ZFIN ID: ZDB-PUB-160804-23
Optic nerve input-dependent regulation of neural stem cell proliferation in the optic tectum of adult zebrafish
Sato, Y., Yano, H., Shimizu, Y., Tanaka, H., Ohshima, T.
Date: 2017
Source: Developmental Neurobiology   77(4): 474-482 (Journal)
Registered Authors: Ohshima, Toshio, Sato, Yuki, Shimizu, Yuki, Tanaka, Hideomi
Keywords: none
MeSH Terms:
  • Animals
  • Brain-Derived Neurotrophic Factor/metabolism*
  • Cell Proliferation/physiology*
  • Disease Models, Animal
  • Neural Stem Cells/cytology
  • Neural Stem Cells/physiology*
  • Neurogenesis/physiology*
  • Optic Nerve Injuries*
  • Receptor, trkB/agonists
  • Receptor, trkB/metabolism*
  • Superior Colliculi/cytology
  • Superior Colliculi/physiology*
  • Zebrafish
  • Zebrafish Proteins/metabolism*
PubMed: 27480480 Full text @ Dev. Neurobiol.
ABSTRACT
Adult neurogenesis attracts broad attention as a possible cure for neurological disorders. However, its regulatory mechanism is still unclear. Therefore, we have been studying the cell proliferation mechanisms of neural stem cells (NSCs) using zebrafish, which have high regenerative potential in the adult brain. We previously reported the presence of neuroepithelial-type NSCs in the optic tectum of adult zebrafish. In the present study, we first confirmed that NSCs in the optic tectum decrease or increase in proportion to projection of the optic nerves from the retina. At four days after optic nerve crush (ONC), BrdU-positive cells decreased in the optic tectum's operation side. In contrast, at three weeks after ONC, BrdU-positive cells increased in the optic tectum's operation side. To study the regulatory mechanisms, we focused on the BDNF/TrkB system as a regulatory factor in the ONC model. We found that bdnf was mainly expressed in the periventricular gray zone (PGZ) of the optic tectum by using in situ hybridization. Interestingly, expression level of bdnf significantly decreased in the optic tectum at four days after ONC, and its expression level tended to increase at 3 weeks after ONC. We conducted rescue experiments using a TrkB agonist and confirmed that decrease of NSC proliferation in the optic tectum by ONC was rescued by TrkB signal activation, suggesting stimuli-dependent regulation of NSC proliferation in the optic tectum of adult zebrafish.
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