Temporal lobe epilepsy (TLE) is a common and often devastating form of human epilepsy that lacks preventive therapy. Evidence from clinical and preclinical studies supports the idea that an episode of prolonged seizures (status epilepticus or SE) contributes to development of TLE. Defining the molecular mechanisms by which SE transforms a normal brain into an epileptic brain is essential for identifying molecular targets fo preventive therapies. Work accomplished during the current funding period revealed that transiently inhibiting the brain-derived neurotrophic factor (BDNF) receptor tyrosine kinase, TrkB, commencing following SE prevented SE-induced TLE. In preliminary studies we have discovered that global inhibition of TrkB signaling exacerbates SE-induced death of neurons, a detrimental outcome that must be mitigated. This led us to seek the downstream signaling pathway by which TrkB promotes epileptogenesis, our preliminary evidence implicating phospholipase Cy1 (PLCy1) as the dominant pathway. Our objective is to define the molecular mechanism by which SE induces TLE. To accomplish this objective, we propose to examine the effect of pharmacological uncoupling of TrkB from PLCy1 on cell death induced by SE in an adult mouse and on TLE induced by SE in a neonatal animal. We also propose to determine precisely when following SE that TrkB must be uncoupled from PLCy1 in order to prevent TLE in adults. Successful completion of the work proposed may pave the way to prevention of a subset of TLE, a common disorder of the human nervous system.

Public Health Relevance

Lack of effective prevention for common disorders of the human nervous system is a glaring unmet medical need critical to the mission of NINDS. The work proposed here represents a novel and innovative approach to uncover molecular signaling mechanisms underlying temporal lobe epilepsy. Such insights may pave the way to prevention of a subset of temporal lobe epilepsy, a common disorder of the human nervous system.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS056217-10
Application #
8866481
Study Section
Clinical Neuroplasticity and Neurotransmitters Study Section (CNNT)
Program Officer
Whittemore, Vicky R
Project Start
2006-07-15
Project End
2018-06-30
Budget Start
2015-07-01
Budget End
2016-06-30
Support Year
10
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Duke University
Department
Neurosciences
Type
Schools of Medicine
DUNS #
044387793
City
Durham
State
NC
Country
United States
Zip Code
27705
Dingledine, Raymond; Coulter, Douglas A; Fritsch, Brita et al. (2017) Transcriptional profile of hippocampal dentate granule cells in four rat epilepsy models. Sci Data 4:170061
Hedrick, Nathan G; Harward, Stephen C; Hall, Charles E et al. (2016) Rho GTPase complementation underlies BDNF-dependent homo- and heterosynaptic plasticity. Nature 538:104-108
Harward, Stephen C; Hedrick, Nathan G; Hall, Charles E et al. (2016) Autocrine BDNF-TrkB signalling within a single dendritic spine. Nature 538:99-103
Puranam, Ram S; He, Xiao Ping; Yao, Lijun et al. (2015) Disruption of Fgf13 causes synaptic excitatory-inhibitory imbalance and genetic epilepsy and febrile seizures plus. J Neurosci 35:8866-81
Gu, Bin; Huang, Yang Zhong; He, Xiao-Ping et al. (2015) A Peptide Uncoupling BDNF Receptor TrkB from Phospholipase C?1 Prevents Epilepsy Induced by Status Epilepticus. Neuron 88:484-91
Harward, Stephen C; McNamara, James O (2014) Aligning animal models with clinical epilepsy: where to begin? Adv Exp Med Biol 813:243-51
Liu, Gumei; Kotloski, Robert J; McNamara, James O (2014) Antiseizure effects of TrkB kinase inhibition. Epilepsia 55:1264-73
Helgager, Jeffrey; Huang, Yang Zhong; Mcnamara, James O (2014) Brain-derived neurotrophic factor but not vesicular zinc promotes TrkB activation within mossy fibers of mouse hippocampus in vivo. J Comp Neurol 522:3885-99
He, Xiao Ping; Wen, Renren; McNamara, James O (2014) Impairment of kindling development in phospholipase C?1 heterozygous mice. Epilepsia 55:456-63
Wang, Hong-Gang; He, Xiao Ping; Li, Qiang et al. (2013) The auxiliary subunit KChIP2 is an essential regulator of homeostatic excitability. J Biol Chem 288:13258-68

Showing the most recent 10 out of 27 publications