Somatic localization of a specific large-conductance calcium-activated potassium channel subtype controls compartmentalized ethanol sensitivity in the nucleus accumbens
Authors
Martin, Gilles E.Puig, Sylvie I.
Pietrzykowski, Andrzej Z.
Feinberg-Zadek, Paula L.
Emery, Patrick
Treistman, Steven N.
UMass Chan Affiliations
Martin LabGraduate School of Biomedical Sciences, Neuroscience Program
Treistman Lab
Emery Lab
Neurobiology
Document Type
Journal ArticlePublication Date
2004-07-23Keywords
Action PotentialsAnimals
Calcium
Cell Compartmentation
Cell Line
Cells, Cultured
Dendrites
Electric Conductivity
Ethanol
Humans
Ion Channel Gating
Kinetics
Large-Conductance Calcium-Activated Potassium Channels
Male
Neurons
Nucleus Accumbens
Patch-Clamp Techniques
Potassium Channels, Calcium-Activated
Protein Subunits
RNA, Messenger
Rats
Rats, Sprague-Dawley
Neuroscience and Neurobiology
Metadata
Show full item recordAbstract
Alcohol is an addictive drug that targets a variety of ion channels and receptors. To address whether the effects of alcohol are compartment specific (soma vs dendrite), we examined the effects of ethanol (EtOH) on large-conductance calcium-activated potassium channels (BK) in cell bodies and dendrites of freshly isolated neurons from the rat nucleus accumbens (NAcc), a region known to be critical for the development of addiction. Compartment-specific drug action was indeed observed. Clinically relevant concentrations of EtOH increased somatic but not dendritic BK channel open probability. Electrophysiological single-channel recordings and pharmacological analysis of the BK channel in excised patches from each region indicated a number of differences, suggestive of a compartment-specific expression of the beta4 subunit of the BK channel, that might explain the differential alcohol sensitivity. These parameters included activation kinetics, calcium dependency, and toxin blockade. Reverse transcription-PCR showed that both BK channel beta1 and beta4 subunit mRNAs are found in the NAcc, although the signal for beta1 is significantly weaker. Immunohistochemistry revealed that beta1 subunits were found in both soma and dendrites, whereas beta4 appeared restricted to the soma. These findings suggest that the beta4 subunit may confer EtOH sensitivity to somatic BK channels, whereas the absence of beta4 in the dendrite results in insensitivity to the drug. Consistent with this idea, acute EtOH potentiated alphabeta4 BK currents in transfected human embryonic kidney cells, whereas it failed to alter alphabeta1 BK channel-mediated currents. Finally, an EtOH concentration (50 mm) that increased BK channel open probability strongly decreased the duration of somatic-generated action potential in NAcc neurons.Source
J Neurosci. 2004 Jul 21;24(29):6563-72. Link to article on publisher's site
DOI
10.1523/JNEUROSCI.0684-04.2004Permanent Link to this Item
http://hdl.handle.net/20.500.14038/38301PubMed ID
15269268Notes
Co-author Paula L. Feinberg-Zadek is a student in the Neuroscience program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.
Related Resources
Rights
Publisher PDF posted after 6 months as allowed by the publisher's author rights policy at http://www.jneurosci.org/sites/default/files/files/JN_License_to_Publish.pdf.ae974a485f413a2113503eed53cd6c53
10.1523/JNEUROSCI.0684-04.2004