Network models incorporating chloride dynamics predict optimal strategies for terminating status epilepticus.

Journal: Neurobiology of disease
Published Date:

Abstract

Status epilepticus (SE), seizures lasting beyond five minutes, is a medical emergency commonly treated with benzodiazepines which enhance GABA receptor (GABAR) conductance. Despite widespread use, benzodiazepines fail in over one-third of patients, potentially due to seizure-induced disruption of neuronal chloride (Cl) homeostasis. Understanding these changes at a network level is crucial for improving clinical translation. Here, we address this using a large-scale spiking neural network model incorporating Cl dynamics, informed by clinical EEG and experimental slice recordings. Our simulations confirm that the GABAR reversal potential (E) dictates the pro- or anti-seizure effect of GABAR conductance modulation, with high E rendering benzodiazepines ineffective or excitatory. We show SE-like activity and E depend non-linearly on Cl extrusion efficacy and GABAR conductance. Critically, cell-type specific manipulations reveal that pyramidal cell, not interneuron, Cl extrusion predominantly determines the severity of SE activity and the response to simulated benzodiazepines. Leveraging these mechanistic insights, we develop a predictive framework mapping network states to Cl extrusion capacity and GABAergic load, yielding a proposed decision-making strategy to guide therapeutic interventions based on initial treatment response. This work identifies pyramidal cell Cl handling as a key therapeutic target and demonstrates the utility of biophysically detailed network models for optimising SE treatment protocols.

Authors

  • Christopher B Currin
    Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Institute of Science and Technology Austria, Klosterneuburg, Austria. Electronic address: chris.currin+chloride@gmail.com.
  • Richard J Burman
    Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa; Department of Paediatric Neurology, University Children's Hospital Zurich and University of Zurich, Zurich, Switzerland; Department of Pharmacology, University of Oxford, United Kingdom; Oxford Epilepsy Research Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
  • Tommaso Fedele
    Department of Neurosurgery, University Hospital Zurich, Zurich, Switzerland.
  • Georgia Ramantani
    Neuropädiatrie, Universitäts-Kinderspital und Universität Zürich, Zurich, Switzerland.
  • Richard E Rosch
    Department of Clinical Neurophysiology, King's College Hospital NHS Foundation Trust, London; Wellcome Centre for Imaging Neuroscience, University College London, London, United Kingdom.
  • Henning Sprekeler
    Department for Electrical Engineering and Computer Science, Technische Universität Berlin, Berlin, Germany.
  • Joseph V Raimondo
    Division of Cell Biology, Department of Human Biology, Neuroscience Institute and Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa. Electronic address: joseph.raimondo@uct.ac.za.