Reduction of thalamic and cortical Ih by deletion of TRIP8b produces a mouse model of human absence epilepsy.
Neurobiol Dis
; 85: 81-92, 2016 Jan.
Article
em En
| MEDLINE
| ID: mdl-26459112
Absence seizures occur in several types of human epilepsy and result from widespread, synchronous feedback between the cortex and thalamus that produces brief episodes of loss of consciousness. Genetic rodent models have been invaluable for investigating the pathophysiological basis of these seizures. Here, we identify tetratricopeptide-containing Rab8b-interacting protein (TRIP8b) knockout mice as a new model of absence epilepsy, featuring spontaneous spike-wave discharges on electroencephalography (EEG) that are the electrographic hallmark of absence seizures. TRIP8b is an auxiliary subunit of the hyperpolarization-activated cyclic-nucleotide-gated (HCN) channels, which have previously been implicated in the pathogenesis of absence seizures. In contrast to mice lacking the pore-forming HCN channel subunit HCN2, TRIP8b knockout mice exhibited normal cardiac and motor function and a less severe seizure phenotype. Evaluating the circuit that underlies absence seizures, we found that TRIP8b knockout mice had significantly reduced HCN channel expression and function in thalamic-projecting cortical layer 5b neurons and thalamic relay neurons, but preserved function in inhibitory neurons of the reticular thalamic nucleus. Our results expand the known roles of TRIP8b and provide new insight into the region-specific functions of TRIP8b and HCN channels in constraining cortico-thalamo-cortical excitability.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tálamo
/
Córtex Cerebral
/
Epilepsia Tipo Ausência
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Proteínas de Membrana
/
Neurônios
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Neurobiol Dis
Assunto da revista:
NEUROLOGIA
Ano de publicação:
2016
Tipo de documento:
Article