Skip to main content

Network oscillations in a neural mass model induced by metabolic modulation are consistent with EEG data of neocortical epileptic seizure onset

In neocortical epilepsy, pathological high-frequency oscillations (pHFOs) are consistently observed in EEG recordings seconds before seizure onset [1]. While this correlation is robust, a causal relationship between pHFOs and seizure onset has not yet been established. It is known, however, that neuronal activity is contingent on sufficient metabolic supply, and links between hypometabolism and epilepsy were observed [2]. Interestingly, although the delay between pHFOs and seizure onset is comparable to the time scale of metabolic supply from the blood stream, the potential effect of pHFOs on metabolic energy homeostasis has never been quantified.

Neurons contributing to pHFOs are known to synchronize their firing, presumably through the opening of axonal gap junctions [3]. We argue that such changes, combined with higher firing rates of the individual neurons, represent a surge of energy expenditure for as long as a several seconds. This is liable to exceed locally available energy reserves. Reduced availability of energy carriers, such as ATP, limits the maximum firing rate of the affected population. Such metabolic constraints arising from pHFOs can alter the balance between excitation and inhibition in the network.

Using different types of neural mass models [4, 5], we demonstrate that even a transient constraint on the maximum rate of one or both populations can lead to persistent limit cycle oscillations consistent with EEG data. By studying the bifurcations of our system with respect to the metabolic vulnerability of each population, we compute the likelihood of seizure onset following pHFOs. These transitions into an oscillatory state depend on the metabolically imposed imbalance between excitation and inhibition, as well as on time-dependent external input to the system. We therefore suggest that seizure initiation in this type of epilepsy may require the coincidence of both synchronized input and the temporary exhaustion of metabolic reserves, explaining why many HFOs occurring between seizures do not trigger an epileptic event.


  1. Worrell GA, Parish L, Cranstoun SD, Jonas R, Baltuch G, Litt B: High-frequency oscillations and seizure generation in neocortical epilepsy. Brain. 2004, 127: 1496-1506. 10.1093/brain/awh149.

    Article  PubMed  Google Scholar 

  2. Hagemann G, Bruehl C, Lutzenburg M, Witte OW: Brain hypometabolism in a model of chronic focal epilepsy in rat neocortex. Epilepsia. 1998, 39 (4): 339-346. 10.1111/j.1528-1157.1998.tb01385.x.

    Article  CAS  PubMed  Google Scholar 

  3. Traub RD, Whittington MA, Buhl EH, LeBeau FEN, Bibbig A, Boyd S, Cross H, Baldeweg T: A possible role for gap junctions in generation of very fast EEG oscillations preceding the onset of, and perhaps initiating, seizures. Epilepsia. 2001, 42 (2): 153-170.

    Article  CAS  PubMed  Google Scholar 

  4. Wilson HR, Cowan JD: Excitatory and inhibitory connections in localized populations of model neurons. Biophys J. 1972, 12: 1-24.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  5. Touboul J, Wendling F, Chauvel P, Faugeras O: Neural mass activity, bifurcations, and epilepsy. Neural Comp. 2011, 23: 3232-3286. 10.1162/NECO_a_00206.

    Article  Google Scholar 

Download references


Florian A. Dehmelt is supported by Ecole Normale Supérieure and the German Research Foundation (DFG). Christian K. Machens is funded via a "chaire d'excellence" of the French Research Agency (ANR) and by the Emmy Noether Program of the DFG.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Florian A Dehmelt.

Rights and permissions

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Reprints and permissions

About this article

Cite this article

Dehmelt, F.A., Machens, C.K. Network oscillations in a neural mass model induced by metabolic modulation are consistent with EEG data of neocortical epileptic seizure onset. BMC Neurosci 14 (Suppl 1), P251 (2013).

Download citation

  • Published:

  • DOI: