Thyrotropin-releasing hormone (TRH) in the brain and pituitary of the teleost, Clarias batrachus and its role in regulation of hypophysiotropic dopamine neurons.

Thyrotropin-releasing hormone (TRH) regulates the hypothalamic-pituitary-thyroid axis in mammals and also regulates prolactin secretion, directly or indirectly via tuberoinfundibular dopamine neurons. Although TRH is abundantly expressed in teleost brain and believed to mediate neuronal communication, empirical evidence is lacking. We analyzed pro-TRH-mRNA expression, mapped TRH-immunoreactive elements in the brain and pituitary, and explored its role in regulation of hypophysiotropic dopamine (DA) neurons in the catfish, Clarias batrachus.