Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive Microelectrodes
In the course of action potential firing, all axons and neurons release K<sup>+</sup> from the intra- cellular compartment into the interstitial space to counteract the depolarizing effect of Na<sup>+</sup> influx, which restores the resting membrane potential. This efflux of...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-01-01
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| Series: | Molecules |
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| Online Access: | https://www.mdpi.com/1420-3049/28/2/523 |
| _version_ | 1797438413205405696 |
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| author | Hana Beswick-Jones Amy J. Hopper Angus M. Brown |
| author_facet | Hana Beswick-Jones Amy J. Hopper Angus M. Brown |
| author_sort | Hana Beswick-Jones |
| collection | DOAJ |
| description | In the course of action potential firing, all axons and neurons release K<sup>+</sup> from the intra- cellular compartment into the interstitial space to counteract the depolarizing effect of Na<sup>+</sup> influx, which restores the resting membrane potential. This efflux of K<sup>+</sup> from axons results in K<sup>+</sup> accumulation in the interstitial space, causing depolarization of the K<sup>+</sup> reversal potential (E<sub>K</sub>), which can prevent subsequent action potentials. To ensure optimal neuronal function, the K<sup>+</sup> is buffered by astrocytes, an energy-dependent process, which acts as a sink for interstitial K<sup>+</sup>, absorbing it at regions of high concentration and distributing it through the syncytium for release in distant regions. Pathological processes in which energy production is compromised, such as anoxia, ischemia, epilepsy and spreading depression, can lead to excessive interstitial K<sup>+</sup> accumulation, disrupting sensitive trans-membrane ion gradients and attenuating neuronal activity. The changes that occur in interstitial [K<sup>+</sup>] resulting from both physiological and pathological processes can be monitored accurately in real time using K<sup>+</sup>-sensitive microelectrodes, an invaluable tool in electrophysiological studies. |
| first_indexed | 2024-03-09T11:37:31Z |
| format | Article |
| id | doaj.art-cdf8f732bb1945548c309c3762368727 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-09T11:37:31Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-cdf8f732bb1945548c309c37623687272023-11-30T23:41:03ZengMDPI AGMolecules1420-30492023-01-0128252310.3390/molecules28020523Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive MicroelectrodesHana Beswick-Jones0Amy J. Hopper1Angus M. Brown2School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UKSchool of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UKSchool of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UKIn the course of action potential firing, all axons and neurons release K<sup>+</sup> from the intra- cellular compartment into the interstitial space to counteract the depolarizing effect of Na<sup>+</sup> influx, which restores the resting membrane potential. This efflux of K<sup>+</sup> from axons results in K<sup>+</sup> accumulation in the interstitial space, causing depolarization of the K<sup>+</sup> reversal potential (E<sub>K</sub>), which can prevent subsequent action potentials. To ensure optimal neuronal function, the K<sup>+</sup> is buffered by astrocytes, an energy-dependent process, which acts as a sink for interstitial K<sup>+</sup>, absorbing it at regions of high concentration and distributing it through the syncytium for release in distant regions. Pathological processes in which energy production is compromised, such as anoxia, ischemia, epilepsy and spreading depression, can lead to excessive interstitial K<sup>+</sup> accumulation, disrupting sensitive trans-membrane ion gradients and attenuating neuronal activity. The changes that occur in interstitial [K<sup>+</sup>] resulting from both physiological and pathological processes can be monitored accurately in real time using K<sup>+</sup>-sensitive microelectrodes, an invaluable tool in electrophysiological studies.https://www.mdpi.com/1420-3049/28/2/523astrocyteaction potentialbufferinginterstitial |
| spellingShingle | Hana Beswick-Jones Amy J. Hopper Angus M. Brown Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive Microelectrodes Molecules astrocyte action potential buffering interstitial |
| title | Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive Microelectrodes |
| title_full | Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive Microelectrodes |
| title_fullStr | Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive Microelectrodes |
| title_full_unstemmed | Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive Microelectrodes |
| title_short | Activity-Dependent Fluctuations in Interstitial [K<sup>+</sup>]: Investigations Using Ion-Sensitive Microelectrodes |
| title_sort | activity dependent fluctuations in interstitial k sup sup investigations using ion sensitive microelectrodes |
| topic | astrocyte action potential buffering interstitial |
| url | https://www.mdpi.com/1420-3049/28/2/523 |
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