Comparative analysis of Meissner's corpuscles in the fingertips of primates

Abstract

Meissner's corpuscles (MC s) are tactile mechanoreceptors found in the glabrous skin of primates, including fingertips. These receptors are characterized by sensitivity to light touch, and therefore might be associated with the evolution of manipulative abilities of the hands in primates. We examined MC s in different primate species, including common marmoset (Callithrix jacchus,n = 5), baboon (Papio anubis,n = 2), rhesus macaque (Macaca mulatta,n = 3), chimpanzee (Pan troglodytes,n = 3), bonobo (Pan paniscus,n = 1) and human (Homo sapiens,n = 8). Fingertips of the first, second and fourth digits were collected from both hands of specimens, dissected and histologically stained using hematoxylin and eosin. The density (MC s per 1 mm 2) and the size (cross‐sectional diameter of MC s) were quantified. Overall, there were no differences in the densities of MC s or their size among the digits or between the hands for any species examined. However,MC s varied across species. We found a trend for higher densities of MC s in macaques and humans compared with chimpanzees and bonobos; moreover, apes had larger MC s than monkeys. We further examined whether the density or size of MC s varied as a function of body mass, measures of dexterity and dietary frugivory. Among these variables, only body size accounted for a significant amount of variation in the size of MC s.