Action potential initiation in neocortical inhibitory interneurons.
PLoS Biol
; 12(9): e1001944, 2014 Sep.
Article
em En
| MEDLINE
| ID: mdl-25203314
ABSTRACT
Action potential (AP) generation in inhibitory interneurons is critical for cortical excitation-inhibition balance and information processing. However, it remains unclear what determines AP initiation in different interneurons. We focused on two predominant interneuron types in neocortex parvalbumin (PV)- and somatostatin (SST)-expressing neurons. Patch-clamp recording from mouse prefrontal cortical slices showed that axonal but not somatic Na+ channels exhibit different voltage-dependent properties. The minimal activation voltage of axonal channels in SST was substantially higher (â¼7 mV) than in PV cells, consistent with differences in AP thresholds. A more mixed distribution of high- and low-threshold channel subtypes at the axon initial segment (AIS) of SST cells may lead to these differences. Surprisingly, NaV1.2 was found accumulated at AIS of SST but not PV cells; reducing NaV1.2-mediated currents in interneurons promoted recurrent network activity. Together, our results reveal the molecular identity of axonal Na+ channels in interneurons and their contribution to AP generation and regulation of network activity.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potenciais de Ação
/
Córtex Pré-Frontal
/
Neocórtex
/
Interneurônios
/
Rede Nervosa
Limite:
Animals
Idioma:
En
Revista:
PLoS Biol
Assunto da revista:
BIOLOGIA
Ano de publicação:
2014
Tipo de documento:
Article
País de afiliação:
China