Divergent effects of oral cannabis oil extracts marketed as C. indica or C. sativa on exertion of cognitive effort in rats.
Hannah G Brodie, Brett A. Hathaway, Andrew Li, S. Baglot, Sukhbir Kaur, M. Hill, C. Winstanley
Behavioral Neuroscience November 17, 2022 DOI: 10.1037/bne0000535 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Population | Male Long-Evans rats |
| Dose | 10 mg/kg THC (highest dose), 3 mg/kg THC (medium dose) |
| Topics | Cannabis |
| Key findings | Both cannabis oils slowed rats' response times at higher doses, but only C. indica oil at the highest dose (10 mg/kg THC) reduced the number of high-effort/high-reward trials chosen; repeated medium dosing (3 mg/kg THC) with either product did not affect choice. The authors argue these results support the suggestion that products marketed as different cannabis cultivars can have dissociable cognitive effects that may not resemble pure THC, and emphasize the importance of route of administration. |
Abstract
The main psychoactive compound within the cannabis plant, Δ9-tetrahydrocannabinol (THC), is thought to drive both the sensation of "high" and the cognitive impairments associated with cannabis consumption. Researchers keen to understand how cannabis impairs cognition have, therefore, studied the behavioral effects of systemic injections of THC in animal models. However, cannabis contains multiple other cannabinoids which may critically modulate the resulting cognitive effects. Users also typically eat or smoke cannabis, leading to concern over the translational validity of pure THC injections. We, therefore, tested whether acute oral administration of two different commercially available cannabis extracts, marketed as C. indica or C. sativa, decreased male Long-Evans rats' willingness to exert greater cognitive effort in order to maximize reward earned, as expected from previous experiments using injected THC. Both oils were matched for THC and cannabidiol content. While both cannabis products slowed response times at higher doses, only C. indica oil at the highest dose administered (10 mg/kg THC) decreased the number of trials on which rats chose to complete high-effort/high-reward trials. Repeated dosing with a medium dose of either cannabinoid product (3 mg/kg THC) did not influence choice. Ex vivo analyses confirmed comparable levels of brain THC after C. indica or C. sativa administration. Although controversial in the field, these results support the suggestion that products marketed as different cannabis cultivars have dissociable cognitive effects that may not resemble pure THC and emphasize the importance of the route of administration in experimental design. (PsycInfo Database Record (c) 2022 APA, all rights reserved).
Comparable studies
Other preclinical and animal studies on cannabis, most cited first.