January 24, 2007

New Dopamine Brain Target Discovered: Potential Breakthrough for Schizophrenia Treatment

Read more... Schizophrenia Biology

A team of Canadian researchers, lead by Dr. Susan George and Dr. Brian O'Dowd at the Centre for Addiction and Mental Health (CAMH), discovered a distinct dopamine signaling system in the brain. Composed of two different types of dopamine receptors, this novel target may have a significant role in understanding and treating schizophrenia.

Published in the Proceedings of the National Academy of Sciences USA (Rashid et al., 2007), this important discovery demonstrates the existence of a Gq/11-coupled signaling unit that triggers a calcium signal, which is turned on by stimulating D1 and D2 dopamine receptors. Unlike other dopamine receptors, this novel unit will only create brain signals when both receptors are stimulated at the same time.

Using animal models. Drs. George and O’Dowd and their team identified this complex by its unique reaction to dopamine or specific drug triggers. Strikingly, stimulating this target with dopamine or specific drugs triggered a rise in calcium in the brain. As calcium has a profound effect on almost all brain function, this rise in calcium causes a cascade of events in the brain. This is the first time that a direct connection between dopamine and calcium signals has been reported.

“This distinct unit provides a novel signaling pathway through which dopamine can impact the function of brain cells”, said Dr. George. “This is significant because signaling through calcium release is a major mechanism regulating many important functions in the brain and we have provided the first direct mechanism by which dopamine can activate a calcium signal.”

This data has significant implications for schizophrenia. Research tells us that people with schizophrenia may have disordered calcium signals, and the major treatments for this disease target the dopamine system. Drs. George and O’Dowd state, "our data links these two pieces of evidence, creating better understanding of the disease and opening the door for a new generation of highly specific drugs that may help alleviate the devastating symptoms of schizophrenia."

The research was funded by grants from the NIH National Institute on Drug Abuse and the Canadian Institutes for Health Research.

For more information on this study view the abstract online here: D1–D2 dopamine receptor heterooligomers with unique pharmacology are coupled to rapid activation of Gq/11 in the striatum.

The Centre for Addiction and Mental Health (CAMH) is one of the largest addiction and mental health organizations in North America and Canada's leading mental health and addiction teaching hospital.


There are previous findings that Calcium has a relationship with Alzheimers also.

Posted by: Barbara Schultheis at March 19, 2007 02:37 PM

Calcium may also play a role in Alzheimer's and other neurological disorders.

Posted by: Barbara Schultheis at March 19, 2007 02:40 PM

My son ,22 years ,had schizophrenia 4 years ago.All these pages you write are useful to doctors not to patient's parents.what is the use of reading all these pages to the patient or hi/her parents ? If they are ever important to us .Please give a brief summary.We waste hours reading them .Thanx.

Posted by: zuhair Ibraheem shamas at October 12, 2007 03:19 PM

Post a comment

Please enter this code to enable your comment -
Remember Me?
(you may use HTML tags for style)
* indicates required