Activity-dependent development of interhemispheric connections in the visual cortex.
Interhemispheric axon fibers connect the two cerebral cortical hemispheres via the corpus callosum and function to integrate information between the hemispheres. In the development of callosal connections, an early phase involves axon guidance molecules and a later phase requires neuronal activity. In addition to the well-studied role of sensory-driven neuronal activity, recent studies have demonstrated an essential role of callosal neuron firing activity in forming axonal projections and dendritic maturation during the developmental period before sensory input is available. Results suggest that factors affecting the cellular excitability of developing callosal neurons can influence the establishment of interhemispheric connections. Possible synaptic and non-synaptic mechanisms for activity-dependent axonal projections are discussed.
Department of Biophysics, Kyoto University Graduate School of Science, Kyoto, Japan. tagawa@neurosci.biophys.kyoto-u.ac.jp
Yoshiaki
Y
Tagawa
Hidenobu
H
Mizuno
Tomoo
T
Hirano
D000818:Animals; D003337:Corpus Callosum / Q000254:growth & development* / Q000502:physiology; D009434:Neural Pathways / Q000254:growth & development / Q000502:physiology*; D009474:Neurons / Q000502:physiology; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*