Mechanism explains complications associated with diabetes

June 23, 2010

New research uncovers a molecular mechanism that links diabetes with an increased risk of cardiovascular problems and sudden cardiac death. The study, published by Cell Press in the June 24 issue of the journal Neuron, finds that high blood sugar prevents vital communication between the brain and the autonomic nervous system, which controls many involuntary activities in the body.

"Diseases, such as diabetes, that disturb the function of the cause a wide range of abnormalities that include poor control of blood pressure, cardiac arrhythmias, and digestive problems," explains senior study author Dr. Ellis Cooper from McGill University in Montreal. "In most people with diabetes, the malfunction of the autonomic nervous system adversely affects their quality of life and shortens life expectancy."

To investigate why the autonomic nervous system malfunctions in diabetics, Dr. Cooper and colleagues examined the transmission of electrical signals from the brain to autonomic neurons. The brain communicates with autonomic neurons at synapses, a small gap between two where electrical signals from one nerve cell are sent to the next by chemical neurotransmitters. "In healthy individuals, synaptic transmission in the autonomic nervous system is strong and stable; however, if synapses on these neurons malfunction due to some disease process, the link between the nervous system and the periphery becomes disrupted," says Dr. Cooper.

Using a mouse model of diabetes, the researchers discovered that elevates reactive oxygen species in autonomic neurons and causes a disruption in synaptic transmission between the brain and the autonomic neurons. The researchers went on to show that this elevation in reactive oxygen species inactivates the neurotransmitter receptors at these synapses causing synaptic transmission to fail.

"Our work provides a new explanation for diabetic-induced disruptions of the autonomic ," concludes Dr. Cooper. "We show that an early step leading to autonomic abnormalities in diabetes is a depression in synaptic transmission triggered by events downstream of high blood sugar and reactive oxygen species. This synaptic depression is apparent as early as 1 week after the onset of diabetes and becomes more severe over time."

More information: Campanucci et al.: “Report: Diabetes Depresses Synaptic Transmission in Sympathetic Ganglia by Inactivating nAChRs through a Conserved Intracellular Cysteine Residue.” Publishing in Neuron 66, 827-834, June 24, 2010. DOI:10.1016/j.neuron.2010.06.010

Related Stories

Recommended for you

Immunotherapy target suppresses pain to mask cancer

May 23, 2017

Once hailed as a breakthrough in cancer treatment, immunotherapies are now raising concerns as doctors note new side effects like severe allergic reactions, acute-onset diabetes and heart damage.

Computations of visual motion in the brain

May 22, 2017

Botond Roska and his group at the FMI have elucidated how the retina and the visual cortex work together in visual motion perception. They found that cortical cells, which respond preferentially to backward image motion, ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

lisasusan23
not rated yet Jun 24, 2010

Major brands always give out their popular brand samples (in a way it is similar to coupons) I alway use qualityhealth to get mine http://bit.ly/bhZA0u enjoy your free samples

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.