Gamlin P D, Zhang H, Clarke R J
Department of Physiological Optics, School of Optometry, University of Alabama at Birmingham 35294, USA.
Exp Brain Res. 1995;106(1):169-76. doi: 10.1007/BF00241367.
In humans and other primates, an increase in luminance in either eye elicits bilateral pupilloconstriction that is essentially equal in both eyes. Current models of the neural substrate for this clinically important light reflex propose that a retinorecipient pretectal nucleus projects bilaterally to the Edinger-Westphal nucleus (EW), which contains the parasympathetic, preganglionic neurons controlling pupilloconstriction. Based on single-unit recording studies in anesthetized cats and rats, it has been further suggested that luminance neurons in only one pretectal nucleus, the pretectal olivary nucleus, mediate this reflex. However, to our knowledge, there have been no comparable electrophysiological studies in primates of the pupillary light reflex or the pretectal luminance neurons that mediate this reflex. To address this issue, single-unit recording and electrical microstimulation studies were carried out in the pretectum of alert, trained, rhesus monkeys. These studies demonstrated that the primate pretectum contains luminance neurons with the characteristics appropriate for mediating the pupillary light reflex and that these neurons are located in one retinorecipient pretectal nucleus, the pretectal olivary nucleus. Electrical microstimulation at the site of these neurons often elicited pupilloconstriction. Our results provide clear evidence for the involvement of the pretectum, and more specifically the pretectal olivary nucleus, in mediating the pupillary light reflex in primates.
在人类和其他灵长类动物中，任何一只眼睛的亮度增加都会引发双眼的瞳孔收缩，且双眼的收缩程度基本相同。目前关于这一具有临床重要性的光反射神经基质的模型提出，一个接受视网膜传入的顶盖前核双侧投射至动眼神经副核（EW），该核包含控制瞳孔收缩的副交感节前神经元。基于对麻醉猫和大鼠的单单位记录研究，进一步表明只有一个顶盖前核，即顶盖前橄榄核中的亮度神经元介导这一反射。然而，据我们所知，在灵长类动物中，尚未有关于瞳孔光反射或介导该反射的顶盖前亮度神经元的类似电生理研究。为解决这一问题，我们在警觉、受过训练的恒河猴的顶盖前区进行了单单位记录和电微刺激研究。这些研究表明，灵长类动物的顶盖前区含有具有介导瞳孔光反射特征的亮度神经元，且这些神经元位于一个接受视网膜传入的顶盖前核，即顶盖前橄榄核中。在这些神经元所在部位进行电微刺激常常会引发瞳孔收缩。我们的结果为顶盖前区，更具体地说是顶盖前橄榄核参与介导灵长类动物的瞳孔光反射提供了明确证据。
