Navigation Links
Melatonin precursor stimulates growth factor circuits in brain
Date:2/4/2010

Scientists at Emory University School of Medicine have discovered unexpected properties for a precursor to melatonin, the hormone that regulates sleep cycles.

Melatonin is produced from the neurotransmitter serotonin in a daily rhythm that peaks at night. Melatonin's immediate precursor, N-acetylserotonin, was not previously thought to have effects separate from those of melatonin or serotonin.

Now an Emory team has shown that N-acetylserotonin can stimulate the same circuits in the brain activated by the growth factor BDNF (brain-derived neurotrophic factor).

The results will be published online this week in the Proceedings of the National Academy of Sciences.

The team was led by Keqiang Ye, associate professor of pathology and laboratory medicine, and P. Michael Iuvone, professor of pharmacology and director of research at Emory Eye Center. Researchers from Morehouse School of Medicine and the University of Wisconsin contributed to the paper.

The discovery has implications for the study of how some antidepressants function and may also explain previous observations that N-acetylserotonin has antidepressant activity in animal models of depression.

"Our results suggest that the molecules and pathways involved in mood regulation and circadian rhythms are intertwined," Ye says.

A lack of BDNF, which pushes brain cells to grow and helps them resist stress, is thought to lie behind depression and several neurodegenerative diseases. Ye and his colleagues have been searching for chemicals that can mimic BDNF by activating TrkB, the receptor for BDNF on cells' surfaces.

Several widely prescribed antidepressants (selective serotonin reuptake inhibitors such as fluoxetine/Prozac) increase levels of serotonin in the brain, but the connections between serotonin levels and depression are complex. Because antidepressants seem to take weeks to display their effects, scientists have proposed that their real targets are BDNF and TrkB.

"We were exploring whether the serotonin system is involved in TrkB signaling," Ye says. "We were surprised to find that N-acetylserotonin, but not serotonin or melatonin, can activate TrkB."

N-acetylserotonin could stimulate TrkB even when BDNF was not present, both in cell culture dishes and in mice, Ye and his colleagues found. It could also protect neurons from overstimulation in the same way that BDNF can.

Melatonin is produced at several sites in the body: the pineal gland, the retina and the intestine. One of the most common strains of laboratory mice (C57Bl6) is deficient in making N-acetylserotonin and melatonin and develops retinal degeneration.

The authors observed that in the retinas of mice that produce adequate melatonin, TrkB is turned on at night, a pattern that matches the appearance of N-acetylserotonin. However, the pattern of TrkB activation is flat in C57Bl6 melatonin-deficient mice.

Ye's laboratory is now investigating the mechanism by which N-acetylserotonin activates TrkB. He says that N-acetylserotonin has a short lifetime in the body but similar compounds that are more stable may be useful in treating neurological diseases.


'/>"/>

Contact: Holly Korschun
hkorsch@emory.edu
404-727-3990
Emory University
Source:Eurekalert

Related medicine news :

1. The hormone of darkness: melatonin could hurt memory formation at night
2. Schiff(R) Melatonin Plus Passes ConsumerLab.com Test for Ingredients and Product Quality
3. Melatonin is an effective treatment for sleep problems in children with autism
4. Melatonin May Ease Sleep Problems in Autistic Children
5. Colorectal cancer: Immunological tests for more accurate detection of cancer precursors
6. Kaiser Permanente Study Finds Drinking Wine May Lower Risk of Barretts Esophagus, Precursor to Nations Fastest Growing Cancer, Esophageal Cancer
7. Drinking wine lowers risk of Barretts esophagus, precursor to nations fastest growing cancer
8. Stem Cells Coaxed to Make Precursors to Egg, Sperm
9. Less HRT, Fewer Cases of Possible Breast Cancer Precursor
10. Social Network for Affordable Health Care Supporters Stimulates a New Level of Interactivity and Dialogue
11. Social Network For Affordable Health Care Supporters Stimulates A New Level of Interactivity and Dialogue
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/25/2016)... ... ... First Choice Emergency Room , the largest network of independent freestanding emergency ... its new Mesquite-Samuell Farm facility. , “We are pleased to announce Dr. Ogunleye ... M. Muzzarelli, Executive Medical Director of First Choice Emergency Room. , Dr. Ogunleye ...
(Date:6/25/2016)... ... 25, 2016 , ... On Friday, June 10, Van Mitchell, Secretary of the ... to iHire in recognition of their exemplary accomplishments in worksite health promotion. , The ... Health & Wellness Symposium at the BWI Marriott in Linthicum Heights. iHire was one ...
(Date:6/24/2016)... ... June 24, 2016 , ... Those who have experienced traumatic events may suffer ... unhealthy avenues, such as drug or alcohol abuse, as a coping mechanism. To avoid ... healthy coping following a traumatic event. , Trauma sufferers tend to feel a range ...
(Date:6/24/2016)... ... 2016 , ... The Pulmonary Hypertension Association (PHA) learned during ... two significant new grants to support its work to advance research and patient ... recognizing patients, medical professionals and scientists for their work in fighting pulmonary hypertension ...
(Date:6/24/2016)... ... June 24, 2016 , ... Comfort Keepers® of San Diego, CA is ... Road To Recovery® program to drive cancer patients to and from their cancer treatments. ... the highest quality of life and ongoing independence. Getting to and from medical ...
Breaking Medicine News(10 mins):
(Date:6/26/2016)... 2016 Jazz Pharmaceuticals plc (Nasdaq: ... Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended ("HSR"), ... Inc. ("Celator"; Nasdaq: CPXX ) expired effective ... As previously announced on May 31, 2016, ... agreement under which Jazz Pharmaceuticals has commenced a tender ...
(Date:6/24/2016)... June 24, 2016  Consumers have taken a ... have placed more emphasis on patient outcomes. ... programs in the pharmaceutical industry have evolved beyond ... pharmaceutical companies are focusing on becoming more patient-oriented ... products and services that improve health. ...
(Date:6/24/2016)... , June 24, 2016   Bay Area ... Network,s Dean Center for Tick Borne Illness ... and Rehabilitation, MIT Hacking Medicine, University of California, ... today announced the five finalists of Lyme ... disease.  More than 100 scientists, clinicians, researchers, entrepreneurs, ...
Breaking Medicine Technology: