Neuroscience 2001 Abstract
| Presentation Number: | 922.10 |
|---|---|
| Abstract Title: | STATE-DEPENDENCE OF PHASE-SENSITIVE HEBBIAN MODIFICATIONS DURING OSCILLATIONS IN RAT VISUAL CORTEX. |
| Authors: |
Wespatat, V.*1
; Tennigkeit, F.1
; Eilers, J.1
; Singer, W.1
1Neurophysiology, Max-Planck Institute for Brain Research, Frankfurt a. M., Germany |
| Primary Theme and Topics |
Synaptic Transmission and Excitability - Synaptic Plasticity -- Other |
| Session: |
922. Synaptic plasticity: other--network activity and modeling Poster |
| Presentation Time: | Thursday, November 15, 2001 9:00 AM-10:00 AM |
| Location: | Exhibit Hall G-27 |
| Keywords: | Plasticity, Oscillation, Neuromodulation |
We have shown previously that Hebbian modifications are sensitive to phase relations between excitatory synaptic inputs and suprathreshold membrane potential oscillations in layer 2/3 visual cortex pyramidal neurons during cholinergic neuromodulation. During bath application of the cholinergic agonist carbachol (5 microM) pairing trains of extracellularly evoked EPSPs in layer 2/3 at 20 Hz with the peaks of suprathreshold 20 Hz Vm oscillations resulted in LTP, while pairing with the oscillation troughs induced LTD (Wespatat et al., SFN 2000). Here, we further investigate how blockade of cholinergic receptors affects the phase-angle sensitivity of Hebbian modifications during oscillations. Bath application of the muscarinic and nicotinic receptor antagonists scopolamine (10 microM) and hexamethonium (100 microM) resulted in LTD with both peak pairing, where EPSPs coincided with postsynaptic discharges and with trough pairing, where EPSPs were shifted 180° out of phase with postsynaptic discharges. Thus, cholinergic receptor blockade abolished the phase-sensitivity of Hebbian modifications. Our results indicate that acetylcholine is released during electrical stimulation in slices and influences the polarity of Hebbian modifications. The data suggest that cholinergic neuromodulation modifies the rules for Hebbian plasticity during oscillations in a state-dependent manner. By means of confocal Ca2+-imaging we currently investigate the hypothesis that Ach interacts selectively with LTP inducing signaling cascades.
Supported by the DFG and Max-Planck Society
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2001 Neuroscience Meeting Planner. San Diego, CA: Society for Neuroscience, 2001. Online.
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