Ethanol effects on electrophysiological properties of astrocytes in striatal brain slices.

• Ethanol (EtOH) is known to alter neuronal physiology, but much less is known about the actions of this drug on glial function. To this end, we examined acute effects of ethanol on resting and voltage-activated membrane currents in striatal astrocytes using rat brain slices. Ten minutes exposure to 50mM EtOH reduced slope conductance by 20%, increased input resistance by 25% and decreased capacitance by 38% but did not affect resting membrane potential. Current generated by a hyperpolarizing pulse was inhibited in a concentration dependent manner in passive astrocytes, while no significant EtOH effect was observed in complex astrocytes or neurons. The EtOH effect was blocked when intracellular KCl was replaced with CsCl, but not during chelation of intracellular calcium with BAPTA. During blockage of gap junction coupling with high intracellular CaCl(2) or extracellular carbenoxolone the EtOH effect persisted but was reduced. Interestingly, EtOH effects were largely irreversible when gap junctions were open, but were fully reversible when gap junctions were closed. Ethanol also reduced the spread to other cells of Lucifer Yellow dye from individual glia filled via the patch pipette. These data suggest that EtOH inhibits a calcium-insensitive potassium channel, most likely a passive potassium channel, but also affects gap junction coupling in a way that is sustained after ethanol withdrawal. Astrocytes play a critical role in brain potassium homeostasis, and therefore EtOH effects on astrocytic function could influence neuronal activity.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Hälsovetenskap -- Beroendelära (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Health Sciences -- Substance Abuse (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Fysiologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Physiology (hsv//eng)

Nyckelord

1-Octanol

pharmacology

Animals

Astrocytes

drug effects

Calcium

physiology

Carbenoxolone

pharmacology

Cell Communication

drug effects

Cell Membrane Permeability

drug effects

Cesium

pharmacology

Chelating Agents

pharmacology

Chlorides

pharmacology

Corpus Striatum

cytology

Egtazic Acid

analogs & derivatives

pharmacology

Ethanol

antagonists & inhibitors

pharmacology

Fluorescent Dyes

analysis

Gap Junctions

drug effects

physiology

Ion Transport

drug effects

Isoquinolines

analysis

Membrane Potentials

drug effects

Microscopy

Fluorescence

Patch-Clamp Techniques

Potassium

physiology

Potassium Channels

drug effects

Potassium Chloride

pharmacology

Rats

Rats

Sprague-Dawley

Publikations- och innehållstyp

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art (ämneskategori)