Epilepsy affects roughly 1% of the human population. For the one third of patients who cannot achieve adequate seizure control with existing medications, one effective alternative is dietary treatment with a high fat and very low carbohydrate ketogenic diet (KD). The KD can be remarkably effective, with ~1/3 of patients becoming seizure free, but the strict diet regimen is difficult for patients to comply with. Learning the still mysterious mechanism of the KD would teach us how the brain may naturally protect itself against seizures, and also permit the design of better dietary treatments and better anticonvulsant medications. On the KD, the brain uses circulating ketone bodies (KB's, esp. 2 hydroxybutyrate and acetoacetate) as an alternate to the usual fuel source, glucose. This change in fuel source somehow produces an anticonvulsant action, but the link remains unknown. A good candidate is an ion channel well known for its sensitivity to metabolism the ATP sensitive K+ channel or KATP channel. Experiments on brain slices show that KBs can, on a fairly rapid time scale (10's of minutes) lead to slowing of spontaneous firing in cells of substantia nigra pars reticulata. KATP channels are important for this effect. The demonstration of a short term in vitro effect of ketone bodies on excitability, and the implication of KATP channels in the effect, offer a new avenue for investigating the mechanism of the ketogenic diet. We will follow up on this lead by asking how KATP channels function in two brain circuits important in epilepsy, and to learn more about possible mechanisms by which these channels may become activated with ketone body metabolism. Substantia nigra pars reticulata neurons and hippocampal dentate granule cells will be the main focus of this work. The effects of ketone bodies on KATP channels and other targets, such as gene expression, are likely due to changes in proximal consequences of the metabolic change. Optical probes for reactive oxygen species, for NADH, and for ATP will be used to learn how central neurons respond to excitation in the presence of different fuel molecules. These experiments will report on how metabolism changes during neuronal activation, and how this is affected by KBs, answering fundamental questions about brain metabolism and function.

Public Health Relevance

One of the best treatments for epilepsy (a seizure disorder affecting roughly 1% of the population) is a very low carbohydrate, high fat ketogenic diet. Because the diet is unpalatable and difficult, it would be useful to understand how it acts on brain cells so that better drug therapies (or easier diets) can be designed. This project will study how ketone bodies produced by the body during the diet act on brain cells to change their activity and prevent seizures, by examining electrical activity and metabolic changes in brain slices from rodents.

National Institute of Health (NIH)
National Institute of Neurological Disorders and Stroke (NINDS)
Research Project (R01)
Project #
Application #
Study Section
Clinical Neuroscience and Disease Study Section (CND)
Program Officer
Whittemore, Vicky R
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Harvard University
Schools of Medicine
United States
Zip Code
Hung, Yin Pun; Yellen, Gary (2014) Live-cell imaging of cytosolic NADH-NAD+ redox state using a genetically encoded fluorescent biosensor. Methods Mol Biol 1071:83-95
Lutas, Andrew; Yellen, Gary (2013) The ketogenic diet: metabolic influences on brain excitability and epilepsy. Trends Neurosci 36:32-40
Tantama, Mathew; Martinez-Francois, Juan Ramon; Mongeon, Rebecca et al. (2013) Imaging energy status in live cells with a fluorescent biosensor of the intracellular ATP-to-ADP ratio. Nat Commun 4:2550
Tantama, Mathew; Hung, Yin Pun; Yellen, Gary (2012) Optogenetic reporters: Fluorescent protein-based genetically encoded indicators of signaling and metabolism in the brain. Prog Brain Res 196:235-63
Tanner, Geoffrey R; Lutas, Andrew; Martinez-Francois, Juan Ramon et al. (2011) Single K ATP channel opening in response to action potential firing in mouse dentate granule neurons. J Neurosci 31:8689-96
Hung, Yin Pun; Albeck, John G; Tantama, Mathew et al. (2011) Imaging cytosolic NADH-NAD(+) redox state with a genetically encoded fluorescent biosensor. Cell Metab 14:545-54
Tantama, Mathew; Hung, Yin Pun; Yellen, Gary (2011) Imaging intracellular pH in live cells with a genetically encoded red fluorescent protein sensor. J Am Chem Soc 133:10034-7
Berg, Jim; Hung, Yin Pun; Yellen, Gary (2009) A genetically encoded fluorescent reporter of ATP:ADP ratio. Nat Methods 6:161-6
Yellen, Gary (2008) Ketone bodies, glycolysis, and KATP channels in the mechanism of the ketogenic diet. Epilepsia 49 Suppl 8:80-2