INVESTIGADORES
SPITZMAUL Guillermo Federico
artículos
Título:
The KCNQ5 potassium channel mediates a component of the afterhyperpolarization current in mouse hippocampus
Autor/es:
ANASTASSIOS V. TZINGOUNIS; MATTHIAS HEIDENREICH; TATJANA KHARKOVETS; GUILLERMO SPITZMAUL; HENRIK S. JENSEN; ROGER A. NICOLL; THOMAS J. JENTSCH
Revista:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Editorial:
NATL ACAD SCIENCES
Referencias:
Lugar: Washington, DC; Año: 2010 vol. 107 p. 12232 - 12237
ISSN:
0027-8424
Resumen:
Mutations in KCNQ2 and KCNQ3 voltage-gated
potassium channels lead to neonatal epilepsy as a consequence of their key role
in regulating neuronal excitability. Previous studies in the brain have focused
primarily on these KCNQ family members, which contribute to M-currents and afterhyperpolarization conductances in multiple brain areas. In
contrast, the function of KCNQ5 (Kv7.5), which also displays widespread
expression in the brain, is entirely unknown. Here, we developed mice that
carry a dominant negative mutation in theKCNQ5pore to probe whether it has a similar function as other KCNQ
channels. This mutation renders KCNQ5dn-containing homomeric and heteromeric
channels nonfunctional. We find that Kcnq5dn/dn mice are viable and
have normal brain morphology. Furthermore, expression and neuronal localization of KCNQ2 and KCNQ3 subunits are unchanged.
However, in the CA3 area of hippocampus, a region that highly expresses KCNQ5
channels, the medium and slow afterhyperpolarization currents are significantly
reduced. In contrast, neither current is affected in the CA1 area of the
hippocampus, a region with low KCNQ5 expression. Our results demonstrate that
KCNQ5 channels contribute to the afterhyperpolarization currents in hippocampus
in a cell type-specific manner.