Sensory abnormalities characterize a wide range of neurodevelopmental disorders. In autism spectrum disorder (ASD), for example, sensory overload is one of the most frequently reported symptoms. Abnormal regulation of sensory information flow (sensory gating) is also observed in schizophrenia and ADHD, and is thought to contribute to overall cognitive dysfunction across all these conditions. Despite its central importance, little is known about the neurobiology of sensory gating, and even less is known about its failure in disease. This proposal aims to address this critical gap. The neocortex is requires for higher level sensory processing, but early processing and transmission of sensory information is performed by the thalamus. We and others have found that thalamic sensory input is controlled by the thalamic reticular nucleus (TRN), a shell of GABAergic neurons surrounding thalamic relay nuclei. The TRN is composed of individual subnetworks, each controlling thalamic flow in a modality-specific manner. Recent clinical data have shown thalamic and TRN dysfunction in neurodevelopmental disorders. Given the critical role for TRN in sensory processing, we expect perturbations in its circuits to pathologically augment cortical sensory input, explaining several clinical symptoms. In sleep, TRN dysfunction may result in increased sensory-related arousals, while in attention irrelevant inputs may become much more distracting. As such, a `leaky thalamus' may have profound consequences on behavior and cognition across disorders. In this proposal, we will test the leaky thalamus framework by manipulating thalamic inhibition in mice while monitoring the impact on sensory function and related behaviors. In addition, we will investigate the therapeutic potential of reversing thalamic inhibition deficits in models of human neurodevelopmental disorders.

Public Health Relevance

Sensory abnormalities characterize a wide range of neurodevelopmental disorders including autism spectrum disorder, schizophrenia and ADHD, and is thought to contribute to overall cognitive dysfunction across all these conditions. Despite its central importance, little is known about the neurobiology of sensory gating, and even less is known about its failure in disease. We will test the hypothesis that defects in thalamus inhibition (a ?leaky thalamus?) play key role in sensory dysfunction and related behaviors. In addition, we will investigate the therapeutic potential of reversing thalamic inhibition deficits in models of human neurodevelopmental disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS098505-02
Application #
9332138
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Gnadt, James W
Project Start
2016-09-01
Project End
2021-06-30
Budget Start
2017-07-01
Budget End
2018-06-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Massachusetts Institute of Technology
Department
Other Basic Sciences
Type
Schools of Arts and Sciences
DUNS #
001425594
City
Cambridge
State
MA
Country
United States
Zip Code
02142
Schmitt, L I; Halassa, M M (2017) Interrogating the mouse thalamus to correct human neurodevelopmental disorders. Mol Psychiatry 22:183-191
Nakajima, Miho; Halassa, Michael M (2017) Thalamic control of functional cortical connectivity. Curr Opin Neurobiol 44:127-131
Liang, Li; Oline, Stefan N; Kirk, Justin C et al. (2017) Scalable, Lightweight, Integrated and Quick-to-Assemble (SLIQ) Hyperdrives for Functional Circuit Dissection. Front Neural Circuits 11:8