Kow L M, Mobbs C V, Pfaff D W
Rockefeller University, Laboratory of Neurobiology and Behavior, New York, NY 10021.
Neurosci Biobehav Rev. 1994 Summer;18(2):251-68. doi: 10.1016/0149-7634(94)90028-0.
Many neurotransmitters and neuropeptides can affect the rodent feminine sexual behavior, lordosis, when administered in the ventromedial hypothalamus (VMH), midbrain central gray (MCG), or other brain regions. A survey of the electrophysiological and biochemical actions of these neural agents revealed that there is a very consistent association between lordosis facilitation with both the activation of the phosphoinositide (PI) pathway and the excitation of VMH and MCG neurons. In contrast, lordosis inhibition is associated, less consistently, with alterations of the adenylate cyclase (AC) system and the inhibition of neuronal activity. The findings that lordosis could be facilitated by going beyond membrane receptors and directly activating the PI pathway, suggest that this second-messenger pathway is a common mediator for the lordosis-facilitating agents. Furthermore, as in the case of stimulating membrane receptors, direct activation of this common mediator also requires estrogen priming for lordosis facilitation. Therefore, it is likely that the PI pathway is modulated by estrogen in the permissive action of estrogen priming. Indeed, a literature review shows that estrogen can affect selective isozymes of key enzyme families of the PI pathway at various levels. Such selective modulations, at several levels, could easily alter the course of a PI cascade; thence, the eventual functional outcome. These findings prompt us to propose that estrogen enables lordosis to be facilitated by a selective modulation of the PI pathway.
许多神经递质和神经肽在注射到腹内侧下丘脑（VMH）、中脑中央灰质（MCG）或其他脑区时，会影响啮齿动物的雌性性行为——脊柱前凸。对这些神经介质的电生理和生化作用进行的一项调查显示，在脊柱前凸促进与磷酸肌醇（PI）途径的激活以及VMH和MCG神经元的兴奋之间，存在非常一致的关联。相比之下，脊柱前凸抑制与腺苷酸环化酶（AC）系统的改变以及神经元活动的抑制之间的关联则不太一致。脊柱前凸可以通过超越膜受体并直接激活PI途径来促进，这一发现表明，这条第二信使途径是促进脊柱前凸的介质。此外，与刺激膜受体的情况一样，直接激活这种常见介质也需要雌激素预处理才能促进脊柱前凸。因此，PI途径很可能在雌激素预处理的允许作用中受到雌激素的调节。事实上，一篇文献综述表明，雌激素可以在多个水平上影响PI途径关键酶家族的选择性同工酶。这种在几个水平上的选择性调节很容易改变PI级联反应的进程，从而改变最终的功能结果。这些发现促使我们提出，雌激素通过对PI途径的选择性调节来促进脊柱前凸。
