Immunohistochemical study of skin reinnervation by regenerative axons

Abstract

The time sequence of sensory and sudomotor nerve regeneration to the mouse footpad was studied between one and seven weeks after crush or section of the sciatic nerve. Protein gene product 9.5, vasoactive intestinal peptide, substance P, and calcitonin gene-related peptide were localized in thick sections by using indirect immunofluorescence techniques and imaged by confocal microscopy. Nerve regeneration was visually assessed in all nerves and quantified in sweat glands. After denervation, protein gene product 9.5 immunoreactivity remained as dim fluorescence within thick fibers of dermal nerve trunks, whereas thin nerve fibers to sweat glands and to epidermis disappeared. By 14 days postcrush and 35 days postsection, the first protein gene product 9.5 immunoreactive regenerating axons appeared in large nerve trunks, quickly extending to epidermis and sweat glands. Reinnervation of Meissner's corpuscles occurred nearly simultaneous with return of epidermal free nerve endings and sudomotor network. Calcitonin gene-related peptide, vasoactive intestinal peptide, and substance P immunoreactivity disappeared completely one week after denervation, then reappeared at 17-18 days postcrush and 35 days postsection. Fewer nerve fibers were immunoreactive to these peptides than to protein gene product 9.5. The overall density of reinnervation, although reduced, more closely resembled normal in the sweat glands and Meissner's corpuscles than in the epidermis. Reinnervation was more successful after crush than after nerve section. The time course for functional return of sweating paralleled the return of protein gene product 9.5 immunoreactivity, whereas appearance of vasoactive intestinal peptide was delayed by several days.

Analyzing Somatosensory Axon Projections with the Sensory Neuron-SpecificAdvillinGene

“…Traditionally, these endings are detected by anti-PGP9.5 antibody staining (Fundin et al, 1997a;Navarro et al, 1997;Rice et al, 1997). Note that anti-PGP9.5 labels all neurons, including sympathetic and motor neurons as well as sensory neurons (Schofield et al, 1995).…”

Wallerian degeneration of zebrafish trigeminal axons in the skin is required for regeneration and developmental pruning

“…Our method provided exceptional temporal and spatial resolution, allowing us to dissect the degeneration process into distinct phases. The degeneration we observed was particularly fast compared with what has been reported for other types of axons (Hoopfer et al, 2006;Navarro et al, 1997;Waller, 1850), perhaps reflecting the fact that we monitored the behavior of single severed axons. In most other studies of vertebrate WD, entire bundles of axons are damaged, often along with associated glia, connective tissue and blood vessels.…”

HSV-mediated gene transfer of vascular endothelial growth factor to dorsal root ganglia prevents diabetic neuropathy

“…47 Sudomotor dysfunction is a common feature of diabetic autonomic neuropathy, and correlates with a reduction in neuropeptide concentration and sweat gland activity. 48 In our study, VEGF expression also preserved autonomic function, measured by pilocarpineinduced sweating. We believe that this most likely results from retrograde transport of the vector from the skin to the autonomic ganglia, although this has not been established conclusively.…”