Chronic exposure to inhaled vaporized cannabis high in Δ9-THC suppresses Adderall-induced brain activity.
Jack M Ognibene, Rajeev I Desai, Praveen P Kulkarni, Craig F. Ferris
Frontiers in Pharmacology 2024 DOI: 10.3389/fphar.2024.1413812 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Exploratory study Peer reviewed |
|---|---|
| Population | Male and female mice |
| Interventions | inhaled vaporized cannabis (10.3% Δ9-THC) placebo |
| Dose | 60 µg |
| Duration | 30 min each day for ten consecutive days, with a 2-week washout |
| Topics | Cannabis |
| Keywords | Bold Accumbens Awake animal imaging Basal ganglia Functional MRI |
| Key points | Chronic exposure to inhaled cannabis blunts the brain's BOLD response to Adderall, an effect that reverses after a two-week washout. |
Abstract
There are increasing reports of the misuse of prescription psychostimulants for cognitive enhancement together with recreational cannabis. This raises a concern that chronic use of cannabis high in Δ9-THC may alter the sensitivity to amphetamines. In this exploratory study we hypothesized chronic exposure to Δ9-THC through vaporized cannabis would diminish the central nervous system (CNS) activity of Adderall. To address this issue we exposed male and female mice to inhaled vaporized cannabis (10.3% Δ9-THC) or placebo for 30 min each day for ten consecutive days. After 24 h, mice were imaged fully awake for changes in BOLD signal following an IP injection of Adderall (60 µg) during the scanning session. After a 2-week washout, without any cannabis or placebo exposure, mice were again imaged and challenged with Adderall during the scanning session. The data were registered to a mouse 3D MRI atlas with 134 brain regions providing site-specific increases and decreases in global brain activity. Mice exposed to cannabis when compared to placebo showed a decrease in brain activation to Adderall. The blunted Adderall response was characterized by a decrease in positive BOLD signal and increase in negative BOLD. The prefrontal cortex, accumbens, ventral pallidum, caudate/putamen, and thalamus were most affected. After a 2-week wash out there were no significant differences between the cannabis and placebo groups when challenged with Adderall. This exploratory study shows that short, daily exposures to inhaled cannabis, something equivalent to recreational use, affects the sensitivity to the psychostimulant Adderall. The reduced Adderall effect on brain activity, particularly circuitry associated with dopaminergic signaling raises concerns about escalation in psychostimulant use.
Comparable studies
Other preclinical and animal studies on cannabis, most cited first.
Citations in the library
Cites 6
- Effects of inhaled cannabis high in Δ9-THC or CBD on the aging brain: A translational MRI and behavioral study Frontiers in Aging Neuroscience February 1, 2023
- Chronic exposure to inhaled vaporized cannabis high in Δ9-THC alters brain structure in adult female mice. Frontiers in Neuroscience 2023
- Marijuana dependence: not just smoke and mirrors. ILAR Journal 2011
- Rimonabant-induced Delta9-tetrahydrocannabinol withdrawal in rhesus monkeys: discriminative stimulus effects and other withdrawal signs. Journal of Pharmacology and Experimental Therapeutics July 2010
- Delta 9-tetrahydrocannabinol induces dopamine release in the human striatum. Neuropsychopharmacology February 2009
and 1 more in the library