Thyroid hormone action on astroglial cells from distinct brain regions during development

Int J Dev Neurosci. 1998 Feb;16(1):19-27. doi: 10.1016/s0736-5748(98)00002-1.

Abstract

Astrocytes are target to triiodothyronine (T3) hormone action during rat brain development. In this work, we show that astrocytes from distinct developing brain regions are differently responsive to thyroid hormone. Distinctly from embryonic or newborn cerebral hemisphere and mesencephalic astrocytes, newborn cerebellar and embryonic hippocampal astrocytes do not change their morphology in response of hormone treatment. We also analysed protein synthesis and secretion from these T3-treated astrocytes. The results showed a significant increase in protein synthesis in astrocytes from older brain regions. Maximum effect, however, was observed in cerebral hemisphere astrocytes from newborn rats. The protein secretion effect was also more evident in the cerebral hemisphere as well as in cerebellar astrocytes from newborn rats. In addition, we examined T3 effects on GFAP/vimentin expression by culturing 6-day old cerebellar astrocytes. In this case T3 seems to induce GFAP expression which might be occurring as a first step to astrocyte differentiation.

MeSH terms

  • Animals
  • Animals, Newborn
  • Astrocytes / drug effects
  • Astrocytes / metabolism
  • Astrocytes / ultrastructure*
  • Blotting, Western
  • Brain / anatomy & histology
  • Brain / growth & development*
  • Brain / ultrastructure*
  • Cell Differentiation / drug effects
  • Cell Division / drug effects
  • Cerebellum / growth & development
  • Cerebellum / metabolism
  • Cerebellum / ultrastructure
  • Electrophoresis, Polyacrylamide Gel
  • Glial Fibrillary Acidic Protein / biosynthesis
  • Rats
  • Triiodothyronine / pharmacology
  • Triiodothyronine / physiology*
  • Vimentin / biosynthesis

Substances

  • Glial Fibrillary Acidic Protein
  • Vimentin
  • Triiodothyronine