Navigation Links
Portion of hippocampus found to play role in modulating anxiety
Date:3/6/2013

New York, NY Columbia University Medical Center (CUMC) researchers have found the first evidence that selective activation of the dentate gyrus, a portion of the hippocampus, can reduce anxiety without affecting learning. The findings suggest that therapies that target this brain region could be used to treat certain anxiety disorders, such as panic disorder and post-traumatic stress syndrome (PTSD), with minimal cognitive side effects. The study, conducted in mice, was published today in the online edition of the journal Neuron.

The dentate gyrus is known to play a key role in learning. Some evidence suggests that the structure also contributes to anxiety. "But until now no one has been able to figure out how the hippocampus could be involved in both processes," said senior author Rene Hen, PhD, professor of neuroscience and pharmacology (in psychiatry) at CUMC.

"It turns out that different parts of the dentate gyrus have somewhat different functions, with the dorsal portion largely dedicated to learning and the ventral portion dedicated to anxiety," said lead author Mazen A. Kheirbek, PhD, a postdoctoral fellow in neuroscience at CUMC.

To examine the role of the dentate gyrus in learning and anxiety, the investigators used a state-of-the-art technique called optogenetics, in which light-sensitive proteins, or opsins, are genetically inserted into neurons in the brains of mice. Neurons with these genes can then be selectively activated or silenced through the application of light (via a fiber-optic strand), allowing researchers to study the function of the cells in real time. Previously, the only way to study the dentate gyrus was to silence portions of it using such long-term manipulations as drugs or lesions, techniques that yielded conflicting results.

In the current study, opsins were inserted into dentate gyrus granule cells (the principal cells of the dentate gyrus). The researchers then activated or silenced the ventral or dorsal portions of the dentate gyrus for three minutes at a time, while the mice were subjected to two well-validated anxiety tests (the elevated plus maze and the open field test).

"Our main findings were that elevating cell activity in the dorsal dentate gyrus increased the animals' desire to explore their environment. But this also disrupted their ability to learn. Elevating activity in the ventral dentate gyrus lowered their anxiety, but had no effect on learning," said Dr. Kheirbek. The effects were completely reversible that is, when the stimulation was turned off, the animals returned to their previous anxiety levels.

"The therapeutic implication is that it may be possible to relieve anxiety in people with anxiety disorders by targeting the ventral dentate gyrus, perhaps with medications or deep-brain stimulation, without affecting learning," said Dr. Hen, who is also director of the Division of Integrative Neuroscience, The New York State Psychiatric Institute, and a member of The Kavli Institute for Brain Science. "Given the immediate behavioral impact of such manipulations, these strategies are likely to work faster than current treatments, such as serotonin reuptake inhibitors."

According to Dr. Hen, such an intervention would probably work best in people with panic disorder or PTSD. "There is evidence that people with these anxiety disorders tend to have a problem with pattern separation the ability to distinguish between similar experiences," he said. "In other words, they overgeneralize, perceiving minor threats to be the same as major ones, leading to a heightened state of anxiety. Such patients could conceivably benefit from therapies that fine-tune hippocampal activity."

Dr. Hen and his team are currently exploring strategies aimed at modulating the activity of the ventral dentate gyrus by stimulating neurogenesis in the ventral dentate gyrus. "Indeed the dentate gyrus is one of the few areas in the adult brain where neurons are continuously produced, a phenomenon termed adult hippocampal neurogenesis," added Dr. Hen.


'/>"/>
Contact: Elizabeth Streich
estreich@columbia.edu
212-305-3689
Columbia University Medical Center
Source:Eurekalert

Related biology news :

1. Virtual women reveal more skin, regardless of body proportions
2. Spatial knowledge vs. spatial choice: The hippocampus as conflict detector?
3. Illinois town provides a historical foundation for todays bee research
4. Controversial dam removals founded on value conflicts
5. Vibrant mix of marine life found at extreme ocean depths, Scripps analysis reveals
6. Sloan Foundation announces 2013 Sloan Research Fellows
7. Dr. Anurag Agrawal to give Founders Memorial lecture at Entomology 2013
8. Entering an Unseen World: A Founding Laboratory and Origins of Modern Cell Biology 1910-1974
9. Gum disease found to worsen infection in animal model of AIDS
10. 24 new species of flower fly have been found in Central and Southern America
11. A neurosteroid found to prevent brain injury caused by HIV/AIDS
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/3/2016)... , June 3, 2016 ... Management) von Nepal ... und Lieferung hochsicherer geprägter Kennzeichen, einschließlich Personalisierung, ... führend in der Produktion und Implementierung von ... der Ausschreibung im Januar teilgenommen, aber Decatur ...
(Date:6/2/2016)... June 2, 2016   The Weather Company , an ... Ads, an industry-first capability in which consumers will be able ... to ask questions via voice or text and receive relevant ... Marketers have long sought an advertising solution ... can be personal, relevant and valuable; and can scale across ...
(Date:6/1/2016)... , June 1, 2016 ... in Election Administration and Criminal Identification to Boost Global ... a recently released TechSci Research report, " Global Biometrics ... Region, Competition Forecast and Opportunities, 2011 - 2021", the ... billion by 2021, on account of growing security concerns ...
Breaking Biology News(10 mins):
(Date:11/30/2016)... BEIJING , Nov. 30, 2016 Novogene ... services and solutions with cutting edge next-generation sequencing (NGS) ... a USD $75 Million [515 Million RMB] B round ... Capital Management ( Shenzhen ) Co., Ltd. ... Innovation") and Shanghai Sigma Square Investment Center LP ("Sigma ...
(Date:11/30/2016)... 30, 2016   Merck , a leading science ... into a set of agreements with Evotec AG, whereby ... of genetic reagents such as CRISPR and shRNA libraries. ... offers an accelerated pathway to explore and identify new ... identification of new targets, a process that can be ...
(Date:11/30/2016)... NC (PRWEB) , ... November 30, 2016 , ... ... engaged in the development of a new orally administered treatment for Alzheimer’s disease ... neuroimaging results of a Phase 2a clinical trial of T3D-959 in mild to ...
(Date:11/30/2016)... ... 30, 2016 , ... ProMIS Neurosciences (“ProMIS” or the “Company”), ... today announced that all five of its validated monoclonal antibody (mAb) therapeutic candidates ... prion-like forms of Amyloid beta (Aß) in vitro. , “We previously demonstrated that ...
Breaking Biology Technology: