Mechanisms, and mRNA expression responses to Se form treatments, by which dopamine and TRH affect prolactin synthesis and release. AC, adenylyl cyclase; CRE, cAMP response element; CREB, cAMP response element-binding protein; DAG, diacylglycerol; DRD2, dopamine receptor D2; EA, ergot alkaloid; ERK, extracellular signal-regulated kinase; IP3, inositol trisphosphate; ISe, sodium selenite; MEK, mitogen-activated protein kinase kinase; MIX, 1:1 mix of ISe and OSe; OSe, SEL-PLEX; Pit-1, pituitary-specific positive transcription factor 1; PKA, protein kinase A; PKC, protein kinase C; PLC, phospholipase C; PRL, prolactin; TRH, thyrotropin-releasing hormone; TRHR, thyrotropin-releasing hormone receptor. A line with arrowhead signifies interaction. A crosshead bar signifies inhibition. A dash line with arrowhead signifies transportation between cellular organelles. Adapted from Ben-Jonathan and Hnasko (2001) and Kanasaki et al. (2015). Sodium selenite (ISe), SEL-PLEX (OSe), or a 1:1 mix of ISe and OSe (MIX).