TRPV1 and major depressive disorder: Subsequent studies further revealed that in a mouse model of chronic pain and depression comorbidity, acupuncture treatment targeting cerebellar regions V, VI, and VII not only downregulated NMDAR expression via the TRPV1 pathway but also enhanced the release of the inhibitory neurotransmitter GABA, alleviating mechanical and thermal hyperalgesia as well as depressive-like behaviors (196).