Further evidence of anxiety- and depression-like behavior for total genetic ablation of cannabinoid receptor type 1
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Updated: Dec 1, 2025
Elevated Plus Maze for Mice
Published on: December 22, 2008
Delia Soriano1, Alicia Brusco1, Laura Caltana1
1Universidad de Buenos Aires, Facultad de Medicina, 1ª Unidad Académica del Departamento de Histología, Biología Celular, Embriología y Genética, Buenos Aires, Argentina; Universidad de Buenos Aires. CONICET, Instituto de Biología Celular y Neurociencia Prof. E. de Robertis (IBCN), Buenos Aires, Argentina.
Abstract:
Cannabinoid receptor type 1 (CB1R) is the most abundant cannabinoid receptor in central nervous system. Clinical studies and animal models have shown that the attenuation of endocannabinoid system signaling correlates with the development of psychiatric disorders such as anxiety, depression and schizophrenia. In the present work, multiple behavioral tests were performed to evaluate behaviors related to anxiety and depression in CB1R+/- and CB1R-/-. CB1R+/- mice had anxiety-related behavior similar to wild type (CB1R+/+) mice, whereas CB1R-/- mice displayed an anxious-like phenotype, which indicates that lower expression of CB1R is sufficient to maintain the neural circuits modulating anxiety. In addition, CB1R-/- mice exhibited alterations in risk assessment and less exploration, locomotion, grooming, body weight and appetite. These phenotypic characteristics observed in CB1R-/- mice could be associated with symptoms observed in human psychiatric disorders such as depression. A better knowledge of the neuromodulatory role of CB1R may contribute to understand scope and limitations of the development of medical treatments.
Insights
Reduced cannabinoid receptor type 1 (CB1R) expression in mice induced anxiety-like behaviors and depression symptoms. This suggests CB1R plays a crucial role in regulating mood and behavior.
Area of Science:
- Neuroscience
- Psychiatry
- Genetics
Background:
- Cannabinoid receptor type 1 (CB1R) is abundant in the central nervous system.
- Endocannabinoid system signaling attenuation correlates with psychiatric disorders like anxiety, depression, and schizophrenia.
Purpose of the Study:
- To evaluate anxiety and depression-related behaviors in mice with varying CB1R expression levels (CB1R+/- and CB1R-/-).
- To understand the role of CB1R in neural circuits modulating anxiety and depression.
Main Methods:
- Utilized multiple behavioral tests to assess anxiety and depression phenotypes in CB1R+/- and CB1R-/- mice.
- Compared behavioral outcomes of genetically modified mice to wild-type (CB1R+/+) controls.
Main Results:
- CB1R-/- mice exhibited an anxious-like phenotype, unlike CB1R+/- mice which showed behavior similar to wild types.
- CB1R-/- mice displayed altered risk assessment, reduced exploration, locomotion, grooming, body weight, and appetite.
- Lower CB1R expression appears sufficient to disrupt neural circuits regulating anxiety.
Conclusions:
- Reduced CB1R expression is linked to anxiety-like behaviors and depressive symptoms in mice.
- Findings suggest CB1R's significant neuromodulatory role in psychiatric disorders.
- Further understanding of CB1R may inform therapeutic strategies for mental health conditions.
