramidal neurons, show that NRe, but not HPC, undergoes marked short-term plasticity at theta, and that HPC, but not NRe, afferents are subject to neuromodulation by acetylcholine acting via muscarinic receptor M2. Finally, we demonstrate that pairing HPC followed by NRe (but not pairing NRe followed by HPC) at theta frequency induces associative, NMDA receptor dependent synaptic plasticity in both inputs to mPFC. These data provide vital physiological phenotypes of the synapses of this circuit and provide a novel mechanism for HPC-NRe-mPFC encoding.

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Short-term plasticity in excitatory synapses of the rat medial preoptic nucleus

Brain Research ◽

10.1016/j.brainres.2006.06.061 ◽

2006 ◽

Vol 1110 (1) ◽

pp. 128-135 ◽

Cited By ~ 6

Author(s):

Evgenya Malinina ◽

Michael Druzin ◽

Staffan Johansson

Keyword(s):

Excitatory Synapses ◽

Preoptic Nucleus ◽

Short Term ◽

Short Term Plasticity ◽

Medial Preoptic Nucleus

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Multiple Forms of Short-Term Plasticity at Excitatory Synapses in Rat Medial Prefrontal Cortex

Journal of Neurophysiology ◽

10.1152/jn.2000.83.5.3031 ◽

2000 ◽

Vol 83 (5) ◽

pp. 3031-3041 ◽

Cited By ~ 132

Author(s):

Chris M. Hempel ◽

Kenichi H. Hartman ◽

X.-J. Wang ◽

Gina G. Turrigiano ◽

Sacha B. Nelson

Keyword(s):

Prefrontal Cortex ◽

Medial Prefrontal Cortex ◽

Dynamic Properties ◽

Specific Property ◽

Pyramidal Cells ◽

Excitatory Synapses ◽

Short Term ◽

Short Term Plasticity ◽

Layer V

Short-term synaptic plasticity, in particular short-term depression and facilitation, strongly influences neuronal activity in cerebral cortical circuits. We investigated short-term plasticity at excitatory synapses onto layer V pyramidal cells in the rat medial prefrontal cortex, a region whose synaptic dynamic properties have not been systematically examined. Using intracellular and extracellular recordings of synaptic responses evoked by stimulation in layers II/III in vitro, we found that short-term depression and short-term facilitation are similar to those described previously in other regions of the cortex. In additition, synapses in the prefrontal cortex prominently express augmentation, a longer lasting form of short-term synaptic enhancement. This consists of a 40–60% enhancement of synaptic transmission which lasts seconds to minutes and which can be induced by stimulus trains of moderate duration and frequency. Synapses onto layer III neurons in the primary visual cortex express substantially less augmentation, indicating that this is a synapse-specific property. Intracellular recordings from connected pairs of layer V pyramidal cells in the prefrontal cortex suggest that augmentation is a property of individual synapses that does not require activation of multiple synaptic inputs or neuromodulatory fibers. We propose that synaptic augmentation could function to enhance the ability of a neuronal circuit to sustain persistent activity after a transient stimulus. This idea is explored using a computer simulation of a simplified recurrent cortical network.

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Plasticity in Prefrontal Cortex Induced by Coordinated Synaptic Transmission Arising from Reuniens/Rhomboid Nuclei and Hippocampus

Cerebral Cortex Communications ◽

10.1093/texcom/tgab029 ◽

2021 ◽

Author(s):

Paul J Banks ◽

E Clea Warburton ◽

Zafar I Bashir

Keyword(s):

Prefrontal Cortex ◽

Pyramidal Neurons ◽

Ex Vivo ◽

Excitatory Synapses ◽

Short Term ◽

Nucleus Reuniens ◽

Short Term Plasticity ◽

Physiological Properties ◽

Theta Frequency ◽

Afferent Inputs

Abstract The nucleus reuniens and rhomboid nuclei of the thalamus (ReRh) are reciprocally connected to a range of higher order cortices including hippocampus (HPC) and medial prefrontal cortex (mPFC). The physiological function of ReRh is well predicted by requirement for interactions between mPFC and HPC, including associative recognition memory, spatial navigation and working memory. Although anatomical and electrophysiological evidence suggests ReRh makes excitatory synapses in mPFC there is little data on the physiological properties of these projections, or whether ReRh and HPC target overlapping cell populations and, if so, how they interact. We demonstrate in ex vivo mPFC slices that ReRh and HPC afferent inputs converge onto more than two-thirds of layer 5 pyramidal neurons, show that ReRh, but not HPC, undergoes marked short-term plasticity during theta frequency transmission, and that HPC, but not ReRh, afferents are subject to neuromodulation by acetylcholine acting via muscarinic receptor M2. Finally, we demonstrate that pairing HPC followed by ReRh (but not pairing ReRh followed by HPC) at theta frequency induces associative, NMDA receptor dependent synaptic plasticity in both inputs to mPFC. These data provide vital physiological phenotypes of the synapses of this circuit and provide a novel mechanism for HPC-ReRh-mPFC encoding.

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