The dopaminergic system in the brain of the native Thai chicken, Gallusdomesticus: Localization and differential expression across the reproductive cycle

Polymorphisms associated with egg number at 300 days of age in chickens

“…However, the results of this study did not find any association between this 24-bp indel and EN300. The dopaminergic system has been shown to play an important role in the regulation of the avian reproductive system and these physiological effects are exerted by activating its receptors (Sartsoongnoen et al, 2008;Xu et al, 2010b). Although Xu et al (2010a) did not find any association between the polymorphisms in the coding region of DRD1 and EN300, variation of the DRD2 gene exhibited a significant association with chicken EN300 in this study.…”

Neuroendocrine regulation of rearing behavior in the native Thai hen

“…Plasma PRL levels are low in reproductively quiescent birds, whereas levels increase in reproductively active laying hens. Circulating PRL levels are elevated throughout incubation (El Halawani et al, 1984;Sharp et al, 1989;Kosonsiriluk et al, 2008;Sartsoongnoen et al, 2008). In birds, it is very well established that PRL secretion is tonically stimulated (Kragt and Meites, 1965;Bern and Nicoll, 1968;Ben-Jonathan et al, 1989) and that VIP is the avian PRL releasing factor (PRF) secreted from neurons located in the infundibular nuclear complex (INF) of the caudo-medial hypothalamus El Halawani et al, 1997;Chaiseha et al, 1998;El Halawani, 1999, 2005).…”

“…Physical contact, as well as visual and/or auditory stimuli from young chicks, is clearly involved in the appearance and maintenance of maternal behavior (Richard-Yris and Opel and Proudman, 1989). Furthermore, PRL has been implicated as a causative factor for reduced circulating gonadotropins and ovarian regression when birds shift from egg-laying to incubation behavior in chickens, turkeys, pigeons, pheasants, mallard ducks, cow birds, and native Thai chickens (Breitenbach and Meyer, 1959;Goldsmith and Williams, 1980;Bluhm et al, 1983;Lea and Sharp, 1989;Zadworny et al, 1989;El Halawani et al, 1997;Kosonsiriluk et al, 2008;Sartsoongnoen et al, 2008). It is apparent that PRL is involved in many aspects of reproductive physiology and behavior.…”

“…To date, the presence of hypothalamic VIP-ir, tyrosine hydroxylase-immunoreactive (TH-ir), and GnRH-I-ir neurons at different reproductive stage and throughout the incubation period have been reported in native Thai chickens Sartsoongnoen et al, 2008Sartsoongnoen et al, , 2012Prakobsaeng et al, 2011). However, no data are available that describe the interrelationship and the functional aspect of the changes in the VIPergic system with PRL levels during rearing behavior in native Thai chickens.…”

Relationship between the Production Traits and three Candidate Genes in the Prolactin’s In/Del×In/Del Population of Silkie Fowl

“…Hens that were treated with dopamine receptor antagonists or receptor blocking agents exhibited a termination in the maintenance of broodiness due to the inhibition of prolactin secretion (Hall et al, 1984). In addition, Sartsoongnoen et al (2008) have found an association between dopamine neurons and the regulation of the reproductive system in Thai chickens. Xu et al (2010) studied 644 female Ningdu Sanhuang chickens and identified 2 variations, A-16105G and T＋619C, in the chicken DRD2 gene.…”