THC improved memory and movement recovery after traumatic brain injury in mice

Mice given THC after a controlled brain injury showed significant recovery of working memory and locomotor function, associated with increased brain repair factors.

Song, Shijie et al.·Cannabis and cannabinoid research·2022·Preliminary EvidenceAnimal StudyAnimal Study
RTHC-04238Animal StudyPreliminary Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
Preliminary Evidence
Sample
Not reported

What This Study Found

THC-treated mice exhibited marked improvement in Y-maze working memory performance and recovered to normal rotarod performance by 2 weeks after brain injury. THC upregulated neurotrophic factors G-CSF, BDNF, and GDNF and increased endocannabinoid 2-AG levels in the brain.

Key Numbers

THC dose: 3 mg/kg IP for 3 days post-injury. Working memory recovered significantly in THC-treated mice. Rotarod performance normalized at 2 weeks. G-CSF, BDNF, and GDNF all significantly upregulated in cerebral cortex, striatum, and hippocampus. 2-AG levels also increased.

How They Did This

C57BL/6J mice underwent controlled cortical impact (CCI) and received THC (3 mg/kg IP) for 3 days. Working memory (Y-maze spontaneous alternations) and locomotor function (rotarod) measured at baseline and 3, 7, and 14 days post-injury. Brain tissue analyzed for neurotrophic factors and endocannabinoid levels.

Why This Research Matters

Traumatic brain injury has limited treatment options. This study suggests THC may promote brain self-repair by upregulating the same neurotrophic factors that have been shown to mediate recovery after TBI and stroke.

The Bigger Picture

While most cannabis research focuses on potential harms, this study suggests THC may have neuroprotective and neuroregenerative properties that could be harnessed therapeutically, at least in the context of acute brain injury.

What This Study Doesn't Tell Us

Animal study with a single THC dose. The injury model (controlled cortical impact) represents only one type of TBI. The timeline was short (14 days). Human TBI is far more complex and variable.

Questions This Raises

  • ?Would THC benefit human TBI patients?
  • ?What is the optimal timing and dose for neuroprotective effects?
  • ?Could the same recovery be achieved with CBD or other cannabinoids without psychoactive effects?

Trust & Context

Key Stat:
Motor function normalized by 2 weeks in THC-treated mice
Evidence Grade:
Preliminary: single animal study with one dose and short follow-up.
Study Age:
Published in 2022.
Original Title:
Administration of Δ9-Tetrahydrocannabinol Following Controlled Cortical Impact Restores Hippocampal-Dependent Working Memory and Locomotor Function.
Published In:
Cannabis and cannabinoid research, 7(4), 424-435 (2022)
Database ID:
RTHC-04238

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

How did THC help after brain injury?

THC increased levels of three neurotrophic factors (G-CSF, BDNF, GDNF) that promote brain repair, as well as the endocannabinoid 2-AG. These changes were associated with recovery of memory and movement.

Was THC given before or after the injury?

After. THC was administered for 3 days following the controlled cortical impact, making this a treatment study rather than a prevention study.

Could this lead to THC treatment for human head injuries?

It is too early to say. Animal TBI models provide important initial data, but human clinical trials would be needed to determine if THC has similar effects in people with brain injuries.

Read More on RethinkTHC

Cite This Study

RTHC-04238·https://rethinkthc.com/research/RTHC-04238

APA

Song, Shijie; Kong, Xiaoyuan; Wang, Bangmei; Sanchez-Ramos, Juan. (2022). Administration of Δ9-Tetrahydrocannabinol Following Controlled Cortical Impact Restores Hippocampal-Dependent Working Memory and Locomotor Function.. Cannabis and cannabinoid research, 7(4), 424-435. https://doi.org/10.1089/can.2021.0053

MLA

Song, Shijie, et al. "Administration of Δ9-Tetrahydrocannabinol Following Controlled Cortical Impact Restores Hippocampal-Dependent Working Memory and Locomotor Function.." Cannabis and cannabinoid research, 2022. https://doi.org/10.1089/can.2021.0053

RethinkTHC

RethinkTHC Research Database. "Administration of Δ9-Tetrahydrocannabinol Following Controll..." RTHC-04238. Retrieved from https://rethinkthc.com/research/song-2022-administration-of-9tetrahydrocannabinol-following

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.