TY - JOUR
T1 - Species differences in androgen receptor expression in the medial preoptic and anterior hypothalamic areas of adult male and female rodents
AU - Jahan, M. R.
AU - Kokubu, K.
AU - Islam, Md N.
AU - Matsuo, C.
AU - Yanai, A.
AU - Wroblewski, G.
AU - Fujinaga, R.
AU - Shinoda, K.
N1 - Funding Information:
We would like to acknowledge the technical expertise of the Institute for Biomedical Research and Education, Yamaguchi University Science Research Center. We are also grateful to Mr. Jun Oba and Mrs. Yumiko Matsuzaki for their technical and administrative assistance. This work was partly supported by a Grant-in-Aid for Scientific Research (B) ( 25293045 ), a Grant-in-Aid for Scientific Research (C) ( 21500326 ), a Grant-in-Aid for Young Scientists (B) ( 26860135 ) from the ‘ Japan Society for the Promotion of Science’ – ‘Japan’ , a research grant from the ‘ Takeda Science Foundation’ – ‘Japan’ and a Research Promotion Grant from the Yamaguchi University Research Project on STRESS. Finally, we cordially thank to the Rotary Yoneyama Memorial Foundation and Ube Nishi Rotary Club , Japan for the Rotary Yoneyama Memorial Doctoral Course Scholarship (YD) awarded to MR Jahan.
Publisher Copyright:
© 2014 IBRO.
PY - 2015/1/2
Y1 - 2015/1/2
N2 - The medial preoptic and anterior hypothalamic areas (MPO/AH) are important androgen targets regulating homeostasis, neuroendocrinology and circadian rhythm as well as instinctive and sociosexual behaviors. Although species differences between rats and mice have been pointed out in terms of morphology and physiology, detailed distributions of androgen receptor (AR) have never been compared between the two rodents. In the present study, AR distribution was examined immunohistochemically in serial sections of the MPO/AH and compared for adult rats and mice. Western blotting and immunohistochemistry clearly demonstrated that AR expression in the brain was stronger in mice than in rats and was stronger in males than in females. In addition, we found (1) an "obliquely elongated calbindin-ir cell island" in mice medial preoptic nucleus (MPN) expressed AR intensely, as well as the sexually dimorphic nucleus in the MPN (SDN-MPN) in rats, strongly supporting a "putative SDN-MPN" previously proposed in mice; (2) AR expression in the suprachiasmatic nucleus (SCN) was much more prominent in mice than in rats and differed in localization between the two species; (3) a mouse-specific AR-ir cell cluster was newly identified as the "tear drop nucleus (TDN)", with male-dominant sexual dimorphism; and (4) two rat-specific AR-ir cell clusters were also newly identified as the "rostral and caudal nebular islands", with male-dominant sexual dimorphism. The present results may provide basic morphological evidence underlying species differences in androgen-modified psychological, physiological and endocrinergic responses. Above all, the findings of the mouse-specific TDN and differing AR expression in the SCN might explain not only species difference in gonadal modification of circadian rhythm, but also distinct structural bases in the context of transduction of SCN oscillation. The current study could also serve as a caution that data on androgen-sensitive functions obtained from one species should not always be directly applied to others among rodents.
AB - The medial preoptic and anterior hypothalamic areas (MPO/AH) are important androgen targets regulating homeostasis, neuroendocrinology and circadian rhythm as well as instinctive and sociosexual behaviors. Although species differences between rats and mice have been pointed out in terms of morphology and physiology, detailed distributions of androgen receptor (AR) have never been compared between the two rodents. In the present study, AR distribution was examined immunohistochemically in serial sections of the MPO/AH and compared for adult rats and mice. Western blotting and immunohistochemistry clearly demonstrated that AR expression in the brain was stronger in mice than in rats and was stronger in males than in females. In addition, we found (1) an "obliquely elongated calbindin-ir cell island" in mice medial preoptic nucleus (MPN) expressed AR intensely, as well as the sexually dimorphic nucleus in the MPN (SDN-MPN) in rats, strongly supporting a "putative SDN-MPN" previously proposed in mice; (2) AR expression in the suprachiasmatic nucleus (SCN) was much more prominent in mice than in rats and differed in localization between the two species; (3) a mouse-specific AR-ir cell cluster was newly identified as the "tear drop nucleus (TDN)", with male-dominant sexual dimorphism; and (4) two rat-specific AR-ir cell clusters were also newly identified as the "rostral and caudal nebular islands", with male-dominant sexual dimorphism. The present results may provide basic morphological evidence underlying species differences in androgen-modified psychological, physiological and endocrinergic responses. Above all, the findings of the mouse-specific TDN and differing AR expression in the SCN might explain not only species difference in gonadal modification of circadian rhythm, but also distinct structural bases in the context of transduction of SCN oscillation. The current study could also serve as a caution that data on androgen-sensitive functions obtained from one species should not always be directly applied to others among rodents.
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U2 - 10.1016/j.neuroscience.2014.11.003
DO - 10.1016/j.neuroscience.2014.11.003
M3 - Article
C2 - 25446364
AN - SCOPUS:84913580672
SN - 0306-4522
VL - 284
SP - 943
EP - 961
JO - Neuroscience
JF - Neuroscience
ER -