The human brain does many amazing things. One of them is taking in continuous streams of data from the external senses―such as sight, sound, smell―and processing them so that they provide a running account of the environment. At the same time, the brain is constantly monitoring the body’s “innards,” so that it can help manage the regulation of key functions ranging from heartbeat and temperature to hunger and thirst.
William Kyle Simmons, Ph.D., of the Laureate Institute for Brain Research in Oklahoma, has been using his 2010 NARSAD Young Investigator Grant to explore brain mechanisms behind the eating disorder anorexia nervosa, in which sufferers, typically women, can literally starve themselves to death. Dr. Simmons and colleagues at the Laureate Institute focused in on a brain region called the insula (there is one in each brain hemisphere), that, among other things, is known to help the body maintain “homeostasis,” or stable conditions for normal functioning.
In a new paper published on September 29th in the journal Nature Neuroscience, Dr. Simmons and colleagues report new discoveries that overturn previously-held beliefs about how the insula is functionally organized. Using advanced imaging technologies, the team studied activity in the insula in response to both pictures of food and the actual taste sensations that the ingestion of food trigger.
Dr. Simmons and colleagues found that the prevailing theories of insula function were incorrect. It was thought the rear portions responded to the senses, and the frontal portions were devoted to coordinating bodily responses needed to maintain homeostasis. But their results suggest the frontal part of the insula helps maintain stable concepts of food categories, while the middle and rear sections “permit contextual flexibility, depending on the current state of the body.” These new findings may offer a fundamentally different approach in developing new treatments and therapies for anorexia nervosa and other eating disorders.
Read the study abstract.