Featured Research

from universities, journals, and other organizations

Studies seek better understanding and treatment of depression

Date:
August 14, 2012
Source:
Georgia Health Sciences University
Summary:
Connecting the dots between two molecules whose levels are decreased in depression and increased by current antidepressants could yield new therapies, researchers say. Serotonin is a neurotransmitter that enables brain cells to communicate and brain-derived neurotropic factor, or BDNF, is a brain-nourishing molecule that also aids connectivity. Popular antidepressants such as Prozac, developed to increase levels of serotonin, have recently been found to also increase BDNF levels.

Connecting the dots between two molecules whose levels are decreased in depression and increased by current antidepressants could yield new therapies, researchers say.

Related Articles


Serotonin is a neurotransmitter that enables brain cells to communicate and brain-derived neurotropic factor, or BDNF, is a brain-nourishing molecule that also aids connectivity. Popular antidepressants such as Prozac, developed to increase levels of serotonin, have recently been found to also increase BDNF levels, said Dr. Anilkumar Pillai, neuroscientist at the Medical College of Georgia at Georgia Health Sciences University.

"We don't know how the molecule, serotonin, which is well-studied in depression, regulates BDNF signaling," Pillai said. He's principal investigator on a five year, $1.5 million grant from the National Institute of Mental Health to help him make the connection.

He suspects a critical piece is the protein transglutaminase 2, or TG2, expressed by brain cells and most other cell types. TG2 plays a role in natural serotonin recycling and potentially is a factor in the serotonin deficiency associated with depression. It also may help explain why levels of serotonin and BDNF seem to rise and fall in sync, Pillai said.

TG2 coverts serotonin to Rac1, a protein that helps rejuvenate BDNF receptors, which typically sit on the surface of brain cells but must periodically move inside to reinvigorate. Depression appears to upset the balance of these complex, critical inner workings. Pillai hypothesizes that the high levels he has found in depression, likely result in too much serotonin conversion leaving too little of the neurotransmitter to properly support brain cell communication. Instead, more Rac1 is produced but -- inexplicably -- its degradation also increases ultimately decreasing BDNF signaling as well.

Pillai has seen the unfortunate chain of events play out in an animal model with increased levels of TG2 and clear signs of depression. "If you can fix problems with the receptor, you should be able to reverse depressive symptoms in these mice," he said

One of the many questions he wants to answer is whether existing antidepressants impact TG2. To help clarify the role of the impaired BDNF receptors, Pillai also wants to know whether giving BDNF to the depressed animal model improves depression. He's using a viral particle to directly activate the BDNF receptor. And he's also giving the TG2 inhibitor cysteamine to an animal model developed by administering stress hormones. He recently published in the journal PLoS One findings that the inhibitor appears effective in normalizing depressive behavior and BDNF levels in that model. Mental stress is a major factor in numerous psychiatric disorders including depression, schizophrenia and anxiety, he noted.

Some antidepressants, such as Prozac, were designed to interfere with a natural recycling of serotonin called reuptake so more serotonin is available where needed to enable cell communication. Pillai said it's not yet clear if serotonin reuptake is the same thing as its conversion to Rac-1.

"We need to learn more about how all these pieces fit to ultimately design new therapies for depression and related psychiatric disorders," he said. Dr. Alvin V. Terry Jr., MCG pharmacologist, is co-investigator on the studies.

Major depressive disorder is the leading cause of disability in Americans age 15-44, affects about 14.8 million adults and is more prevalent in women, according to the National Institute of Mental Health.


Story Source:

The above story is based on materials provided by Georgia Health Sciences University. The original article was written by Toni Baker. Note: Materials may be edited for content and length.


Journal Reference:

  1. Anilkumar Pillai, Davide Bruno, Antero S. Sarreal, Raymundo T. Hernando, Leslie A. Saint-Louis, Jay Nierenberg, Stephen D. Ginsberg, Nunzio Pomara, Pankaj D. Mehta, Henrik Zetterberg, Kaj Blennow, Peter F. Buckley. Plasma BDNF Levels Vary in Relation to Body Weight in Females. PLoS ONE, 2012; 7 (7): e39358 DOI: 10.1371/journal.pone.0039358

Cite This Page:

Georgia Health Sciences University. "Studies seek better understanding and treatment of depression." ScienceDaily. ScienceDaily, 14 August 2012. <www.sciencedaily.com/releases/2012/08/120814110951.htm>.
Georgia Health Sciences University. (2012, August 14). Studies seek better understanding and treatment of depression. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2012/08/120814110951.htm
Georgia Health Sciences University. "Studies seek better understanding and treatment of depression." ScienceDaily. www.sciencedaily.com/releases/2012/08/120814110951.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Mind & Brain News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Tryptophan Isn't Making You Sleepy On Thanksgiving

Tryptophan Isn't Making You Sleepy On Thanksgiving

Newsy (Nov. 27, 2014) — Tryptophan, a chemical found naturally in turkey meat, gets blamed for sleepiness after Thanksgiving meals. But science points to other culprits. Video provided by Newsy
Powered by NewsLook.com
Are Female Bosses More Likely To Be Depressed?

Are Female Bosses More Likely To Be Depressed?

Newsy (Nov. 24, 2014) — A new study links greater authority with increased depressive symptoms among women in the workplace. Video provided by Newsy
Powered by NewsLook.com
Winter Can Cause Depression — Here's How To Combat It

Winter Can Cause Depression — Here's How To Combat It

Newsy (Nov. 23, 2014) — Millions of American suffer from seasonal depression every year. It can lead to adverse health effects, but there are ways to ease symptoms. Video provided by Newsy
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) — Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins