TrkB signaling regulates the developmental maturation of the somatosensory cortex.

摘要: In the rodent central nervous system, region of cortex that responds to facial whisker stimulation is anatomically segregated into discrete regions called barrels. Each barrel made up layer IV cortical neurons receive input from a separate via innervation thalamus. It has been shown neurotrophins play important roles in development and plasticity thalamic axon visual retrosplenial cortex. We now extend those findings investigation role neurotrophin signaling formation. show receptor TrkB expressed thalamus during time innervation. The two ligands, brain derived neurotrophic factor (BDNF) neurotrophin-4 (NT-4), are at this time. Mice lacking demonstrate developmental delay segregation axons within mutants, abnormally uniform postnatal day 4 compared their control littermates, but clear barrels 2 days later. This phenotype recapitulated BDNF mutant mice, not NT-4 mice. These results sole ligand responsible for phenotype. Analysis conditional knockout mice lack cortex, thalamus, does segregation. indicate expression appropriate timing development.