オプシン5下垂体ニューロンによる紫光による発熱抑制
Kevin X Zhang1,2,3,4, Shane D'Souza1,2,3, Brian A Upton1,2,3,4
1The Visual Systems Group, Abrahamson Pediatric Eye Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
Nature
|September 4, 2020
まとめ
バイオレット光は,下垂体にあるオプシン5 (OPN5) ニューロンを含む脳の深い経路を活性化します. この経路は通常,茶色脂肪組織 (BAT) の熱生成を抑制し,体温を調節する.
科学分野:
- 神経科学
- 生理学
- 生物化学
背景:
- オプシンは動物における光検出器として機能するGタンパク質結合受容体である.
- オプシン5 (OPN5) は,可視紫光に敏感な保存されたオプシンである.
- OPN5は網膜,皮膚,特に下垂体前視野 (POA) に見られます.
研究 の 目的:
- 脳内の新しい光感知経路を調査するために
- 熱調節における下垂体前視領域 (POA) のOPN5の役割を決定する.
- OPN5がブラウン脂肪組織 (BAT) の活動に影響を与えるメカニズムを解明する.
主な方法:
- OPN5のPOAニューロンの発現分析
- OPN5を発現するPOAニューロンの化学的刺激
- OPN5ゼロのマウスの現象分析
- バイオレット光による光刺激実験
- 細胞内cAMPレベルをex vivoで測定する
主要な成果:
- OPN5は,グルタマタージック熱感POAニューロンで発現する.
- OPN5を発現するPOAニューロンは,BAT活動を投影し,抑制する.
- OPN5ゼロのマウスは,BATの過剰活動,高体温,過剰な発熱を示しています.
- バイオレット光刺激により,野生型マウスのBAT温度が急激に低下しますが,OPN5ゼロマウスはそうではありません.
- 紫色の光は OPN5 を発現するPOAニューロンのcAMPを増加させます
結論:
- 脳の奥深くにある紫色の光感受体経路は,POA内のOPN5を巻き込み,BATの熱生成を調節する.
- この経路は通常,BAT活動を抑制します.
- POAのOPN5は,体温とエネルギー消費を調節するための新しいターゲットです.
関連する概念動画
Photoreceptors and Visual Pathways
8.3K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
8.3K
Thermoregulation
2.1K
The human body has a sophisticated thermoregulation system that employs negative feedback mechanisms to maintain an optimal core temperature. When the core temperature drops, peripheral and central thermoreceptors send signals to the hypothalamus, activating the heat-promoting center. This center triggers several responses aimed at increasing the core temperature. First, vasoconstriction reduces the flow of warm blood from internal organs to the skin so that the heat is not lost from the skin,...
2.1K
Thermosensation
33.3K
Peripheral thermosensation is the perception of external temperature. A change in temperature (on the surface of the skin and other tissues) is detected by a family of temperature-sensitive ion channels called Transient Receptor Potential, or TRP, receptors. These receptors are located on free nerve endings. Those detecting cold temperatures are closer to the surface of the skin than the nerve endings detecting warmth. These thermoTRP channels, while temperature selective, have relatively...
33.3K
Body Temperature
3.8K
The body's temperature, measured in degrees, is determined by the balance between heat production and dissipation to the surrounding environment. For instance, if exercising vigorously, the body will produce more heat, causing sweat and dissipating that heat. Despite extreme environmental conditions and physical exertion, the human temperature-control system maintains a constant core body temperature (the temperature of deep tissues, which are the tissues located beneath the skin and other...
3.8K
Homeostatic Imbalances in Body Temperature
3.1K
Hyperthermia occurs when the body's temperature becomes unusually high, often due to heat exposure, intense physical activity, or certain illnesses. This condition can create a dangerous cycle where elevated body temperature increases the metabolic rate, generating more heat and potentially leading to organ failure and brain damage. A severe form of hyperthermia, called heat stroke, can raise body temperature to life-threatening levels. Fever, on the other hand, is a controlled form of...
3.1K
Diencephalon: Hypothalamus and Coordination
3.1K
The hypothalamus is a small yet highly complex and essential brain region that plays a crucial role in regulating various bodily functions. Anatomically, it is located at the base of the brain, just above the brainstem and below the thalamus, forming part of the limbic system.
The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and...
The hypothalamus interacts with other brain regions, including the pituitary gland, through a direct physical connection called the hypothalamic-pituitary axis. The hypothalamus receives somatic and visceral inputs and...
3.1K


