A new study published in the journal Aging Medicine found that cannabinoid CB1 receptor expression was significantly reduced in multiple brain regions of patients with Alzheimer’s disease, with lower levels tied to greater amyloid-beta and tau pathology.
Researchers from Georg-August-University and the Department of Nuclear Medicine at University Medical Center Göttingen in Germany analyzed post-mortem brain tissue from patients with sporadic Alzheimer’s disease and non-demented control subjects. The study focused on the hippocampus, medial frontal gyrus and superior temporal gyrus, all regions involved in memory, cognition or Alzheimer’s-related brain changes.
The study found that CB1 receptor expression was significantly lower in all three regions among Alzheimer’s patients. Researchers also found that lower CB1 receptor levels were associated with higher levels of tau pathology in each region, while amyloid-beta pathology was negatively correlated with CB1 expression in the medial frontal gyrus and superior temporal gyrus.
Researchers said the findings were consistent with results from two Alzheimer’s mouse models, where CB1 receptor expression was also reduced in specific brain regions.
The study did not find a connection between CB1 receptor levels and cognitive status, age, ApoE genotype, sex or markers of neuroinflammation.
Researchers concluded that the findings support a potential role for CB1 receptors in Alzheimer’s disease and warrant further research into whether the receptor could serve as a biomarker or therapeutic target. While the study does not show that cannabis or cannabinoids can treat Alzheimer’s, it adds to evidence that the endocannabinoid system may be involved in the disease and that cannabinoids warrant further study as a potential treatment option.
