Sensory Perception, Polio-like Outbreaks (Abstract Science: Oct. 15-19)
The fight against cancer using healthy cells, sensory gating is attracting more interest in neuroscience, and a mysterious polio-like disease is affecting children everywhere.
(NY Times, 10/18/2018, Carl Zimmer)
Cancer is a disease of mutations. Tumor cells are riddled with genetic mutations not found in healthy cells. Scientists estimate that it takes five to 10 key mutations for a healthy cell to become cancerous. Some of these mutations can be caused by assaults from the environment, such as ultraviolet rays and cigarette smoke. Others arise from harmful molecules produced by the cells themselves. In recent years, researchers have begun taking a closer look at these mutations, to try to understand how they arise in healthy cells, and what causes these cells to later erupt into full-blown cancer. The research has produced some major surprises. For instance, it turns out that a large portion of the cells in healthy people carry far more mutations than expected, including some mutations thought to be the prime drivers of cancer. These mutations make a cell grow faster than others, raising the question of why full-blown cancer isn’t far more common. These lurking mutations went unnoticed for so long because the tools for examining DNA were too crude. If scientists wanted to sequence the entire genome of tumor cells, they had to gather millions of cells and analyze all of the DNA. A mutation, to be detectable, had to be very common.
(Neuroscience News, 10/18/2018, University of Tübingen)
When we interact with the world, such as when we reach out to touch an object, the brain actively changes incoming sensory signals based on anticipation. This so-called ‘sensory gating’ has now been investigated by neuroscientists at the University of Tübingen. In rats touching objects with their whiskers, they found that these touch signals from active sensory perception were reduced by gating signals from higher brain areas. Sensory gating has attracted much interest in different branches of neuroscience and psychology. There is evidence that schizophrenic disorders impair sensory gating, leading to hallucinations where one’s own voice seems to be that of somebody else. The phenomenon addresses the philosophical question about how we construct our world at the most basic level: do we faithfully represent stimuli from the outside world, or do we have preconceptions about the world that we use like a template, only noticing when they fail to account for what we see or feel? Psychology has found evidence to support both lines of arguing.
(Science News, 10/16/2018, Aimee Cunningham)
U.S. health officials are investigating an outbreak of a mysterious, polio-like disease that causes weakness in one or more limbs. The rare disease — acute flaccid myelitis, or AFM — has sickened 62 people, mostly children, in 22 states so far this year and is suspected in 65 more cases. Starting with an outbreak of 120 cases that brought the disease to national attention in 2014, close to 400 cases have been confirmed in the United States. So far, the US Centers for Disease Control and Prevention (CDC) has been unable to figure out what’s causing the outbreaks. “This is a mystery,” Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases in Atlanta, said during a news briefing. “We haven’t solved it yet.” Although the disease is frightening, fewer than one in a million people in the United States get AFM every year, based on CDC data collected since 2014. “Parents need to know that acute flaccid myelitis is very rare, even with the increase in cases that we’re seeing now,” she said. Even so, the CDC recommends that patients who develop sudden weakness in their arms or legs seek immediate medical care.
---Compiled by Social Media Specialist Jillian Scola