Adult Neurogenesis Is Regulated by the Endocannabinoid and Kisspeptin Systems

Area of Science:

• Neuroscience
• Endocrinology
• Molecular Biology

Background:

• Neurogenesis, a key form of adult brain plasticity, is influenced by various signaling pathways.
• The interplay between the Kisspeptin System (KPS) and Endocannabinoid System (ECS) in regulating hippocampal neurogenesis remains largely unexplored.

Purpose of the Study:

• To investigate the potential crosstalk between KPS and ECS on hippocampal neurogenesis in male adolescent rats.
• To characterize the expression of Kiss1, Kisspeptin receptor (Kiss1R), cannabinoid receptor 1 (CB1R), and Transient Receptor Potential Vanilloid 1 (TRPV1) in the rat hippocampus.

Main Methods:

• Male adolescent rats were treated with kisspeptin-10 (KP10) and anandamide (AEA), alone or with a CB1R antagonist (SR141716A).
• Expression levels of Kiss1, Kiss1R, CB1R, TRPV1, estrogen receptor α (ER-α), GAPDH, SIRT1, BDNF, and c-Jun were analyzed.

Main Results:

• Both KPS and ECS were found to inhibit neurogenesis by reducing ERK signaling.
• TRPV1 expression was upregulated by both KP10 and AEA, indicating a potential common pathway.
• KP10 reduced CB1R expression in the dentate gyrus, whereas AEA did not.
• KPS, distinct from ECS, promoted ER-α, GAPDH, SIRT1, BDNF, and c-Jun expression.

Conclusions:

• The interaction between ECS and KPS plays a role in the fine-tuning of hippocampal neurogenesis.
• KPS exhibits a novel role in regulating neurogenesis, influencing neurotrophic factors and estrogen signaling pathways.