Fernandes Giselle, Lam Ruby, Park Jiho, Drummond Gabrielle T, Sur Mriganka
Picower Institute for Learning and Memory, Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
Boston Children's Hospital and Harvard Medical School teaching hospital, Boston, USA, 02115, 300 Longwood Avenue, MA.
Adv Exp Med Biol. 2025;1477:35-61. doi: 10.1007/978-3-031-89525-8_2.
Norepinephrine (NE) and its methylated form, epinephrine (Epi), are catecholamines that serve as both neurotransmitters and hormones, regulating a wide array of physiological functions. In the central nervous system (CNS), NE acts as a neurotransmitter, primarily released by the locus coeruleus (LC), to regulate vigilance states and optimize behavioral performance. It is also the primary neurotransmitter of the peripheral, sympathetic nervous system, responsible for tonic and reflexive changes to cardiovascular tone. Conversely, Epi operates primarily as a hormone released by the adrenal medulla, to regulate metabolic homeostasis and orchestrate the body's response to acute stress. While there is no evidence for direct connections between the central and peripheral adrenergic systems, various feedforward and feedback circuits enable them to collaborate and synchronize brain-body responses to stimuli. A notable example of this interaction is evident in the body's response to stress, where multiple adrenergic systems work in concert to elicit a fight-or-flight response to perceived danger. Reciprocal communication between the LC, other adrenergic systems in the brain, and the NE-driven sympathetic nervous system induces a state of heightened arousal, enhances the processing of sensory stimuli, and facilitates adaptive behavioral responses to stressors.In this chapter, we will explore adrenergic systems in the brain and body and share evidence for multiple channels of communication between them. We will trace the anatomical connections and physiological characteristics of NE-producing neurons in the brain and the peripheral nervous system. We will also describe adrenergic systems in the body, projections of the sympathetic postganglionic neurons, the vasal ganglia of the cranial nerve, and release of NE and Epi by the adrenal medulla into the bloodstream. Importantly, this chapter will elucidate the circuits and pathways of communication between NE in the central and peripheral nervous systems that regulate and synchronize cognitive processes and physiological responses. Finally, we will explore various neurological disorders, including chronic pain and Alzheimer's disease (AD), that show evidence for deficits in adrenergic systems and disruption of the communication between the brain and body.
去甲肾上腺素（NE）及其甲基化形式肾上腺素（Epi）是儿茶酚胺，它们既是神经递质又是激素，调节着广泛的生理功能。在中枢神经系统（CNS）中，NE作为神经递质，主要由蓝斑（LC）释放，以调节警觉状态并优化行为表现。它也是外周交感神经系统的主要神经递质，负责心血管张力的持续性和反射性变化。相反，Epi主要作为肾上腺髓质释放的激素，调节代谢稳态并协调身体对急性应激的反应。虽然没有证据表明中枢和外周肾上腺素能系统之间存在直接联系，但各种前馈和反馈回路使它们能够协作并同步脑-体对刺激的反应。这种相互作用的一个显著例子在身体对压力的反应中很明显，多个肾上腺素能系统协同工作，以对感知到的危险引发战斗或逃跑反应。LC、大脑中的其他肾上腺素能系统以及NE驱动的交感神经系统之间的相互通信会诱发高度唤醒状态，增强感觉刺激的处理，并促进对应激源的适应性行为反应。在本章中，我们将探索大脑和身体中的肾上腺素能系统，并分享它们之间多种通信渠道的证据。我们将追踪大脑和外周神经系统中产生NE的神经元的解剖学联系和生理特征。我们还将描述身体中的肾上腺素能系统、交感神经节后神经元的投射、脑神经的血管神经节以及肾上腺髓质将NE和Epi释放到血液中的过程。重要的是，本章将阐明中枢和外周神经系统中NE之间调节和同步认知过程及生理反应的通信回路和途径。最后，我们将探索各种神经系统疾病，包括慢性疼痛和阿尔茨海默病（AD），这些疾病显示出肾上腺素能系统存在缺陷以及脑-体通信中断的证据。
