Denervation and age modify neuromuscular positional selectivity
| Autor: | S. R. Chadaram, Michael B. Laskowski |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Denervation
Neurite General Neuroscience Age Factors Motor pool Anatomy Biology Muscle Denervation Rats Rats Sprague-Dawley Cellular and Molecular Neuroscience nervous system Embryonic spinal cord Animals Newborn Spinal Cord Pregnancy Neurites Animals Axon guidance Female Muscle membrane Muscle Skeletal Neuroscience |
| Zdroj: | Journal of neurobiology. 56(4) |
| ISSN: | 0022-3034 |
| Popis: | The rostrocaudal position of neurons within the spinal motor pool maps systematically onto the surface of several muscles in mammals. In an effort to understand the mechanisms that generate such maps, we have been studying choices made by embryonic spinal cord neurons on muscle membrane substrates in the in vitro stripe assay. In this report we explore the effects of postnatal age of the muscle on neurite choice, and how prior denervation modifies this choice. Our results further differentiate rostral from caudal motor neurons in preferring one substrate to another. First, caudal neurites prefer to grow on P6 neonatal caudal over rostral membranes, but lose this ability to distinguish axial position of origin in older muscles. Rostral neurites prefer growth on rostral membranes, but this preference also diminishes with age. Second, when adult muscles have been denervated, both rostral and caudal neurites regain their positional growth selectivity. Third, caudal neurites are particularly sensitive to substrate choice. When growing on a preferred substrate (gluteus) caudal neurites prefer neonatal over adult membranes. These results support the concept of fundamental differences in the growth preferences of rostral and caudal spinal neurites. These differences will assist in the identification of molecular guidance cues that determine the formation of neuromuscular positional maps. |
| Databáze: | OpenAIRE |
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