Cannabis during pregnancy: A way to transfer an impairment to later life

Abstract

Epidemiological studies examining the influence of cannabis across the lifespan show that exposure to cannabis during gestation or during the perinatal period is associated with later‐life mental health issues that manifest during childhood, adolescence, and adulthood. The risk of later‐life negative outcomes following early exposure is particularly high in persons who have specific genetic variants, implying that cannabis usage interacts with genetics to heighten mental health risks. Prenatal and perinatal exposure to psychoactive components has been shown in animal research to be associated with long‐term effects on neural systems relevant to psychiatric and substance use disorders. The long‐term molecular, epigenetic, electrophysiological, and behavioral consequences of prenatal and perinatal exposure to cannabis are discussed in this article. Animal and human studies, as well as in vivo neuroimaging methods, are used to provide insights into the changes induced in the brain by cannabis. Here, based on the literature from both animal models and humans, it can be concluded that prenatal cannabis exposure alters the developmental route of several neuronal regions with correlated functional consequences evidenced as changes in social behavior and executive functions throughout life.

Utility of the Zebrafish Model for Studying Neuronal and Behavioral Disturbances Induced by Embryonic Exposure to Alcohol, Nicotine, and Cannabis

“…Prenatal exposure to alcohol, nicotine, or cannabis in rodents has been shown to produce a wide range of behavioral changes in the offspring that may begin early in life and last long into adulthood, with parallel effects observed in human studies. There are several comprehensive reviews of the behavioral outcomes of prenatal exposure to these drugs of abuse [45][46][47][48], with some reports examining rodents at a young age [49][50][51][52][53][54]. In a recent study from our laboratory [4], we demonstrated in early postnatal rats that prenatal exposure to alcohol, at a relatively low concentration and for only 5 days, produces a number of drug-induced behaviors in the offspring, consistent with those described in clinical studies of children [26,[55][56][57][58][59].…”

“…Behavioral changes have also been observed in young rodents, as shown by altered locomotor activity in pre-weanling rats [68] and increased anxietylike and impulsive behaviors in adolescent rats [69]. Prenatal exposure to cannabis in rodents has similar effects on drug-related behaviors [48,70,71], including a small increase in anxiety and impulsive risk-taking behavior during adolescence [72,73]. Further, longlasting alterations in drug-seeking behavior have been shown after prenatal exposure to tetrahydrocannabinol (THC), the primary psychoactive molecule in cannabis that crosses the fetoplacental barrier [74], which include an increase in behavioral sensitivity to this drug in pre-adolescent rats [73] and also in heroin self-administration in adult rats [75].…”

“…These findings are consistent with results of a study of Hcrt neurons which support a role for this peptide in multiple aspects of nicotine intake behavior, including the willingness to work and seek this rewarding substance and the emotional response associated with nicotine consumption [92]. While there are few studies in rodents of the effects of prenatal cannabis exposure on neuronal peptides, with one suggesting that prenatal cannabis exposure has no effect on cell proliferation in the dentate gyrus [94], there are reports suggesting that prenatal cannabis exposure alters the developmental route of several neuronal regions in the brain, with these effects correlated with functional consequences [48]. There is also evidence that prenatal exposure to THC stimulates mRNA expression of Enk in the amygdala of adults while reducing it in the nucleus accumbens early in development [75], and that adolescent exposure to THC stimulates the Dyn kappa receptor in the nucleus accumbens [95].…”