NEURAL STEROIDOGENIC ENZYMES AND BRAIN FUNCTION

描述（申请人摘要）：类固醇对 大脑的发育和功能。传统上，大脑被认为是一个 在性腺中合成的性类固醇的作用靶点，或较小的 肾上腺，因为这些器官中的每一个都表达所有的酶， 催化胆固醇转化为活性性类固醇。在 在过去的二十年里，有证据表明，一些类固醇激素 在中枢神经系统中发现了这种酶，这表明大脑 自身可以合成活性甾体信号分子。然而，尽管如此， 尽管在脑组织中发现了它们， 证实了这些酶在大脑中的功能作用。我们认为 脑中合成的类固醇可能有助于组织和激活 鸣禽的特殊行为行为和神经解剖学研究表明 一些激素依赖的功能发生在鸣禽身上， 从外周检测到类固醇信号。这些功能可以 由局部非系统类固醇信号激活我们得到了支持 因为我们已经发现了神经表达和/或活动， 需要所有4种类固醇生成酶（CYP 11 A1、3B-HSD、CYP 17和CYP 19） 成人胆固醇转化为孕激素、雄激素和雌激素 斑胸草雀，包括小脑浦肯野区所有酶的表达 细胞这些研究的目的是更充分地探讨这一假设， 确定1）脑中每种类固醇生成酶的mRNA是否被翻译 转化为功能性蛋白质，特别是在成年斑胸草雀的浦肯野细胞中; 2)如果类固醇生成酶的神经表达与 组织的神经歌曲控制电路和歌曲学习， 正在发育的斑胸草雀和鸣禽，以及3）如果神经表达 类固醇生成酶与性激活有关 当循环类固醇为基础时， 成年麻雀我们相信这些研究将大大有助于 我们对大脑类固醇生成能力的理解， 类固醇作为神经信号分子的概念。

DESCRIPTION (applicant's abstract): Steroids have profound effects on the development and function of the brain. Traditionally, the brain is viewed as a target for action of sex steroids synthesized in the gonads, or to a lesser degree the adrenals, since each of these organs express all the enzymes that catalyze the conversion of cholesterol into the active sex steroids. In the last two decades, evidence has emerged indicating that some steroidogenic enzymes could be found in the central nervous system, suggesting that the brain itself could synthesize the active steroidal signaling molecules. Nevertheless, despite their identification in brain tissue, there is little evidence confirming a functional role for these enzymes in brain. We believe that steroids synthesized in brain may contribute to the organization and activation of specific behaviors in songbirds. Behavioral and neuroanatomical studies show that some steroid-dependent functions occur in songbirds in the absence of detectable steroid signaling from the periphery. These functions may be activated by a local, non-systemic steroidal signal. We have obtained support for this hypothesis in that we have found neural expression and/or activity of all 4 steroidogenic enzymes (CYP11A1, 3B-HSD, CYP17, and CYP19) required for the conversion of cholesterol to progestins, androgens, and estrogens in adult zebra finches, including expression of all enzymes in cerebellar Purkinje cells. The goal of these studies is to explore this hypothesis more fully by determining 1) if mRNA for each steroidogenic enzyme in brain is translated into functional protein, especially in Purkinje cells of adult zebra finches; 2) if neural expression of steroidogenic enzymes is associated with the organization of the neural song control circuit and with song learning in developing zebra finches and song sparrows, and 3) if neural expression of steroidogenic enzymes is associated with the activation of sex steroid-dependent behavioral functions when circulating steroids are basal in adult song sparrows. We believe these studies will contribute significantly to our understanding of the steroidogenic capability of the brain, and expand concepts of steroids as neural signaling molecules.