Neuroscience 2000 Abstract
| Presentation Number: | 812.9 |
|---|---|
| Abstract Title: | Effects of chronic WIN 55,212-2 and Δ<SUP>9</SUP>-THC treatment on cannabinoid receptor activity in mouse brain. |
| Authors: |
Sim-Selley, L.*1
; Martin, B. R.1
1Dept. of Pharmacology & Toxicology, Virginia Commonwealth University, Richmond, VA |
| Primary Theme and Topics |
D. Neurotransmitters, Modulators, Transporters, and Receptors - 54. Cannabinoids |
| Secondary Theme and Topics | J. Disorders of the Nervous System and Aging<br />- 146. Drugs of abuse: opioids and others |
| Session: |
812. Cannabinoids: analgesia Poster |
| Presentation Time: | Thursday, November 9, 2000 8:00 AM-9:00 AM |
| Location: | Hall G-J |
| Keywords: | GTP Binding Protein, Desensitization, Tolerance |
Chronic administration of Δ9-THC (THC), a partial agonist for cannabinoid (CB1) receptor activation of G-proteins, produces dramatic desensitization of CB1 receptors throughout the brain. These studies were conducted to compare the effects of THC treatment with those produced by WIN 55,212-2 (WIN), a full agonist for CB1-mediated G-protein activation in brain. Mice were treated twice daily (s.c.) for 15 days with escalating doses of WIN (3-48 mg/kg), THC (10-160 mg/kg) or vehicle. Animals were either examined for tolerance in behavioral assays or brains were collected and processed for CB1-stimulated [35S]GTPγS autoradiography. Chronic treatment with either WIN or THC produced tolerance to CB1-mediated effects on spontaneous activity, hypothermia and antinociception. Densitometric analysis revealed decreased CB1-stimulated [35S]GTPγS binding in all regions examined in THC- and WIN-treated brains. CB1-stimulated G-protein activity in THC-treated animals was generally lower than in WIN-treated animals, although this effect was significant only in several regions, including hippocampus, caudate-putamen and cerebellum. These results demonstrate that chronic administration of either full or partial cannabinoid agonists produces desensitization throughout the brain, and suggest that administration of a partial agonist may lead to more desensitization in some regions.
Supported by Supported by DA-00287 (LJS) and DA-03672 (BRM) from NIDA.
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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