Regional variation in the density of Meissner's corpuscles in human fingers.

Manual therapies in medicine rely on a physician's ability to sense and respond to tactile cues from their hands to inform them of symptoms within the patient. Sensory cues through skin may not be equally sensitive among all people, and little is known about the variation in distribution of sensory corpuscles in the human hand. Variation of corpuscle numbers studied in living people are limited to less invasive techniques, limiting their accuracy. Body-donor studies that thoroughly sample the distribution throughout the hand are extremely rare, usually only including a small number of sites around the hand and only a small number of individuals. Does the distribution of Meissner's corpuscles vary greater between individuals, between fingers, along the finger, or at specialized regions of the fingers themselves (pads, over interphalangeal joints, tips)? We tested whether there were significant differences between finger regions (fingertips vs. pads, vs. interphalangeal joints), or from proximal to distal, or between digits, or between individuals by histologically sampling human body-donors to science. There were significant differences in the quantity of Meissner's corpuscles between finger regions, from proximal to distal regions along digits, between individuals, but not between digits. Specifically, fingertips demonstrated higher counts of Meissner's corpuscles than pads and interphalangeal joints, more distally located regions (i.e. tips and distal pads) demonstrated higher Meissner's corpuscles than more proximal regions, and most individuals demonstrated significantly different average amounts of total Meissner's corpuscles from each other. Our results suggest that variability exists in the amounts and distribution of Meissner's corpuscles both between and within fingers of human subjects.