Deficits in skilled motor and auditory learning in a rat model of Rett syndrome
Katherine S Adcock1,2, Abigail E Blount3, Robert A Morrison4,3
1School of Behavioral and Brain Sciences, The University of Texas at Dallas, 800 West Campbell Road, Richardson, TX, 75080-3021, USA. Katherine.Adcock@utdallas.edu.
Background:
Rett syndrome is an X-linked neurodevelopmental disorder caused by a mutation in the gene MECP2. Individuals with Rett syndrome display developmental regression at an early age, and develop a range of motor, auditory, cognitive, and social impairments. Several studies have successfully modeled some aspects of dysfunction and Rett syndrome-like phenotypes in transgenic mouse and rat models bearing mutations in the MECP2 gene. Here, we sought to extend these findings and characterize skilled learning, a more complex behavior known to be altered in Rett syndrome.
Methods:
We evaluated the acquisition and performance of auditory and motor function on two complex tasks in heterozygous female Mecp2 rats. Animals were trained to perform a speech discrimination task or a skilled forelimb reaching task.
Results:
Our results reveal that Mecp2 rats display slower acquisition and reduced performance on an auditory discrimination task than wild-type (WT) littermates. Similarly, Mecp2 rats exhibit impaired learning rates and worse performance on a skilled forelimb motor task compared to WT.
Conclusions:
Together, these findings illustrate novel deficits in skilled learning consistent with clinical manifestation of Rett syndrome and provide a framework for development of therapeutic strategies to improve these complex behaviors.
