Deducing the Reproductive, Behavioral, and Learning Effects of Developmental Cannabinoid Exposure in Zebrafish

With the spreading legalization of marijuana, it is important to investigate the effects of two of its active ingredients—Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD). THC and CBD differ in that THC exerts psychoactive effects, while CBD does not. Thus, CBD is renowned for its analgesic effects in treating a variety of ailments, for example, childhood drug-resistant epilepsy. In addition, there is an increase in reports of prenatal CBD usage. As it is increasingly used, research has fallen far behind the proliferation of CBD and more needs to be done, particularly in the developmental realm. This study utilizes a developmental origins of health and disease (DOHaD) multigenerational paradigm after an embryo-larval exposure of F0 zebrafish to several low concentrations of THC (0.024, 0.12, 0.6 mg/L; 0.08, 0.4, 2 μM) and CBD (0.006, 0.03, 0.15 mg/L; 0.02, 0.1, 0.5 μM). Three primary tests were conducted: a reproductive assessment, an adult behavioral Open Field Test, and a learning and memory T-maze test. In terms of reproduction, fecundity was significantly reduced in several exposed F0 groups, but not in F1 groups. In the Open Field Test, there were no significant findings in the F0 fish, but there were significantly altered behaviors measured in the F1 fish whose parents were exposed to the highest concentration of THC. The T-maze is an ongoing experiment and has not produced any significant outcomes in relation to learning and memory. The results of this experiment reveal the need for increased investigation into the lifelong and multigenerational effects of developmental THC and CBD exposure