Modulation of calcium-activated potassium small conductance (SK) current in rat dopamine neurons of the ventral tegmental area.
Neurosci Lett
; 348(3): 180-4, 2003 Sep 18.
Article
em En
| MEDLINE
| ID: mdl-12932823
ABSTRACT
Block of calcium-sensitive potassium SK current (gKCa([SK])) by apamin or bicuculline methiodide potentiates burst firing in dopamine neurons in the presence of N-methyl-D-aspartate (NMDA). The purpose of this study was to test the hypothesis that calcium entry through NMDA-gated channels can potentiate gKCa([SK]) in dopamine neurons in the ventral tegmental area. We used microelectrodes to record an outward tail current that was evoked by membrane depolarization under single-electrode voltage-clamp. Using bicuculline methiodide (50 microM) as a reversible inhibitor of gKCa([SK]), we found that NMDA (15 microM) reduced the peak amplitude of the outward tail current by 39%. Contrary to expectations, our results suggest that stimulation of NMDA receptors reduces the calcium-activated potassium gKCa([SK]), an effect that could facilitate NMDA-dependent burst firing.
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Base de dados:
MEDLINE
Assunto principal:
Canais de Potássio
/
Dopamina
/
Área Tegmentar Ventral
/
Canais de Potássio Cálcio-Ativados
/
Neurônios
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article