PubMed: Experimenter administered Δ<sup>9</sup>-THC decreases nicotine self-administration in a rat model

PubMed: Experimenter administered Δ<sup>9</sup>-THC decreases nicotine self-administration in a rat model

Pharmacol Biochem Behav. 2023 Sep 8:173632. doi: 10.1016/j.pbb.2023.173632. Online ahead of print.


BACKGROUND: The co-use of nicotine and cannabis has been steadily rising in the United States. Rodent studies suggest that delta-9-tetrahydrocannabinol (THC) could increase addictive qualities of nicotine, but whether repeated THC exposure alters self-administration of nicotine has not been tested. We hypothesized that THC would increase the reinforcing effects of nicotine and alter nicotine intake.

METHODS: Adult male and female Sprague-Dawley rats were treated with THC (0, 3, 30 mg/kg) daily for 14 days prior to and during training for intravenous self-administration of nicotine. Rats were allowed to self-administer nicotine for several weeks, then tested for sensitivity to nicotine dose through multiple determinations of a nicotine dose-effect curve with or without THC pretreatment. A separate set of rats were trained on fixed ratio responding for sucrose and assessed for THC effects on behavior.

RESULTS: Post-session THC decreased nicotine self-administration in male and female rats throughout acquisition and maintenance and increased the latency to stable rates of nicotine intake during acquisition. Post-session THC shifted nicotine dose-effect curves downward, and pre-session THC suppressed responding at higher nicotine doses. Unlike nicotine, responding for sucrose was not affected by post-session THC. Pre-session THC decreased responding for sucrose, particularly for THC-naïve rats.

CONCLUSIONS: Repeated post-session THC decreased nicotine-taking behaviors but did not alter sucrose responding. Thus, post-session THC may alter sensitivity to nicotine. Pre-session THC treatment decreased lever pressing in both sucrose and nicotine studies, indicating this effect was nonspecific. These studies show that THC modulates patterns of nicotine intake in rat models.

PMID:37690617 | DOI:10.1016/j.pbb.2023.173632–a3-xbLzPoB9xM&fc=20220928170152&ff=20230911190700&v=2.17.9.post6+86293ac September 10, 2023 10:00 am