NEWS BRIEFS

Can hearing loss be reversed?

Research reveals clues that could regrow the cells that help us hear

The most common cause of hearing loss is progressive because cochlear hair cells—the primary cells to detect sound waves— cannot regenerate if damaged or lost. People who have repeated exposure to loud noises, like military personnel, construction workers, and musicians, are most at risk for this type of hearing loss. But, it can happen to anyone over time. Birds and fish can regenerate these hair cells, and now researchers at the Del Monte Institute for Neuroscience are getting closer to identifying the mechanisms that may promote this type of regeneration in mammals, as explained in research recently published in Frontiers in Cellular Neuroscience.

Researchers found how the activation of the growth gene ERBB2 pathway triggers a cascading series of cellular events by which cochlear support cells multiply and activate other neighboring stem cells to become new sensory hair cells. This is a significant advance toward the ultimate goal of generating new cochlear hair cells in mammals, according to the senior author of the study, Patricia White, PhD, professor of Neuroscience and Otolaryngology at the University of Rochester Medical Center.

Researchers identify neurons that "learn" to smell a threat

Whether consciously or not, when entering a new space, we use our sense of smell to assess whether it is safe or a threat. In fact, for much of the animal kingdom, this ability is necessary for survival and reproduction. Researchers are finding new clues to how the olfactory sensory system aids in threat assessment and have found neurons that “learn” if a smell is a threat.

In a paper published in the Journal of Neuroscience, researchers in the lab of Julian Meeks, PhD, associate professor of Neuroscience, describe that they were able to identify a specific set of neurons in the accessory olfactory system in mice that can learn the scent of another mouse that is a potential threat. The experiment abolished the ramping aggression that is typically exhibited by mice and indicates that this early sensory inhibitory neuron population plays a critical role in regulating the behavioral response to social smells.

Small, involuntary eye movements help us see a stable world

Our eyes are never at rest. They remain in motion, even between our voluntary gaze shifts, through fixational eye movements—small, continuous shifts of the eye that we are not aware of making. Scientists have long sought to understand how humans can perceive the world as stable while our eyes are constantly moving. Past research has suggested that, in the intervals between voluntary gaze shifts, the human visual system builds a picture of a stable world by relying solely on sensory inputs from fixational eye movements. According to new research by a team at the University of Rochester published in Nature Communications, however, there may be another contributing factor.

Michele Rucci, PhD, a professor in the Department of Brain and Cognitive Sciences and at the University’s Center for Visual Science, and first author Zhetuo Zhao, a PhD student in Rucci’s lab— report that the visual system not only receives sensory inputs from fixational eye movements but also possesses knowledge of the motor behavior involved in those movements. The results of the research reveal that spatial representations—that is, the locations of objects in relation to other objects—are based on a combination of sensory and motor activity from both voluntary and involuntary eye movements, which is contrary to the prevailing understanding of this phenomenon.

Iron & the brain: Where and when neurodevelopmental disabilities may begin during pregnancy

Numerous studies have found that mothers with low iron levels during pregnancy have a higher risk of giving birth to a child that develops cognitive impairments like autism, attention deficit syndrome, and learning disabilities. The laboratory of Margot Mayer-Proschel, PhD, a professor of Biomedical Genetics and Neuroscience, was the first to demonstrate that the brains of animals born to iron-deficient mice react abnormally to excitatory brain stimuli, and that iron supplements given at birth do not prevent functional impairment that appears later in life.

Most recently, her lab has made significant progress in the quest to find the cellular origin for the impairment and has identified a new embryonic neuronal progenitor cell target for gestational iron deficiency as described in a study published in the journal Development

Through the eye of the beholder: People with autism may process illusory shapes differently

URMC researchers used Pac-Man-shaped images that create the illusion of a shape in the empty space to better understand how the brains of children with autism process visual information.

The process in our brain that allows us to see visual distinctions may not be happening the same way in the brains of children with autism spectrum disorder. Researchers in the Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory used visual illusions—groups of Pac-Man-shaped images that create the illusion of a shape in the empty space—and revealed that children with autism did not automatically process the illusory shapes as well as children without autism. It suggests that something is going awry in the feedback processing pathways in their brain.

“How our brain puts together pieces of an object or visual scene is important in helping us interact with our environments,” said Emily Knight, MD, PhD, assistant professor of Neuroscience and Pediatrics at the University of Rochester Medical Center, and first author on a study in the Journal of Neuroscience. “When we view an object or picture, our brains use processes that consider our experience and contextual information to help anticipate sensory inputs, address ambiguity, and fill in the missing information.”

The stars in the brain may be information regulators

Long thought of as “brain glue,” the star-shaped cells called astrocytes may be a key player in the brain’s ability to process external and internal information simultaneously—a task essential to our very survival. Nathan Smith, PhD, associate professor of Neuroscience, published a paper in Trends in Neuroscience that explores how astrocytes may play a crucial role in brain processing information.

Previous research has shown astrocytes sense the moment neurons send a message and can simultaneously sense sensory inputs. These external signals could come from various senses such as sight or smell. Astrocytes respond to this influx of information by modifying their calcium Ca2+ signaling directed towards neurons, providing them with the most suitable information to react to the stimuli. The authors hypothesize that this astrocytic Ca2+ signaling may be an underlying factor in how neurons communicate and what may happen when a signal is disrupted. But much is still unknown in how astrocytes and neuromodulators, the signals sent between neurons, work together.

NEURO2ALL holds first outreach event at RMSC

The Neuroscience Diversity Commission group NEURO2ALL held an event to teach kids, and adults, about the brain at the Rochester Museum and Science Center (RMSC). The group set up experiments to show how the brain works with our eyes and ears and even how it helps us taste. Kids were also given a backpack with brain facts and experiments to continue to learn about the brain at home. NEURO2ALL fosters curiosity around brain science, empowering the next generation of neuroscientists.

Graduate students participating in the new course Science Outreach to All at the University of Rochester School of Medicine and Dentistry helped organize this interactive event.