Patterned stimulation at the theta frequency is optimal for the induction of hippocampal long-term potentiation

  title={Patterned stimulation at the theta frequency is optimal for the induction of hippocampal long-term potentiation},
  author={John R. Larson and Darryl Wong and Gary Lynch},
  journal={Brain Research},
Short, high frequency stimulation bursts (4 pulses at 100 Hz) were applied to Schaffer/commissural projections to the CA1 field of rat hippocampal slices at 0.1, 0.2, 1.0 or 2.0-s intervals to assess their efficacy in eliciting long-term potentiation (LTP). Bursts repeated at 2-s intervals induced very little LTP; shorter repetition intervals reliably elicited LTP, with the 200-ms repetition interval producing the greatest potentiation. A short-term potentiation effect, which was maximal 20 s… 
Theta pattern stimulation and the induction of LTP: the sequence in which synapses are stimulated determines the degree to which they potentiate
Induction of long-term potentiation by asynchronous stimulation of converging afferents was studied in hippocampal slices and indicated that sustained depolarization after synaptic activation could contribute to LTP induction by prolonging the activity of N-methyl-D-aspartate receptor-gated channels.
LTP in hippocampal area CA1 is induced by burst stimulation over a broad frequency range centered around delta.
The data show that CA1 synapses are more broadly tuned for potentiation than previously appreciated, and N-methyl-d-aspartic acid receptors were more important for LTP induction by burst stimulation than L-type calcium channels, and NMDA receptors were even more critical for short-duration potentiation.
Stable hippocampal long-term potentiation elicited by ‘theta’ pattern stimulation
It is suggested that, for most rats, LTP elicited by theta pattern stimulation is stable until such time that stimulation-recording arrangements begin to deteriorate, which is about the point at which the responses began their rapid decline.
Activity-induced depression of synaptic inhibition during LTP-inducing patterned stimulation
It is suggested that patterns of stimulation that approximate bursting neuronal activity during theta rhythm result in a transient loss of inhibition during the primed stimulation that brings about a prolongation of the synaptic response that allows short bursts of excitatory synaptic activity to depolarize postsynaptic cells sufficiently to trigger LTP.
Lonf-term potentiation in the dentate gyrus is preferentially induced at theta rhythm periodicity
In urethane-anesthetized rats, high frequency stimulation was applied to the medial perforant pathway at various time intervals following stimulation of the same pathway by a single pulse of equal intensity, suggesting the correlation between theta rhythm periodicity and LTP is a general phenomenon within the hippocampal formation.
Reversal of LTP by theta frequency stimulation
The results suggest that the hippocampal theta rhythm promotes both the induction of LTP and its subsequent reversal with the latter process involving activation of adenosine receptors, and may function to refine or sharpen recently encoded representations.
Temporal pattern sensitivity of long-term potentiation in hippocampal CA1 neurons
It is found that LTP can be induced by an electrical stimulation whose frequency is comparable to that of the naturally occurring firing activity of hippocampal neurons if the stimulating pulseinterval train has a special time structure.
Induction and reversal of long-term potentiation by low- and high- intensity theta pattern stimulation
The results suggest that depotentiation induced by maximal TB stimulation and LTD induced by low-frequency stimulation are distinct phenomena, yet share some characteristics common to forms synaptic plasticity mediated by NMDA receptor activation.
Factors regulating the magnitude of long-term potentiation induced by theta pattern stimulation
The hypothesis is that the magnitude of NMDA receptor mediated currents affects the degree of potentiation produced by individual theta bursts while the duration of the currents is related to the limit on the maximum LTP induced by a series of bursts.
Theta-burst LTP
It is argued that theta-burst LTP represents a minimal model for stable, non-decremental LTP that is more sensitive to a variety of experimental manipulations than is LTP induced by other stimulation paradigms.


Inhibitory modulation of long-term potentiation: Evidence for a postsynaptic locus of control
The results support Marr's proposal that local inhibitory networks may set the threshold for producing long-term synaptic modification and do not support Hebb's nor Uttley's proposal since the long- term synaptic modification did not depend on either the occurrence or the absence of a postsynaptic action potential.
Long-term potentiation phenomena in the rat limbic forebrain
The result indicates that the potentiation produced by kindling may be based upon the same mechanism as the LTP effect, and the effect of this potentiation on subsequent tests of short-term and long-term potentiation.
Intracellular injections of EGTA block induction of hippocampal long-term potentiation
It is reported that intracellular injections of the calcium chelator EGTA block the development of LTP and this results strongly suggest that LTP is caused by a modification of the postsynaptic neurone and that its induction depends on the level of free calcium.
Facilitated induction of hippocampal long-lasting potentiation during blockade of inhibition
Study of long-lasting potentiation in the hippocampal slice preparation (CA1 region) in conditions where postsynaptic inhibition was reduced by application of γ-aminobutyric acid (GABA) receptor blockers found that in addition to their direct effect on inhibition, GABA blockers dramatically facilitated the induction ofLong- lasting potentiation.
Long‐term synaptic enhancement and short‐term potentiation in rat fascia dentata act through different mechanisms
1. The component processes contributing to post‐activation change in synaptic efficacy in the perforant pathway to the fascia dentata were studied in rats under sodium pentobarbitone anaesthesia.
The Hippocampus as a Cognitive Map
Table of Contents: Chapter 1 - Remembrance of places past: a history of theories of space / Chapter 2 - Spatial behaviour / Chapter 3 - Anatomy / Chapter 4 - Physiology / Chapter 5 - Introduction to