Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus.
In a neuronal population, several combinations of its ionic conductances are used to attain a specific firing phenotype. Some neurons present heterogeneity in their firing, generally produced by expression of a specific conductance, but how additional conductances vary along in order to homeostatica...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Frontiers Media S.A.
2016-10-01
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| Series: | Frontiers in Cellular Neuroscience |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fncel.2016.00249/full |
| _version_ | 1818299235055960064 |
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| author | Cesar Celis Ceballos Shuang Li Antonio C Roque Thanos Tzounopoulos Ricardo M Leao |
| author_facet | Cesar Celis Ceballos Shuang Li Antonio C Roque Thanos Tzounopoulos Ricardo M Leao |
| author_sort | Cesar Celis Ceballos |
| collection | DOAJ |
| description | In a neuronal population, several combinations of its ionic conductances are used to attain a specific firing phenotype. Some neurons present heterogeneity in their firing, generally produced by expression of a specific conductance, but how additional conductances vary along in order to homeostatically regulate membrane excitability is less known. Dorsal cochlear nucleus principal neurons, fusiform neurons, display heterogeneous spontaneous action potential activity and thus represent an appropriate model to study the role of different conductances in establishing firing heterogeneity. Particularly, fusiform neurons are divided into quiet, with no spontaneous firing, or active neurons, presenting spontaneous, regular firing. These modes are determined by the expression levels of an intrinsic membrane conductance, an inwardly rectifying potassium current (IKir). In this work, we tested whether other subthreshold conductances vary homeostatically to maintain membrane excitability constant across the two subtypes. We found that Ih expression covaries specifically with IKir in order to maintain membrane resistance constant. The impact of Ih on membrane resistance is dependent on the level of IKir expression, being much smaller in quiet neurons with bigger IKir, but Ih variations are not relevant for creating the quiet and active phenotypes. Finally, we demonstrate that the individual proportion of each conductance, and not their absolute conductance, is relevant for determining the neuronal firing mode. We conclude that in fusiform neurons the variations of their different subthreshold conductances are limited to specific conductances in order to create firing heterogeneity and maintain membrane homeostasis. |
| first_indexed | 2024-12-13T04:47:59Z |
| format | Article |
| id | doaj.art-28eccc6789ac422baf2c2f1ec6f4c3d9 |
| institution | Directory Open Access Journal |
| issn | 1662-5102 |
| language | English |
| last_indexed | 2024-12-13T04:47:59Z |
| publishDate | 2016-10-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cellular Neuroscience |
| spelling | doaj.art-28eccc6789ac422baf2c2f1ec6f4c3d92022-12-21T23:59:05ZengFrontiers Media S.A.Frontiers in Cellular Neuroscience1662-51022016-10-011010.3389/fncel.2016.00249224019Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus.Cesar Celis Ceballos0Shuang Li1Antonio C Roque2Thanos Tzounopoulos3Ricardo M Leao4University of São PauloUniversity of PittsburghUniversity of São PauloUniversity of PittsburghUniversity os São PauloIn a neuronal population, several combinations of its ionic conductances are used to attain a specific firing phenotype. Some neurons present heterogeneity in their firing, generally produced by expression of a specific conductance, but how additional conductances vary along in order to homeostatically regulate membrane excitability is less known. Dorsal cochlear nucleus principal neurons, fusiform neurons, display heterogeneous spontaneous action potential activity and thus represent an appropriate model to study the role of different conductances in establishing firing heterogeneity. Particularly, fusiform neurons are divided into quiet, with no spontaneous firing, or active neurons, presenting spontaneous, regular firing. These modes are determined by the expression levels of an intrinsic membrane conductance, an inwardly rectifying potassium current (IKir). In this work, we tested whether other subthreshold conductances vary homeostatically to maintain membrane excitability constant across the two subtypes. We found that Ih expression covaries specifically with IKir in order to maintain membrane resistance constant. The impact of Ih on membrane resistance is dependent on the level of IKir expression, being much smaller in quiet neurons with bigger IKir, but Ih variations are not relevant for creating the quiet and active phenotypes. Finally, we demonstrate that the individual proportion of each conductance, and not their absolute conductance, is relevant for determining the neuronal firing mode. We conclude that in fusiform neurons the variations of their different subthreshold conductances are limited to specific conductances in order to create firing heterogeneity and maintain membrane homeostasis.http://journal.frontiersin.org/Journal/10.3389/fncel.2016.00249/fullCochlear NucleusIon Channelsinput resistanceIhSubthreshold currents |
| spellingShingle | Cesar Celis Ceballos Shuang Li Antonio C Roque Thanos Tzounopoulos Ricardo M Leao Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus. Frontiers in Cellular Neuroscience Cochlear Nucleus Ion Channels input resistance Ih Subthreshold currents |
| title | Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus. |
| title_full | Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus. |
| title_fullStr | Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus. |
| title_full_unstemmed | Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus. |
| title_short | Ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus. |
| title_sort | ih equalizes membrane input resistance in a heterogeneous population of fusiform neurons in the dorsal cochlear nucleus |
| topic | Cochlear Nucleus Ion Channels input resistance Ih Subthreshold currents |
| url | http://journal.frontiersin.org/Journal/10.3389/fncel.2016.00249/full |
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