Vaporized Δ9-tetrahydrocannabinol exposure in utero has negative effects on attention in a dose- and sex-dependent manner.
Samantha L Penman, Nicole M Roeder, Jia Wang, Brittany J Richardson, Lily Freeman-Striegel, Alexis Krayevsky, Rina D Eiden, Saptarshi Chakraborty, Panayotis K Thanos
Pharmacology, biochemistry, and behavior September 1, 2024 DOI: 10.1016/j.pbb.2024.173808 via PubMed
Summary
Prenatal exposure to vaporized THC, the psychoactive component of cannabis, may lead to attention deficits and altered memory performance in adolescence. In a rodent study, pregnant rats inhaled THC daily from early pregnancy until birth. Their offspring, raised on either a standard or high-fat diet, were tested in early and late adolescence. Low-dose THC exposure reduced object exploration in memory and attention tests, indicating decreased attention. Female offspring showed even lower attention than males. Some learning pattern differences appeared in the high-dose group during early adolescence, but final memory performance was unaffected. This is the first study to examine vaporized THC's effects on adolescent memory and attention.
Study at a glance
| Characteristics | Randomized controlled trial Peer reviewed |
|---|---|
| Population | Pregnant rats and their offspring |
| Topics | Cannabis |
| Keywords | Attention Cognition Memory Prenatal |
| Citations | 9 |
| Key finding | Prenatal vaporized THC exposure led to decreased attention in offspring, with females more affected, and did not impair ultimate memory performance. |
Abstract
There has been an increasing use of cannabis during pregnancy in recent years. Studies have indicated that THC exposure in utero may increase the risk of attention deficits and memory impairments in adolescence. The goal of the present study is to investigate the effects of vaporized THC exposure during pregnancy on offspring memory and attention performance in early and late adolescence. Pregnant dams were exposed to vaporized THC (10 mg or 40 mg) daily from gestational day 2 until labor. Pups were given either a standard or a high-fat diet at weaning and tested in early and late adolescence in two memory tests, the Novel Object Recognition (NOR) test and the Morris Water Maze (MWM) test, and a test of attention, the Object-Based Attention (OBA) test. Rats exposed to low-dose THC showed significantly decreased object exploration in both the NOR and OBA tests, indicating decreased attention. Object exploration time in OBA was significantly lower in females than males. Additionally, post hoc analysis of MWM tests showed some differences in learning patterns for HD THC offspring in early adolescence, possibly due to diet interaction, but ultimate performance was not impacted. While there are existing studies examining prenatal exposure to THC in rodents, this is the first to our knowledge examining memory and attention in adolescence following vaporized THC exposure in utero, and we find indications that prenatal THC exposure may lead to attention deficits and altered memory performance.