Synaptic Basis for Whisker Deprivation-Induced Synaptic Depression in Rat Somatosensory Cortex
Open Access
- 19 April 2006
- journal article
- research article
- Published by Society for Neuroscience in Journal of Neuroscience
- Vol. 26 (16), 4155-4165
- https://doi.org/10.1523/jneurosci.0175-06.2006
Abstract
Whisker deprivation weakens excitatory layer 4 (L4) inputs to L2/3 pyramidal cells in rat primary somatosensory (S1) cortex, which is likely to contribute to whisker map plasticity. This weakening has been proposed to represent long-term depression (LTD) induced by sensory deprivation in vivo. Here, we studied the synaptic expression mechanisms for deprivation-induced weakening of L4-L2/3 inputs and assessed its similarity to LTD, which is known to be expressed presynaptically at L4-L2/3 synapses. Whisker deprivation increased the paired pulse ratio at L4-L2/3 synapses and slowed the use-dependent block of NMDA receptor currents by MK-801 [(5S,10R)-(+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imine maleate], indicating that deprivation reduced transmitter release probability at these synapses. In contrast, deprivation did not alter either miniature EPSC amplitude in L2/3 neurons or the amplitude of quantal L4-L2/3 synaptic responses measured in strontium, indicating that postsynaptic responsiveness was unchanged. In young postnatal day 12 (P12) rats, at least 4 d of deprivation were required to significantly weaken L4-L2/3 synapses. Similar weakening occurred when deprivation began at older ages (P20), when synapses are mostly mature, indicating that weakening is unlikely to represent a failure of synaptic maturation but instead represents a reduction in the strength of existing synapses. Thus, whisker deprivation weakens L4-L2/3 synapses by decreasing presynaptic function, similar to known LTD mechanisms at this synapse.Keywords
This publication has 68 references indexed in Scilit:
- Two Coincidence Detectors for Spike Timing-Dependent Plasticity in Somatosensory CortexJournal of Neuroscience, 2006
- Requirement for the RIIβ Isoform of PKA, But Not Calcium-Stimulated Adenylyl Cyclase, in Visual Cortical PlasticityJournal of Neuroscience, 2004
- Presynaptic Mechanism Underlying cAMP-Dependent Synaptic PotentiationJournal of Neuroscience, 2004
- Modulation of spike timing by sensory deprivation during induction of cortical map plasticityNature Neuroscience, 2004
- Synaptic basis for developmental plasticity in somatosensory cortexCurrent Opinion in Neurobiology, 2004
- Short-Term Synaptic PlasticityAnnual Review of Physiology, 2002
- CORTICAL PLASTICITY: From Synapses to MapsAnnual Review of Neuroscience, 1998
- The probability of transmitter release at a mammalian central synapseNature, 1993
- High Probability Opening of NMDA Receptor Channels by L-GlutamateScience, 1992
- Mechanisms generating the time course of dual component excitatory synaptic currents recorded in hippocampal slicesNeuron, 1990