Voltage-gated Na<sup>+</sup> channels enhance the temporal filtering properties of electrosensory neurons in the torus


Abstract:

Regenerative processes enhance postsynaptic potential (PSP) amplitude and behaviorally relevant temporal filtering in more than one-third of electrosensory neurons in the torus semicircularis of Eigenmannia. Data from in vivo current-clamp intracellular recordings indicate that these "regenerative PSPs" can be divided in two groups based on their half-amplitude durations: constant duration (CD) and variable duration (VD) PSPs. CD PSPs have half-amplitude durations of between 20 and 60 ms that do not vary in relation to stimulus periodicity. In contrast, the half-amplitude durations of VD PSPs vary in relation to stimulus periodicity and range from approximately 10 to 500 ms. Injection of 0.1 nA sinusoidal current through the recording electrode demonstrated that CD PSPs and not VD PSPs can be elicited by voltage fluctuations alone. In addition, CD PSPs were blocked by intracellular application of either QX-314 or QX-222, whereas VD PSPs were not. These in vivo data suggest, therefore, that CD PSPs are mediated by voltage-dependent Na+ conductances.

Año de publicación:

2003

Keywords:

    Fuente:

    scopusscopus

    Tipo de documento:

    Article

    Estado:

    Acceso restringido

    Áreas de conocimiento:

      Áreas temáticas de Dewey:

      • Sistemas fisiológicos específicos de los animales
      • Temas específicos de historia natural de los animales
      • Fisiología humana