A new study sheds light--both literally and figuratively--on the intricate brain cell connections responsible for anxiety.
Scientists at Stanford University recently used light to activate mouse neurons and precisely identify neural circuits that increase or decrease anxiety-related behaviors. Pinpointing the origin of anxiety brings psychiatric professionals closer to understanding anxiety disorders, the most common class of psychiatric disease.
A research team led by Karl Deisseroth, associate professor of psychiatry and behavioral sciences and bioengineering, identified two key pathways in the brain: one which promotes anxiety, and one which alleviates anxiety.
The pathways are in a brain region called the amygdala. Prior research suggests the amygdala plays a role in anxiety, but earlier studies used widespread modifications of the amygdala, through drugs or physical disruption of the brain region, to study the way in which it affects anxiety. This new work, published in this week's Nature, uses a tool called optogenetics--developed by Deisseroth and recently named Method of the Year by Nature Methods--to specifically tease out which pathways contribute to anxiety.
Optogenetics combines genetics and optical science to selectively manipulate the way a neuron fires in the brain. Neurons are electrically excitable cells that convey information through electrical and chemical signaling.
Directed genetic manipulations cause specific neurons to assemble a light-activated protein normally found in algae and bacteria. When triggered by certain wavelengths of light, these proteins allow researchers to increase or decrease neuronal activity in the brain and observe the effects on rodent models in an experiment.
Using optogenetic manipulation of various amygdala pathways, Deisseroth and colleagues examined how mouse behavior was affected. Since mice display anxiety-related behaviors in open spaces, they measured changes in anxiety by analyzing how much time mice spent exploring the center of an open field, or exploring the length of a platform without walls.
While optogenetics has been used to study amygdala function in behaviorally-conditioned fear, this is the first time it has been used to study anxiety. "Fear and anxiety are different," Deisseroth explained. "Fear is a response to an immediate threat, but anxiety is a heightened state of apprehension with no immediate threat. They share the same outputs, for example physical manifestations such as increased heart rate, but their controls are very different."
Anxiety disorders are the most prevalent among all psychiatric diseases, and include diseases such as post-traumatic stress disorder, obsessive-compulsive disorder and phobias. Anxiety also contributes to other major psychiatric disorders such as depression and substance abuse.
"Now that we know that these cell projections [in the amygdala] exist, we can first use this knowledge to understand anxiety more than we do now," Deisseroth noted.
Deisseroth has previously used optogenetics to study deep brain stimulation in Parkinson's disease. This research was detailed last year in the journal Science and reported online by the National Science Foundation (NSF).
"Deep brain stimulation is increasingly being considered for psychiatric disorders, so after studying Parkinson's disease, we started building towards research on psychiatric disorders," Deisseroth commented. Next he wants to use these tools to study depression and autism spectrum disorders.
Groundwork for the optogenetics technique was funded by NSF. This research was supported by the National Alliance for Research on Schizophrenia and Depression, the National Institutes of Health and NSF.Media Contacts
Bobbie Mixon | EurekAlert!
Symbiotic bacteria: from hitchhiker to beetle bodyguard
28.04.2017 | Johannes Gutenberg-Universität Mainz
Nose2Brain – Better Therapy for Multiple Sclerosis
28.04.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
28.04.2017 | Event News
20.04.2017 | Event News
18.04.2017 | Event News
28.04.2017 | Medical Engineering
28.04.2017 | Earth Sciences
28.04.2017 | Life Sciences