Navigation Links
Millisecond brain signals predict response to fast-acting antidepressant
Date:10/2/2008

Images of the brain's fastest signals reveal an electromagnetic marker that predicts a patient's response to a fast-acting antidepressant, researchers have discovered.

"Such biomarkers that identify who will benefit from a new class of antidepressants could someday minimize trial-and-error prescribing and speed delivery of care for what can be a life-threatening illness," said Carlos Zarate, M.D., of the National Institute of Mental Health (NIMH), Mood and Anxiety Disorders Program.

In the new study at the National Institutes of Health in Bethesda, MD, depressed patients showed increasing activity in a mood-regulating hub near the front of the brain while viewing flashing frightful faces the more the increase, the better their response to an experimental fast-acting medication called ketamine. By contrast, healthy controls showed decreasing activity in this brain area under the same conditions.

Zarate, Giacomo Salvadore, M.D., Brian Cornwell, Ph.D., and NIMH colleagues report on their discovery online in Biological Psychiatry September 24, 2008.

Two years ago, Zarate and colleagues reported that ketamine, which targets the brain chemical glutamate, can lift depressions in just hours, instead of the weeks it takes conventional antidepressants, which work through the brain chemical serotonin. Evidence suggests that glutamate likely acts closer to the source of the depression than serotonin, and is not dependant on slower mechanisms, such as the synthesis of new neurons.

Earlier imaging studies with conventional antidepressants had hinted that increased activity of the mood-regulating hub, called the anterior cingulate cortex (ACC), signals a better response.

To find out if ACC activity might also forecast response to glutamate-targeting medications, the NIMH researchers imaged the brain activity of 11 depressed patients and 11 healthy participants, using magnetoencephalography (MEG). This imaging technology can non-invasively detect brain electromagnetic activity lasting only milliseconds the speed of communications in neural circuits whereas other functional brain imaging techniques can only capture activity that last seconds or minutes, and some involve radiation exposure.

This precise timing enabled the MEG scanner to capture the brain's split-second responses to rapidly flashing pictures of fearful faces, a task known to activate the ACC. While healthy participants' ACC activity dropped off as they quickly habituated to the faces, patients' ACC activity showed an opposite trend. The more robust this increase, the more symptoms improved just four hours after a patient received a single infusion of ketamine.

"The ACC may be slow to respond, but not completely impaired, in patients who respond to ketamine," explained Cornwell.

The lag in ACC activity could be a window into the dysfunctional workings of the glutamate-related circuitry targeted by the medication, the researchers suggest. Ketamine's side effects make it a poor candidate for becoming a practical antidepressant, but the new findings are helping to focus the search for new treatments that work through the same mechanism, they say.


'/>"/>

Contact: Jules Asher
NIMHpress@nih.gov
301-443-4536
NIH/National Institute of Mental Health
Source:Eurekalert  

Related biology news :

1. Invasion of the brain tumors
2. HIV is a double hit to the brain
3. AIDS interferes with stem cells in the brain
4. 60 second test could help early diagnosis of common brain diseases
5. U of MN researchers discover noninvasive diagnostic tool for brain diseases
6. U of Minnesota researchers discover noninvasive diagnostic tool for brain diseases
7. Influence of sex and handedness on brain is similar in capuchin monkeys and humans
8. Inside the brain of a crayfish
9. Specific brain protein required for nerve cell connections to form and function
10. Brains timing linked with timescales of the natural visual world
11. Adult brain can change, study confirms
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Millisecond brain signals predict response to fast-acting antidepressant
(Date:4/26/2016)... LONDON , April 26, 2016 ... a product subsidiary of Infosys (NYSE: ... to integrate the Onegini mobile security platform with ... http://photos.prnewswire.com/prnh/20151104/283829LOGO ) The integration will ... to access and transact across channels. Using this ...
(Date:4/15/2016)... April 15, 2016 Research ... Gait Biometrics Market 2016-2020,"  report to their offering.  ... ) , ,The global gait biometrics market is ... during the period 2016-2020. Gait analysis ... can be used to compute factors that are ...
(Date:3/31/2016)... , March 31, 2016  Genomics firm Nabsys ... founding CEO, Barrett Bready , M.D., who returned ... of the original technical leadership team, including Chief Technology ... of Product Development, Steve Nurnberg and Vice President of ... to the company. Dr. Bready served as ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... ... June 27, 2016 , ... Newly ... technologies, services and solutions to the healthcare market. The company's primary focus is ... manufacturing, sales and marketing strategies that are necessary to help companies efficiently bring ...
(Date:6/24/2016)... DIEGO , June 24, 2016 ... more sensitively detects cancers susceptible to PARP inhibitors ... circulating tumor cells (CTCs). The new test has ... HRD-targeted therapeutics in multiple cancer types. ... targeting DNA damage response pathways, including PARP, ATM, ...
(Date:6/23/2016)... , June 23, 2016   Boston ... of novel compounds designed to target cancer stemness ... has been granted Orphan Drug Designation from the ... treatment of gastric cancer, including gastroesophageal junction (GEJ) ... inhibitor designed to inhibit cancer stemness pathways by ...
(Date:6/23/2016)...  The Prostate Cancer Foundation (PCF) is pleased to announce 24 ... for prostate cancer. Members of the Class of 2016 were selected from a ... Read More About the Class of 2016 PCF Young Investigators ... ... ...
Breaking Biology Technology: