Gene Controlling Circadian Rhythms May Be Involved In Onset Of Bipolar Disorder
Disrupt the gene that regulates the biological clocks in mice and they become manic, exhibiting behaviors similar to humans with bipolar disorder, UT Southwestern Medical Center researchers have found.
In a study available online in the Proceedings of the National Academy of Sciences, scientists from UT Southwestern show that the Clock gene, which controls the body's circadian rhythms, may be integrally involved in the development of bipolar disorder. Circadian rhythms include the daily ups-and-downs of waking, eating and other processes such as body temperature, hormone levels, blood pressure and heart activity.
"There's evidence suggesting that circadian genes may be involved in bipolar disorder," said Dr. Colleen McClung, assistant professor of psychiatry and the study's senior author. "What we've done is taken earlier findings a step further by engineering a mutant mouse model displaying an overall profile that is strikingly similar to human mania, which will give us the opportunity to study why people develop mania or bipolar disorder and how they can be treated."
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The researchers also injected a functional Clock gene protein - basically giving the mice their Clock gene back - into a specific region of the brain that controls reward functions and where dopamine cells are located. Dopamine is a neurotransmitter associated with the "pleasure system" of the brain and is released by naturally rewarding experiences such as food, sex and the use of certain drugs. This also resulted in the mice going back to normal behaviors.
"While the Clock gene is expressed throughout the brain, it's really only been studied in one particular brain region, which is the one that's involved in circadian rhythms," said Dr. McClung. "This is one of the first studies to show that Clock has a major effect on behavior in a different brain region - specifically the one that controls reward responses and mood."
Disrupt the gene that regulates the biological clocks in mice and they become manic, exhibiting behaviors similar to humans with bipolar disorder, UT Southwestern Medical Center researchers have found.
In a study available online in the Proceedings of the National Academy of Sciences, scientists from UT Southwestern show that the Clock gene, which controls the body's circadian rhythms, may be integrally involved in the development of bipolar disorder. Circadian rhythms include the daily ups-and-downs of waking, eating and other processes such as body temperature, hormone levels, blood pressure and heart activity.
"There's evidence suggesting that circadian genes may be involved in bipolar disorder," said Dr. Colleen McClung, assistant professor of psychiatry and the study's senior author. "What we've done is taken earlier findings a step further by engineering a mutant mouse model displaying an overall profile that is strikingly similar to human mania, which will give us the opportunity to study why people develop mania or bipolar disorder and how they can be treated."
[...]
The researchers also injected a functional Clock gene protein - basically giving the mice their Clock gene back - into a specific region of the brain that controls reward functions and where dopamine cells are located. Dopamine is a neurotransmitter associated with the "pleasure system" of the brain and is released by naturally rewarding experiences such as food, sex and the use of certain drugs. This also resulted in the mice going back to normal behaviors.
"While the Clock gene is expressed throughout the brain, it's really only been studied in one particular brain region, which is the one that's involved in circadian rhythms," said Dr. McClung. "This is one of the first studies to show that Clock has a major effect on behavior in a different brain region - specifically the one that controls reward responses and mood."
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