研究人員在11月號(hào)的《自然—神經(jīng)科學(xué)》期刊上報(bào)告,，兩性在習(xí)慣形成方面的不同源于染色體,，而不是以前認(rèn)為的性荷爾蒙,。大腦和行為中的絕大多數(shù)差異與荷爾蒙有關(guān)，但新研究提出了可能由染色體通過另一種途徑導(dǎo)致的部分性別差異,。
Jane Taylor和同事研究了擁有XY染色體和卵巢的雄性變異小鼠,，以及擁有XX染色體和睪丸的雌性變異小鼠，了解它們的行為學(xué)習(xí)能力,。與擁有XY染色體的雄性小鼠相比,，擁有XX染色體的雌性小鼠，無(wú)論是否擁有卵巢或睪丸或二者都被切除,，都能更快形成與食物強(qiáng)化刺激相關(guān)的習(xí)慣,。習(xí)慣是以指數(shù)級(jí)的方式形成的，相當(dāng)于從偶爾服藥到藥物成癮,。
新研究表明,，女性比男性能更快地養(yǎng)成習(xí)慣。未來(lái)對(duì)這種影響機(jī)制的研究將深入了解這種差異性,。（科學(xué)時(shí)報(bào)）
原始出處:
Nature Neuroscience 10, 1398 - 1400 (2007)
Published online: 21 October 2007 | doi:10.1038/nn1994
Sex chromosome complement regulates habit formation
Jennifer J Quinn1, Paul K Hitchcott1, Elizabeth A Umeda2, Arthur P Arnold2 & Jane R Taylor1
Sex differences in brain function and behavior are regularly attributed to gonadal hormones. Some brain sexual dimorphisms, however, are direct actions of sex chromosome genes that are not mediated by gonadal hormones. We used mice in which sex chromosome complement (XX versus XY) and gonadal sex (ovaries versus testes) were independent, and found that XX mice showed faster food-reinforced instrumental habit formation than XY mice, regardless of gonadal phenotype.
Division of Molecular Psychiatry, Yale University, Connecticut Mental Health Center Abraham Ribicoff Research Facilities, 34 Park Street, New Haven, Connecticut 06508, USA.
Department of Physiological Science, University of California, Los Angeles, Box 951606, 4117 Life Sciences Building, Los Angeles, California 90095-1606, USA.
Correspondence to: Jane R Taylor1 e-mail: jane.taylor@yale.edu
