Ethanol and cannabinoids interact to alter behavior in a zebrafish fetal alcohol spectrum disorder model

Abstract

Background: Recent work suggests that endocannabinoids (eCBs) may signal through the sonic hedgehog signaling pathway. We therefore hypothesized that combined ethanol and eCB exposure during defined stages of zebrafish embryogenesis will produce deficits comparable to human fetal alcohol spectrum disorder (FASD). Methods: Zebrafish embryos were exposed to ethanol or cannabinoid agonists alone or in combination at defined developmental stages and assessed for changes in brain morphology or expression of marker genes such as pax6a. Juvenile fish were then assessed for risk-taking/anxiety-like behavior using the novel tank dive test. Results: Either chronic or acute exposure to high doses of the CB1R agonist ACEA resulted in FASD phenotypes. However, acute subthreshold doses of CB1R agonist alone, or combined with 0.5% ethanol, did not induce morphological phenotypes, but did induce dysmorphogenesis when combined with acute 1% ethanol. Phenotypes were rescued using the CB1R antagonist SR141716A. In addition, JZL195, a dual inhibitor of FAAH and MAGL, two degradative enzymes for eCBs, induced FASD phenotypes in the presence of subthreshold ethanol, confirming the activation of common signaling pathways by ethanol and eCBs. We next analyzed the effects of ethanol and CB1R agonist on juvenile zebrafish behavior and show that ACEA or ethanol alone did not alter behavior, but combined ACEA and ethanol increased risk-taking behavior. Conclusions: These studies demonstrate that pathological and behavioral phenotypes associated with FASD are induced by exposure to CB1R agonists and suggest that combined exposure to lower levels of alcohol and marijuana may be capable of inducing FASD-like morphological and behavioral impairments.

Cannabinoids differentially modulate behavioral and developmental responses to ethanol in Drosophila

“…In vivo studies using the rodent models have revealed that postnatal exposure to ethanol increased the levels of AEA (Vinod et al, 2006) but not 2-AG and CB 1 receptors, thus leading to neurodegeneration through the AEA/CB 1 receptor signaling pathway (Subbanna et al, 2013). It was recently shown that AEA analog, Arachidonoyl-20-chloroethylamide, with low amount of ethanol induced dysmorphogenesis in zebrafish (Boa-Amponsem et al, 2019). In addition, we also observe a slight delay in ethanol-induced pupal development and decrease in viability with CBD treatment although the difference was insignificant.…”

The Effects of Cannabis on Female Reproductive Health Across the Life Course

“…6 Perturbations to this system have a range of cellular effects and may affect cognitive, behavioral, and emotional development in childhood. 6,49,50 Several longitudinal studies have reported on the association between prenatal cannabis exposure and childhood neurodevelopmental outcomes. [51][52][53] Tennes et al assessed weight, height, and psychomotor outcomes in 129 infants, 1 year after delivery.…”

Marijuana and Opioid Use during Pregnancy: Using Zebrafish to Gain Understanding of Congenital Anomalies Caused by Drug Exposure during Development

“…Chronic exposure to CNR1 agonist ACEA (6 mg/L suspended in ethanol) from 6 to 24 hpf induced microphthalmia, but a lower concentration of ACEA (3 mg/L) did not. However, when the embryos were treated with the combinations of 3 mg/L ACEA and 0.5% ethanol, the larvae had smaller eyes, suggesting a synergistic effect of CNR1 agonist and alcohol on interfering eye development [ 90 ]. Binge-like exposure of ACEA (3 and 12 mg/L) on eye development was examined by treating embryos during key developmental time points including the first hour of gastrulation (5.25–6.25 hpf), transition from gastrulation to neurulation (8–10 hpf) or during the formation of the five-vesicle brain (24–27 hpf).…”

“…Lower concentration (3 mg/L) of ACEA alone did not cause microphthalmia, but when treated with ethanol (1%), ACEA synergized with ethanol to induce microphthalmia. This study highlights the synergistic interaction of the CNR1 agonist and alcohol and shows how alcohol exposure exacerbates the defects caused by ACEA exposure [ 90 ]. Smaller eyes were also reported following waterborne exposure to CBD and THC [ 84 ].…”