EXPRESSION OF TRKB RECEPTOR ISOFORMS IN THE DEVELOPING AVIAN VISUAL SYSTEM

摘要: The expression of novel TrkB receptor transcripts has been characterized to understand the potentially diverse roles brain- derived neurotrophic factor (BDNF) in developing avian visual system. In situ localization with an extracellular domain probe common all labeled a sub-population large retinal ganglion cells as well many associated nuclei, including neuronal layers within tectum that receive innervation. Because potential for structurally and functionally distinct receptors from gene locus, cDNA cloning reverse transcription-PCR analysis were used further analyze isoform retina tectum. Receptor isoforms sequenced contained deletion N terminus, putative ligand-binding domain, or cytoplasmic juxtamembrane (JM) domain. Two JM insertion sequences also identified, one which exhibits weak homology beta-actin was found both kinase-containing (TK+) kinase (KD) isoforms. retina, TK+ mRNA is upregulated during period cell (RGC) death, consistent proposed role BDNF tectal-derived survival RGCs. However, indicates this structure contains responsive throughout development. expressed tectum, it conceivable mediates autocrine/paracrine signaling these structures anterograde retinotectal trophic support.