News Briefs

The Art of Smell

Research suggests the brain processes smell both like a painting and a symphony

New research published in Cell Reports suggests that our brain processes smell in multiple ways – like a painting – a snapshot of the flickering activity of cells – captured in a moment in time, and like a symphony, an evolving ensemble of different cells working together to capture the scent.

Krishnan Padmanabhan, Ph.D., an associate professor of Neuroscience lead the study that developed a model to simulate the workings of the early olfactory system – the network the brain relies on for smelling. Employing computer simulations, he and graduate student Zhen Chen found a specific set of connections, called centrifugal fibers, which carry impulses from other parts of the central nervous system to the early sensory regions of the brain, played a critical role. These centrifugal fibers act as a switch, toggling between different strategies to efficiently represent smells. When the centrifugal fibers were in one state, the cells in the piriform cortex – where the perception of an odor forms – relied on the pattern of activity within a given instant in time. When the centrifugal fibers were in the other state, the cells in the piriform cortex improved both the accuracy and the speed with which cells detected and classified the smell by relying on the patterns of brain activity across time.

“These findings reveal a core principle of the nervous system, flexibility in the kinds of calculations the brain makes to represent aspects of the sensory world,” said Padmanabhan. “Our work provides scientists with new tools to quantify and interpret the patterns of activity of the brain.”

Daily steroids safe and slow progression of Duchenne muscular dystrophy

New research published in JAMA recommends daily steroid doses for children with Duchenne muscular dystrophy (DMD), marking a significant change in how the disease is treated. University of Rochester Medical Center neurologist Robert Griggs, M.D., and Michela Guglieri, M.D., with Newcastle University in the U.K., led the study, which was conducted by a global team of researchers dedicated to improving care for this fatal disease. DMD is a condition found almost exclusively in boys and characterized by muscle weakness, which appears at age 3-4 and progresses rapidly, leading to significant disability and often fatal by late teens.

Participants were assigned to three groups consisting of daily regimens of prednisone or deflazacort, or intermittent prednisone, and followed for three years. The researchers found that the daily regimens of both drugs significantly slowed disease progression as measured by strength testing and muscle function, as compared to the intermittent group. While the daily regimen increased side effects overall, there were minimal serious side effects.