Parkinson D, Coscia E, Daw N W
Department of Cell Biology and Physiology, Washington University Medical School, St. Louis, MO 63110.
Brain Res. 1988 Aug 2;457(1):70-8. doi: 10.1016/0006-8993(88)90058-3.
The concentration and location of adrenergic receptors in cat visual cortex have been determined by radioligand binding techniques using [3H]prazosin (alpha 1-adrenergic receptors), [3H]yohimbine (alpha 2-adrenergic receptors) and [3H]dihydroalprenolol (beta-adrenergic receptors). Saturable high affinity binding sites for all of these ligands were found. The beta-adrenergic receptor population was resolved into beta 1- and beta 2-sites that were present in the ratio 35:65. The laminar distributions of the alpha 1-, alpha 2- and beta-adrenergic receptors were different. The alpha 1- and beta-adrenergic receptors were very similarly localized, being seen in upper layers (I, II and III) and lower layers (layers V and VI). The labelling in upper layers was greater than that in lower layers, more so for alpha 1-adrenergic receptors than beta-adrenergic receptors. alpha 2-Adrenergic receptors were seen in a single band that occupied layer II and III but did extend to the pial surface. These results indicate that the effect of norepinephrine on neuronal activity in cat visual cortex will depend upon the layer in which it is released. Our results provide a basis for further physiological studies of the role of norepinephrine in the processing of visual information.
利用[3H]哌唑嗪（α1 - 肾上腺素能受体）、[3H]育亨宾（α2 - 肾上腺素能受体）和[3H]二氢阿普洛尔（β - 肾上腺素能受体），通过放射性配体结合技术确定了猫视觉皮层中肾上腺素能受体的浓度和位置。发现所有这些配体都有可饱和的高亲和力结合位点。β - 肾上腺素能受体群体可分为β1和β2位点，其比例为35:65。α1、α2和β - 肾上腺素能受体的层状分布不同。α1和β - 肾上腺素能受体的定位非常相似，见于上层（I、II和III层）和下层（V和VI层）。上层的标记比下层多，α1 - 肾上腺素能受体比β - 肾上腺素能受体更明显。α2 - 肾上腺素能受体见于占据II层和III层但延伸至软脑膜表面的单一带中。这些结果表明去甲肾上腺素对猫视觉皮层神经元活动的影响将取决于其释放的层。我们的结果为进一步研究去甲肾上腺素在视觉信息处理中的作用提供了生理学基础。
