Control of serotonergic signaling by chimeric light aactivated receptors

描述（由申请人提供）：哺乳动物大脑中的血清素能传递系统在各种生理功能中发挥重要作用，如情绪，性行为，睡眠/觉醒周期，血压控制和呼吸。5 -羟色胺通过5HT受体介导其作用，5HT受体是G蛋白偶联受体，在5HT神经元及其靶脑中表达。5HT受体5HT- 1a与Gi/o信号通路偶联，已被描述为在焦虑和抑郁行为中发挥重要作用。它也是治疗许多神经精神疾病的重要药物靶点。因此，了解这种受体途径如何在大脑和活体动物中调节5 -羟色胺能的音调、功能和5 -羟色胺相关行为是非常重要的。在这里，我描述了一种开发激活5HT-1A特异性受体途径的光激活gpcr的方法。我将通过改变脊椎动物视紫红质的细胞内结构域，将其与5HT-1A受体交换，从而产生一个嵌合受体。然后，我将描述这种嵌合受体的功能，并评估其在异源表达系统中激活5HT特异性信号的能力。最后，我将评估其在5HT-1A受体敲除小鼠中拯救生理表型的能力。这种嵌合受体将使神经元功能受体通路的精确表征成为可能，这将是药理学操作的重大进步，药理学操作受其药代动力学的限制，并且在活的、完整的动物中使用可能很麻烦。这种光激活的工具可以用来精确地操纵特定神经元群体中的血清素能信号级联，这将导致对正常生理学的更清晰理解，并可能导致新的治疗方法。血清素在许多生理功能和许多精神疾病中起着至关重要的作用，然而，特定的血清素受体与功能和疾病的关系在很大程度上是未知的。为了解决这个问题，我建议开发和测试光激活分子，以激活神经元中特定的血清素途径。

DESCRIPTION (provided by applicant): The serotonergic transmitter system in the mammalian brain plays important roles in various physiological functions such as mood, sexual behavior, sleep/wake cycle, blood pressure control and breathing. Serotonin mediates its effect via 5HT receptors, which are G protein coupled receptors that are expressed within 5HT neurons and their targets within the brain. The 5HT receptor, 5HT-1 A, which couple to the Gi/o signaling pathway, has been described to play major roles for anxiety and depressive behaviors. It is also and important drug target for treating many neuropsychiatric disorders. It is therefore of great importance to understand how this receptor pathway acts to modulate serotonergic tone, function, and 5HT related behaviors within the brain and in the living animals. Here, I describe a method to develop light activated GPCRs that activates the 5HT-1A specific receptor pathway. I will generate a chimeric receptor by mutating the intracellular domains of vertebrate rhodopsin by exchanging them for those of the 5HT-1A receptor. I will then characterize the function of this chimeric receptor and assess its ability to activate 5HT specific signaling in a heterologous expression system. Finally, I will assess its ability to rescue physiological phenotypes in 5HT-1A receptor knock-out mice. This chimeric receptor will enable the precise characterization of receptor pathways on neuronal function and would be a significant advance over pharmacologic manipulations, which are limited by their pharmacokinetics and can be cumbersome to use in live, intact animals. This light activated tool could be used to precisely manipulate serotonergic signaling cascades in a defined population of neurons, which will lead to a clearer understanding of normal physiology and may lead to novel therapeutics. Serotonin plays a critical role in many physiological functions and many psychiatric disorders, however the involvement of specific serotonin receptors with function and disease is largely unknown. To address this problem, I propose to develop and test light activated molecules that will activate a specific serotonin pathway in neurons.