Flügge G
German Primate Center, Göttingen, Germany.
Int Rev Cytol. 2000;195:145-213. doi: 10.1016/s0074-7696(08)62705-9.
Monoamine receptors are membrane-bound receptors that are coupled to G-proteins. Upon stimulation by agonists, they initiate a cascade of intracellular events that guide biochemical reactions of the cell. In the central nervous system, they undergo diverse regulatory processes, among which are receptor desensitization, internalization into the cell, and downregulation. These processes vary among different types of monoamine receptors. alpha 2-Adrenoceptors are often downregulated by agonists, and beta-adrenoceptors are internalized rapidly. Others, such as serotonin1A-receptors, are controlled tightly by steroid hormones. Expression of these receptors is reduced by the "stress hormones" glucocorticoids, whereas gonadal hormones such as testosterone can counterbalance the glucocorticoid effects. Because of this, the pattern of monoamine receptors in certain brain regions undergoes dynamic changes when there are elevated concentrations of agonists or when the hormonal milieu changes. Stress is a physiological situation accompanied by the high activity of brain monoaminergic systems and dramatic changes in peripheral hormones. Resulting alterations in monoamine receptors are considered to be in part responsible for changes in the behavior of an individual.
单胺受体是与G蛋白偶联的膜结合受体。在激动剂刺激下，它们引发一系列细胞内事件，指导细胞的生化反应。在中枢神经系统中，它们经历多种调节过程，其中包括受体脱敏、内化进入细胞以及下调。这些过程在不同类型的单胺受体之间有所不同。α2-肾上腺素能受体常被激动剂下调，而β-肾上腺素能受体则迅速内化。其他受体，如5-羟色胺1A受体，则受类固醇激素严格控制。这些受体的表达会被“应激激素”糖皮质激素降低，而诸如睾酮等性腺激素可以抵消糖皮质激素的作用。因此，当激动剂浓度升高或激素环境发生变化时，某些脑区的单胺受体模式会发生动态变化。应激是一种生理状态，伴随着脑单胺能系统的高活性和外周激素的显著变化。单胺受体由此产生的改变被认为部分导致了个体行为的变化。
