Neuroscience 2003 Abstract
| Presentation Number: | 644.15 |
|---|---|
| Abstract Title: | Acute delta-9-tetrahydrocannabinol activates A9/A10 dopamine neurons in non-human primates as indicted by expression of c-Fos. |
| Authors: |
Roth, R. H.*1
; Elsworth, J. D.1
; Jentsch, J. D.2
; Verrico, C. D.3
; Redmond, D. E.1
; Morrow, B. A.1
1Pharmacol., Yale Univ. Sch. Med, New Haven, CT 2CA, 333 Cedar St, 06520-8066, 3USA, 333 Cedar St, 06520-8066, |
| Primary Theme and Topics |
Neurological and Psychiatric Conditions - Addiction and Drugs of Abuse -- Opioids and others |
| Secondary Theme and Topics | Synaptic Transmission and Excitability<br />- Neurotransmitters<br />-- Catecholamines |
| Session: |
644. Addiction and Drugs of Abuse: Opioids & Others IV Poster |
| Presentation Time: | Tuesday, November 11, 2003 10:00 AM-11:00 AM |
| Location: | Morial Convention Center - Hall F-I, Board # VV45 |
| Keywords: | IMMEDIATE EARLY GENE, VENTRAL TEGMENTAL AREA, MONKEY, SUBSTANTIA NIGRA |
Delta-9-tetrahydrocannabinol (THC) is the major psychoactive constituent of marijuana and is thought to be responsible for acute and long-term behavioral effects seen in humans potentially through a dysfunction of the frontal cortex. In the rat, acute exposure to THC increases cortical dopamine (DA) turnover and disrupts short-term memory (Neuropsychopharm 16:426-432, 1997). In this current study, we examined the effects of a single dose of THC on midbrain DA neurons in non-human primates using the immediate-early gene, c-fos, as an indicator of the initiation of long-term adaptation brought on by acute activation. Twelve male, adult African green monkeys of St Kitts origin (Cercopithecus aethiops sabaeus) were given a single injection of vehicle or THC, 1.25 mg/kg or 2.5 mg/kg. After 1 hour, the monkeys were overdosed on pentobarbital, perfused with saline, and the brains were placed in 4% formalin for 24 hours. The midbrains were cut into 50 μm sections and stained for Fos-immunoreactivity (Fos-ir) and then for tyrosine hydroxylase-ir (TH-ir) to indicate activated midbrain DA neurons. Behavioral changes were most noticable at the highest THC dose: sedation and some motor slowing. Immunochemical data were analyzed using a repeated measures ANOVA with the between factor being the dose of THC and the within factor being region. Analysis indicated that THC treatment resulted in a dose-dependent activation of Fos expression in A9/A10 DA neurons. Dopamine neurons in the A10 region demonstrated a greater activation than in the A9. These data indicate that a single dose of THC activated midbrain DA neurons and may contribute to the acute memory deficits. The acute activation of c-fos is thought to indicate the initiation of longer-term changes that may develop with chronic THC use.
Supported by MH14092
Sample Citation:
[Authors]. [Abstract Title]. Program No. XXX.XX. 2003 Neuroscience Meeting Planner. New Orleans, LA: Society for Neuroscience, 2003. Online.
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