Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blocking enzyme found to ease anxiety without causing sedation

02.10.2002


Suggests new route to treat anxiety without sedating or addicting side effects



The trouble with most anti-anxiety drugs is that they tend to sedate, not just relax. A research team led by scientists at UCSF’s Ernest Gallo Clinic and Research Center has shown that de-activating a common enzyme in neurons reduces anxiety without inducing sedation. The study in mice suggests a new route to treat anxiety while avoiding sedating and possibly addicting effects.

The research, published in the October issue of The Journal of Clinical Investigation, also showed that blocking the enzyme reduced levels of stress hormones. The same issue of the journal includes a commentary on the research (Anxiolytic Drug Targets: Beyond the Usual Suspects) by Joshua A. Gordon of Columbia University’s Center for Neurobiology and Behavior.


Anti-anxiety drugs such as Valium often leave people sedated, less capable at mental tasks, and can become addicting, whereas drugs without these side effects -- such as some antidepressants -- may not reduce anxiety as well, said Robert Messing, MD, UCSF professor of neurology at the Gallo Research Center and senior author on the paper.

But in the new study, mice lacking the enzyme showed reduced anxiety while maintaining normal levels of alertness and learning abilities, the researchers reported.

The enzyme, known as protein kinase C epsilon (PKC epsilon), is present in many neurons in the brain, but its role is not well known. Its ability to affect anxiety but not sedation may stem from indirect, rather than direct action, the researchers found.

When the neurotransmitter GABA binds to proteins on the surface of many neurons, known as GABA-A receptors, the neurons become less active, which tends to reduce anxiety. Drugs such as Valium act by increasing the action of GABA at the GABA-A receptors. A group of brain molecules derived from progesterone, known as neurosteroids, also act to increase the action at the GABA-A receptor, and thereby reduce anxiety. But PKC epsilon appears to make the GABA-A receptor less sensitive to the neurosteroids, increasing anxiety. Experiments using brain membranes and studies of mouse behavior showed that knocking out PKC epsilon increases GABA-A receptor sensitivity to neurosteroids, and thereby decreases anxiety.

"PKC modulates the modulator," Messing said. Because it is an intermediary, it is a promising focus for drugs that could decouple the biochemical pathway that leads to anxiety from the pathway that leads to sedation, he said.

The researchers focused on physiological and behavioral effects of knocking out the PKC gene. Messing and his colleagues developed the strain of PKC knockout mice in 1998 and have been studying the neurological effects.

In tests that measure the tendency of mice to avoid heights and exposed environments, the research showed that PKC epsilon-knockout mice expressed less anxiety-like behavior than wild-type mice. The mice also had lower levels of the stress hormone corticosterone. When GABA-A receptor activity was chemically blocked, anxiety and stress hormone levels increased to normal.

Other studies by Messing and colleagues have shown that knocking out the PKC epsilon gene reduces pain related to inflammation and decreases consumption of alcohol in mice. Work by others indicates that knocking out PKC epsilon reduces fertility of female mice by weakening their immune function. But a drug designed to inhibit PKC epsilon might well avoid this side effect, since it would not knock out all enzyme function, Messing noted.

"Although we don’t yet know precisely how PKC epsilon normally affects GABA-A receptors, the research clearly shows its effect on anxiety-related behavior," Messing said. "A drug based on this finding may well treat anxiety without compromising alertness or cognitive abilities."

Wallace Ravven | EurekAlert!
Further information:
http://www.ucsf.edu/

More articles from Health and Medicine:

nachricht How cancer metastasis happens: Researchers reveal a key mechanism
19.01.2018 | Weill Cornell Medicine

nachricht Researchers identify new way to unmask melanoma cells to the immune system
17.01.2018 | Duke University Medical Center

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Let the good tubes roll

19.01.2018 | Materials Sciences

How cancer metastasis happens: Researchers reveal a key mechanism

19.01.2018 | Health and Medicine

Meteoritic stardust unlocks timing of supernova dust formation

19.01.2018 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>