Prof John Gordon Ralph Jefferys, BSc, PhD
Team Leader
Department of Physiology, Second Faculty of Medicine, Charles University
Scientific background
My main expertise is in the cellular physiology of neurons of the hippocampus and cortex and their organisation into functional networks, and especially in the pathophysiology of epilepsy. The principles that govern the operation of local circuits and assemblies of neurons are fundamental for understanding both the normal and pathological brain, because they provide the pivotal link between cellular and molecular studies on the one hand, and the behaviour of the whole organism on the other. Training in general physiology at UCL, and experience in Biomedical Engineering at Purdue helped set the scene for our current whole organism research (see Research interests below).
Research interests
Our main research interest is in physiological consequences of chronic epilepsy and of seizures in general. The primary motivation is to understand, and ultimately to prevent, sudden unexpected death in epilepsy (SUDEP), which results in premature deaths in approximately 1 in 1000 people with epilepsy each year. We study breathing and cardiac function during and following seizures to see how they are modified by the disease. Clinical evidence suggests that failure to breathe is the direct cause of SUDEP, but during the preceding minutes the activity of both heart and lungs is disrupted. The challenge is to work out the features necessary for SUDEP and to identify means of correcting or attenuating them.
Selected publications
Jefferys, John GR, Alexander Ashby‐Lumsden, and Thelma A. Lovick. “Cardiac effects of repeated focal seizures in rats induced by intrahippocampal tetanus toxin: Bradyarrhythmias, tachycardias, and prolonged interictal QT interval.” Epilepsia 61.4 (2020): 798-809.
Jefferys, John GR, et al. “Brainstem activity, apnea, and death during seizures induced by intrahippocampal kainic acid in anaesthetized rats.” Epilepsia 60.12 (2019): 2346-2358.
Lovick, Thelma A., and John GR Jefferys. “Acute and chronic cardiorespiratory consequences of focal intrahippocampal administration of seizure-inducing agents. Implications for SUDEP.” Autonomic Neuroscience 235 (2021): 102864.
Chang, Wei-Chih, et al. “Loss of neuronal network resilience precedes seizures and determines the ictogenic nature of interictal synaptic perturbations.” Nature neuroscience 21.12 (2018): 1742-1752.
https://www.sciencedirect.com/science/article/pii/S0969996124003371