| Presentation Number: |
139.18 |
| Abstract Title: |
Spontaneous synaptic release onto specific types of neocortical neurons, and its nicotinic regulation. |
| Authors: |
Mancilla, J. G.*1;
Amitai, Y.1;
Connors, B. W.1
1Neuroscience, Brown University, Providence, RI
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| Primary Theme and Topics |
F. Sensory Systems
- 72. Somatosensory cortex and thalamocortical relationships
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| Secondary Theme and Topics |
D. Neurotransmitters, Modulators, Transporters, and Receptors
- 41. Acetylcholine receptors: nicotinic
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| Session: |
139. Acetylcholine receptors: nicotinic IV
Poster |
| Presentation Time: |
Sunday November 5, 2000 2:00 PM-3:00 PM |
| Location: |
Convention Center Exhibit Hall, Poster Board FF-8 |
| Keywords: |
barrel cortex, interneurons, EPSPs, presynaptic
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Studies suggest that both pre- and postsynaptic cells may determine synapse properties. We compared spontaneous excitatory synaptic events on various cell types in the barrel cortex. Whole-cell recordings of spontaneous EPSPs were obtained from layer 4 of rat thalamocortical slices. Three groups of neurons were identified by their shape under IR-DIC and their firing patterns: regular spiking (RS) excitatory cells, and 2 types of inhibitory interneurons: fast-spiking (FS), and low threshold-spiking (LTS) cells. LTS cells had much lower EPSP frequencies than FS cells (2±1 Hz vs. 20±8 Hz, respectively; mean±SD). The mean frequency of EPSPs in RS cells was 13±4 Hz. Application of TTX had no effect on EPSP frequency in any cell type, indicating that spontaneous action potentials did not contribute to release. Nicotine (2 μM) significantly increased EPSP frequency in FS and RS cells (by 25%), without changing their amplitude distributions, but had no effect on LTS cells. The nicotine effect was doubled when bath [Ca2+] was reduced from 2 to 1 mM. Our results suggest that synapses onto the two types of interneurons have very different characteristics of release and regulation, consistent with the differences in their evoked release patterns.
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| Supported by NNIH to BWC, and BSF to YA and BWC. |
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| Sample Citation: |
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[Authors]. [Abstract Title]. Program No. XXX.XX. 2000 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2000. Online.
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| Copyright © 2000-2010 Society for Neuroscience; all rights reserved. Permission to republish any abstract or part of any abstract in any form must be obtained in writing by SfN office prior to publication.
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