What does high-THC smoke during pregnancy do to rat offspring?
Daily high-THC Cannabis smoke from GD6–20 did not change dam weight gain or litter size, but raised male:female ratio, reduced adult open-field inner-zone exploration, and improved touchscreen discrimination, with subtle male amygdala gene changes.
Source
Repeated Exposure to High-THC <i>Cannabis</i> Smoke during Gestation Alters Sex Ratio, Behavior, and Amygdala Gene Expression of Sprague Dawley Rat Offspring
Study at a glance
- Design
- Animal / in-vitro — Pregnant Sprague Dawley rats exposed daily to combusted high-THC Cannabis smoke (GD6–20) vs room air; offspring behavior and amygdala RNA-seq
- N
- N=22 · 22 dams (smoke n=12, air n=10); offspring behavior cohorts n=40 and n=37
- Population
- Pregnant Sprague Dawley rats and their adult offspring
- Outcome
- Maternal physiology, litter sex ratio, anxiety-like and touchscreen cognition, amygdala gene expression
Structured fields used in claim comparison tables when every cited study has a complete layer.
What they did
Exposed 12 pregnant rats to 200 mg combusted Mohawk flower (~19.51% THC) for 15 min/day GD6–20 versus 10 room-air dams, then tested adult offspring in open field, EPM, social interaction, pairwise discrimination/reversal, and amygdala RNA-seq.
What they found
Dams had lower body temperature and more fecal boli after smoke; maternal weight gain, food intake, gestation length, and litter weight were unchanged. Cannabis litters had a higher male-to-female ratio. Adult offspring explored the open-field inner zone less, were unaltered on EPM/social tests, outperformed controls on visual PD/RL, and males showed subtle amygdala transcript shifts.
The limits
What it doesn't show
Rat smoke exposure is not human prenatal cannabis use; there was no CBD-matched or pair-fed human cohort, and improved touchscreen scores do not equal better real-world cognition.
Key terms
- Form of exposure
- Combusted high-THC flower smoke (Mohawk, 19.51% THC, <0.07% CBD), not injected THC.
- GD6 to GD20
- Gestational days of daily 15-minute smoke or room-air exposure.
- Open-field inner zone
- Center exploration used as an anxiety-like measure; reduced after prenatal smoke.
- Pairwise discrimination / reversal
- Touchscreen visual learning tasks on which Cannabis offspring performed better.
- Amygdala RNA-seq
- Transcriptome of adult offspring amygdala showing subtle developmental/cellular gene shifts in some males.
Flashcards
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Quiz yourself
Smoke vs air dam n was:
Common questions
How many dams?
22 females (12 smoke, 10 room air) plus 12 males for breeding.
Did litter size or dam weight change?
No significant change in maternal weight gain, food intake, gestation length, litter number, or litter weight.
What happened to sex ratio?
Male-to-female ratio increased in Cannabis-exposed litters.
Which behavior changed?
Less inner-zone open-field exploration; EPM and social interaction unchanged.
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