Regional distribution of neurotrophin receptors in the developing auditory brainstem.

摘要: Neuron survival and axonal regeneration become severely limited during early postnatal development. In conjunction with our recent organotypic analysis of in the auditory midbrain, we wished to determine whether neurotrophins could serve as a trophic substance period. Therefore, current study examines development three neurotrophin receptor tyrosine kinases (TrkA, TrkB, TrkC) gerbil brainstem. Immunoreactivity TrkA, nerve growth-factor receptor, was observed nonneuronal cells first two weeks. cochlear nucleus mature animals, however, there TrkA-positive neuronal subpopulation. contrast, immunoreactivity TrkB TrkC (the receptors for brain-derived neurotrophic factor neurotrophin-3, respectively) displayed widespread distribution At day 0, staining virtually absent from nuclei, although immunopositive neurons were present mesencephalic trigeminal nucleus. By 7, TrkB- TrkC-positive most brainstem nuclei. 15, throughout inferior colliculus (IC), nucleus, medial lateral nuclei trapezoid body, superior olive, whereas labeled only subpopulation within central IC. The on both somata dendrites, generally restricted cell bodies. 30, immunostaining body extremely strong staining, followed by decreased dramatically 21. Observations at ultrastructural level confirmed localization TrkC. Immunostaining largely postsynaptic density synaptic profiles dendrites somata. summary, this illustrates differential pattern between general increase expression is well correlated onset sound-evoked activity system, its suggests that it may be involved modulation or maintenance physiology.