Contribution of Individual Spikes in Burst-Induced Long-Term Synaptic Modification

2006 ◽  
Vol 95 (3) ◽  
pp. 1620-1629 ◽  
Author(s):  
Robert C. Froemke ◽  
Ishan A. Tsay ◽  
Mohamad Raad ◽  
John D. Long ◽  
Yang Dan
Keyword(s):  
High Frequency ◽  
Spike Timing ◽  
Relative Timing ◽  
Short Term ◽  
Burst Frequency ◽  
Synaptic Modification ◽  
Visual Cortical ◽  
Cortical Slices ◽  
Dependent Interaction

Long-term synaptic modification depends on the relative timing of individual pre- and postsynaptic spikes, but the rules governing the effects of multispike bursts remain to be fully understood. In particular, some studies suggest that the spike timing dependence of synaptic modification breaks down with high-frequency bursts. In this study, we characterized the effects of pre- and postsynaptic bursts on long-term modification of layer 2/3 synapses in visual cortical slices from young rats. We found that, while pairing-induced synaptic modification depends on the burst frequency, this dependence can be explained in terms of the timing of individual pre- and postsynaptic spikes. Later spikes in each burst are less effective in synaptic modification, but spike efficacy is regulated differently in pre- and postsynaptic bursts. Presynaptically, spike efficacy is progressively weakened, in parallel with short-term synaptic depression. Postsynaptically, spike efficacy is suppressed to a lesser extent, and it depends on postsynaptic potassium channel activation. Such timing-dependent interaction among multiple spikes can account for synaptic modifications induced by a variety of spike trains, including the frequency-dependent transition from depression to potentiation induced by a postsynaptic burst preceding a presynaptic burst.

A Calcium-Based Simple Model of Multiple Spike Interactions in Spike-Timing-Dependent Plasticity

2013 ◽  
Vol 25 (7) ◽  
pp. 1853-1869 ◽  
Author(s):  
Takumi Uramoto ◽  
Hiroyuki Torikai
Keyword(s):  
Synaptic Weight ◽  
Spike Timing ◽  
State Variables ◽  
Spike Timing Dependent Plasticity ◽  
Dependent Plasticity ◽  
Synaptic Modification ◽  
Proposed Model ◽  
Layer 2 ◽  
Visual Cortical ◽  
Cortical Slices

Spike-timing-dependent plasticity (STDP) is a form of synaptic modification that depends on the relative timings of presynaptic and postsynaptic spikes. In this letter, we proposed a calcium-based simple STDP model, described by an ordinary differential equation having only three state variables: one represents the density of intracellular calcium, one represents a fraction of open state NMDARs, and one represents the synaptic weight. We shown that in spite of its simplicity, the model can reproduce the properties of the plasticity that have been experimentally measured in various brain areas (e.g., layer 2/3 and 5 visual cortical slices, hippocampal cultures, and layer 2/3 somatosensory cortical slices) with respect to various patterns of presynaptic and postsynaptic spikes. In addition, comparisons with other STDP models are made, and the significance and advantages of the proposed model are discussed.

Cibenzoline for High-Frequency Ventricular Arrhythmias: A Short-Term Comparison With Quinidine and a Long-Term Follow-up

1987 ◽  
Vol 27 (4) ◽  
pp. 283-287 ◽  
Author(s):  
Prasad R. Palakurthy ◽  
Claudio Maldonado ◽  
Gurbachan Sohi ◽  
Nancy C. Flowers
Keyword(s):  
High Frequency ◽  
Ventricular Arrhythmias ◽  
Short Term ◽  
Long Term Follow Up

scholarly journals Can a simple, short-term memory task help to screen dyslexia?

2019 ◽  
Author(s):  
Nick Perham ◽  
Toni Howell ◽  
Andy Watt
Keyword(s):  
High Frequency ◽  
Short Term Memory ◽  
Memory Task ◽  
Compulsory Education ◽  
Low Frequency ◽  
Short Term ◽  
Term Order ◽  
Significant Difference ◽  
Support Students

AbstractFunding to support students with dyslexia in post-compulsory education is under pressure and more efficient assessments may offset some of this shortfall. We tested potential tasks for screening dyslexia: recall of adjective-noun, compared to noun-adjective, pairings (syntax) and recall of high versus low frequency letter pairings (bigrams). Students who reported themselves as dyslexic failed to show a normal syntax effect (greater recall of adjective-noun compared to noun-adjective pairings) and no significant difference in recall between the two types of bigrams whereas students who were not dyslexic showed the syntax effect and a bias towards recalling high frequency bigrams. Findings are consistent with recent explanations of dyslexia suggesting that those affected find it difficult to learn and utilise sequential long-term order information (Szmalec et al. Journal of Experimental Psychology: Learning, Memory & Cognition, 37(5) ,1270-1279, 2011). Further, ROC curve analyses revealed both tasks showed acceptable diagnostic properties as they were able to discriminate between the two groups of participants.

scholarly journals Spans attributed to short-term memory are explained by sensitivity to long-term statistics in both musicians and individuals with dyslexia

2019 ◽  
Author(s):  
Eva Kimel ◽  
Atalia Hai Weiss ◽  
Hilla Jakoby ◽  
Luba Daikhin ◽  
Merav Ahissar
Keyword(s):  
High Frequency ◽  
Opposite Effect ◽  
Short Term Memory ◽  
Native Language ◽  
Short Term ◽  
Good Readers ◽  
Syllable Frequency ◽  
Term Memory

AbstractReduced short-term memory (STM) of individuals with dyslexia (IDDs) and enhanced STM of musicians are well documented, yet their causes are disputed. We hypothesized that their STMs reflect their sensitivities to accumulative long-term stimuli statistics. Indeed, when performing an STM task, IDDs had reduced benefit from syllable frequency, whereas musicians manifested an opposite effect, compared to controls. Interestingly, benefit from sequence-repetition did not significantly differ between groups, suggesting that it relies on different mechanisms. To test the generality of this separation across populations, we recruited a group of good-readers, whose native language contains a smaller fraction of the high-frequency syllables. Their span for these “high-frequency” syllables was small, yet their benefit from sequence-repetition was adequate. These experiments indicate that sensitivity to long-term stimuli distribution, and not to sequential repetition, is reduced in IDDs and enhanced in musicians, and this accounts for differences in their STM performance.

scholarly journals Trigeminal high-frequency stimulation produces short- and long-term modification of reflex blink gain

2014 ◽  
Vol 111 (4) ◽  
pp. 888-895 ◽  
Author(s):  
Michael Ryan ◽  
Jaime Kaminer ◽  
Patricia Enmore ◽  
Craig Evinger
Keyword(s):  
High Frequency ◽  
Eyelid Conditioning ◽  
High Frequency Stimulation ◽  
Short Term ◽  
Long Term Depression ◽  
Delay Conditioning ◽  
Essential Blepharospasm ◽  
Reflex Blink ◽  
Frequency Stimulation

Reflex blinks provide a model system for investigating motor learning in normal and pathological states. We investigated whether high-frequency stimulation (HFS) of the supraorbital branch of the trigeminal nerve before the R2 blink component (HFS-B) decreases reflex blink gain in alert rats. As with humans (Mao JB, Evinger C. J Neurosci 21: RC151, 2001), HFS-B significantly reduced blink size in the first hour after treatment for rats. Repeated days of HFS-B treatment produced long-term depression of blink circuits. Blink gain decreased exponentially across days, indicating a long-term depression of blink circuits. Additionally, the HFS-B protocol became more effective at depressing blink amplitude across days of treatment. This depression was not habituation, because neither long- nor short-term blink changes occurred when HFS was presented after the R2. To investigate whether gain modifications produced by HFS-B involved cerebellar networks, we trained rats in a delay eyelid conditioning paradigm using HFS-B as the unconditioned stimulus and a tone as the conditioned stimulus. As HFS-B depresses blink circuits and delay conditioning enhances blink circuit activity, occlusion should occur if they share neural networks. Rats acquiring robust eyelid conditioning did not exhibit decreases in blink gain, whereas rats developing low levels of eyelid conditioning exhibited weak, short-term reductions in blink gain. These results suggested that delay eyelid conditioning and long-term HFS-B utilize some of the same cerebellar circuits. The ability of repeated HFS-B treatment to depress trigeminal blink circuit activity long term implied that it may be a useful protocol to reduce hyperexcitable blink circuits that underlie diseases like benign essential blepharospasm.

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