# "Anxiety Circuit" in amygdala - Great journal article



## Guest (Mar 10, 2011)

http://www.physorg.com/news/2011-03-scientists-anti-anxiety-circuit-brain-region.html

Beginning of article, see link for entire article:
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*Scientists discover anti-anxiety circuit in brain region considered the seat of fear*
_*March 9, 2011*_

_*A new study supports the role of a brain region called the amygdala in processing anxiety. In this 3-D magnetic resonance imaging (MRI) rendering of a human brain, functional MRI (fMRI) activation of the amygdala is highlighted in red. Credit: NIMH Clinical Brain Disorders Branch*_

"Stimulation of a distinct brain circuit that lies within a brain structure typically associated with fearfulness produces the opposite effect: Its activity, instead of triggering or increasing anxiety, counters it.

That's the finding in a paper by Stanford University School of Medicine researchers to be published online March 9 in Nature. In the study, Karl Deisseroth, MD, PhD, and his colleagues employed a mouse model to show that stimulating activity exclusively in this circuit enhances animals' willingness to take risks, while inhibiting its activity renders them more risk-averse. This discovery could lead to new treatments for anxiety disorders, said Deisseroth, an associate professor of bioengineering and of psychiatry and behavioral science.

_*The investigators were able to pinpoint this particular circuit only by working with a state-of-the-art technology called optogenetics, pioneered by Deisseroth at Stanford, which allows brain scientists to tease apart the complex circuits that compose the brain so these can be studied one by one.*_

*"Anxiety is a poorly understood but common psychiatric disease," said Deisseroth, who is also a practicing psychiatrist. More than one in four people, in the course of their lives, experience bouts of anxiety symptoms sufficiently enduring and intense to be classified as a full-blown psychiatric disorder. In addition, anxiety is a significant contributing factor in other major psychiatric disorders from depression to alcohol dependence, Deisseroth said.
*
Most current anti-anxiety medications work by suppressing activity in the brain circuitry that generates anxiety or increases anxiety levels. Many of these drugs are not very effective, and those that are have significant side effects such as addiction or respiratory suppression, Deisseroth said. "The discovery of a novel circuit whose action is to reduce anxiety, rather than increase it, could point to an entire strategy of anti-anxiety treatment," he added.

Ironically, the anti-anxiety circuit is nestled within a brain structure, the amygdala, long known to be associated with fear. Generally, stimulating nervous activity in the amygdala is best known to heighten anxiety. So the anti-anxiety circuit probably would have been difficult if not impossible to locate had it not been for optogenetics, a new technology in which nerve cells in living animals are rendered photosensitive so that action in these cells can be turned on or off by different wavelengths of light. The technique allows researchers to selectively photosensitize particular sets of nerve cells. Moreover, by delivering pulses of light via optical fibers to specific brain areas, scientists can target not only particular nerve-cell types but also particular cell-to-cell connections or nervous pathways leading from one brain region to another. The fiber-optic hookup is both flexible and pain-free, so experimental animals' actual behavior as well as their brain activity can be monitored."


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## Visual (Oct 13, 2010)

Dreamer* said:


> http://www.physorg.com/news/2011-03-scientists-anti-anxiety-circuit-brain-region.html
> 
> Beginning of article, see link for entire article:
> -------------------------------
> ...


Thank you for the article.

_Ironically, the anti-anxiety circuit is nestled within a brain structure, the amygdala, long known to be associated with fear. Generally, stimulating nervous activity in the amygdala is best known to heighten anxiety._

It is funny that they view it as ironic - it would seem logical that a perceptual organ (fight/flight in this case) would have regulation of its function within or next to the organ. Many brain/body structures have proximity in relationship to functions.

The amygdala is a dopamine-rich organ and some consider it part of the basal-ganglia (known for dopamine dependence for movement). Sometime it is called "the emotional brain" due to function for proper emotional reaction.

It is a major player in social interaction and its size and activity have shown connections with autism, bipolar disorder, borderline personality disorder, depression, schizophrenia, social phobia, &#8230;

So as research grows, such as this article, more effective management could result.

With my experience of brain injury, many symptoms are a matter of lack of regulation/control of various circuits. While levodopa is often considered 'stimulating', in my case it enables 'stuck' circuits resulting in calming and regaining control of feelings among other things.

While use of dopamine increasing medication isn't common, it is interesting that some with various mood disorders find it helpful. Recently noticed that some on Social Anxiety forums actually use levodopa for their anxiety and/or sleep dysfunction.

Of course management of mood disorder and DPD is rarely straight forward. Regarding brain injury, when damage/loss-of-control was at it's peek, Gabapentin (anti-seizure) was needed - no amount of levodopa was enough. And one of the more common dopamine agonists, Wellbutrin (also increases norepinephrine) often proves to be too stimulating in all but the smallest dosages.

It is neat they can selectively stimulate small neuron groups with light.


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## Brando2600 (Apr 22, 2010)

Nice find, how did you?


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## Guest (Mar 10, 2011)

Visual, I think they're just emphasizing something "ironic" ...



> Ironically, *the anti-anxiety circuit* is nestled within a brain structure, the amygdala, long known to be associated with fear. Generally, stimulating nervous activity in the amygdala is best known to heighten anxiety.


The amygdala is the seat of fear, but they find it also has ANTI-anxiety properties. They have been going on the interaction of various systems. Say the HPA Axis (Hypothalamus, Pituitary, Adrenal). The hippocampus has been implicated.

The brain is so complex, researchers come upon things -- with this cool new technology -- that contradict former assumptions.


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## Guest (Mar 10, 2011)

Brando2600 said:


> Nice find, how did you?


Well, with all my mental health advocacy, I am a member of a LOT of groups and I receive email newsletters and snail mail newsletters.

On Facebook I also subscribe to a lot of mental health groups.

Forgot where I got this. *Mental Health America* has great research updates. *Minds on the Edge* on FB. *NAMI -- I'm a member and go to conferences, do local volunteer stuff when I'm up to it.*. I also read the Health section in the New York Times which has amazing articles often referring back to the actual article. Also, I have done -- not so much recently -- research on PubMed.

If you go to my website, I have references to many books and articles dealing with anxiety, DP, mental illness. But as it goes, this stuff is out of date in 15 minutes.

I really suggest if you're a FB member to at least check out these organizations there.
Tons of info out there. TOO much!

I'd say Mental Health America -- no cost to get the newsletter online has a lot of good news on research with links, etc.

Also groups I'm a member of, "No Kidding, Me Too!" and "BringChage2Mind" -- have done fundraising walks for BC2M and NAMI. You meet a lot of people with a LOT of information to share.


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## Speechless (Nov 23, 2009)

Thank god for these brain researchers and scientists.


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## fuxxors500 (Oct 5, 2008)

What you posted is precisely the theoretical basis for the Linden Method, just so you know. I haven't been on this forum in a long time but I was browsing recently and saw this post. We had a heated debate about the Linden Method many months ago via e-mail Dreamer, I'm not sure if you remember. This research you posted is exactly what Charles Linden describes in his method. You insisted in the e-mail that you were very familiar with his method and knew his theory, but I don't think you ever actually looked into it. I admit I don't like the way he presents his findings. His method comes across as pop-psychology and he seems to be oblivious to the difference between anecdotal and empirical proof, BUT I still believe his theory is correct. You should look into it. I'll be coming back on here eventually to talk about it.


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