Publications by authors named "H Katsumaru"

A ciliated protozoan, Halteria grandinella, swam backward rapidly with a migration distance per second attaining 100 times the cell size. This high swimming velocity was accompanied by a high frequency of ciliary beating. Recordings with a high-speed digital video (10(3) frames/s) revealed that the frequency during forward and backward swimming was, respectively, 105 +/- 10 Hz and 260 +/- 30 Hz.

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Article Synopsis
  • During CNS development, commissural axons navigate towards the ventral midline, then change direction after crossing the floor plate.
  • The study identified that nectin-1 and -3, which are adhesion molecules, play a critical role in the axonal guidance by localizing asymmetrically at these contact points.
  • Disruption of the interaction between nectin-1 and -3 led to abnormal axon behavior and failure to properly change direction in the axons, highlighting their importance in axonal trajectory regulation.
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Spine-like dendritic protrusions (SLDPs) emanating from developing dendrites have been proposed to play an important role in early synaptogenesis. We previously analyzed synaptic termination sites on soma-dendritic membrane of newborn cats and found that corticorubral (CR) axons form synapses preferentially on SLDPs (Saito et al., 1997).

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Ordered neuronal connections in mature brains are thought to be sculpted from initially diffuse projections by elimination of inappropriate projections and strengthening of appropriate ones. Although evidence suggests that neuronal activity plays a role in these processes, the mechanism behind the modification of neuronal connections remains obscure. To gain insight into the mechanisms of axonal elimination and projection strengthening, we examined the morphology of individual axons that were to be eliminated as well as the consequences of partial denervation.

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In order to discover molecules involved in axonal outgrowth during development of the central nervous system (CNS), monoclonal antibodies (MAbs) were raised against homogenates of the early postnatal rat cerebral cortex. A novel MAb, 5H, was obtained which recognizes a developmentally regulated antigen in the CNS. In the cerebral cortex of postnatal (PN) day 0-6 rats, 5H-immunoreactive punctate or fiber-like processes were observed.

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