Neuroscience 2000 Abstract
| Presentation Number: | 751.1 |
|---|---|
| Abstract Title: | Novelty-induced facilitation of LTP is not modulated by acetylcholine or norepinephrine. |
| Authors: |
Davis-Hart, C. D.*1
; Derrick, B. E.1
1Cajal Neuroscience Research Center, Division of Life Sciences, The University of Texas at San Antonio, San Antonio, TX |
| Primary Theme and Topics |
I. Neural Basis of Behavior - 109. Learning and memory: pharmacology |
| Secondary Theme and Topics | C. Excitable Membranes and Synaptic Transmission<br />- 33. Synaptic plasticity |
| Session: |
751. Learning and memory: pharmacology--biogenic amines and stress Poster |
| Presentation Time: | Wednesday, November 8, 2000 1:00 PM-2:00 PM |
| Location: | Hall G-J |
| Keywords: | Dentate Gyrus, Novelty, Exploration, Propranolol |
Our previous studies demonstrate that exposure to a novel environment during induction of the medial perforant path-dentate gyrus (DG) synapse in freely-moving rats increases the probability, magnitude and longevity of LTP (Davis-Hart, SFN, 1997).Our studies also indicate this facilitation effect is independent from general arousal, ongoing theta rhythm, ambulation, or increases in brain temperature (Davis-Hart, SFN, 1998,1999). However, prior exposure to novel stimuli reduces the facilitation (Davis-Hart, SFN, 1999), suggesting that facilitation was dependent on novel stimuli within the environment. Exploration increases several neuromodulators in the hippocampus, including norepinephrine and acetylcholine, which are known to produce physiological states conducive to LTP induction. We therefore examined whether noradrenergic or cholinergic systems are involved in novelty-induced facilitation of LTP. Perforant path-DG responses were collected daily for 1 week in the home cage. Following collection of stable baseline responses in the home cage, the β-adrenergic receptor antagonist, propranolol HCl (10 mg/kg IP) or the cholinergic receptor antagonist, atropine sulfate (30 mg/kg IP) or equal volumes of water were administered i.p. Thirty minutes after the administration of drug or water, animals were placed in a novel environment, after which LTP was induced using theta burst stimulation. Following tetanus, animals were returned to the home cage. Daily responses were recorded for an additional 2 weeks. Neither propranolol HCl nor atropine sulfate significantly altered the facilitation of LTP magnitude or longevity as compared to vehicle controls. Thus, the phenomenon of novelty-induced facilitation of LTP is not mediated by β-adrenergic or muscarinic receptors. We are investigating other neuromodulatory systems that are active during exploratory behaviors and that may mediate this effect.
Supported by DA 11983 (BED)
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2000 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2000. Online.
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