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Subcellular compartmentalization of a potassium channel (Kv1.4): preferential distribution in dendrites and dendritic spines of neurons in the dorsal cochlear nucleus

Authors

  • José M. Juiz,

    1. 1 Facultad de Medicina, Campus de Albacete, Universidad de Castilla-La Mancha, 02071, Albacete, Spain 2 Instituto de Neurociencias, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 3 Department of Biochemistry and Molecular Biology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 4 Department of Pharmacology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain
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    • These two authors made equally important contributions to this work.

  • 1 Rafael Luján,

    1. 1 Facultad de Medicina, Campus de Albacete, Universidad de Castilla-La Mancha, 02071, Albacete, Spain 2 Instituto de Neurociencias, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 3 Department of Biochemistry and Molecular Biology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 4 Department of Pharmacology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain
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    • These two authors made equally important contributions to this work.

  • 1 Eduardo Domínguez del Toro,

    1. 1 Facultad de Medicina, Campus de Albacete, Universidad de Castilla-La Mancha, 02071, Albacete, Spain 2 Instituto de Neurociencias, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 3 Department of Biochemistry and Molecular Biology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 4 Department of Pharmacology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain
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  • 2,3 V. Fuentes,

    1. 1 Facultad de Medicina, Campus de Albacete, Universidad de Castilla-La Mancha, 02071, Albacete, Spain 2 Instituto de Neurociencias, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 3 Department of Biochemistry and Molecular Biology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 4 Department of Pharmacology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain
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  • 2 Juan J. Ballesta,

    1. 1 Facultad de Medicina, Campus de Albacete, Universidad de Castilla-La Mancha, 02071, Albacete, Spain 2 Instituto de Neurociencias, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 3 Department of Biochemistry and Molecular Biology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 4 Department of Pharmacology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain
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  • and 2,4 Manuel Criado 1,3

    1. 1 Facultad de Medicina, Campus de Albacete, Universidad de Castilla-La Mancha, 02071, Albacete, Spain 2 Instituto de Neurociencias, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 3 Department of Biochemistry and Molecular Biology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain 4 Department of Pharmacology, Universidad Miguel Hernández, Campus de San Juan, 03550 San Juan, Alicante, Spain
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: Dr José M. Juiz, as above.
E-mail: juiz@med-ab.uclm.es

Abstract

Voltage-dependent ion channels have specific patterns of distribution along the neuronal plasma membrane of dendrites, cell bodies and axons, which need to be unravelled in order to understand their contribution to neuronal excitability and firing patterns. We have investigated the subcellular compartmentalization of Kv1.4, a transient, fast-inactivating potassium channel, in fusiform cells and related interneurons of the rat dorsal cochlear nucleus. A polyclonal antibody which binds to a region near the N-terminus domain of a Kv1.4 channel was raised in rabbits. Using a high-resolution combination of immunocytochemical methods, Kv1.4 was localized mainly in the apical dendritic trunks and cell bodies of fusiform cells, as well as in dendrites and cell bodies of interneurons of the dorsal cochlear nucleus, likely cartwheel cells. Quantitative immunogold immunocytochemistry revealed a pronounced distal to proximal gradient in the dendrosomatic distribution of Kv1.4. In plasma membrane localizations, Kv1.4 was preferentially present in dendritic spines, either in the spine neck or in perisynaptic locations, always away from the postsynaptic density. These findings indicate that Kv1.4 is largely distributed in dendritic compartments of fusiform and cartwheel cells of the dorsal cochlear nucleus. Its preferential localization in dendritic spines, where granule cell axons make powerful excitatory synapses, suggests a role for this voltage-dependent ion channel in the regulation of dendritic excitability and excitatory inputs.

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