Document Detail


Increased expression of insulin-like growth factor-I (IGF-I) during embryonic development produces neocortical overgrowth with differentially greater effects on specific cytoarchitectonic areas and cortical layers.
MedLine Citation:
PMID:  15707676     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The in vivo actions of insulin-like growth factor-I (IGF-I) on the growth and development of the cerebral cortex were investigated in transgenic (Tg) mice that overexpress IGF-I in the brain, beginning as early as embryonic day (E) 13. Compared to non-Tg littermate controls, Tg mice at postnatal day (P) 12 exhibited significant increases in total cortical volume (31%) and in total neuron number (27%). The numerical density of neurons did not differ significantly between Tg and control mice, except in layer I. Comparing cytoarchitectonic areas in Tg mice, significantly greater increases in cortical volume were found for the motor cortex (42%), compared to somatosensory cortex (35%). Similarly, greater increases in total neuron number were found for motor cortex (44%) compared to somatosensory cortex (28%). Comparing individual cortical layers in Tg mice, the greatest increase in neuron number was found in layer I for both motor (93%) and somatosensory (76%) regions, followed by layer V (36-53%)>II/III (26-47%)>VI (26-37%)>IV (22-34%). Our results demonstrate that increased expression of IGF-I in vivo during embryonic and early postnatal development produces substantial overgrowth of the neocortex. IGF-I-mediated growth and development exhibits differential effects in some cytoarchitectonic areas and in lamina-specific neuron populations, most notably the neurons of layer I.
Authors:
Rebecca D Hodge; A Joseph D'Ercole; John R O'Kusky
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Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2004-12-30
Journal Detail:
Title:  Brain research. Developmental brain research     Volume:  154     ISSN:  0165-3806     ISO Abbreviation:  Brain Res. Dev. Brain Res.     Publication Date:  2005 Feb 
Date Detail:
Created Date:  2005-02-14     Completed Date:  2005-06-27     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  8908639     Medline TA:  Brain Res Dev Brain Res     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  227-37     Citation Subset:  IM    
Affiliation:
Department of Pathology and Laboratory Medicine, University of British Columbia, B.C. Research Institute for Children's and Women's Health, 950 West 28th Avenue, Vancouver, British Columbia, Canada, V5Z 4H4.
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MeSH Terms
Descriptor/Qualifier:
Age Factors
Analysis of Variance
Animals
Animals, Newborn
Cell Count / methods
Cerebral Cortex* / anatomy & histology,  growth & development,  metabolism
Embryo, Mammalian
Embryonic Development / physiology*
Gene Expression Regulation, Developmental / physiology*
Humans
Insulin-Like Growth Factor I / genetics,  metabolism*
Intermediate Filament Proteins / genetics,  metabolism
Mice
Mice, Transgenic
Nerve Tissue Proteins / genetics,  metabolism
Neurons / physiology*
Grant Support
ID/Acronym/Agency:
HD08299/HD/NICHD NIH HHS
Chemical
Reg. No./Substance:
0/Intermediate Filament Proteins; 0/Nerve Tissue Proteins; 0/nestin; 67763-96-6/Insulin-Like Growth Factor I

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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