Volume 16, Number 19,
Issue of October 1, 1996
pp. 6175-6182
Copyright ©1996 Society for Neuroscience
Consequences of Trisomy 16 for Mouse Brain Development:
Corticogenesis in a Model of Down Syndrome
Received April 26, 1996; revised July 1, 1996; accepted July 7, 1996.
Tarik F. Haydar1,
Mary
E. Blue3, 4,
Mark E. Molliver4, 5,
Bruce K. Krueger1, and
Paul J. Yarowsky2
Departments of 1 Physiology and
2 Pharmacology and Experimental Therapeutics, University of
Maryland School of Medicine, Baltimore, Maryland 21201, 3 Neuroscience Laboratory, Kennedy-Krieger Research
Institute, Baltimore, Maryland 21205, and Departments of
4 Neurology and 5 Neuroscience, The Johns
Hopkins University School of Medicine, Baltimore, Maryland 21205
We have studied abnormalities in the tangential and radial
expansion of the cerebral cortex during fetal development in the
trisomy 16 (Ts16) mouse, a model for human trisomy 21 (Down syndrome).
Slowed tangential expansion of the neuroepithelium in Ts16 resulted in
a reduction of final telencephalic size and is predicted to decrease
the number of radial cortical units in the mature brain. In addition,
radial growth of the Ts16 cortex was delayed at the time of peak
cortical neurogenesis in normal mice, but by embryonic day 18 the
cortex reached normal thickness. Because mouse chromosome 16 shares
many genes with human chromosome 21, abnormalities in Ts16 brain
development may parallel abnormalities in trisomy 21.
Key words:
cerebral cortex;
development;
histogenesis;
Down
syndrome;
trisomy 16;
mental retardation