Conditional transgenic suppression of M channels in mouse brain reveals functions in neuronal excitability, resonance and behavior.
Nat Neurosci
; 8(1): 51-60, 2005 Jan.
Article
em En
| MEDLINE
| ID: mdl-15608631
ABSTRACT
In humans, mutations in the KCNQ2 or KCNQ3 potassium-channel genes are associated with an inherited epilepsy syndrome. We have studied the contribution of KCNQ/M-channels to the control of neuronal excitability by using transgenic mice that conditionally express dominant-negative KCNQ2 subunits in brain. We show that suppression of the neuronal M current in mice is associated with spontaneous seizures, behavioral hyperactivity and morphological changes in the hippocampus. Restriction of transgene expression to defined developmental periods revealed that M-channel activity is critical to the development of normal hippocampal morphology during the first postnatal weeks. Suppression of the M current after this critical period resulted in mice with signs of increased neuronal excitability and deficits in hippocampus-dependent spatial memory. M-current-deficient hippocampal CA1 pyramidal neurons showed increased excitability, reduced spike-frequency adaptation, attenuated medium afterhyperpolarization and reduced intrinsic subthreshold theta resonance. M channels are thus critical determinants of cellular and neuronal network excitability, postnatal brain development and cognitive performance.
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Base de dados:
MEDLINE
Assunto principal:
Comportamento Animal
/
Encéfalo
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Canais de Potássio de Abertura Dependente da Tensão da Membrana
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Epilepsia
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Proteínas do Tecido Nervoso
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Neurônios
Limite:
Animals
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article