Depression-prone rats show reduced endocannabinoid signaling, with differences between brain hemispheres
Rats bred for depression-like behavior had lower 2-AG levels in left-brain regions and altered endocannabinoid system components, with changes varying by hemisphere.
Quick Facts
What This Study Found
2-AG was lower in the left hippocampus and left prefrontal cortex of depression-prone FSL rats compared to controls. AEA was higher in the right hippocampus. CB1 receptor and FAAH protein levels were decreased in the left hippocampus, while mRNA for multiple eCB components was decreased in the right prefrontal cortex.
Key Numbers
2-AG was significantly lower in left hippocampus and left prefrontal cortex of FSL rats. AEA was elevated in right hippocampus. Plasma AEA was increased and 2-AG decreased in FSL rats.
How They Did This
Compared endocannabinoid levels (LC/MRM), receptor expression (qPCR), and protein levels (Western blot) in left and right prefrontal cortex and hippocampus of Flinders Sensitive Line (depression model) vs. Flinders Resistant Line rats.
Why This Research Matters
If depression involves hemisphere-specific endocannabinoid deficits, treatments targeting the eCB system might need to account for lateralized brain function, a nuance most current approaches overlook.
The Bigger Picture
The endocannabinoid system is increasingly implicated in depression, but this study adds an unexpected layer: the changes are not uniform across the brain. Left-right differences may help explain why depression manifests differently across individuals.
What This Study Doesn't Tell Us
Animal model using inbred rat strains, which may not fully represent human depression. Small sample sizes typical of such studies. Hemisphere-specific findings need replication.
Questions This Raises
- ?Do humans with depression show similar hemisphere-specific endocannabinoid differences?
- ?Could lateralized eCB deficits explain why some people respond to cannabinoid treatments and others do not?
Trust & Context
- Key Stat:
- Hemisphere-specific deficits
- Evidence Grade:
- Preliminary: animal model with no direct human data.
- Study Age:
- Published in 2019.
- Original Title:
- Hemisphere-dependent endocannabinoid system activity in prefrontal cortex and hippocampus of the Flinders Sensitive Line rodent model of depression.
- Published In:
- Neurochemistry international, 125, 7-15 (2019)
- Authors:
- Kirkedal, C, Elfving, B, Müller, H K, Moreira, F A, Bindila, L, Lutz, B, Wegener, G, Liebenberg, N
- Database ID:
- RTHC-02108
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
What is the endocannabinoid system's role in depression?
Endocannabinoids like 2-AG and AEA help regulate mood. This study found depression-prone rats had reduced eCB signaling, particularly in left-brain regions.
Why do left and right brain differences matter?
If endocannabinoid deficits in depression are lateralized, it could explain individual variation in symptoms and treatment responses.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-02108APA
Kirkedal, C; Elfving, B; Müller, H K; Moreira, F A; Bindila, L; Lutz, B; Wegener, G; Liebenberg, N. (2019). Hemisphere-dependent endocannabinoid system activity in prefrontal cortex and hippocampus of the Flinders Sensitive Line rodent model of depression.. Neurochemistry international, 125, 7-15. https://doi.org/10.1016/j.neuint.2019.01.023
MLA
Kirkedal, C, et al. "Hemisphere-dependent endocannabinoid system activity in prefrontal cortex and hippocampus of the Flinders Sensitive Line rodent model of depression.." Neurochemistry international, 2019. https://doi.org/10.1016/j.neuint.2019.01.023
RethinkTHC
RethinkTHC Research Database. "Hemisphere-dependent endocannabinoid system activity in pref..." RTHC-02108. Retrieved from https://rethinkthc.com/research/kirkedal-2019-hemispheredependent-endocannabinoid-system-activity
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.