MRI makes connection between diabetes, CNS

Feb 28, 2006

The brain has not traditionally been considered a target for diabetic complications, but new research has shown that the disease does have particular effects on the central nervous system (CNS). These may include impaired learning and memory, neurodegeneration, and loss of synaptic plasticity.

However, "the underlying mechanisms responsible for these changes are poorly understood," according to a poster presentation at the 2006 Society of Critical Care Medicine meeting in San Francisco.

Dr. Peter Ferrazzano and colleagues conducted an MRI experiment to study the extent of diabetes on the CNS and cerebrovascular volume (CBV) in particular. Ferrazzano and his co-authors are from the Columbia University College of Physicians and Surgeons and the Morgan Stanley Children's Hospital of New York-Presbyterian, both in New York City.

For this study, six male mice had diabetes induced until their blood glucose level was over 250. They underwent imaging before induction, one week after, and 12 weeks after on a 9.4-tesla MR system (Bruker BioSpin, Billerica, MA).

According to their results, the authors noticed a greater CBV in the dentate gyrus in the diabetic mice, which was an unexpected finding. "If this holds up in our future studies, two possible mechanisms might account for the finding," the authors added.

The first could be pathologic angiogenesis, which has been shown to increase as CBV increases. A previous MRI study at Henry Ford Health Sciences Center in Detroit found dynamic changes of brain angiogenesis after neural progenitor cell transplantation in the living adult rat subjected to embolic stroke (NeuroImage, November 15, 2005, Vol. 28:3, pp. 698-707).

The second explanation could be regional excitotoxicity, the authors said. Excitotoxity injury occurs when there is an excessive activation of neuronal amino acid receptors. This may lead to the death of neurons in particular disease states (American Journal of Neuroradiology, November-December 2001, Vol. 22:10: pp. 1813-1824).

By Shalmali Pal
AuntMinnie.com staff writer
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