The objective is to isolate chemical agents from a peripheral receptor in the skin which will attract or nourish sensory nerves. This may be of benefit to individuals who have suffered sensory loss due to nerve trauma or burn wounds.
The specific aims are to determine if; 1) special cells in the epidermis, called Merkel cells, attract sensory nerves to the skin; 2) the number of Merkel cell receptors a nerve can support is fixed or determined by receptor availability; and 3) the regeneration of these receptors in adult animals differs from their fetal development. To test whether Merkel cells attract sensory neurons, Merkel cell rich epidermis will be cultured in vitro in the presence of dorsal root sensory ganglia. The outgrowth of neurites from the ganglia will be compared with that of ganglia cultured alone or in the presence of simple epidermis devoid of receptor cells. This will also be tested in vivo by transplanting Merkel cell receptors, called touch domes, into denervated regions of skin and seeing if nerves will be induced to reinnervate the skin. Skin will be examined by silver stains for nerves, electron microscopy and nerve recordings. Whether the number of touch dome receptors a sensory nerve can innervate is fixed will be examined by manipulating the number of domes normally present in a cutaneous nerve field by excising and transplanting them. After making experimental changes in dome patterns, the sensory nerve will be crushed. One month after the nerve has regenerated, it will be recorded from again to determine the number of receptors it now innervates. Sites where domes were excised from will be examined by electron microscopy and nerve recordings to monitor the processes of dome receptor regeneration.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Unknown (R23)
Project #
5R23NS023165-03
Application #
3450005
Study Section
Communication Sciences and Disorders (CMS)
Project Start
1985-12-01
Project End
1988-11-30
Budget Start
1987-12-01
Budget End
1988-11-30
Support Year
3
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Utah
Department
Type
Schools of Medicine
DUNS #
City
Salt Lake City
State
UT
Country
United States
Zip Code
84112
English, K B; Stayner, N; Krueger, G G et al. (1992) Functional innervation of cultured skin grafts. J Invest Dermatol 99:120-8
English, K B; Stayner, N; Krueger, G et al. (1992) Tactile function in skin-equivalent grafts. Exp Neurol 115:104-8
Boyce, S T; Foreman, T J; English, K B et al. (1991) Skin wound closure in athymic mice with cultured human cells, biopolymers, and growth factors. Surgery 110:866-76
English, K B; Hammond, E H; Stayner, N (1990) Primary culture of cells arising from a neuroendocrine skin carcinoma. Am J Dermatopathol 12:589-97