Amperometric bio-sensing of lactate and oxygen concurrently with local field potentials during status epilepticus

Eliana Fernandes, Ana Ledo, Greg A. Gerhardt, Rui M. Barbosa

Research output: Contribution to journalArticlepeer-review


Epilepsy is a prevalent neurological disorder with a complex pathogenesis and unpredictable nature, presenting limited treatment options in >30 % of affected individuals. Neurometabolic abnormalities have been observed in epilepsy patients, suggesting a disruption in the coupling between neural activity and energy metabolism in the brain. In this study, we employed amperometric biosensors based on a modified carbon fiber microelectrode platform to directly and continuously measure lactate and oxygen dynamics in the brain extracellular space. These biosensors demonstrated high sensitivity, selectivity, and rapid response time, enabling in vivo measurements with high temporal and spatial resolution. In vivo recordings in the cortex of anaesthetized rats revealed rapid and multiphasic fluctuations in extracellular lactate and oxygen levels following neuronal stimulation with high potassium. Furthermore, real-time measurement of lactate and oxygen concentration dynamics concurrently with network electrical activity during status epilepticus induced by 4-aminopyridine (4-AP) demonstrated phasic changes in lactate levels that correlated with bursts of electrical activity, while tonic levels of lactate remained stable during seizures. This study highlights the complex interplay between lactate dynamics, electrical activity, and oxygen utilization in epileptic seizures.

Original languageEnglish
Article number125302
StatePublished - Feb 1 2024

Bibliographical note

Funding Information:
This work was supported by the European Regional Development Fund ( ERDF ) through the COMPETE 2020 – Operational Programme for Competitiveness and Internationalization and Portuguese National Funds via FCT – Fundação para a Ciência e a Tecnologia , under projects UIDB/04539/2020 , UIDP/04539/2020 and 2022.09869.BD .

Publisher Copyright:
© 2023 The Authors


  • Carbon fiber microelectrode
  • In vivo electrochemistry
  • Lactate biosensor
  • Local field potentials
  • Oxygen sensor
  • Status epilepticus

ASJC Scopus subject areas

  • Analytical Chemistry


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