It is thought that dermatomes are established during development as a result of competition between afferents of neighbouring segments. @entity19 that overexpress neurotrophins in the skin provide an interesting model to test this hypothesis, as they possess increased numbers of sensory neurons, and @entity272 . When dermatomal boundaries were mapped in adult @entity19 , it was found that those in nerve growth factor and @entity9140 overexpressers were indistinguishable from wild-type animals but that overlap between adjacent segments was greatly reduced in @entity9139 ( @entity9139 ) overexpressers. However, dermatomes in heterozygous @entity9139 knockout @entity19 displayed no more overlap than wild-types. In order to quantify differences across strains, innervation territories of thoracic dorsal cutaneous nerves were mapped and measured in adult @entity19 . Overlap between adjacent dorsal cutaneous nerves was normal in nerve growth factor overexpressing @entity19 , but much reduced in @entity9139 overexpressers. However, this restriction was not reflected in the central projection of the dorsal cutaneous nerve, creating a mismatch between peripheral and central projections. Dorsal cutaneous nerve territories were also mapped in neonatal @entity19 aged postnatal day 7-8. In neonates, nerve territories of @entity9139 overexpressers overlapped less than wild-types, but in neonates of both strains the amount of overlap was much greater than in the adult. These results indicate that substantial separation of dermatomes occurs postnatally, and that excess @entity9139 enhances this process, resulting in more restricted dermatomes. It may exert its effects either by enhancing competition, or by direct effects on the stability and formation of sensory endings in the skin.

Excess target-derived XXXX alters the segmental innervation of the skin.

@entity19 :: ('10090', 'Species') :: ['mice', 'Mice'] @entity9140 :: ('12064(Tax:10090)', 'Gene') :: ['brain-derived neurotrophic factor'] @entity9139 :: ('18205(Tax:10090)', 'Gene') :: ['neurotrophin-3', 'NT-3'] @entity272 :: ('MESH:D012871', 'Disease') :: ['display hyperinnervation of the skin']
@entity9139 :: (18205(Tax:10090),Gene) :: ['neurotrophin-3']
