Experimenter administered Δ9-THC decreases nicotine self-administration in a rat model.
Antony D Abraham, Jenny L Wiley, Julie A Marusich
Pharmacology, biochemistry, and behavior October 2023 DOI: 10.1016/j.pbb.2023.173632 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Population | Adult male and female Sprague-Dawley rats |
| Interventions | Delta-9-tetrahydrocannabinol (THC) Nicotine |
| Dose | 0, 3, 30 mg/kg THC |
| Duration | 14 days of THC treatment prior to and during training, followed by several weeks of self-administration |
| Topics | Cannabis |
| Keywords | Co-abuse Delta-9-tetrahydrocannabinol Nicotine Polysubstance use Self-administration |
| Key findings | Post-session THC decreased nicotine self-administration in male and female rats during acquisition and maintenance, increased the latency to stable nicotine intake, and shifted nicotine dose-effect curves downward, while not affecting sucrose responding. Pre-session THC suppressed responding at higher nicotine doses but also decreased sucrose responding, indicating a nonspecific effect. The authors conclude that THC modulates patterns of nicotine intake in rat models. |
Abstract
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. 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. 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. 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.