Premium
Somatosensory organization and behavior in naked mole‐rats: II. Peripheral structures, innervation, and selective lack of neuropeptides associated with thermoregulation and pain
Author(s) -
Park Thomas J.,
Comer Christopher,
Carol Andrew,
Lu Ying,
Hong H.S.,
Rice Frank L.
Publication year - 2003
Publication title -
journal of comparative neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.855
H-Index - 209
eISSN - 1096-9861
pISSN - 0021-9967
DOI - 10.1002/cne.10824
Subject(s) - biology , hair follicle , mole , somatosensory system , anatomy , substance p , endocrinology , medicine , neuropeptide , neuroscience , receptor , biochemistry
African naked mole‐rats are subterranean rodents that have a robust orienting response to stimulation of unique vibrissa‐like body hairs that are widely spaced over an otherwise hairless skin. To determine whether these large body hairs have a specialized organization similar to facial vibrissae, the structure and innervation of facial vibrissa follicles, body hair follicles, and intervening skin in naked mole‐rats was compared with that in rats and a furred African mole‐rat species (the common mole‐rat). Immunofluorescence and lectin‐binding analyses revealed that the body hair follicles in naked mole‐rats were exceptionally large and well innervated, similar to guard hairs of furred species. However, these body vibrissae lacked the anatomic specializations and unique types of innervation affiliated with follicle sinus complexes of facial vibrissae. In contrast to the furred species, naked mole‐rats had a paucity of Aβ‐fiber Merkel endings at all peripheral locations. Naked mole‐rats also were completely lacking in cutaneous C‐fibers immunoreactive for substance P and calcitonin gene‐related peptide. In contrast, the hairless skin of the naked mole‐rats had an exceptional abundance of presumptive Aδ‐fibers. The unusual features of the cutaneous innervation in naked mole‐rats are presumably adaptations to their subterranean environment and that they are the only known poikilothermic mammal. The features of this mammalian model system provide unique opportunities to discriminate mechanisms related to tactile spatial orientation, vascular regulation, and nociception. J. Comp. Neurol. 465:104–120, 2003. © 2003 Wiley‐Liss, Inc.