Fear in a mouse brain looks much the same as fear in a human brain.
When a frightening stimulus is encountered, the thalamus shoots a message to the amygdala — the primitive part of the brain — even before it informs the parts responsible for higher cognition. The amygdala then goes into its hard-wired fight-or-flight response, triggering a host of predictable symptoms, including racing heart, heavy breathing, startle response, and sweating.
The similarities of fear response in the brains of mice and men have allowed scientists to understand the neural circuitry and molecular processes of fear and fear behaviors perhaps better than any other response. That understanding has spurred breakthroughs in treatments for psychiatric disorders that are underpinned by fear.
Anxiety disorders are one of the most common mental illnesses in the country, with nearly one-third of Americans experiencing symptoms at least once during their lives. There are generalized anxiety disorders and fear-related disorders, which include panic disorders, phobias, and post-traumatic stress disorder (PTSD).
Emory psychiatrist and researcher Kerry Ressler is on the front lines of fear-disorder research. In his lab at Yerkes National Primate Research Center, he studies the molecular and cellular mechanisms of fear learning and extinction in mouse models. At Grady Memorial Hospital, he investigates the psychology, genetics, and biology of PTSD. And through the Grady Trauma Project, he works to draw attention to the problem of inner city intergenerational violence.
"If you look at Kerry’s work, it can seem like it’s all over the place — he’s got so many studies going on, and he collaborates with so many other scientists," says Barbara Rothbaum, associate vice chair of clinical research in psychiatry and director of the Trauma and Anxiety Recovery Program at Emory. "But they are all pieces to the same puzzle. All his work, from molecular to clinical to policy, fits together and starts telling a story." A Howard Hughes Medical Institute investigator, Ressler was recently elected to the Institute of Medicine — one of the highest honors in the fields of health and medicine. He was named a member of a new national PTSD consortium led by Draper Laboratory. And he recently appeared on the Charlie Rose show’s brain series.
Panic attacks seem to tie the fear-related disorders together, he explained on Charlie Rose. Everyone experiences fear, which evolved as a survival mechanism, but it only rises to a clinical level when people are unable to function normally in the face of it. For instance, PTSD includes not only intrusive thoughts, memories, nightmares, and startle responses, but also the concept of avoidance, which may extend to other areas of the individual’s life.
"There’s a patient I’ve seen who was attacked in a dark alley," Ressler shared on the show. "Initially it just felt dangerous to go out at night, but after a while she grew afraid of men and couldn’t go to that part of town. Then she couldn’t leave her house, and finally, her bedroom. The world got more and more dangerous."
The ultimate comeback: Bringing the dead back to life
A radical procedure that involves replacing a patients’ blood with cold salt water could retrieve people from the brink of death, says David Robson.
“When you are at 10C, with no brain activity, no heartbeat, no blood – everyone would agree that you’re dead,” says Peter Rhee at the University of Arizona, Tucson. “But we can still bring you back.”
Should Humanity Try to Contact Intelligent Aliens?
Astronomers have detected nearly 2,000 alien planets to date. As that number continues to rise, so too does the prospect of finding intelligent extraterrestrial life.
In terms of the search for extraterrestrial intelligence (SETI), it may no longer be a matter of answering the “are we alone” question, some scientists say. Rather, just how crowded is the universe?
Supermassive black hole blows molecular gas out of a galaxy at 1 million kilometres per hour
- Long-held mystery surrounding the evolution of galaxies solved by academics at the University of Sheffield
- Findings deepen our understanding of the future of our own galaxy, which will collide with Andromeda in 5 billion years
New research by academics at the University of Sheffield has solved a long-standing mystery surrounding the evolution of galaxies, deepening our understanding of the future of the Milky Way.
The supermassive black holes in the cores of some galaxies drive massive outflows of molecular hydrogen gas. As a result, most of the cold gas is expelled from the galaxies. Since cold gas is required to form new stars, this directly affects the galaxies’ evolution.
Scientists Criticize Europe’s $1.6B Brain Project
Dozens of neuroscientists are protesting Europe’s $1.6 billion attempt to recreate the functioning of the human brain on supercomputers, fearing it will waste vast amounts of money and harm neuroscience in general.
The 10-year Human Brain Project is largely funded by the European Union. In an open letter issued Monday, more than 190 neuroscience researchers called on the EU to put less money into the effort to “build” a brain, and to invest instead in existing projects.
If the EU doesn’t adopt their recommendations, the scientists said, they will boycott the Human Brain Project and urge colleagues to do the same.
If you rub your closed eyes, you’ll “see” a virtual rainbow of colors, shapes, squiggles, and lines. Those are called phosphenes, and the eye and the brain work together to create these weird little visual blips.
Phosphenes occur when there is no external visual stimulus. That can happen when you close your eyes or when you’re focused on scenery with little to no input as to depth or changes, such as a dark highway at night.
People who spend long periods of time in sensory deprivation or meditation often report seeing visions, which can be chalked up to the appearance of phosphenes.
The presence of physical stimulus to the eye, like pushing on the eyeball, will create temporary phosphenes, and more traumatic events like head injuries can create permanent squiggles.
In these cases, phosphenes are present because the visual centers of the brain are active without the presence of external visual stimuli.
For example, when conscious patients undergoing brain surgery had different areas of their brains electrically stimulated, they reported seeing phosophenes.
In studies of blind people, it’s been found that the appearance of phosphenes happens in different areas along the sight pathway between the eye and the brain, depending on what part of the visual system has been damaged.
Humans aren’t the only ones who can see these dancing bits of light and color—the phenomenon has been observed in animals as well.
Short Sleep, Aging Brain
Researchers at Duke-NUS Graduate Medical School Singapore (Duke-NUS) have found evidence that the less older adults sleep, the faster their brains age. These findings, relevant in the context of Singapore’s rapidly ageing society, pave the way for future work on sleep loss and its contribution to cognitive decline, including dementia.
Past research has examined the impact of sleep duration on cognitive functions in older adults. Though faster brain ventricle enlargement is a marker for cognitive decline and the development of neurodegenerative diseases such as Alzheimer’s, the effects of sleep on this marker have never been measured.
Master Switch for Myelination in Human Brain Stem Cells is Identified
Finding is key to developing MS treatments using stem cells.
Scientists at the University at Buffalo have identified the single transcription factor or “master switch” that initiates the critical myelination process in the brain. Funded by New York Stem Cell Science, the research will be published online in Proceedings of the National Academy of Sciences (PNAS) on June 30.
The identification of this factor, SOX10, in human brain cells, brings researchers closer to the goal of treating multiple sclerosis (MS) by transplanting into patients the brain cells that make myelin.
Sorting Out Emotions
Evaluating another person’s emotions based on facial expressions can sometimes be a complex task. As it turns out, this process isn’t so easy for the brain to sort out either.
Building on previous studies targeting the amygdala, a region in the brain known to be important for the processing of emotional reactions, a team of researchers from Caltech, Cedars-Sinai Medical Center, and Huntington Memorial Hospital in Pasadena, have found that some brain cells recognize emotions based on the viewer’s preconceptions rather than the true emotion being expressed. In other words, it’s possible for the brain to be biased. The team was able to record these responses from single neurons using existing electrodes—indicated by the arrows in the MRI image at right—placed in the brains of patients who were being treated for epilepsy.
Which Planets Are Most Likely to Harbor Intelligent Life?
A half century after its humble beginning, the Drake equation still guides the search for extraterrestrial life.
A few days before Halloween in 1961, a young astronomer was mulling over a fairly serious problem.
Soon the astronomer, Frank Drake, would be convening a meeting at the National Radio Astronomy Observatory in Green Bank, West Virginia, to discuss what was still a fringe, eyebrow-raising topic: the search for intelligent extraterrestrial life. Drake had invited everyone he could think of with an interest in the scientific search for E.T.—all 12 of them—to the meeting.
Reality is a set of ideas that predicts the observations we make.
-Brian Schmidt, an Australian National University cosmology professor, speaking about “The Astronomical Revolution” on June 24, 2014, at the Euroscience Open Forum. Schmidt is a winner of the 2011 Nobel Prize for Physics based on his work uncovering the accelerating expansion of the universe.
Researchers with Oregon Health & Science University’s Vollum Institute have given science a new and unprecedented 3-D view of one of the most important receptors in the brain — a receptor that allows us to learn and remember, and whose dysfunction is involved in a wide range of neurological diseases and conditions, including Alzheimer’s, Parkinson’s, schizophrenia and depression.
The unprecedented view provided by the OHSU research, published online June 22 in the journal Nature, gives scientists new insight into how the receptor — called the NMDA receptor — is structured. And importantly, the new detailed view gives vital clues to developing drugs to combat the neurological diseases and conditions.
"This is the most exciting moment of my career," said Eric Gouaux, a senior scientist at the Vollum Institute and a Howard Hughes Medical Institute investigator. "The NMDA receptor is one of the most essential, and still sometimes mysterious, receptors in our brain. Now, with this work, we can see it in fascinating detail."
Receptors facilitate chemical and electrical signals between neurons in the brain, allowing those neurons to communicate with each other. The NMDA (N-methyl-D-aspartate) receptor is one of the most important brain receptors, as it facilitates neuron communication that is the foundation of memory, learning and thought. Malfunction of the NMDA receptor occurs when it is increasingly or decreasingly active and is associated with a wide range of neurological disorders and diseases. Alzheimer’s disease, Parkinson’s disease, depression, schizophrenia and epilepsy are, in many instances, linked to problems with NMDA activity.
Scientists across the world study the NMDA receptor; some of the most notable discoveries about the receptor during the past three decades have been made by OHSU Vollum scientists.
The NMDA receptor makeup includes receptor “subunits” — all of which have distinct properties and act in distinct ways in the brain, sometimes causing neurological problems. Prior to Gouaux’s study, scientists had only a limited view of how those subtypes were arranged in the NMDA receptor complex and how they interacted to carry out specific functions within the brain and central nervous system.
Gouaux’s team of scientists – Chia-Hsueh Lee, Wei Lu, Jennifer Michel, April Goehring, Juan Du and Xianqiang Song – created a 3-D model of the NMDA receptor through a process called X-ray crystallography. This process throws x-ray beams at crystals of the receptor; a computer calibrates the makeup of the structure based on how those x-ray beams bounce off the crystals. The resulting 3-D model of the receptor, which looks something like a bouquet of flowers, shows where the receptor subunits are located, and gives unprecedented insight into their actions.
"This new detailed view will be invaluable as we try to develop drugs that might work on specific subunits and therefore help fight or cure some of these neurological diseases and conditions," Gouaux said. "Seeing the structure in more detail can unlock some of its secrets — and may help a lot of people."