THC and CBD had different effects on brain growth factor in the adolescent hippocampus | Research

The takeaway

In animal models, adolescent THC and CBD exposure had distinct effects on brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the hippocampus, a region critical for learning and memory.

Neurodevelopment researchers, adolescent health specialists, and neuroscientists studying cannabinoid effects on brain maturation.

THC and CBD produced distinct BDNF expression patterns in adolescent brain

What the researchers found

THC and CBD produced different patterns of BDNF and TrkB expression changes in the adolescent hippocampus. These findings suggest the two major cannabinoids may have opposing or distinct effects on neurodevelopmental signaling during a critical growth period.

Why it matters

BDNF is essential for synaptic plasticity, learning, and memory. If cannabis compounds alter BDNF signaling during adolescent brain development, it could help explain the cognitive effects reported in teen cannabis users.

The numbers in context

THC and CBD produced distinct patterns of BDNF and TrkB expression in the adolescent hippocampus. Effects differed between the two cannabinoids.

How the study worked

Animal study examining the effects of adolescent THC and CBD exposure on BDNF and TrkB receptor expression in the hippocampus using molecular biology techniques.

What this study cannot tell us

Animal study with unknown human translational relevance. Doses and timing may not reflect human adolescent cannabis use patterns. Molecular expression changes may not directly translate to functional cognitive effects. Single brain region examined.

How to read the evidence

Animal study providing mechanistic insight. Cannot be directly applied to human adolescent brain development.

When this study was published

Published 2023.

The bigger picture

Adolescent brain development involves massive synaptic remodeling guided by neurotrophic factors like BDNF. Disrupting these signals with exogenous cannabinoids during this window could have lasting consequences for cognitive function.

Questions still open

Do the opposing BDNF effects of THC and CBD explain why CBD may be neuroprotective while THC may be harmful during adolescence? Would combined THC+CBD exposure produce different BDNF changes than either alone?

Common questions

How does cannabis affect the developing teenage brain?

This animal study found THC and CBD changed levels of BDNF, a protein critical for brain cell growth and connections, in the adolescent hippocampus. The two cannabinoids had different effects, suggesting they may impact brain development differently. Whether these molecular changes translate to cognitive effects in human teens is unknown.

What is BDNF and why does it matter?

Brain-derived neurotrophic factor (BDNF) supports neuron survival, growth, and the formation of new connections. It is especially important during adolescence when the brain undergoes major remodeling. Changes in BDNF levels could affect learning, memory, and emotional regulation.

Read the original research

Effects of Tetrahydrocannabinol and Cannabidiol on Brain-Derived Neurotrophic Factor and Tropomyosin Receptor Kinase B Expression in the Adolescent Hippocampus.

Cannabis and cannabinoid research, 8(4), 612-622

View on PubMed ↗Publisher’s paper ↗

Citation

Winstone, Joanna; Shafique, Hana; Clemmer, Madeleine E; Mackie, Ken; Wager-Miller, Jim. (2023). Effects of Tetrahydrocannabinol and Cannabidiol on Brain-Derived Neurotrophic Factor and Tropomyosin Receptor Kinase B Expression in the Adolescent Hippocampus.. Cannabis and cannabinoid research, 8(4), 612-622. https://doi.org/10.1089/can.2021.0025