Rett syndrome (RTT) is a severe neurodevelopmental disorder causing progressive loss of motor and cognitive functions, impaired social interactions, anxiety, and seizures in young girls. Mutations in the gene encoding MeCP2 (methyl-CpG binding protein 2) are the cause of RTT. It has been hypothesized that defects of neuronal circuit development and function are responsible for neurological symptoms of RTT. The majority of RTT patients have recurrent seizures, suggesting that hyperexcitation of the neocortex is a common feature of RTT. Consistent with clinical data, MeCP2-deficient mice also show cortical hyperexcitation and seizures. Besides epilepsy, hyperexcitation of the neocortex may have major roles in cognitive and behavioral defects of RTT. Reducing cortical hyperexcitation is a potential treatment strategy for RTT. However, mechanisms underlying cortical hyperexcitation in RTT are poorly understood. This application will test the hypothesis that loss of MeCP2 in excitatory neurons in the cortex causes hyperexcitation by downregulating GABAergic transmission in the cortex. In testing this hypothesis, we take advantage of genetic manipulation in the mouse, electrophysiology, and our expertise in physiology and development of cortical neurons. The two specific aims are: 1) to determine the role of MeCP2 in regulating inhibitory neurotransmission in the cortex;and 2) to investigate of the effects of MeCP2 deficiency on cortical excitability and seizures.

Public Health Relevance

Rett syndrome is a pervasive brain disorder with no cure and limited treatments. This research will advance our understanding of the pathogenesis of Rett syndrome, and provide opportunity for the development of new and improved treatments.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Small Research Grants (R03)
Project #
1R03NS082658-01A1
Application #
8633913
Study Section
Developmental Brain Disorders Study Section (DBD)
Program Officer
Mamounas, Laura
Project Start
2013-09-01
Project End
2015-08-31
Budget Start
2013-09-01
Budget End
2014-08-31
Support Year
1
Fiscal Year
2013
Total Cost
$87,500
Indirect Cost
$37,500
Name
Jackson Laboratory
Department
Type
DUNS #
042140483
City
Bar Harbor
State
ME
Country
United States
Zip Code
04609
Zhang, Wen; Peterson, Matthew; Beyer, Barbara et al. (2014) Loss of MeCP2 from forebrain excitatory neurons leads to cortical hyperexcitation and seizures. J Neurosci 34:2754-63