Takahashi L K, Lisk R D
Endocrinology. 1986 Dec;119(6):2744-54. doi: 10.1210/endo-119-6-2744.
Diencephalic and mesencephalic neural sites regulating the biphasic effect of progesterone (P) were investigated using the hormone implantation technique in ovariectomized female golden hamsters primed with estrogen. Double barreled cannulae were implanted unilaterally and bilaterally in the medial preoptic area, anterior hypothalamus, ventromedial hypothalamus (VMH), central gray, or interpeduncular nucleus. Testing was conducted using a sequential paradigm; facilitation tests commenced after 44 h of estrogen priming. P-filled cannulae placed in the VMH region facilitated lordosis behavior in 42% and 60% of unilaterally and bilaterally implanted females, respectively. In the anterior hypothalamus, only P implants adjacent to the VMH area effectively promoted receptivity. Lordosis behavior was also observed in 20-36% of females with P implants in the medial preoptic area. P implants in central gray and interpeduncular nucleus regions had no significant facilitating effect on sexual behavior. Tests for inhibition occurred 24 h after facilitation testing and consisted of a pretest, followed by systemic P administration and a behavioral test 4-5 h later. During the pretest for inhibition, females that were receptive in the facilitation test attacked males more rapidly than previously nonreceptive animals and showed decrements in lordosis scores after systemic P delivery. This biphasic effect of P completely inhibited receptivity among several animals in the VMH group. Additional experiments, however, investigating the biphasic effect of P implants in the VMH suggested that the occurrence of copulation in the facilitation test may have been involved in mediating the subsequent increase in aggressive behavior and the suppression of sexual responsiveness in the inhibition test. Nevertheless, a final experiment showed that when P was implanted sequentially in the VMH, facilitation and, more importantly, a later reduction in lordosis behavioral scores occurred even when copulation was eliminated in the facilitation test. P implants in mesencephalic regions exerted no significant inhibitory effect on receptivity. These findings demonstrate that the biphasic action of P in the female hamster is regulated by nerve cells located in the diencephalon, especially in the VMH region.
采用激素植入技术，在经雌激素预处理的去卵巢雌性金黄地鼠中，研究了调节孕酮（P）双相作用的间脑和中脑神经位点。将双管套管单侧或双侧植入内侧视前区、下丘脑前部、腹内侧下丘脑（VMH）、中央灰质或脚间核。测试采用序贯范式；在雌激素预处理44小时后开始促进测试。置于VMH区域的P填充套管分别使42%和60%的单侧和双侧植入雌性动物的脊柱前凸行为得到促进。在下丘脑前部，只有紧邻VMH区域的P植入物能有效促进接受性。在视前内侧区植入P的雌性动物中，也有20 - 36%出现脊柱前凸行为。在中央灰质和脚间核区域植入P对性行为无显著促进作用。抑制测试在促进测试后24小时进行，包括一次预测试，随后全身给予P，并在4 - 5小时后进行行为测试。在抑制预测试期间，在促进测试中具有接受性的雌性动物比之前无接受性的动物更快地攻击雄性，并且在全身给予P后脊柱前凸评分降低。P的这种双相作用完全抑制了VMH组中几只动物的接受性。然而，进一步研究VMH中P植入物双相作用的实验表明，促进测试中的交配行为可能参与介导了随后攻击行为的增加以及抑制测试中性反应性的抑制。尽管如此，最后一项实验表明，当在VMH中依次植入P时，即使在促进测试中消除交配行为，仍会出现促进作用，更重要的是，随后脊柱前凸行为评分会降低。中脑区域植入P对接受性无显著抑制作用。这些发现表明，雌性仓鼠中P的双相作用受位于间脑，特别是VMH区域的神经细胞调节。
