C Jung1, R B Illing. 1. Neurobiologisches Forschungslabor der Universitäts-HNO-Klinik Freiburg.
Abstract
BACKGROUND: An important factor in the clinical outcome of cochlear implantation is the age of the patient. Compared to older patients, children with congenital deafness have a better outcome when the implantation is made before the age of 2 years. The cause may lie in the molecular biology of the brain, which changes during postnatal maturation. METHODS: Protein probes were obtained from tissue of the rat inferior colliculus at different ages. The probes were analyzed using 2-dimensional SDS electrophoresis. RESULTS: The expression of GAP-43, a protein expressed by neurons during axonal outgrowth and synaptogenesis, and the total number of the protein species showed a significant reduction during ontogenesis. This shows that while neurons gradually assume their specific function, they downregulate GAP-43 and the molecular complexity decreases. CONCLUSIONS: Due to a lack of neuronal pluripotency at later developmental stages, the flexibility to adapt to the afferent activation provided by a cochlear implant is increasingly limited.
BACKGROUND: An important factor in the clinical outcome of cochlear implantation is the age of the patient. Compared to older patients, children with congenital deafness have a better outcome when the implantation is made before the age of 2 years. The cause may lie in the molecular biology of the brain, which changes during postnatal maturation. METHODS: Protein probes were obtained from tissue of the rat inferior colliculus at different ages. The probes were analyzed using 2-dimensional SDS electrophoresis. RESULTS: The expression of GAP-43, a protein expressed by neurons during axonal outgrowth and synaptogenesis, and the total number of the protein species showed a significant reduction during ontogenesis. This shows that while neurons gradually assume their specific function, they downregulate GAP-43 and the molecular complexity decreases. CONCLUSIONS: Due to a lack of neuronal pluripotency at later developmental stages, the flexibility to adapt to the afferent activation provided by a cochlear implant is increasingly limited.
Authors: Paul J Govaerts; Carina De Beukelaer; Kristin Daemers; Geert De Ceulaer; Marjan Yperman; Thomas Somers; Isabelle Schatteman; F Erwin Offeciers Journal: Otol Neurotol Date: 2002-11 Impact factor: 2.311