Central anatomy of individual rapidly adapting low-threshold mechanoreceptors innervating the "hairy" skin of newborn mice: early maturation of hair follicle afferents - PubMed (original) (raw)

. 2001 Jul 30;436(3):304-23.

Affiliations

PMID: 11438932

Central anatomy of individual rapidly adapting low-threshold mechanoreceptors innervating the "hairy" skin of newborn mice: early maturation of hair follicle afferents

C J Woodbury et al. J Comp Neurol. 2001.

Abstract

Adult skin sensory neurons exhibit characteristic projection patterns in the dorsal horn of the spinal gray matter that are tightly correlated with modality. However, little is known about how these patterns come about during the ontogeny of the distinct subclasses of skin sensory neurons. To this end, we have developed an intact ex vivo somatosensory system preparation in neonatal mice, allowing single, physiologically identified cutaneous afferents to be iontophoretically injected with Neurobiotin for subsequent histological analyses. The present report, centered on rapidly adapting mechanoreceptors, represents the first study of the central projections of identified skin sensory neurons in neonatal animals. Cutaneous afferents exhibiting rapidly adapting responses to sustained natural stimuli were encountered as early as recordings were made. Well-stained representatives of coarse (tylotrich and guard) and fine-diameter (down) hair follicle afferents, along with a putative Pacinian corpuscle afferent, were recovered from 2-7-day-old neonates. All were characterized by narrow, uninflected somal action potentials and generally low mechanical thresholds, and many could be activated via deflection of recently erupted hairs. The central collaterals of hair follicle afferents formed recurrent, flame-shaped arbors that were essentially miniaturized replicas of their adult counterparts, with identical laminar terminations. The terminal arbors of down hair afferents, previously undescribed in rodents, were distinct and consistently occupied a more superficial position than tylotrich and guard hair afferents. Nevertheless, the former extended no higher than the middle of the incipient substantia gelatinosa, leaving a clear gap more dorsally. In all major respects, therefore, hair follicle afferents display the same laminar specificity in neonates as they do in adults. The widely held misperception that their collaterals extend exuberant projections into pain-specific regions of the dorsal horn during early postnatal life is shown to have multiple, deep-rooted underpinnings.

PubMed Disclaimer

Cited by

Nociceptors lacking TRPV1 and TRPV2 have normal heat responses.
Woodbury CJ, Zwick M, Wang S, Lawson JJ, Caterina MJ, Koltzenburg M, Albers KM, Koerber HR, Davis BM. Woodbury CJ, et al. J Neurosci. 2004 Jul 14;24(28):6410-5. doi: 10.1523/JNEUROSCI.1421-04.2004. J Neurosci. 2004. PMID: 15254097 Free PMC article.
The functional organization of cutaneous low-threshold mechanosensory neurons.
Li L, Rutlin M, Abraira VE, Cassidy C, Kus L, Gong S, Jankowski MP, Luo W, Heintz N, Koerber HR, Woodbury CJ, Ginty DD. Li L, et al. Cell. 2011 Dec 23;147(7):1615-27. doi: 10.1016/j.cell.2011.11.027. Cell. 2011. PMID: 22196735 Free PMC article.
TRPV1 unlike TRPV2 is restricted to a subset of mechanically insensitive cutaneous nociceptors responding to heat.
Lawson JJ, McIlwrath SL, Woodbury CJ, Davis BM, Koerber HR. Lawson JJ, et al. J Pain. 2008 Apr;9(4):298-308. doi: 10.1016/j.jpain.2007.12.001. Epub 2008 Jan 28. J Pain. 2008. PMID: 18226966 Free PMC article.
The specification and wiring of mammalian cutaneous low-threshold mechanoreceptors.
Olson W, Dong P, Fleming M, Luo W. Olson W, et al. Wiley Interdiscip Rev Dev Biol. 2016 May-Jun;5(3):389-404. doi: 10.1002/wdev.229. Epub 2016 Mar 17. Wiley Interdiscip Rev Dev Biol. 2016. PMID: 26992078 Free PMC article. Review.
The cellular and molecular basis of direction selectivity of Aδ-LTMRs.
Rutlin M, Ho CY, Abraira VE, Cassidy C, Bai L, Woodbury CJ, Ginty DD. Rutlin M, et al. Cell. 2014 Dec 18;159(7):1640-51. doi: 10.1016/j.cell.2014.11.038. Cell. 2014. PMID: 25525881 Free PMC article.

Central anatomy of individual rapidly adapting low-threshold mechanoreceptors innervating the "hairy" skin of newborn mice: early maturation of hair follicle afferents - PubMed (original) (raw)