Ulibarri C, Yahr P
Department of Psychobiology, University of California, Irvine 92717.
Behav Neural Biol. 1988 Jan;49(1):27-44. doi: 10.1016/s0163-1047(88)91192-2.
Gerbils display a sexually dimorphic scent marking behavior that responds to testosterone (T) in adulthood and develops under the influence of testosterone perinatally. A complex of cell groups between the preoptic area and anterior hypothalamus of the gerbil brain is also sexually dimorphic and responsive to testosterone. One of these cell groups, the sexually dimorphic area pars compacta (SDApc), usually exists only in males. Even when given testosterone, adult female gerbils rarely have an SDApc. To determine if the SDApc develops under the influence of testosterone, male gerbils were castrated or given sham operations on the day they were born or 1 day later, or were not manipulated. Female gerbils were injected subcutaneously with 0, 50, or 100 micrograms testosterone propionate (TP) on the day after birth. When given ovarian transplants as adults, neonatally castrated males scent marked at low levels typical of females. Neonatally androgenized females given testosterone as adults scent marked at high levels typical of males. Neonatal castration did not affect the probability that the SDApc would develop, but neonatal androgenization did. Half the females given either dose of TP as neonates had SDApcs bilaterally. The sizes of the SDApcs present in females depended on the dose of testosterone given neonatally. The larger dose produced larger SDApcs. The 100-micrograms dose of TP also defeminized gonadotropin secretion, but the 50-micrograms dose did not. The castration of males neonatally prevented the defeminization normally caused by endogenous testosterone. Both groups of neonatally castrated males formed corpora lutea in their ovarian transplants, but control males did not.
沙鼠表现出一种性别二态性的气味标记行为，这种行为在成年期对睾酮（T）有反应，并在围产期受睾酮影响而发育。沙鼠脑视前区和下丘脑前部之间的一组细胞群也具有性别二态性，且对睾酮有反应。这些细胞群之一，即性别二态性致密部（SDApc），通常只存在于雄性沙鼠中。即使给予睾酮，成年雌性沙鼠也很少有SDApc。为了确定SDApc是否在睾酮的影响下发育，雄性沙鼠在出生当天或出生后1天被阉割或进行假手术，或者不进行处理。雌性沙鼠在出生后第二天皮下注射0、50或100微克丙酸睾酮（TP）。成年后进行卵巢移植时，新生期阉割的雄性沙鼠的气味标记水平较低，表现出典型的雌性特征。成年后给予睾酮的新生期雄激素化雌性沙鼠的气味标记水平较高，表现出典型的雄性特征。新生期阉割并不影响SDApc发育的概率，但新生期雄激素化会影响。新生期接受任一剂量TP的雌性沙鼠中有一半双侧都有SDApc。雌性沙鼠中存在的SDApc的大小取决于新生期给予的睾酮剂量。剂量越大，SDApc越大。100微克剂量的TP也使促性腺激素分泌去雌性化，但50微克剂量则没有。雄性沙鼠新生期阉割可防止内源性睾酮通常引起的去雌性化。两组新生期阉割的雄性沙鼠在其卵巢移植中都形成了黄体，但对照雄性沙鼠则没有。
