Purkinje

Purkinje refers to Jan Evangelista Purkinje (1787–1869), a Czech anatomist and physiologist, and to several anatomical elements named in his honor. The most widely recognized are Purkinje cells in the cerebellar cortex, Purkinje fibers in the cardiac conduction system, and the Purkinje effect in vision.

Purkinje cells are large neurons located in the Purkinje cell layer of the cerebellar cortex. They receive input from granule cells via parallel fibers and from climbing fibers from the inferior olive, and they provide inhibitory output to the deep cerebellar nuclei and vestibular nuclei through GABAergic synapses. Their distinctive, highly branched dendritic trees integrate motor signals, contributing to the coordination and learning of movements.

Purkinje fibers are specialized cardiomyocytes that form a network within the heart’s inner subendocardial layer. They rapidly conduct electrical impulses from the bundle of His to the ventricles, ensuring timely and synchronized ventricular contraction. Together with the His-Purkinje system, these fibers help coordinate the heartbeat and maintain efficient pumping.

The Purkinje effect, also known as the Purkinje phenomenon, describes a shift in color perception under low illumination. As the eye moves from photopic (daylight) to scotopic (night) vision, sensitivity shifts toward shorter wavelengths, making blue-green colors relatively brighter while reds become less prominent. The effect is named for Purkinje, who first described related observations in vision research.