๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Identification of the delayed rectifier potassium channel, Kv1.6, in cultured astrocytes

โœ Scribed by Sharon L. Smart; Martha M. Bosma; Bruce L. Tempel

Publisher
John Wiley and Sons
Year
1997
Tongue
English
Weight
162 KB
Volume
20
Category
Article
ISSN
0894-1491

No coin nor oath required. For personal study only.

โœฆ Synopsis

Astrocytes are an abundant glial cell type of the central nervous system that appear to play a role in regulating extracellular potassium concentrations in brain, thereby contributing to the maintenance of normal neuronal activity. Voltage-gated potassium conductances, shown to be present in astrocytes, may be involved in this and other astrocytic functions. Toward defining the role of voltage-gated potassium channels in astrocytes, total RNA prepared from cultured mouse cortical astrocytes was screened, using a reverse transcriptase-polymerase chain reaction (RT-PCR) approach, for the expression of several members of the Shaker-like potassium channel subfamily (Kv1.1-Kv1.6). A relatively high level of Kv1.6 transcript was identified by RT-PCR and then confirmed and quantitated by ribonuclease protection assays using a Kv1.6-specific riboprobe. Immunocytochemical staining showed double-labeling of glial fibrillary acidic protein-positive cells with antibody specific for the Kv1.6 channel. The Kv1.6 protein expression was variable among the individual astrocytes. Outward voltage-gated currents were studied in astrocytes in primary culture using the Nystatin-perforated patch voltage clamp technique. Outward potassium currents were observed in all cells studied, and this current was partially blocked by perfusion with 100 nM dendrotoxin (DTX) in 14 of 16 cells tested. This DTX-sensitive current appeared to be a sustained outward potassium current, consistent with the suggestion that the Shaker-like potassium channel Kv1.6 underlies a portion of the delayed rectifier potassium current in cultured mouse cortical astrocytes.

๐Ÿ“œ SIMILAR VOLUMES

Sustained upregulation in embryonic spin
Sustained upregulation in embryonic spinal neurons of a Kv3.1 potassium channel gene encoding a delayed rectifier current
โœ Gurantz, Devorah ;Lautermilch, Nathan J. ;Watt, Stephen D. ;Spitzer, Nicholas C. ๐Ÿ“‚ Article ๐Ÿ“… 2000 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 229 KB ๐Ÿ‘ 1 views

Differentiation of electrical excitability entails changes in the currents that generate action potentials in spinal neurons of Xenopus embryos, resulting in reduced calcium entry during impulses generated at later stages of development. A dramatic increase in delayed rectifier current (I Kv ) durin

When, where, and how much? Expression of
When, where, and how much? Expression of the Kv3.1 potassium channel in high-frequency firing neurons
โœ Gan, Li ;Kaczmarek, Leonard K. ๐Ÿ“‚ Article ๐Ÿ“… 1998 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 246 KB ๐Ÿ‘ 1 views

The Kv3.1 potassium channel gene is expressed in neurons that fire action potentials at high frequencies. Neurons that express this gene, such as auditory brain stem neurons, have high-threshold voltage-dependent potassium currents that activate and deactivate unusually rapidly, and whose characteri

Mutation analysis of the inwardly rectif
Mutation analysis of the inwardly rectifying K+ channels KCNJ6 (GIRK2) and KCNJ3 (GIRK1) in juvenile myoclonic epilepsy
โœ Hallmann, Kerstin; Durner, Martina; Sander, Thomas; Steinlein, Ortrud K. ๐Ÿ“‚ Article ๐Ÿ“… 2000 ๐Ÿ› John Wiley and Sons ๐ŸŒ English โš– 30 KB ๐Ÿ‘ 1 views

Genetic factors play a major role in the etiology of idiopathic generalized epilepsy. However, in most syndromes, especially the common ones, multiple genetic factors seem to be involved. Mutations in K + channel genes have previously found to be associated with epilepsy both in humans and in mice.