Non-linear leak currents affect mammalian neuron physiology
In their seminal works on squid giant axons, Hodgkin and Huxley approximated the membrane leak current as Ohmic, i.e. linear, since in their preparation, sub-threshold current rectification due to the influence of ionic concentration is negligible. Most studies on mammalian neurons have made the sam...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-11-01
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| Series: | Frontiers in Cellular Neuroscience |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fncel.2015.00432/full |
| _version_ | 1818650101079343104 |
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| author | Shiwei eHuang Shiwei eHuang Sungho eHong Erik eDe Schutter |
| author_facet | Shiwei eHuang Shiwei eHuang Sungho eHong Erik eDe Schutter |
| author_sort | Shiwei eHuang |
| collection | DOAJ |
| description | In their seminal works on squid giant axons, Hodgkin and Huxley approximated the membrane leak current as Ohmic, i.e. linear, since in their preparation, sub-threshold current rectification due to the influence of ionic concentration is negligible. Most studies on mammalian neurons have made the same, largely untested, assumption. Here we show that the membrane time constant and input resistance of mammalian neurons (when other major voltage-sensitive and ligand-gated ionic currents are discounted) varies non-linearly with membrane voltage, following the prediction of a Goldman-Hodgkin-Katz-based passive membrane model. The model predicts that under such conditions, the time constant/input resistance-voltage relationship will linearize if the concentration differences across the cell membrane are reduced. These properties were observed in patch-clamp recordings of cerebellar Purkinje neurons (in the presence of pharmacological blockers of other background ionic currents) and were more prominent in the sub-threshold region of the membrane potential. Model simulations showed that the non-linear leak affects voltage-clamp recordings and reduces temporal summation of excitatory synaptic input. Together, our results demonstrate the importance of trans-membrane ionic concentration in defining the functional properties of the passive membrane in mammalian neurons as well as other excitable cells. |
| first_indexed | 2024-12-17T01:44:51Z |
| format | Article |
| id | doaj.art-1968a0fb2ba4472ba767cffe91d6eb58 |
| institution | Directory Open Access Journal |
| issn | 1662-5102 |
| language | English |
| last_indexed | 2024-12-17T01:44:51Z |
| publishDate | 2015-11-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cellular Neuroscience |
| spelling | doaj.art-1968a0fb2ba4472ba767cffe91d6eb582022-12-21T22:08:13ZengFrontiers Media S.A.Frontiers in Cellular Neuroscience1662-51022015-11-01910.3389/fncel.2015.00432160172Non-linear leak currents affect mammalian neuron physiologyShiwei eHuang0Shiwei eHuang1Sungho eHong2Erik eDe Schutter3Okinawa Institute of Science and Technology Graduate UniversityAustralian National UniversityOkinawa Institute of Science and Technology Graduate UniversityOkinawa Institute of Science and Technology Graduate UniversityIn their seminal works on squid giant axons, Hodgkin and Huxley approximated the membrane leak current as Ohmic, i.e. linear, since in their preparation, sub-threshold current rectification due to the influence of ionic concentration is negligible. Most studies on mammalian neurons have made the same, largely untested, assumption. Here we show that the membrane time constant and input resistance of mammalian neurons (when other major voltage-sensitive and ligand-gated ionic currents are discounted) varies non-linearly with membrane voltage, following the prediction of a Goldman-Hodgkin-Katz-based passive membrane model. The model predicts that under such conditions, the time constant/input resistance-voltage relationship will linearize if the concentration differences across the cell membrane are reduced. These properties were observed in patch-clamp recordings of cerebellar Purkinje neurons (in the presence of pharmacological blockers of other background ionic currents) and were more prominent in the sub-threshold region of the membrane potential. Model simulations showed that the non-linear leak affects voltage-clamp recordings and reduces temporal summation of excitatory synaptic input. Together, our results demonstrate the importance of trans-membrane ionic concentration in defining the functional properties of the passive membrane in mammalian neurons as well as other excitable cells.http://journal.frontiersin.org/Journal/10.3389/fncel.2015.00432/fullPassive membrane propertiesionic concentration-dependenceGoldman-Hodgkin-Katz equationtime constant and input resistancecerebellar Purkinje neurons. |
| spellingShingle | Shiwei eHuang Shiwei eHuang Sungho eHong Erik eDe Schutter Non-linear leak currents affect mammalian neuron physiology Frontiers in Cellular Neuroscience Passive membrane properties ionic concentration-dependence Goldman-Hodgkin-Katz equation time constant and input resistance cerebellar Purkinje neurons. |
| title | Non-linear leak currents affect mammalian neuron physiology |
| title_full | Non-linear leak currents affect mammalian neuron physiology |
| title_fullStr | Non-linear leak currents affect mammalian neuron physiology |
| title_full_unstemmed | Non-linear leak currents affect mammalian neuron physiology |
| title_short | Non-linear leak currents affect mammalian neuron physiology |
| title_sort | non linear leak currents affect mammalian neuron physiology |
| topic | Passive membrane properties ionic concentration-dependence Goldman-Hodgkin-Katz equation time constant and input resistance cerebellar Purkinje neurons. |
| url | http://journal.frontiersin.org/Journal/10.3389/fncel.2015.00432/full |
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