Tiny probes could be useful for monitoring patients with Parkinson’s and other diseases. Anne Trafton | MIT News Office Dopamine, a signaling molecule used throughout the brain, plays a major role in regulating our mood, as well as controlling movement. Many disorders, including Parkinson’s disease, depression, and schizophrenia, are linked to dopamine deficiencies. MIT neuroscientists have now devised a way to measure dopamine in the brain for more than a year, which they believe will help them to learn much more about its role in both healthy and diseased brains. Stimulating the brain’s caudate nucleus generates a negative outlook that clouds decision-making. Anne Trafton | MIT News Office Many patients with neuropsychiatric disorders such as anxiety or depression experience negative moods that lead them to focus on the possible downside of a given situation more than the potential benefit. MIT neuroscientists have now pinpointed a brain region that can generate this type of pessimistic mood. In tests in animals, they showed that stimulating this region, known as the caudate nucleus, induced animals to make more negative decisions: They gave far more weight to the anticipated drawback of a situation than its benefit, compared to when the region was not stimulated. This pessimistic decision-making could continue through the day after the original stimulation. MIT neuroscientist is recognized for her pioneering work on the complexity and function of the basal ganglia. Sabbi Lall | McGovern Institute for Brain Research Institute Professor Ann Graybiel, a professor in the Department of Brain and Cognitive Sciences and member of MIT’s McGovern Institute for Brain Research, is being recognized by the Gruber Foundation for her work on the structure, organization, and function of the once-mysterious basal ganglia. She was awarded the prize alongside Okihide Hikosaka of the National Institute of Health's National Eye Institute and Wolfram Schultz of the University of Cambridge in the U.K. The basal ganglia have long been known to play a role in movement, and the work of Graybiel and others helped to extend their roles to cognition and emotion. Dysfunction in the basal ganglia has been linked to a host of disorders including Parkinson’s disease, Huntington’s disease, obsessive-compulsive disorder and attention-deficit hyperactivity disorder, and to depression and anxiety disorders. Graybiel’s research focuses on the circuits thought to underlie these disorders, and on how these circuits act to help us form habits in everyday life. Study identifies neurons that fire at the beginning and end of a behavior as it becomes a habit. Anne Trafton | MIT News Office Our daily lives include hundreds of routine habits. Brushing our teeth, driving to work, or putting away the dishes are just a few of the tasks that our brains have automated to the point that we hardly need to think about them. Although we may think of each of these routines as a single task, they are usually made up of many smaller actions, such as picking up our toothbrush, squeezing toothpaste onto it, and then lifting the brush to our mouth. This process of grouping behaviors together into a single routine is known as “chunking,” but little is known about how the brain groups these behaviors together. Miniaturized system could be used to treat neurological disorders that affect specific brain regions. Anne Trafton | MIT News Office MIT researchers have devised a miniaturized system that can deliver tiny quantities of medicine to brain regions as small as 1 cubic millimeter. This type of targeted dosing could make it possible to treat diseases that affect very specific brain circuits, without interfering with the normal function of the rest of the brain, the researchers say. Using this device, which consists of several tubes contained within a needle about as thin as a human hair, the researchers can deliver one or more drugs deep within the brain, with very precise control over how much drug is given and where it goes. In a study of rats, they found that they could deliver targeted doses of a drug that affects the animals’ motor function. Neuroscientists find chronic stress skews decisions toward higher-risk options.
Anne Trafton | MIT News Office Making decisions is not always easy, especially when choosing between two options that have both positive and negative elements, such as deciding between a job with a high salary but long hours, and a lower-paying job that allows for more leisure time. MIT neuroscientists have now discovered that making decisions in this type of situation, known as a cost-benefit conflict, is dramatically affected by chronic stress. In a study of mice, they found that stressed animals were far likelier to choose high-risk, high-payoff options. |