A triple play for thyroid hormone.

A class of thyroid hormone metabolites has dramatic physiological effects on metabolism and heart rate by still-unknown mechanisms of action. A recent study has discovered that thyronamines can inhibit neuronal reuptake of neurotransmitters and prevent the intracellular transport of monoamines for release. This discovery presents a third signaling pathway for thyroid hormone, expands the role that thyroid plays in the central nervous system, and suggests mechanisms of action for the effects of thyronamine-derived neuromodulators.