November 25, 2014

UChicago scientists link autism to cognitive impairments in mice

A team of scientists, led by two UChicago researchers, has reached a new understanding of the link between autism and cognitive impairments typically associated with the condition.

A new paper published in Nature Communications by Christian Hansel, UChicago neuroscience professor, and postdoctoral fellow Claire Piochon, along with several others, points to a specific neurobiological pathway that plays a role in impaired learning and motor control that commonly accompany Autism Spectrum Disorder (ASD). The hope is that through this research clinicians will eventually be able to understand how best to treat people with ASD.

To conduct this research the scientists bred mice to have a genetic aberration similar in effect to one that commonly occurs in people with ASD. The scientists also used a control group of mice without the aberration. The differences between the two types of mice became apparent when they were put through a series of tests for motor responsiveness. The response times of those mice with the genetic aberration were typically much slower than those without.

This led the researchers to look more deeply into the cerebellum—the part of the brain concerned with motor function—of mice with the genetic aberration, specifically the Purkinje cell. This cell, discovered and named after Czech researcher Jan Purkinje, who notably coined the term “plasma” for blood fluid, is crucial in the regulation of brain signals.

The scientists’ research points to the idea that the Purkinje cells in mice with ASD are less functional than the Purkinje cells in normal, healthy mice. The scientists can examine this functionality by measuring the presence of climbing fibers, another crucial part of the cerebellum, in each Purkinje cell.

When a mouse’s cerebellum is working normally, a Purkinje cell only receives one climbing fiber signal, but when a mouse has the symptoms of ASD a Purkinje cell receives many. This creates an information overload in the cerebellum of the mouse and decreases its ability to function.

This information overload is similar to the information overload commonly associated with the cognitive deficiency in people with ASD. With this new information, scientists can better understand ASD and possibly lead to treatment options for those with the condition.