Thursday, December 31, 2009

Runaway Vigilance Hormone Linked to Panic Attacks

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Hi Everyone, I hope you are doing well. I am doing good. I had a great Christmas with my family, I hope you did too. I was happy to read this breakthrough about Panic Disorder. That is what I have but is controlled with paxil. New break throughs can lead to even better treatments for everyone. I will be sharing any updates on this discovery I receive. Happy New Year, may all of us have better mental health in 2010 and feel the peace that the women expresses in the picture above. Thanks for visiting my blog, Take Care, Janet:)

Science Update
December 28, 2009
Runaway Vigilance Hormone Linked to Panic Attacks
Translational Experiments in Rats, Humans Suggest New Medication Target

A study has linked panic disorder to a wayward hormone in a brain circuit that regulates vigilance. While too little of the hormone, called orexin, is known to underlie narcolepsy, the new study suggests that too much of it may lead to panic attacks that afflict 6 million American adults.

"Targeting the brain's orexin system may hold promise for a new generation of anti-anxiety treatments," said Thomas R. Insel, M.D., Director of the National Institute of Mental Health (NIMH), part of the National Institutes of Health. "This is a good example of how translational experiments in rats and humans can potentially yield clinical benefits."

NIMH grantee Anantha Shekhar, M.B., Ph.D., and colleagues at Indiana University and Lund University, report on their findings online Dec. 27, 2009 in the journal Nature Medicine. They showed that blocking orexin gene expression or its receptor prevented panic attack-like responses in rats. The study also revealed that panic disorder patients have excess levels of the hormone.

Background
Orexin, also called hypocretin, is secreted exclusively in a circuit emanating from the brain's hypothalamus, known to regulate arousal, wakefulness and reward.

Panic attacks can be experimentally-induced by infusing susceptible humans with a normally innocuous salt called sodium lactate. The salt similarly triggers panic-like anxiety behaviors in susceptible rat strains, suggesting that something is altered in their arousal circuit. Since sodium lactate activated orexin-secreting neurons in panic-prone rats but not in control rats, the researchers hypothesized that something might be orexin.

Results of This Study
The investigators first discovered that increased gene expression in orexin-secreting neurons correlated with increases in anxiety-like behavior in panic-prone rats following sodium lactate infusions. Using a technique called RNA interference, they then protected the panic-prone rats from developing anxiety behaviors following the infusions by first injecting them with a genetically-engineered agent that prevented orexin genes from turning on. Blocking orexin receptors with a drug that specifically binds to it also blocked the anxiety like behavior following the infusions. This mirrored effects, seen in both rats and humans, of benzodiazepine medications used to treat panic disorder.

The excess sleepiness of narcolepsy, traced a decade ago to loss of orexin-secreting neurons in the arousal circuit, might seem to be an opposite state of a panic attack. However, the researchers demonstrated in rats that such sedation could not account for orexin's effects on anxiety. Also in rats, they traced orexin neurons to their end target to pinpoint the specific brain site that accounts for the anxiety effects, disentangled from cardio-respiratory components of the panic response.

Finally, by measuring orexin in cerebrospinal fluid of 53 patients, the researchers showed that those with just panic disorder had higher levels of orexin than those with both panic disorder and depression.
Significance

Taken together, these results and other evidence suggest a critical role for an overactive orexin system in producing panic attacks, say the researchers.
What's Next?

Medications that block the orexin receptor may provide a new therapeutic approach for the treatment of panic disorder, they add.

The research was also supported, in part, by NIH's National Center for Research Resources.

Reference
A key role for orexin in panic anxiety. Johnson PL, Truitt W, Fitz SD, Kelley PE, Dietrich A, Sanghani S, Traskman-Bendz L, Goddard AW, Brundin, L, Shekhar A. Nature Medicine. Epub 2009 Dec 27.

3 comments:

  1. what rubbish, panic attacks are a state of mind, people who trigger a panic dissorder then have a different state of mind which then will effect chemical changes in the brain, its the state of mind that causes the chemical changes, panic dissorder is easily eradicated, change your mind, you change your chemical balance, very easy

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  2. Dear Anonymous,
    I feel sorry you feel that way. But it is a free world and your free to think what you want. I personally suffer from Panic Attacks, well at least I did. I tried to get rid of them on my own and I could not. I need medicine, my daughter also does.I also use relaxation methods to change my mind and chemicals in my brain. I could have been a lot worse off and suffered the way my mother did if you read her story. You must of never lived with anyone with a Mental Illness because of your lack of compassion
    Take Care,
    Janet :)

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