The NINDS has issued U- and R-series RFAs this year to discover drugs to prevent the development of epilepsy after brain injury. The rate-limiting factors in the response to the RFAs are the lack of highly scalable models of epilepsy after brain injury, and the means to quantify epileptogenesis. The hippocampal slice is a compelling model of traumatic brain injury, and organotypic cultures of these slices provide a unique window into recovery after severe shear injury. We re-discovered the utility of the organotypic slice culture as an accelerated model of post traumatic epileptogenesis 20 years after epileptic activity in this preparation was first described. The epilepsy research community lost 20 years of use of this exceptionally powerful model largely because inadequate standardization created a perception of inadequate reproducibility. We propose to optimize the organotypic slice preparation for the study of epileptogenesis, focusing on 3 key questions to maximize its utility: First, what are the best means to quantify epileptogenesis in this preparation? We have developed methods for continuous electrographic recordings and automated seizure detection algorithms that make feasible the parallel processing of arrays of epileptogenic slice cultures. We will determine whether the methods that we have devised for quantification of in vivo epileptogenesis can be applied to these culture arrays. Second, what are the optimum culture conditions for epileptogenesis in slice cultures? This preparation was never optimized for the study of epilepsy, so we need to ascertain that metabolic substrates and products do not limit the quantity of epileptic activity. Third, what surrogate markers can be used to accelerate the use of this system for screening? Although quantification of epileptogenesis from electrographic recordings is the gold standard, our preliminary data suggest that there are potentially promising markers such as extracellular lactate levels and intracellular chloride and calcium levels that can be used as the basis of fluorescence assays that will substantially accelerate throughput with this model. Together, these studies will enable a new, rapid, highly scalable, readily transferrable, and quantifiable assay of post traumatic epileptogenesis that will accelerate both fundamental research into pathogenesis and the search for therapeutic strategies.

Public Health Relevance

Organotypic brain slice cultures are a potentially powerful model of post traumatic epilepsy, but this preparation was never optimized for the study of epilepsy. We have the experience with both the culture and seizure quantification necessary to develop this preparation to the point that it can become a rapid, highly scalable, reproducible and transferrable, and quantifiable model of post traumatic epilepsy. Such a model will profoundly increase our capacity to seek new cures for epilepsy after brain injury.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS077908-03
Application #
8456201
Study Section
Special Emphasis Panel (ZMH1-ERB-C (05))
Program Officer
Fureman, Brandy E
Project Start
2011-08-01
Project End
2015-04-30
Budget Start
2013-05-01
Budget End
2014-04-30
Support Year
3
Fiscal Year
2013
Total Cost
$413,377
Indirect Cost
$134,251
Name
Massachusetts General Hospital
Department
Type
DUNS #
073130411
City
Boston
State
MA
Country
United States
Zip Code
02199
Lillis, K P; Staley, K J (2018) Optogenetic dissection of ictogenesis: in search of a targeted anti-epileptic therapy. J Neural Eng 15:041001
Lillis, Kyle P; Wang, Zemin; Mail, Michelle et al. (2015) Evolution of Network Synchronization during Early Epileptogenesis Parallels Synaptic Circuit Alterations. J Neurosci 35:9920-34
Park, Kyung-Il; Dzhala, Volodymyr; Saponjian, Yero et al. (2015) What Elements of the Inflammatory System Are Necessary for Epileptogenesis In Vitro? eNeuro 2:
Berdichevsky, Yevgeny; Dryer, Alexandra M; Saponjian, Yero et al. (2013) PI3K-Akt signaling activates mTOR-mediated epileptogenesis in organotypic hippocampal culture model of post-traumatic epilepsy. J Neurosci 33:9056-67
Berdichevsky, Yevgeny; Dzhala, Volodymyr; Mail, Michelle et al. (2012) Interictal spikes, seizures and ictal cell death are not necessary for post-traumatic epileptogenesis in vitro. Neurobiol Dis 45:774-85
Glicksman, Marcie A (2011) The preclinical discovery of amyotrophic lateral sclerosis drugs. Expert Opin Drug Discov 6:1127-38
Dyhrfjeld-Johnsen, J; Berdichevsky, Y; Swiercz, W et al. (2010) Interictal spikes precede ictal discharges in an organotypic hippocampal slice culture model of epileptogenesis. J Clin Neurophysiol 27:418-24