Figure 1.

Genomic mechanisms of thyroid hormones action in the brain. Genomic actions of T₃ are dependent on gene transcription mediated by its binding to nuclear TRα and TRβ, and the formation of heterodimer complex with RXR (RXR-TR) that binds to a TRE, located at the regulatory region of T₃ target genes. This activity is regulated by an exchange of CoR for CoA. CoA, Co-activator; CoR, Co-repressor; RXR, Retinoid X receptor; TR, Thyroid hormone receptor; TRE, Thyroid response element; T₃, 3,5,3′-triiodo-L-thyronine.