scholarly journals Perceptual correlates of homosynaptic long-term potentiation in human nociceptive pathways: a replication study

2021 ◽  
Vol 8 (1) ◽  
pp. 200830
Author(s):  
E. N. van den Broeke ◽  
T. Vanmaele ◽  
A. Mouraux ◽  
A. Stouffs ◽  
J. Biurrun-Manresa ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Long Term Potentiation ◽  
Control Site ◽  
Replication Study ◽  
Nociceptive Pathways ◽  
Term Potentiation ◽  
Perceived Pain ◽  
Before And After ◽  
Treated Site

Animal studies have shown that high-frequency stimulation (HFS) of peripheral C-fibres induces long-term potentiation (LTP) within spinal nociceptive pathways. The aim of this replication study was to assess if a perceptual correlate of LTP can be observed in humans. In 20 healthy volunteers, we applied HFS to the left or right volar forearm. Before and after applying HFS, we delivered single electrical test stimuli through the HFS electrode while a second electrode at the contra-lateral arm served as a control condition. Moreover, to test the efficacy of the HFS protocol, we quantified changes in mechanical pinprick sensitivity before and after HFS of the skin surrounding both electrodes. The perceived intensity was collected for both electrical and mechanical stimuli. After HFS, the perceived pain intensity elicited by the mechanical pinprick stimuli applied on the skin surrounding the HFS-treated site was significantly higher compared to control site (heterotopic effect). Furthermore, we found a higher perceived pain intensity for single electrical stimuli delivered to the HFS-treated site compared to the control site (homotopic effect). Whether the homotopic effect reflects a perceptual correlate of homosynaptic LTP remains to be elucidated.

Priming-Induced Shift in Synaptic Plasticity in the Rat Hippocampus

1999 ◽  
Vol 82 (4) ◽  
pp. 2024-2028 ◽  
Author(s):  
Hongyan Wang ◽  
John J. Wagner
Keyword(s):  
Synaptic Plasticity ◽  
Hippocampal Slices ◽  
Long Term Potentiation ◽  
Crossover Point ◽  
Term Potentiation ◽  
Before And After ◽  
History Of ◽  
The Brain ◽  
Dependent Mechanism

The activity history of a given neuron has been suggested to influence its future responses to synaptic input in one prominent model of experience-dependent synaptic plasticity proposed by Bienenstock, Cooper, and Munro (BCM theory). Because plasticity of synaptic plasticity (i.e., metaplasticity) is similar in concept to aspects of the BCM proposal, we have tested the possibility that a form of metaplasticity induced by a priming stimulation protocol might exhibit BCM-like characteristics. CA1 field excitatory postsynaptic potentials (EPSPs) obtained from rat hippocampal slices were used to monitor synaptic responses before and after conditioning stimuli (3–100 Hz) of the Schaffer collateral inputs. A substantial rightward shift (>5-fold) in the frequency threshold between long-term depression (LTD) and long-term potentiation (LTP) was observed <1 h after priming. This change in the LTD/P crossover point occurred at both primed and unprimed synaptic pathways. These results provide new support for the existence of a rapid, heterosynaptic, experience-dependent mechanism that is capable of modifying the synaptic plasticity phenomena that are commonly proposed to be important for developmental and learning/memory processes in the brain.

Neurophysiological Correlates of Nociceptive Heterosynaptic Long-Term Potentiation in Humans

2010 ◽  
Vol 103 (4) ◽  
pp. 2107-2113 ◽  
Author(s):  
Emanuel N. van den Broeke ◽  
Clementina M. van Rijn ◽  
José A. Biurrun Manresa ◽  
Ole K. Andersen ◽  
Lars Arendt-Nielsen ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Pain Perception ◽  
Event Related Potentials ◽  
Long Term Potentiation ◽  
P300 Amplitude ◽  
Experimental Conditions ◽  
Term Potentiation ◽  
Before And After ◽  
Related Potentials

Long-term potentiation (LTP) is a cellular model of synaptic plasticity and reflects an increase of synaptic strength. LTP is also present in the nociceptive system and is believed to be one of the key mechanisms involved in the manifestations of chronic pain. LTP manifested as an increased response in pain perception can be induced in humans using high-frequency electrical stimulation (HFS). The aim of this study was to induce spinal heterosynaptic LTP using HFS and investigate its heterotopic effects on event-related potentials (ERPs) to repeated nonpainful cutaneous stimuli as a possible electrophysiological cortical correlate of sensitization. Twenty-two healthy subjects were randomly assigned to one of the two experimental conditions: HFS and control stimulation. Before and after the stimulation, both conditions received heterotopic mechanical (pinprick) and paired nonpainful electrical test stimuli to quantify and confirm the effects of HFS on the behavioral level. ERPs to paired nonpainful electrical stimulation were measured simultaneously. Conditioning HFS resulted in significant heterotopic effects after 30 min, including increased perceived intensity in response to (pinprick) mechanical and paired nonpainful electrical stimulation compared with control. The paired nonpainful electrical stimuli were accompanied by significantly enhanced responses regarding the ERP N1-P2 peak-to-peak and P300 amplitude compared with control. These findings suggest that HFS is capable of producing heterosynaptic spinal LTP that can be measured not only behaviorally but also using ERPs.

Quantal mechanism of long-term potentiation in hippocampal mossy-fiber synapses

1994 ◽  
Vol 71 (6) ◽  
pp. 2552-2556 ◽  
Author(s):  
Z. Xiang ◽  
A. C. Greenwood ◽  
E. W. Kairiss ◽  
T. H. Brown
Keyword(s):  
Pyramidal Neurons ◽  
Mossy Fiber ◽  
Classical Method ◽  
Brain Slices ◽  
Long Term Potentiation ◽  
Quantal Size ◽  
Term Potentiation ◽  
Before And After ◽  
Whole Cell Recordings

1. The quantal mechanism underlying the expression of long-term potentiation (LTP) was studied in the mossy-fiber (mf) synapses of the rat hippocampus. Whole-cell recordings were used to measure the excitatory postsynaptic currents (EPSCs) before and after LTP induction in brain slices maintained at 31 +/- 1 degrees C. 2. Evoked EPSCs were recorded from 473 CA3 pyramidal neurons. The mf synapses were stimulated using paired pulses (40-ms interpulse interval) repeated every 2–10 s. At least 400 pairs of mf responses were obtained before and during the expression of LTP, which was produced by high-frequency (100 Hz) mf stimulation. Sufficiently stationary data were obtained from five neurons that exhibited LTP and that also satisfied strict criteria and procedures that are necessary for eliciting and identifying unitary mf responses. 3. Three independent lines of evidence implicated a presynaptic component to the mechanism underlying mf LTP. The first was based on a graphical version of the classical method of variance. The graphical variance (GV) method was evaluated by clamping the cell at two different holding potentials during paired-pulse facilitation (PPF). The results indicated that the GV method can distinguish changes in mean quantal content m and mean quantal size q in rat mf synapses. The same analysis, when applied to PPF before and after LTP induction, indicated that both result from an increase in m. 4. The second line of evidence was based on the classical method of failures. Consistent with the inference that mf LTP is due to an increase in m, there was a statistically significant reduction in the number of quantal release failures.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Causal evidence for LTP-based interference in visual learning

2018 ◽  
Author(s):  
Ji Won Bang ◽  
Diana Milton ◽  
Yuka Sasaki ◽  
Takeo Watanabe ◽  
Dobromir Rahnev
Keyword(s):  
Human Subjects ◽  
Visual Learning ◽  
Strong Support ◽  
Long Term Potentiation ◽  
Control Site ◽  
Theta Burst Stimulation ◽  
Term Potentiation ◽  
Theta Burst ◽  
Continuous Theta Burst Stimulation

AbstractTraining related skills in close succession results in interference but the reasons for this interference are not understood. Here we test the hypothesis that interference occurs due to competition of long-term potentiation (LTP): the LTP induced by one task impedes the LTP induced by the other. Human subjects performed two consecutive training sessions on different Gabor orientations. Immediately after the offset of the first training, we applied continuous theta burst stimulation (cTBS) to interfere with the LTP processes produced by the first training. We found that cTBS to a control site (vertex) resulted in substantial anterograde interference for the second training. Critically, cTBS to the visual cortex not only disrupted learning on the immediately preceding training, but also released the second training from the anterograde interference. These results provide strong support for the LTP-based theory of interference and suggest the possibility of directly manipulating the competition between different learning periods.

Modality-specific sensory changes in humans after the induction of long-term potentiation (LTP) in cutaneous nociceptive pathways

Pain ◽  
2007 ◽  
Vol 128 (3) ◽  
pp. 254-263 ◽  
Author(s):  
Stefanie Lang ◽  
Thomas Klein ◽  
Walter Magerl ◽  
Rolf-Detlef Treede
Keyword(s):  
Long Term Potentiation ◽  
Nociceptive Pathways ◽  
Term Potentiation ◽  
Sensory Changes

scholarly journals Long-Term Potentiation in Spinal Nociceptive Pathways as a Novel Target for Pain Therapy

2011 ◽  
Vol 7 ◽  
pp. 1744-8069-7-20 ◽  
Author(s):  
Ruth Ruscheweyh ◽  
Oliver Wilder-Smith ◽  
Ruth Drdla ◽  
Xian-Guo Liu ◽  
Jürgen Sandkühler
Keyword(s):  
Pain Therapy ◽  
Long Term Potentiation ◽  
Nociceptive Pathways ◽  
Term Potentiation ◽  
Novel Target

scholarly journals Modulation of binocular rivalry with rapid monocular visual stimulation

2020 ◽  
Author(s):  
Dania Abuleil ◽  
Daphne McCulloch ◽  
Heidi Patterson ◽  
Benjamin Thompson
Keyword(s):  
Binocular Rivalry ◽  
Control Experiment ◽  
Visual Stimulation ◽  
Gain Control ◽  
Long Term Potentiation ◽  
Control Mechanisms ◽  
Term Potentiation ◽  
Monocular Stimulation ◽  
Before And After

AbstractRapid visual stimulation can increase synaptic efficacy by repeated synaptic activation. This long-term potentiation-like (LTP-like) effect can induce increase human visual cortex excitability. To examine the effect of rapid visual stimulation on perception, we tested the hypothesis that rapid monocular visual stimulation would increase the dominance of the stimulated eye in a binocular rivalry task. Participants (n = 25) viewed orthogonal 0.5 cpd gratings presented in a dichoptic anaglyph to induce binocular rivalry. Rivalry dynamics (alternation rate, dominance, and piecemeal durations) were recorded before and after 2 min of rapid monocular stimulation (9Hz flicker of one grating) or a binocular control condition (9Hz alternation of the orthogonal gratings viewed binocularly). Rapid monocular stimulation did not affect alternation rates or piecemeal percept duration. However, unexpectedly, rivalry dominance of the stimulated eye was significantly reduced. A control experiment revealed that this effect could not be explained by monocular adaptation. Together, the results suggest that rapid monocular stimulation boosts dominance in the non-stimulated eye, possibly by activating homeostatic interocular gain control mechanisms.

Bidirectional Synaptic Plasticity Correlated With the Magnitude of Dendritic Calcium Transients Above a Threshold

2001 ◽  
Vol 85 (1) ◽  
pp. 399-406 ◽  
Author(s):  
R. J. Cormier ◽  
A. C. Greenwood ◽  
J. A. Connor
Keyword(s):  
Synaptic Plasticity ◽  
Long Term Potentiation ◽  
Ca1 Neurons ◽  
Test Stimulation ◽  
Term Potentiation ◽  
Hippocampal Ca1 ◽  
Before And After ◽  
Activity Dependent ◽  
Stimulation Of

The magnitude of postsynaptic Ca2+ transients is thought to affect activity-dependent synaptic plasticity associated with learning and memory. Large Ca2+ transients have been implicated in the induction of long-term potentiation (LTP), while smaller Ca2+ transients have been associated with long-term depression (LTD). However, a direct relationship has not been demonstrated between Ca2+ measurements and direction of synaptic plasticity in the same cells, using one induction protocol. Here, we used glutamate iontophoresis to induce Ca2+ transients in hippocampal CA1 neurons injected with the Ca2+-indicator fura-2. Test stimulation of one or two synaptic pathways before and after iontophoresis showed that the direction of synaptic plasticity correlated with glutamate-induced Ca2+ levels above a threshold, below which no plasticity occurred (∼180 nM). Relatively low Ca2+ levels (180–500 nM) typically led to LTD of synaptic transmission and higher levels (>500 nM) often led to LTP. Failure to show plasticity correlated with Ca2+ levels in two distinct ranges: <180 nM and ∼450–600 nM, while only LTD occurred between these ranges. Our data support a class of models in which failure of Ca2+ transients to affect transmission may arise either from insufficient Ca2+ to affect Ca2+-sensitive proteins regulating synaptic strength through opposing activities or from higher Ca2+ levels that reset activities of such proteins without affecting the net balance of activities. Our estimates of the threshold Ca2+ level for LTD (∼180 nM) and for the transition from LTD to LTP (∼540 nM) may assist in constraining the molecular details of such models.

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