Sinpru Panpradap, Sartsoongnoen Natagarn, Rozenboim Israel, Porter Tom E, El Halawani Mohamed E, Chaiseha Yupaporn
School of Biology, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, Thailand.
Program of Biology, Faculty of Science and Technology, Nakhon Ratchasima Rajabhat University, Nakhon Ratchasima, Thailand.
Gen Comp Endocrinol. 2018 Jul 1;263:32-42. doi: 10.1016/j.ygcen.2018.04.013. Epub 2018 Apr 13.
The mesotocinergic (MTergic) and dopaminergic (DAergic) systems have been documented to play pivotal roles in maternal behaviors in native Thai chickens. In native Thai chickens, plasma prolactin (PRL) concentrations are associated with maternal behaviors, which are also controlled by the DAergic system. However, the role of MT in conjunction with the roles of DA and PRL on the neuroendocrine regulation of the transition from incubating to rearing behavior has never been studied. Therefore, the aim of this study was to investigate the association of MT, DA, and PRL during the transition from incubating to rearing behavior in native Thai hens. Using an immunohistochemistry technique, the numbers of MT-immunoreactive (-ir) and tyrosine hydroxylase-ir (TH-ir, a DA marker) neurons were compared between incubating hens (INC; n = 6) and hens for which the incubated eggs were replaced with 3 newly hatched chicks for 3 days after 6, 10, and 14 days of incubation (REC; n = 6). Plasma PRL concentrations were determined by enzyme-linked immunosorbent assay. The results revealed that the numbers of MT-ir neurons within the nucleus supraopticus, pars ventralis (SOv), nucleus preopticus medialis (POM), and nucleus paraventricularis magnocellularis (PVN) increased in the REC hens when compared with those of the INC hens at 3 different time points (at days 9, 13, and 17). On the other hand, the number of TH-ir neurons in the nucleus intramedialis (nI) decreased in the REC13 and REC17 hens when compared with those of the INC hens. However, the number of TH-ir neurons in the nucleus mamillaris lateralis (ML) only decreased in the REC13 hens when compared with the INC13 hens. The decrease in the numbers of TH-ir neurons within the nI and ML is associated with the decrease in the levels of plasma PRL. This study suggests that the presence of either eggs or chicks is the key factor regulating the MTergic system within the SOv, POM, and PVN and the DAergic system within the nI and ML during the transition from incubating to rearing behavior in native Thai chickens. The results further indicate that these two systems play pivotal roles in the transition from incubating to rearing behavior in this equatorial species.
在泰国本土鸡中，中催产素能（MTergic）和多巴胺能（DAergic）系统已被证明在母性行为中发挥关键作用。在泰国本土鸡中，血浆催乳素（PRL）浓度与母性行为相关，而母性行为也受DAergic系统控制。然而，MT与DA和PRL在从抱窝行为向育雏行为转变的神经内分泌调节中的联合作用从未被研究过。因此，本研究的目的是调查泰国本土母鸡从抱窝行为向育雏行为转变过程中MT、DA和PRL之间的关联。使用免疫组织化学技术，比较了抱窝母鸡（INC；n = 6）和在孵化6、10和14天后将孵化的蛋换成3只新孵出的小鸡并饲养3天的母鸡（REC；n = 6）中MT免疫反应性（-ir）神经元和酪氨酸羟化酶免疫反应性（TH-ir，一种DA标记物）神经元的数量。通过酶联免疫吸附测定法测定血浆PRL浓度。结果显示，与INC母鸡相比，REC母鸡在3个不同时间点（第9、13和17天）视上核腹侧部（SOv）、视前内侧核（POM）和室旁核大细胞部（PVN）内MT-ir神经元的数量增加。另一方面，与INC母鸡相比，REC13和REC17母鸡内侧核（nI）中TH-ir神经元的数量减少。然而，与INC13母鸡相比，仅REC13母鸡外侧乳头核（ML）中TH-ir神经元的数量减少。nI和ML内TH-ir神经元数量的减少与血浆PRL水平的降低有关。本研究表明，在泰国本土鸡从抱窝行为向育雏行为转变过程中，蛋或小鸡的存在是调节SOv、POM和PVN内的MTergic系统以及nI和ML内的DAergic系统的关键因素。结果进一步表明，这两个系统在这个赤道物种从抱窝行为向育雏行为的转变中起关键作用。
