Change of expression of full-length and truncated TrkBs in the developing monkey central nervous system.
We examined the expression of full-length TrkB (TrkBTK+) and truncated TrkB (TrkBTK-) in the central nervous system (CNS) of the macaque monkey (Macaca fascicularis) using a western blot analysis. At the adult stage, the levels of TrkBTK+ in cerebral cortices were higher than those in other structures of CNS and the expressions of TrkBTK+ in the association cortices (except area PE) were relatively lower than those in the primary cortices. In contrast, TrkBTK- in the hippocampus and the cerebellum was significantly higher than in other structures. In various developing cerebral cortices, TrkBTK+ was detected at the same levels from embryonic day 120 (E120) to the adult period. In contrast, the expression of TrkBTK- increased remarkably after the newborn stage (NB), reached the maximum level at postnatal day 60 (P60) and maintained the same level into adulthood. The peaks of TrkBTK- in the association cortices were more delayed than in the primary cortices. The expression of TrkBTK- occurred at a time that correlates with the elimination of axons and the down-regulation of neuropeptides. The present study suggests that TrkBTK- plays an important role in the axonal remodelling and that it may act as a negative effector of TrkBTK+ in the primate CNS, reducing responsiveness to BDNF and/or NT-4/5.
Ohira
K
K
Department of Cellular and Molecular Biology, Primate Research Institute, Kyoto University, Aichi, Japan.
Shimizu
K
K
Hayashi
M
M
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development / Q000378:metabolism*; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D002490:Central Nervous System / Q000196:embryology* / Q000254:growth & development* / Q000378:metabolism; D002540:Cerebral Cortex / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D004622:Embryo, Mammalian / Q000378:metabolism / Q000502:physiology; D005314:Embryonic and Fetal Development / Q000502:physiology; D008252:Macaca fascicularis / Q000196:embryology; D010446:Peptide Fragments / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D013116:Spinal Cord / Q000196:embryology / Q000254:growth & development / Q000378:metabolism