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Archive - Aug 18, 2018

Perinatal Hypoxia Associated with Long-Term Cerebellar Learning Deficits and Purkinje Cell Misfiring

Oxygen deprivation associated with preterm birth leaves telltale signs on the brains of newborns in the form of alterations to cerebellar white matter at the cellular and the physiological levels. Now, an experimental model of this chronic hypoxia reveals that those cellular alterations have behavioral consequences. Chronic sublethal hypoxia is associated with locomotor miscoordination and long-term cerebellar learning deficits in a clinically relevant model of neonatal brain injury, according to a study led by Children's National Health System researchers published online August 13, 2018 in Nature Communications. The open-access article is titled “Neonatal Brain Injury Causes Cerebellar Learning Deficits and Purkinje Cell Dysfunction.” Using high-tech optical and physiological methods that allow researchers to turn neurons on and off and an advanced behavioral tool, the research team finds that Purkinje cells fire significantly less often after injury due to perinatal hypoxia. However, an off-the-shelf medicine now used to treat epilepsy enables those specialized brain cells to regain their ability to fire, improving locomotor performance. Step out of the car onto the pavement, hop up to the level of the curb, stride to the entrance, and climb a flight of stairs. Or, play a round of tennis. The cerebellum coordinates such locomotor performance and muscle memory, guiding people of all ages as they adapt to a changing environment. "Most of us successfully coordinate our movements to navigate the three-dimensional spaces we encounter daily," says Vittorio Gallo, PhD, Children's Chief Research Officer and the study's senior author. "After children start walking, they also have to learn how to navigate the environment and the spaces around them." These essential tasks, Dr.

Genetic Differences in Trees’ Susceptibility to Mountain Pine Beetle

A University of Montana (UM) researcher has discovered that mountain pine beetles may avoid certain trees within a population they normally would kill due to genetics in the trees. UM Professor Dr. Diana Six made the discovery after studying mature whitebark and lodgepole trees that were the age and size that mountain pine beetle prefer, but had somehow escaped attack during a recent outbreak. After DNA screening, survivor trees were all found to contain a similar genetic makeup that was distinctly different from that of the general population that were mostly susceptible to the beetle. "Our findings suggest that survivorship is genetically based and, thus, heritable," Dr. Six said, "which is what gives us hope." In western North America, whitebark pine, a high elevation keystone species recommended for listing as an endangered species, and lodgepole pine, a widespread ecologically and economically important tree, have experienced extensive mortality in recent climate-driven outbreaks of the mountain pine beetle. "Our results suggest that surviving trees possess a wealth of information that can be used to inform our understanding of the genetic and phenotypic bases for resistance and to develop management approaches that support forest adaptation," Dr. Six said. The study was published July 23, 2018 in Frontiers in Plant Science. The open-access article is titled “Are Survivors Different? Genetic-Based Selection of Trees by Mountain Pine Beetle During a Climate Change-Driven Outbreak in a High-Elevation Pine Forest.”

[Press release] [Frontiers in Plant Science article]