Neuroscience Program, Tulane University, New Orleans, LA; Tulane Brain Institute, Tulane University, New Orleans, LA.
Neuroscience Program, Tulane University, New Orleans, LA; Tulane Brain Institute, Tulane University, New Orleans, LA; Psychology Department, Tulane University, New Orleans, LA.
Neuroscience. 2019 May 15;406:487-495. doi: 10.1016/j.neuroscience.2019.03.041. Epub 2019 Mar 26.
Previous work from our lab revealed that adult female rats have increased levels of myelin basic protein (MBP), a marker for myelination, in the orbitofrontal cortex (OFC) as compared to adult males. The goal of the present study was to determine the role of gonadal hormones, acting either in adulthood or at puberty, in the development of an adult sex difference in OFC levels of MBP. In an initial experiment, we replicated our previous results demonstrating that gonadally intact female rats have increased levels of MBP in the OFC as compared to males. In a second experiment, gonadectomy in adulthood did not alter MBP levels in rats of either sex. In a third experiment, gonadectomy immediately prior to pubertal onset resulted in significant reduction of levels of MBP in adult females but not males. This reduction eliminated the sex difference in adult MBP levels in the OFC. These results reveal puberty to be an organizational time point for a sex difference in the OFC of adult rats in levels of a marker of myelination. This neuroanatomical difference may contribute to observed sex differences in OFC-associated behaviors including in inhibitory control.
先前我们实验室的工作表明，成年雌性大鼠眶额皮层（OFC）中的髓鞘碱性蛋白（MBP）水平高于成年雄性大鼠，MBP 是髓鞘形成的标志物。本研究的目的是确定性腺激素在成年期或青春期的作用，是否会导致 OFC 中 MBP 水平出现成年性别差异。在最初的实验中，我们复制了之前的结果，表明与雄性大鼠相比，未去势的雌性大鼠 OFC 中的 MBP 水平更高。在第二个实验中，成年期的性腺切除术并没有改变两性大鼠的 MBP 水平。在第三个实验中，青春期前立即进行性腺切除术导致成年雌性大鼠的 MBP 水平显著降低，但雄性大鼠则没有。这种降低消除了 OFC 中成年 MBP 水平的性别差异。这些结果表明青春期是成年大鼠 OFC 中髓鞘形成标志物水平出现性别差异的组织形成时间点。这种神经解剖学差异可能导致观察到与 OFC 相关的行为中的性别差异，包括抑制控制。
