Publications by authors named "T Iwasato"

For neural circuit construction in the brain, coarse neuronal connections are assembled prenatally following genetic programs, being reorganized postnatally by activity-dependent mechanisms to implement area-specific computational functions. Activity-dependent dendrite patterning is a critical component of neural circuit reorganization, whereby individual neurons rearrange and optimize their presynaptic partners. In the rodent primary somatosensory cortex (barrel cortex), driven by thalamocortical inputs, layer 4 (L4) excitatory neurons extensively remodel their basal dendrites at neonatal stages to ensure specific responses of barrels to the corresponding individual whiskers.

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  • - Increased lactate levels from glycolysis are being studied as potential markers for metabolic changes in neurons, linked to a drop in brain pH, which has been associated with various neuropsychiatric disorders like schizophrenia and autism.
  • - Research shows that these pH and lactate changes are common across different animal models, including those for depression, epilepsy, and Alzheimer's disease, though findings vary, particularly within the autism spectrum.
  • - A large-scale analysis indicated that higher lactate levels correlate with worse working memory performance, suggesting that altered brain chemistry might reflect underlying conditions across multiple disorders.
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  • Individual neurons in sensory cortices develop specific receptive fields influenced by their dendritic patterns, which are shaped during the neonatal period through activity-dependent plasticity.
  • Using improved imaging techniques with higher resolution, the study tracked the rapid changes in dendrite morphology of spiny stellate (SS) neurons in the mouse primary somatosensory cortex over an 8-hour period.
  • The results showed that the basal dendrites of L4 neurons were highly dynamic, with frequent actions like emergence, elongation, and retraction of dendritic branches occurring, indicating a trial-and-error process crucial for developing their oriented structure.
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Dendritic refinement is a critical component of activity-dependent neuronal circuit maturation, through which individual neurons establish specific connectivity with their target axons. Here, we demonstrate that the developmental shift of Golgi polarity is a key process in dendritic refinement. During neonatal development, the Golgi apparatus in layer 4 spiny stellate (SS) neurons in the mouse barrel cortex lose their original apical positioning and acquire laterally polarized distributions.

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The cerebral cortex comprises a complex and exquisite network of neuronal circuits that is formed during development. To explore the molecular mechanisms involved in cortical circuit formation, the tactile somatosensory pathway that connects the whiskers and cortex of rodents is a useful model. Here, we analyzed the roles of Ras GTPase-activating proteins (RasGAPs) in the circuit formation in the somatosensory cortex layer 4 (L4).

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