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Marcantoni A, Chiantia G, Tomagra G, Hidisoglu E, Franchino C, Carabelli V, Carbone E. Two firing modes and well-resolved Na +, K +, and Ca 2+ currents at the cell-microelectrode junction of spontaneously active rat chromaffin cell on MEAs. Pflugers Arch 2023; 475:181-202. [PMID: 36260174 PMCID: PMC9849155 DOI: 10.1007/s00424-022-02761-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 09/23/2022] [Accepted: 10/07/2022] [Indexed: 02/01/2023]
Abstract
We recorded spontaneous extracellular action potentials (eAPs) from rat chromaffin cells (CCs) at 37 °C using microelectrode arrays (MEAs) and compared them with intracellularly recorded APs (iAPs) through conventional patch clamp recordings at 22 °C. We show the existence of two distinct firing modes on MEAs: a ~ 4 Hz irregular continuous firing and a frequent intermittent firing mode where periods of high-intraburst frequency (~ 8 Hz) of ~ 7 s duration are interrupted by silent periods of ~ 12 s. eAPs occurred either as negative- or positive-going signals depending on the contact between cell and microelectrode: either predominantly controlled by junction-membrane ion channels (negative-going) or capacitive/ohmic coupling (positive-going). Negative-going eAPs were found to represent the trajectory of the Na+, Ca2+, and K+ currents passing through the cell area in tight contact with the microelectrode during an AP (point-contact junction). The inward Nav component of eAPs was blocked by TTX in a dose-dependent manner (IC50 ~ 10 nM) while the outward component was strongly attenuated by the BK channel blocker paxilline (200 nM) or TEA (5 mM). The SK channel blocker apamin (200 nM) had no effect on eAPs. Inward Nav and Cav currents were well-resolved after block of Kv and BK channels or in cells showing no evident outward K+ currents. Unexpectedly, on the same type of cells, we could also resolve inward L-type currents after adding nifedipine (3 μM). In conclusion, MEAs provide a direct way to record different firing modes of rat CCs and to estimate the Na+, Ca2+, and K+ currents that sustain cell firing and spontaneous catecholamines secretion.
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Affiliation(s)
- Andrea Marcantoni
- grid.7605.40000 0001 2336 6580Department of Drug Science, Laboratory of Cell Physiology and Molecular Neuroscience, N.I.S. Centre, University of Torino, Corso Raffaello 30, 10125 Turin, Italy
| | - Giuseppe Chiantia
- grid.7605.40000 0001 2336 6580Department of Neuroscience, University of Torino, 10125 Turin, Italy
| | - Giulia Tomagra
- grid.7605.40000 0001 2336 6580Department of Drug Science, Laboratory of Cell Physiology and Molecular Neuroscience, N.I.S. Centre, University of Torino, Corso Raffaello 30, 10125 Turin, Italy
| | - Enis Hidisoglu
- grid.7605.40000 0001 2336 6580Department of Drug Science, Laboratory of Cell Physiology and Molecular Neuroscience, N.I.S. Centre, University of Torino, Corso Raffaello 30, 10125 Turin, Italy
| | - Claudio Franchino
- grid.7605.40000 0001 2336 6580Department of Drug Science, Laboratory of Cell Physiology and Molecular Neuroscience, N.I.S. Centre, University of Torino, Corso Raffaello 30, 10125 Turin, Italy
| | - Valentina Carabelli
- grid.7605.40000 0001 2336 6580Department of Drug Science, Laboratory of Cell Physiology and Molecular Neuroscience, N.I.S. Centre, University of Torino, Corso Raffaello 30, 10125 Turin, Italy
| | - Emilio Carbone
- grid.7605.40000 0001 2336 6580Department of Drug Science, Laboratory of Cell Physiology and Molecular Neuroscience, N.I.S. Centre, University of Torino, Corso Raffaello 30, 10125 Turin, Italy
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Hyun NG, Hyun K, Oh S, Lee K. Analysis of temperature-dependent abnormal bursting patterns of neurons in Aplysia. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2020; 24:349-362. [PMID: 32587129 PMCID: PMC7317177 DOI: 10.4196/kjpp.2020.24.4.349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/14/2020] [Accepted: 05/29/2020] [Indexed: 11/28/2022]
Abstract
Temperature affects the firing pattern and electrical activity of neurons in animals, eliciting diverse responses depending on neuronal cell type. However, the mechanisms underlying such diverse responses are not well understood. In the present study, we performed in vitro recording of abdominal ganglia cells of Aplysia juliana, and analyzed their burst firing patterns. We identified atypical bursting patterns dependent on temperature that were totally different from classical bursting patterns observed in R15 neurons of A. juliana. We classified these abnormal bursting patterns into type 1 and type 2; type 1 abnormal single bursts are composed of two kinds of spikes with a long interspike interval (ISI) followed by short ISI regular firing, while type 2 abnormal single bursts are composed of complex multiplets. To investigate the mechanism underlying the temperature dependence of abnormal bursting, we employed simulations using a modified Plant model and determined that the temperature dependence of type 2 abnormal bursting is related to temperature-dependent scaling factors and activation or inactivation of potassium or sodium channels.
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Affiliation(s)
- Nam Gyu Hyun
- Department of Physics, Jeju National University, Jeju 63243, Korea
| | | | - Saecheol Oh
- Department of Anesthesiology and Pain Medicine, Daejeon St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Daejeon 34943, Korea
| | - Kyungmin Lee
- Laboratory for Behavioral Neural Circuitry and Physiology, Department of Anatomy, Brain Science and Engineering Institute, School of Medicine, Kyungpook National University, Daegu 41944, Korea
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