TY - JOUR
T1 - Differential roles of hypothalamic serotonin receptor subtypes in the regulation of prolactin secretion in the turkey hen
AU - Bakken, Thomas
AU - Kang, Seong Wook
AU - Kosonsiriluk, Sunantha
AU - Kuwayama, Takehito
AU - Chaiseha, Yupaporn
AU - El Halawani, Mohamed E.
N1 - Funding Information:
This work was supported by National Research Initiative Competitive Grant ( 2007-35203-18072 and 2012-67015-19297 ) from the USDA Cooperative State Research, Education and Extension Service .
PY - 2014/1
Y1 - 2014/1
N2 - In the turkey, exogenous serotonin (5-hydroxytryptamine, 5-HT) increases prolactin (PRL) secretion by acting through the dopaminergic (DAergic) system. In the present study, infusion of the 5-HT2C receptor agonist, (R)(-)-DOI hydrochloride (DOI), into the third ventricle stimulates PRL secretion, whereas the 5-HT1A receptor agonist, (+/-)-8-OH-DPAT hydrobromide (DPAT), inhibits PRL secretion. Using the immediate-early gene, c-fos, as an indicator of neuronal activity, in situ hybridization histochemistry showed preferential c-fos co-localization within tyrosine hydroxylase immunoreactive neurons (the rate limiting enzyme in DA synthesis) in the areas of the nucleus preopticus medialis (POM) and the nucleus premammillaris (PMM), in response to DPAT and DOI, respectively. To clarify the involvement of 5-HT1A and 5-HT2C receptors in PRL regulation, their mRNA expression was determined on hypothalamic tissue sections from birds in different reproductive stages. A significant difference in 5-HT1A receptor was observed, with the POM of hypoprolactinemic short day and photorefractory birds showing the highest expression. 5-HT2C receptors mRNA did not change during the reproductive cycle. The data presented support the notion that DA neurons in the PMM and POM mediate the stimulatory and inhibitory effects of 5-HT, respectively, on PRL secretion and the 5-HTergic system can both stimulate and inhibit PRL secretion.
AB - In the turkey, exogenous serotonin (5-hydroxytryptamine, 5-HT) increases prolactin (PRL) secretion by acting through the dopaminergic (DAergic) system. In the present study, infusion of the 5-HT2C receptor agonist, (R)(-)-DOI hydrochloride (DOI), into the third ventricle stimulates PRL secretion, whereas the 5-HT1A receptor agonist, (+/-)-8-OH-DPAT hydrobromide (DPAT), inhibits PRL secretion. Using the immediate-early gene, c-fos, as an indicator of neuronal activity, in situ hybridization histochemistry showed preferential c-fos co-localization within tyrosine hydroxylase immunoreactive neurons (the rate limiting enzyme in DA synthesis) in the areas of the nucleus preopticus medialis (POM) and the nucleus premammillaris (PMM), in response to DPAT and DOI, respectively. To clarify the involvement of 5-HT1A and 5-HT2C receptors in PRL regulation, their mRNA expression was determined on hypothalamic tissue sections from birds in different reproductive stages. A significant difference in 5-HT1A receptor was observed, with the POM of hypoprolactinemic short day and photorefractory birds showing the highest expression. 5-HT2C receptors mRNA did not change during the reproductive cycle. The data presented support the notion that DA neurons in the PMM and POM mediate the stimulatory and inhibitory effects of 5-HT, respectively, on PRL secretion and the 5-HTergic system can both stimulate and inhibit PRL secretion.
KW - Birds
KW - Dopamine
KW - Prolactin
KW - Serotonin receptor
KW - Vasoactive intestinal peptide
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U2 - 10.1016/j.acthis.2013.06.002
DO - 10.1016/j.acthis.2013.06.002
M3 - Article
C2 - 23886495
AN - SCOPUS:84894903885
SN - 0065-1281
VL - 116
SP - 131
EP - 137
JO - Acta Histochemica
JF - Acta Histochemica
IS - 1
ER -
