Electrophysiology and pharmacology of outward potassium currents in semicircular canal hair cells of toadfish, Opsanus tau

Steinacker, A.; Monterrubio, J.; Perez, Rogelio; Mensinger, Allen F.; Marı́n, Antonio

doi:10.1016/s0378-5955(97)00038-5

Cited by 11 publications

(8 citation statements)

References 38 publications

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“…Basolateral currents have been characterized in type II hair cells from a variety of vestibular organs, including the horizontal crista of the toadfish (Steinacker et al 1997), various cristae of frogs (Marcotti et al 1999a;Masetto et al 1994;Norris et al 1992;Prigioni et al 1996;Russo et al 1995Russo et al , 1996, and vestibular organs of mammals Griguer et al 1993a;Holt et al 1999;Lennan et al 1999;Rennie and Ashmore 1991;Rennie et al 2001) and birds Masetto and Correia 1997;Masetto et al 2000;Weng and Correia 1999). Many of these studies are similar to ours in using solitary cells isolated by enzymatic dissociation (Griguer et al 1993a;Lang and Correia 1989;Lennan et al 1999;Rennie and Ashmore 1991;Rennie et al 2001).…”

Section: Comparison Of Our Type II Cells With Those Obtained From Othsupporting

confidence: 54%

Regional Analysis of Whole Cell Currents From Hair Cells of the Turtle Posterior Crista

Brichta¹,

Aubert

Eatock

et al. 2002

Journal of Neurophysiology

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Regional analysis of whole cell currents from hair cells of the turtle posterior crista. J Neurophysiol 88: 3259 -3278, 2002; 10.1152/jn.00770.2001. The turtle posterior crista is made up of two hemicristae, each consisting of a central zone containing type I and type II hair cells and a surrounding peripheral zone containing only type II hair cells and extending from the planum semilunatum to the nonsensory torus. Afferents from various regions of a hemicrista differ in their discharge properties. To see if afferent diversity is related to the basolateral currents of the hair cells innervated, we selectively harvested type I and II hair cells from the central zone and type II hair cells from two parts of the peripheral zone, one near the planum and the other near the torus. Voltage-dependent currents were studied with the whole cell, ruptured-patch method and characterized in voltage-clamp mode. We found regional differences in both outwardly and inwardly rectifying voltage-sensitive currents. As in birds and mammals, type I hair cells have a distinctive outwardly rectifying current (I K,L ), which begins activating at more hyperpolarized voltages than do the outward currents of type II hair cells. Activation of I K,L is slow and sigmoidal. Maximal outward conductances are large. Outward currents in type II cells vary in their activation kinetics. Cells with fast kinetics are associated with small conductances and with partial inactivation during 200-ms depolarizing voltage steps. Almost all type II cells in the peripheral zone and many in the central zone have fast kinetics. Some type II cells in the central zone have large outward currents with slow kinetics and little inactivation. Although these currents resemble I K,L , they can be distinguished from the latter both electrophysiologically and pharmacologically. There are two varieties of inwardly rectifying currents in type II hair cells: activation of I K1 is rapid and monoexponential, whereas that of I h is slow and sigmoidal. Many type II cells either have both inward currents or only have I K1 ; very few cells only have I h . Inward currents are less conspicuous in type I cells. Type II cells near the torus have smaller outwardly rectifying currents and larger inwardly rectifying currents than those near the planum, but the differences are too small to account for variations in discharge properties of bouton afferents innervating the two regions of the peripheral zone. The large outward conductances seen in central cells, by lowering impedances, may contribute to the low rotational gains of some central-zone afferents.

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Section: Comparison Of Our Type II Cells With Those Obtained From Othsupporting

confidence: 54%

Regional Analysis of Whole Cell Currents From Hair Cells of the Turtle Posterior Crista

Brichta¹,

Aubert

Eatock

et al. 2002

Journal of Neurophysiology

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“…In non-mammalian vertebrates, hair cells with greater expression of BK channels are capable of higher resonant frequencies and thus are better at encoding higher frequency sounds [101]. This has been shown to be the case in physiological recordings of dissociated hair cells from the closely related toadfish [104; 105; 106]. This led to the hypothesis that an increase in BK channel expression should be seen in reproductive animals whose saccules are better capable of encoding higher frequency ranges than non-reproductive animals (Fig.…”

Section: Seasonal Enhancement Of Hearingmentioning

confidence: 99%

Neuroendocrine control of seasonal plasticity in the auditory and vocal systems of fish

Forlano

Sisneros

Rohmann

et al. 2015

Frontiers in Neuroendocrinology

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Seasonal changes in reproductive-related vocal behavior are widespread among fishes. This review highlights recent studies of the vocal plainfin midshipman fish, Porichthys notatus, a neuroethological model system used for the past two decades to explore neural and endocrine mechanisms of vocal-acoustic social behaviors shared with tetrapods. Integrative approaches combining behavior, neurophysiology, neuropharmacology, neuroanatomy, and gene expression methodologies have taken advantage of simple, stereotyped and easily quantifiable behaviors controlled by discrete neural networks in this model system to enable discoveries such as the first demonstration of adaptive seasonal plasticity in the auditory periphery of a vertebrate as well as rapid steroid and neuropeptide effects on vocal physiology and behavior. This simple model system has now revealed cellular and molecular mechanisms underlying seasonal and steroid-driven auditory and vocal plasticity in the vertebrate brain.

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“…However, we and others (Kharkovets, et al, 2000; have detected KCNQ4 in the vestibular HCs at much earlier time points than both g K,L acquisition and calyx formation, suggesting that its expression in the vestibular HCs is not associated to the presence of either one of the type I HCs hallmarks. Indeed, calyx formation and g K,L acquisition in type I HCs have been shown to be completely independent from each other (Steinacker, et al, 1997;Rusch et al 1998). Furthermore, earlier reports on HC formation in mice lacking the neurotrophin receptors Ntrk2 and Ntrk3 have elegantly demonstrated that innervation is not required for HC formation and/or differentiation (Fritzsch, et al, 1997a;1997b).…”

Section: Type I and Type Ii Hcs Morphophysiological Maturation And Inmentioning

confidence: 99%

“…It was suggested that KCNQ4 detection only in type I but not in type II HCs was closely related to the presence of the calyx nerve ending innervating type I but not type II HCs. K + channels, including, including KCNQ4, are critical elements in the development and functional maturation of cochlea and vestibular HCs (Valli, et al, 1990;Steinacker, et al, 1997;Marcotti and Kros, 1999;Si, et al, 2003). Most past evidences suggest that neither calyx formation nor innervation of any kind is required for electrophysiological and morphological differentiation and maturation of type I and type II HCs (Bianchi et al 1996;Fritzsch et al 1997;Rusch et al 1998;Matei et al 2005).…”

Section: Introductionmentioning

confidence: 99%

Developmental expression of Kcnq4 in vestibular neurons and neurosensory epithelia

Rocha-Sánchez

Morris

Kachar³

et al. 2007

Brain Research

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Sensory signal transduction of the inner ear afferent neurons and hair cells (HCs) requires numerous ionic conductances. The KCNQ4 voltage-gated M-type potassium channel is thought to set the resting membrane potential in cochlear HCs. Here we describe the spatiotemporal expression patterns of Kcnq4 and the associated alternative splice forms in the HCs of vestibular labyrinth. Whole mount immunodetection, qualitative and quantitative RT-PCR were performed to characterize the expression patterns of Kcnq4 transcripts and proteins. A topographical expression and upregulation of Kcnq4 during development was observed and indicated that Kcnq4 is not restricted to either a specific vestibular structure or cell type, but is present in afferent calyxes, vestibular ganglion neurons, and both type I and type II HCs. Of the four alternative splice variants, Kcnq4_v1 transcripts were the predominant form in the HCs, while Kcnq4_v3 was the major variant in the vestibular neurons. Differential quantitative expression of Kcnq4_v1 and Kcnq4_v3 were respectively detected in the striolar and extra-striolar regions of the utricle and saccule. Analysis of gerbils and rats yielded results similar to those obtained in mice, suggesting that the spatiotemporal expression pattern of Kcnq4 in the vestibular system is conserved among rodents. Analyses of vestibular HCs of Bdnf conditional mutant mice, which are devoid of any innervation, demonstrate that regulation of Kcnq4 expression in vestibular HCs is independent of innervation.

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Electrophysiology and pharmacology of outward potassium currents in semicircular canal hair cells of toadfish, Opsanus tau

Cited by 11 publications

References 38 publications

Regional Analysis of Whole Cell Currents From Hair Cells of the Turtle Posterior Crista

Regional Analysis of Whole Cell Currents From Hair Cells of the Turtle Posterior Crista

Neuroendocrine control of seasonal plasticity in the auditory and vocal systems of fish

Developmental expression of Kcnq4 in vestibular neurons and neurosensory epithelia

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