Neuroscience 2005 Abstract
| Presentation Number: | 382.14 |
|---|---|
| Abstract Title: | Activity-dependent silencing of AMPA and kainate signaling at glutamate synapses on interneurons in the CA1 stratum radiatum. |
| Authors: |
Riebe, I. M.*1
; Gustafsson, B.1
; Hanse, E.1
1Physiology and Pharmacology, Göteborg, Sweden |
| Primary Theme and Topics |
Neural Excitability, Synapses, and Glia: Cellular Mechanisms - Synaptic Plasticity -- Long-term depression (LTD) |
| Secondary Theme and Topics | Development<br />- Synaptogenesis and Activity-Dependent Development<br />-- Synaptogenesis and activity-dependent plasticity |
| Session: |
382. LTD I Poster |
| Presentation Time: | Monday, November 14, 2005 9:00 AM-10:00 AM |
| Location: | Washington Convention Center - Hall A-C, Board # E68 |
| Keywords: | LTD, SILENT SYNAPSE, SYNAPTIC PLASTICITY |
Glutamate ionotropic transmission from Schaffer collateral axons onto GABAergic interneurons differs from that on the principal CA1 pyramidal cells. For example, many glutamate synapses on interneurons contain postsynaptic kainate receptors and calcium permeable AMPA receptors. We have previously shown, in the developing (< 2 week old) rat, that many glutamate synapses on interneurons, like those on pyramidal neurons, exhibit AMPA silent synapses and activity-dependent AMPA silencing (Riebe et al SfN 2004, Xiao et al Nat Neurosci 7:236). In the present study we report that AMPA silencing is observed not only in interneurons in the developing brain, but also in interneurons from the adult (> 40 day old) animal. Stimulating the Schaffer collaterals with 0.2 Hz, while voltage-clamping the interneuron at -80 mV, resulted in a rapid decrease of the naïve AMPA EPSC magnitude, stabilizing at 48±12% (n=5) of the initial value. This decrease was similar to that obtained in developing animals (66±8%, n=9) and it was accompanied by a corresponding decrease in the 1/CV² (41±9%, n=5), but no change in paired-pulse ratio. Consistent with previous studies the AMPA EPSC was followed by a slow kainate component both in adult and developing interneurons. This kainate component showed a stimulation-induced silencing (to 67±10%, 1/CV² to 67±15%) in parallel with that of the AMPA EPSCs. Our demonstration of AMPA and kainate silencing in interneurons contributes to the emerging picture of glutamate synapses on interneurons as more plastic than was previously thought.
Supported by Swedish Research Council
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2005 Neuroscience Meeting Planner. Washington, DC: Society for Neuroscience, 2005. Online.
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