Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons
The O-LM cell type mediates feedback inhibition onto hippocampal pyramidal cells and gates information flow in the CA1. Its functions depend on the presence of voltage-gated channels (VGCs), which affect its integrative properties and response to synaptic input. Given the challenges associated with...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-02-01
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| Series: | Frontiers in Synaptic Neuroscience |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fnsyn.2015.00002/full |
| _version_ | 1818470413349421056 |
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| author | Vladislav eSekulic Vladislav eSekulic Tse-Chiang eChen J. Josh eLawrence J. Josh eLawrence Frances K. Skinner Frances K. Skinner Frances K. Skinner |
| author_facet | Vladislav eSekulic Vladislav eSekulic Tse-Chiang eChen J. Josh eLawrence J. Josh eLawrence Frances K. Skinner Frances K. Skinner Frances K. Skinner |
| author_sort | Vladislav eSekulic |
| collection | DOAJ |
| description | The O-LM cell type mediates feedback inhibition onto hippocampal pyramidal cells and gates information flow in the CA1. Its functions depend on the presence of voltage-gated channels (VGCs), which affect its integrative properties and response to synaptic input. Given the challenges associated with determining densities and distributions of VGCs on interneuron dendrites, we take advantage of computational modeling to consider different possibilities. In this work, we focus on hyperpolarization-activated channels (h-channels) in O-LM cells. While h-channels are known to be present in O-LM cells, it is unknown whether they are present on their dendrites. In previous work, we used ensemble modeling techniques with experimental data to obtain insights into potentially important conductance balances. We found that the best O-LM models that included uniformly distributed h-channels in the dendrites could not fully capture the sag response. This led us to examine activation kinetics and non-uniform distributions of h-channels in the present work. In tuning our models, we found that different kinetics and non-uniform distributions could better reproduce experimental O-LM cell responses. In contrast to CA1 pyramidal cells where higher conductance densities of h-channels occur in more distal dendrites, decreasing conductance densities of h-channels away from the soma were observed in O-LM models. Via an illustrative scenario, we showed that having dendritic h-channels clearly speeds up back-propagating action potentials in O-LM cells, unlike when h-channels are present only in the soma. Although the present results were morphology-dependent, our work shows that it should be possible to determine the distributions and characteristics of O-LM cells with recordings and morphologies from the same cell. We hypothesize that h-channels are distributed in O-LM cell dendrites and endow them with particular synaptic integration properties that shape information flow in hippocampus. |
| first_indexed | 2024-04-13T21:37:03Z |
| format | Article |
| id | doaj.art-79b7d6618bbd4d62a708b91a71fb183f |
| institution | Directory Open Access Journal |
| issn | 1663-3563 |
| language | English |
| last_indexed | 2024-04-13T21:37:03Z |
| publishDate | 2015-02-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Synaptic Neuroscience |
| spelling | doaj.art-79b7d6618bbd4d62a708b91a71fb183f2022-12-22T02:28:56ZengFrontiers Media S.A.Frontiers in Synaptic Neuroscience1663-35632015-02-01710.3389/fnsyn.2015.00002113143Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneuronsVladislav eSekulic0Vladislav eSekulic1Tse-Chiang eChen2J. Josh eLawrence3J. Josh eLawrence4Frances K. Skinner5Frances K. Skinner6Frances K. Skinner7Toronto Western Research InstituteUniversity of TorontoToronto Western Research InstituteUniversity of MontanaUniversity of MontanaToronto Western Research InstituteUniversity of TorontoUniversity of TorontoThe O-LM cell type mediates feedback inhibition onto hippocampal pyramidal cells and gates information flow in the CA1. Its functions depend on the presence of voltage-gated channels (VGCs), which affect its integrative properties and response to synaptic input. Given the challenges associated with determining densities and distributions of VGCs on interneuron dendrites, we take advantage of computational modeling to consider different possibilities. In this work, we focus on hyperpolarization-activated channels (h-channels) in O-LM cells. While h-channels are known to be present in O-LM cells, it is unknown whether they are present on their dendrites. In previous work, we used ensemble modeling techniques with experimental data to obtain insights into potentially important conductance balances. We found that the best O-LM models that included uniformly distributed h-channels in the dendrites could not fully capture the sag response. This led us to examine activation kinetics and non-uniform distributions of h-channels in the present work. In tuning our models, we found that different kinetics and non-uniform distributions could better reproduce experimental O-LM cell responses. In contrast to CA1 pyramidal cells where higher conductance densities of h-channels occur in more distal dendrites, decreasing conductance densities of h-channels away from the soma were observed in O-LM models. Via an illustrative scenario, we showed that having dendritic h-channels clearly speeds up back-propagating action potentials in O-LM cells, unlike when h-channels are present only in the soma. Although the present results were morphology-dependent, our work shows that it should be possible to determine the distributions and characteristics of O-LM cells with recordings and morphologies from the same cell. We hypothesize that h-channels are distributed in O-LM cell dendrites and endow them with particular synaptic integration properties that shape information flow in hippocampus.http://journal.frontiersin.org/Journal/10.3389/fnsyn.2015.00002/fullDendritesHippocampusInterneuronsmulti-compartment modelIhh-channels |
| spellingShingle | Vladislav eSekulic Vladislav eSekulic Tse-Chiang eChen J. Josh eLawrence J. Josh eLawrence Frances K. Skinner Frances K. Skinner Frances K. Skinner Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons Frontiers in Synaptic Neuroscience Dendrites Hippocampus Interneurons multi-compartment model Ih h-channels |
| title | Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons |
| title_full | Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons |
| title_fullStr | Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons |
| title_full_unstemmed | Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons |
| title_short | Dendritic distributions of Ih channels in experimentally-derived multi-compartment models of oriens-lacunosum/moleculare (O-LM) hippocampal interneurons |
| title_sort | dendritic distributions of ih channels in experimentally derived multi compartment models of oriens lacunosum moleculare o lm hippocampal interneurons |
| topic | Dendrites Hippocampus Interneurons multi-compartment model Ih h-channels |
| url | http://journal.frontiersin.org/Journal/10.3389/fnsyn.2015.00002/full |
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