rethinkTHC Search
Menu
Study breakdown

Prenatal THC exposure in rats led to impaired emotional memory and increased alcohol-seeking in adolescent offspring

Animal StudyPreliminary evidence
The takeaway

Rat offspring exposed to THC in utero showed impaired emotional memory, decreased neuropeptide Y neurons in limbic regions, and increased alcohol drinking and relapse behavior during adolescence.

Prenatal health researchers, people interested in cannabis use during pregnancy

THC-exposed offspring showed both impaired emotional memory and increased alcohol-seeking behavior

What the researchers found

In utero THC-exposed adolescent rats showed impaired aversive limbic memory (but intact neutral memory), decreased NPY-positive neurons in limbic regions, altered Homer protein expression, and increased alcohol consumption, relapse, and compulsive-like drinking behavior in operant chambers.

Why it matters

As cannabis use during pregnancy increases alongside legalization, understanding potential long-term effects on offspring brain development and vulnerability to addiction is a growing public health concern.

The numbers in context

THC dose: 2 mg/kg subcutaneous to pregnant dams. Offspring showed decreased NPY-positive neurons and region-specific Homer protein changes. Increased alcohol drinking, relapse, and conflict behavior were observed in operant chamber testing.

How the study worked

Pregnant rats received subcutaneous THC (2 mg/kg) during gestation. Adolescent male offspring were assessed in two cohorts: one for behavioral reactivity, memory, and neurobiological markers (NPY, Homer proteins); another for instrumental learning and alcohol self-administration through early adulthood.

What this study cannot tell us

Animal model with subcutaneous THC administration, which differs from human cannabis use routes and patterns; only male offspring studied; single THC dose level.

How to read the evidence

Single animal study with one dose level and only male offspring examined.

When this study was published

Published in 2020.

The bigger picture

This study links prenatal THC exposure to both cognitive and addiction-related outcomes in offspring, suggesting the endocannabinoid system disruption during fetal development may have cascading effects.

Questions still open

  • Would female offspring show similar vulnerabilities? Do these findings translate to the doses and routes typical of human prenatal cannabis exposure?

Common questions

Did prenatal THC affect all types of memory in the offspring?
No. Neutral declarative memory was intact, but aversive limbic memory, which requires integrating emotional and environmental information, was impaired. This selective deficit points to specific brain circuits being affected.
Does this prove prenatal cannabis use causes alcohol problems in children?
This is an animal study using a controlled THC dose, so direct translation to humans is uncertain. However, it provides biological plausibility for a link between prenatal cannabinoid exposure and later addiction vulnerability.

Read the original research

In utero Δ9-tetrahydrocannabinol exposure confers vulnerability towards cognitive impairments and alcohol drinking in the adolescent offspring: Is there a role for neuropeptide Y?

Journal of psychopharmacology (Oxford, England), 34(6), 663-679

Citation

Brancato, Anna; Castelli, Valentina; Lavanco, Gianluca; Marino, Rosa Anna Maria; Cannizzaro, Carla. (2020). In utero Δ9-tetrahydrocannabinol exposure confers vulnerability towards cognitive impairments and alcohol drinking in the adolescent offspring: Is there a role for neuropeptide Y?. Journal of psychopharmacology (Oxford, England), 34(6), 663-679. https://doi.org/10.1177/0269881120916135

Explore the wider topic