On their way to that goal, the scientists recently published their latest discoveries in Science, a leading journal for original scientific research, global news and commentary.
About the same time, Charles Gray, professor in MSU's Department of Cell Biology and Neuroscience, learned that he was one of four U.S. scientists to receive a prestigious award that will help fund his research for three more years. The McKnight Endowment Fund for Neuroscience awarded Gray a $300,000 Memory and Cognitive Disorders Award, which will give him $100,000 each year from 2013 through 2015. The other awards went to researchers at Stanford University, Columbia University and Carnegie Mellon University.
"It was a good week," Gray said.
For the paper published Nov. 23 in Science, Gray was principal investigator of a five-year research project, funded by the National Institute of Mental Health (NIMH) and the National Institute of Neurological Disorders and Stroke (NINDS), where researchers studied how visual objects were held in short-term memory.
Focusing on two key regions in the cerebral cortex - the prefrontal and posterior parietal areas that are critically involved in cognition, attention and short-term memory -- the scientists discovered that signals in both regions synchronized with one another when objects were held in short-term memory.
"The discovery demonstrates that the two regions closely coordinate their activities in a manner that depends on what is being held in memory," Gray said.
This process occurs even when the cortical regions are widely separated from each other and their connections are relatively weak, he added. Each region contains billions of nerve cells, but the number of nerves connecting them amounts to a tiny fraction of the population.
"The Holy Grail of neuroscience has been to understand how and where information is encoded in the brain. This study provided more evidence that large-scale electrical oscillations across distant brain regions may carry information for visual memories," said NIMH Director Thomas R. Insel, M.D.
Gray, referring to the possible communication between the two regions of the brain, said, "We don't fully understand the communication."
The new study provides key insights into the details of the process, however.
"The brain is extraordinarily complex, and the signals that move between regions are very sophisticated," Gray said. "Historically, it has been very difficult to make sense out of them."
The cerebral cortex alone has approximately 100 regions for which researchers are beginning to determine their function, Gray said. The regions sometimes act alone and other times cooperate and function together. They are responsible for nearly all cognitive and mental functions, ranging from perception and voluntary movement to attention, reasoning and memory.
"When we pay attention, remember, make decisions or feel certain emotions, our cortex is critically involved," Gray said.
The cerebral cortex lies over and around most of the structures of the brain. It's also connected heavily to structures inside the brain, such as the thalamus and Basal Ganglia which are both necessary for memory, Gray said. The thalamus relays sensory and motor signals and regulates sleep, consciousness and arousal. Both the cortex and thalamus work together with the Basal Ganglia, which are associated with habits, learning and motor control.
As a result of the brain's complexity, studying it is a long, slow process, Gray continued. But understanding the communication process could help scientists develop strategies for treating people where communication within the brain is believed to be disrupted. Those conditions include Parkinson's disease, autism, depression and schizophrenia, among others.
Gray, who has worked with neurosurgical teams in California where he helped measure brain activity in patients being treated for Parkinson's disease, co-authored the paper that was published in Science. The work was done together with lead author Rodrigo Salazar and Nick Dotson, both in MSU's Department of Cell Biology and Neuroscience; and Steve Bressler, a neuroscientist at Florida Atlantic University and long-time collaborator of Gray's.
Science is published weekly by the American Association for the Advancement of Science (AAAS), the largest general scientific society in the world.
The Memory and Cognitive Disorders Awards support innovative research by U.S. scientists who are exploring new ways to diagnose, prevent and treat neurological and psychiatric diseases, especially those related to memory and cognition. The awards encourage projects that link basic and clinical neuroscience, with the long-term goal of helping to translate laboratory discoveries into diagnoses and therapies for brain disorders.
In Gray's case, he is seeking a deeper understanding of the physiology of short-term memory, attention and decision making. Based on funding from NINDS, his laboratory has developed an instrument that can measure neural activity at a very high resolution from many locations. It provides an advantage over currently available technologies, enabling observation of how large circuits in the brain behave in real time. During the three years of his McKnight Award, Gray plans to measure neural activity from large areas of the brain to obtain a broad perspective on how and where information is encoded when something is held in short-term memory.
"Understanding just how the brain creates and retrieves memories, and how brain systems can go awry, is the foundation for development of therapies for human brain diseases," said Eric Nestler, chairman of the McKnight awards committee. "These research efforts seek to advance understanding of the brain and bring new insights to bear on this important quest."
Evelyn Boswell, (406) 994-5135 or firstname.lastname@example.org