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Pascual D, Brauns L, Domes R, Tisler M, Kögel M, Stumpf A, Kirschniak A, Rolinger J, Kraushaar U, Jones PD. A flexible implant for acute intrapancreatic electrophysiology. Biomed Microdevices 2023; 25:35. [PMID: 37646842 DOI: 10.1007/s10544-023-00662-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2023] [Indexed: 09/01/2023]
Abstract
Microelectrode arrays (MEAs) have proven to be a powerful tool to study electrophysiological processes over the last decades with most technology developed for investigation of the heart or brain. Other targets in the field of bioelectronic medicine are the peripheral nervous system and its innervation of various organs. Beyond the heart and nervous systems, the beta cells of the pancreatic islets of Langerhans generate action potentials during the production of insulin. In vitro experiments have demonstrated that their activity is a biomarker for blood glucose levels, suggesting that recording their activity in vivo could support patients suffering from diabetes mellitus with long-term automated read-out of blood glucose concentrations. Here, we present a flexible polymer-based implant having 64 low impedance microelectrodes designed to be implanted to a depth of 10 mm into the pancreas. As a first step, the implant will be used in acute experiments in pigs to explore the electrophysiological processes of the pancreas in vivo. Beyond use in the pancreas, our flexible implant and simple implantation method may also be used in other organs such as the brain.
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Affiliation(s)
- Domenic Pascual
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Lisa Brauns
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Ruth Domes
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | | | - Marco Kögel
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Angelika Stumpf
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Andreas Kirschniak
- Department of Surgery and Transplantation, Tübingen University Hospital, Tübingen, Germany
- Department of General and Visceral Surgery, Maria Hilf Hospital Mönchengladbach, Mönchengladbach, Germany
| | - Jens Rolinger
- Department of Surgery and Transplantation, Tübingen University Hospital, Tübingen, Germany
- Department of General and Visceral Surgery, Maria Hilf Hospital Mönchengladbach, Mönchengladbach, Germany
| | - Udo Kraushaar
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Peter D Jones
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany.
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Carpentier N, Cecchin T, Koessler L, Louis-Dorr V, Jonas J, Vignal JP, Carpentier M, Szurhaj W, Bourgin P, Maillard L. Stereo-electroencephalography identifies N2 sleep and spindles in human hippocampus. Clin Neurophysiol 2017; 128:1696-1706. [PMID: 28755545 DOI: 10.1016/j.clinph.2017.06.248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Revised: 05/17/2017] [Accepted: 06/15/2017] [Indexed: 11/28/2022]
Abstract
OBJECTIVES To describe the hippocampal stereo-electroencephalogram during sleep according to sleep stages (including N2 sleep) and cycles, together with the hippocampal spindles. METHODS All patients with drug-resistant focal epilepsy undergoing intra-hippocampal implantation between August 2012 and June 2013 at Nancy University Hospital were screened. Six patients with explored hippocampus devoid of pathological features were analyzed. During one night, we identified continuous periods of successive N2, N3 and REM sleep for two full cycles. We performed a spectral analysis of the hippocampal signal for each labeled sleep period. RESULTS N2, N3 and REM sleeps were individualized according to their spectral powers, for each frequency band and sleep cycle. Hippocampal spindles showed dynamic intrinsic properties, the 11.5-16Hz frequency band being mainly dominant, whereas the 9-11.5Hz frequency band heightening during the beginning and the end of the transient. For N3 and REM sleep stages, the power of the hippocampal signal was significantly decreased between the first and the second sleep cycle. CONCLUSION Distinct N2 sleep, fast spindles and homeostatic profile are all common properties shared by hippocampus and cortex during sleep. SIGNIFICANCE The close functional link between hippocampus and cortex may have various sleep-related substrates.
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Affiliation(s)
| | - Thierry Cecchin
- CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Laurent Koessler
- CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Valérie Louis-Dorr
- CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Jacques Jonas
- Department of Neurology, Nancy University Hospital, Nancy, France; CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Jean-Pierre Vignal
- Department of Neurology, Nancy University Hospital, Nancy, France; CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
| | - Marc Carpentier
- Division of Clinical Epidemiology, Geneva University Hospitals, Geneva, Switzerland
| | - William Szurhaj
- Department of Neurology, Salengro University Hospital, Lille, France
| | - Patrice Bourgin
- Sleep Disorder Center and CNRS UPR3212, Strasbourg University Hospital, Strasbourg, France
| | - Louis Maillard
- Department of Neurology, Nancy University Hospital, Nancy, France; CNRS, CRAN, UMR 7039, Nancy, France; Université de Lorraine, CRAN, UMR 7039, Nancy, France
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