title: A cannabinoid analogue of Delta9-tetrahydrocannabinol disrupts neural development in chick.
abstract: Marijuana is the most commonly abused illicit drug by pregnant women. Its major psychoactive constituent, Delta(9)-THC (Delta(9)-tetrahydrocannabinol), crosses the placenta and accumulates in the foetus, potentially harming its development. In humans, marijuana use in early pregnancy is associated with miscarriage, a fetal alcohol-like syndrome, as well as learning disabilities, memory impairment, and ADHD in the offspring. Classical studies in the 1970 s have reached disparate conclusions as to the teratogenic effects of cannabinoids in animal models. Further, there is very little known about the immediate effects of Delta(9)-THC on early embryogenesis. We have used the chick embryo as a model in order to characterize the effects of a water-soluble Delta(9)-THC analogue, O-2545, on early development. Embryos were exposed to the drug (0.035 to 0.35 mg/ml) at gastrulation and assessed for morphological defects at stages equivalent to 9-14 somites. We report that O-2545 impairs the formation of brain, heart, somite, and spinal cord primordia. Shorter incubation times following exposure to the drug show that O-2545 interferes with the initial steps of head process and neural plate formation. Our results indicate that the administration of the cannabinoid O-2545 during early embryogenesis results in embryotoxic effects and serves to illuminate the risks of marijuana exposure during the second week of pregnancy, a time point at which most women are unaware of their pregnancies.
authors.affiliation: Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, USA. dpsychoyos@ibt.tamhsc.edu
authors.forename: Delphine
authors.initials: D
authors.lastname: Psychoyos
authors.forename: Basalingappa
authors.initials: B
authors.lastname: Hungund
authors.forename: Thomas
authors.initials: T
authors.lastname: Cooper
authors.forename: Richard H
authors.initials: RH
authors.lastname: Finnell
mesh_terms: D000818:Animals; D002642:Chick Embryo; D013759:Dronabinol / Q000633:toxicity*; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects; D009436:Neural Tube Defects / Q000139:chemically induced*; D055495:Neurogenesis / Q000187:drug effects*; D011619:Psychotropic Drugs / Q000633:toxicity*; D019170:Somites / Q000166:cytology / Q000187:drug effects
chemical_list: D011619:Psychotropic Drugs; D013759:Dronabinol