(+/-)Cyclazocine blocks the dopamine response to nicotine

Area of Science:

• Neuroscience
• Pharmacology
• Addiction Research

Background:

• (+/-)Cyclazocine, developed in 1962, acts as a mu opioid antagonist and kappa opioid agonist.
• Its known modulation of dopamine release suggests potential in treating drug abuse.
• Previous research indicated a reduction in cocaine self-administration by (+/-)cyclazocine.

Purpose of the Study:

• To investigate the effect of (+/-)cyclazocine on the dopaminergic effects of nicotine.
• To determine if (+/-)cyclazocine alters nicotine's rewarding pathways in the brain.

Main Methods:

• In vivo microdialysis was employed in awake, freely moving rats.
• The study examined the impact of (+/-)cyclazocine (0.5 mg/kg, i.p.) on dopamine response to nicotine (0.32 mg/kg, i.v.).
• Measurements were taken in the nucleus accumbens, a key area for reward.

Main Results:

• (+/-)Cyclazocine significantly attenuated nicotine-induced increases in extracellular dopamine levels.
• The drug enhanced nicotine-induced increases in dopamine metabolites.
• (+/-)Cyclazocine alone did not significantly alter basal dopamine levels, though enantiomers showed effects.

Conclusions:

• The findings suggest that both (+) and (-) enantiomers contribute to the racemic effects of (+/-)cyclazocine.
• (+/-)Cyclazocine may reduce the rewarding effects of nicotine.
• This compound shows promise as a potential novel therapeutic for smoking cessation.