Sensory hypersensitivity is commonly seen in FXS patients and the FXS mouse model - the Fmr1 knockout (KO). Recent data suggests that this abnormality stems from hyperexcitability in sensory circuits. We have established that cortical microcircuits are hyperexcitable in the Fmr1 KO mouse model, and that sensory responses are enhanced in Fmr1 KO mice and FXS patients. Thus, investigation of sensory sensitivities is clinically relevant, but perhaps more important is the promise of sensory system studies to advance understanding of the mechanisms and consequences of hyperexcitability in neocortical circuitry that could represent a primary pathophysiological factor impacting the development of a wide range of perceptual, cognitive, and language skills in FXS. Further, we have identified biochemical signaling mechanisms that may underlie hyperexcitability involving processes that we and others have uncovered that can be examined in detail in KO mouse models and tested in FXS patients to develop a foundation for novel therapeutic development. The striking consistency of findings across levels of investigation and species offers an unprecedented opportunity to investigate mechanisms of brain dysfunction in a mouse disease model and translate it directly to patients - a multidisciplinary mission that is ideal for a Center environment. Our Center is organized to pursue precisely this aim with a tightly integrated and highly novel scientific program of translational research. Project 1 (Huber/Gibson;UTSW;co-investigators) will determine the cellular, molecular and synaptic mechanisms of auditory neocortical dysfunction using in vitro brain slices in FXS mouse models. Project 2 (Razak/Etheii/Binder;UCR;co-investigators) will study auditory sensory processing deficits in vivo in FXS mouse models, test mechanisms, and examine developmental and structural correlates of these deficits. Project 3 (Sweeney/Byerly, UTSW, co-investigators) will investigate auditory cortical processing deficits using novel neurophysiological strategies in individuals with FXS. All Projects will examine candidate mechanisms of sensory hyperexcitability with an acute pharmacological probe strategy to test mechanisms of interest in parallel studies of mice and patients.

Public Health Relevance

Sensory hypersensitivity and processing deficits significantly contribute to behavioral problems associated with Fragile X Syndrome (FXS);hyperexcitability and alterations sensory neocortex likely underlies these problems. We propose a multilevel, integrated approach to determine the pathophysiology of sensory neocortical dysfunction and directly link this to sensory processing deficits in FXS mouse models and patients. Candidate therapeutics to correct sensory processing deficits will be tested in mice and patients.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Specialized Center--Cooperative Agreements (U54)
Project #
1U54HD082008-01
Application #
8793241
Study Section
Special Emphasis Panel (ZHD1-DSR-Y (53))
Program Officer
Urv, Tiina K
Project Start
2014-09-22
Project End
2019-05-31
Budget Start
2014-09-22
Budget End
2015-05-31
Support Year
1
Fiscal Year
2014
Total Cost
$1,766,233
Indirect Cost
$453,188
Name
University of Texas Sw Medical Center Dallas
Department
Neurosciences
Type
Schools of Medicine
DUNS #
800771545
City
Dallas
State
TX
Country
United States
Zip Code
75390