Insulin-like growth factor I mRNA levels are developmentally regulated in specific regions of the rat brain

Mark A. Bach, Zila Shen-Orr, William L. Lowe, Charles T. Roberts, Derek Leroith

Research output: Contribution to journalArticlepeer-review

133 Scopus citations


The expression of mRNAs encoding insulin-like growth factor I (IGF-I) and the IGF-I receptor in the developing rat brain from embryonic day 16 to postnatal day 82 was analyzed using solution hybridization-RNase protection assays. Four distinct developmental patterns in the steady-state levels of IGF-I mRNA were seen. Specifically, the olfactory bulb showed a high perinatal level of IGF-I mRNA which declined dramatically by postnatal day 8. In contrast, cerebral cortex displayed maximal levels of IGF-I mRNA at postnatal day 8 and 13, which subsequently declined to adult levels (P82). A third developmental pattern was seen in the hypothalamus, where IGF-I mRNA increased from E16 up to postnatal day 3 and remained elevated thereafter. Finally, IGF-I mRNA levels in brainstem and cerebellum remained unchanged throughout the time period studied. We conclude that there are specific regional patterns of IGF-I gene expression in the developing rat brain. In contrast, IGF-I receptor gene expression did not exhibit any region-specific developmental changes. The developmental patterns of IGF-I gene expression seen in this study further substantiate the potential role of IGF-I in normal brain development.

Original languageEnglish (US)
Pages (from-to)43-48
Number of pages6
JournalMolecular Brain Research
Issue number1
StatePublished - Apr 1991
Externally publishedYes


  • Brain development
  • Insulin-like growth factor I
  • Insulin-like growth factor I receptor

ASJC Scopus subject areas

  • Molecular Biology
  • Cellular and Molecular Neuroscience


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