OBJECTIVES: The study investigated the role of prolactin (PRL) in modulating STAT5 and electrical activity of magnocellular neurones in the supraoptic (SO) nucleus of male rats. METHODS: Evidence of expression of STAT5 in the SO nucleus was investigated by immunocytochemical methods. Effect of blocking prolactin receptors on STAT 5 expression was investigated by Western blotting following transfection of SO neurones with a dominant negative mutant form of the PRL receptor. Prolactin-induced changes in electrical activity were investigated by extracellular recording in hypothalamic slices. RESULTS: A high proportion of SO neurones in male rats expressed immunoreactive STAT5. Levels of activated STAT5 within the SO nucleus of PRL-treated rats was reduced following transfection with a dominant negative mutant form of the PRL receptor, as compared to rats transfected with wild type PRL receptor. Electrophysiological recordings from the SO nucleus in horizontal brain slices showed that approximately 25% of neurones were responsive to PRL, with both inhibitory and excitatory effects being observed. Cells displaying PRL responses included pharmacologically-identified oxytocinergic neurones. CONCLUSIONS: Collectively, the results suggest that central PRL targets neurones of the SO nucleus, influencing both activation of the JAK-STAT signalling pathway and neuronal excitability. Whilst the functional significance of this interaction remains to be established, it might be important in co-ordinating oxytocin secretion with physiological events associated with changes in plasma PRL, or in mediating a feedback loop in the oxytocinergic regulation of lactotrophs.
OBJECTIVES: The study investigated the role of prolactin (PRL) in modulating STAT5 and electrical activity of magnocellular neurones in the supraoptic (SO) nucleus of male rats. METHODS: Evidence of expression of STAT5 in the SO nucleus was investigated by immunocytochemical methods. Effect of blocking prolactin receptors on STAT 5 expression was investigated by Western blotting following transfection of SO neurones with a dominant negative mutant form of the PRL receptor. Prolactin-induced changes in electrical activity were investigated by extracellular recording in hypothalamic slices. RESULTS: A high proportion of SO neurones in male rats expressed immunoreactive STAT5. Levels of activated STAT5 within the SO nucleus of PRL-treated rats was reduced following transfection with a dominant negative mutant form of the PRL receptor, as compared to rats transfected with wild type PRL receptor. Electrophysiological recordings from the SO nucleus in horizontal brain slices showed that approximately 25% of neurones were responsive to PRL, with both inhibitory and excitatory effects being observed. Cells displaying PRL responses included pharmacologically-identified oxytocinergic neurones. CONCLUSIONS: Collectively, the results suggest that central PRL targets neurones of the SO nucleus, influencing both activation of the JAK-STAT signalling pathway and neuronal excitability. Whilst the functional significance of this interaction remains to be established, it might be important in co-ordinating oxytocin secretion with physiological events associated with changes in plasma PRL, or in mediating a feedback loop in the oxytocinergic regulation of lactotrophs.
Authors: Rachael A Augustine; Sharon R Ladyman; Gregory T Bouwer; Yousif Alyousif; Tony J Sapsford; Victoria Scott; Ilona C Kokay; David R Grattan; Colin H Brown Journal: J Physiol Date: 2017-03-23 Impact factor: 5.182
Authors: A Sirzen-Zelenskaya; A E Gonzalez-Iglesias; J Boutet de Monvel; R Bertram; M E Freeman; U Gerber; M Egli Journal: J Neuroendocrinol Date: 2011-10 Impact factor: 3.627
Authors: David J Hodson; Marie Schaeffer; Nicola Romanò; Pierre Fontanaud; Chrystel Lafont; Jerome Birkenstock; François Molino; Helen Christian; Joe Lockey; Danielle Carmignac; Marta Fernandez-Fuente; Paul Le Tissier; Patrice Mollard Journal: Nat Commun Date: 2012-01-03 Impact factor: 14.919