NEUROPEPTIDES RECEPTORS AND PHOTOPERIODISM

许多脊椎动物显示促性腺激素的季节性变化 分泌、性行为和体重。 的影响 性腺类固醇激素对这些功能的影响随时间而变化， 年 日照长度的波动提供了 引发这些变化的环境线索， 光周期信号通过神经内分泌系统传递到神经内分泌大脑。 松果体 这些现象都体现在黄金 仓鼠，这将是拟议的研究对象。 的 负责松果体介导的神经化学机制 人们对这些变化仍知之甚少。 对阿片类药物的反应 然而，激动剂和拮抗剂取决于光周期， 日照长度可能影响神经肽的浓度 包括内源性鸦片剂。 日照长度可能会影响反应- 通过调节性腺类固醇激素的表达， 在特定的大脑区域编码它们的基因。 拟议的实验将利用体外受体 放射自显影，以确定日照长度和 性腺类固醇在阿片受体调节中的作用， 确定松果体在这些影响中的作用。 的 μ、δ和κ受体的数量和定位将 在不同的光周期和类固醇条件下进行检查。 这些操作对模式的影响， β内啡肽、甲硫氨酸脑啡肽和强啡肽的免疫染色将 也被研究。 阿片肽、雄激素和雌激素受体 基因表达将在特定位点使用原位定量， 杂交方法 阿片类药物调节男性性行为的位点 将通过全身和颅内应用阿片类药物进行检查 受体激动剂和拮抗剂。 在不同的实验中， 雌性仓鼠，光周期的神经化学基础 对性感受性的诱导的影响将被检查 通过研究雌激素和光照的相互作用， 催产素和GABA-a受体的调节。 通过控制光周期和性腺类固醇浓度， 将决定内源性阿片类药物在整合中的作用 内部和外部产生的信号。 这将 有助于我们理解特定的 内分泌和行为协调中的神经肽 过程，阐明环境和激素对CNS的影响 功能，扩大我们对大脑可塑性的认识，并 对与滥用有关的阿片类药物的反应性实行管制， 成瘾

Many vertebrate species display seasonal changes in gonadotropin secretion, sexual behavior, and body weight. The effects of gonadal steroid hormones upon these functions vary with time of year. Fluctuations in daylength provide the proximate environmental cue which triggers these changes, and the photoperiodic signal is relayed to the neuroendocrine brain by the pineal gland. These phenomena are exemplified in the golden hamster, which will be the subject of the proposed research. The neurochemical mechanisms which are responsible for pineal-mediated changes remain poorly understood. Responsiveness to opiate agonists and antagonists depends upon photoperiod, however, and daylength may influence the concentration of neuropeptides including endogenous opiates. Daylength may influence respon- siveness to gonadal steroid hormones by regulating the expression of the genes which encode them in specific brain regions. The proposed experiments will utilize in vitro receptor autoradiography to determine the interaction between daylength and gonadal steroids in the regulation of opiate receptors, and establish the role of the pineal gland in these effects. The quantity and localization of mu, delta, and kappa receptors will be examined under different photoperiodic and steroidal conditions. The influence of these manipulations on the pattern of immunostaining of beta endorphin, met-enkephalin,and dynorphin will also be studied. Opiate peptide, androgen and estrogen receptor gene expression will be quantified in specific loci using in situ hybridization. Loci at which opiates regulate male sexual behavior will be examined by systemic and intracranial application of opiate receptor agonists and antagonists. In separate experiments on female hamsters, the neurochemical basis of photoperiodic influences on the induction of sexual receptivity will be examined by study of the interaction between estradiol and daylength in the regulation of oxytocin and GABA-a receptors. By manipulating photoperiod and gonadal steroid concentrations, we will determine the role of endogenous opiates in the integration of internally and externally generated signals. This will contribute to our understanding of the role of specific neuropeptides in the coordination of endocrine and behavioral processes, elucidate environmental and hormonal influences on CNS function, expand our knowledge of brain plasticity, and indi- cate controls over responsiveness to opiates relevant to abuse and addiction.