Expression and functional roles of Kv7/KCNQ/M-channels in rat medial entorhinal cortex layer II stellate cells.
The medial entorhinal cortex (MEC) is important for spatial navigation and memory. Stellate cells (SCs) of MEC layer II provide major input to the hippocampus, and are thought to be the neuronal correlate of the grid cells. Their electrophysiological properties have been used to explain grid field formation. However, little is known about the functional roles of potassium channels in SCs. M-current is a slowly activating potassium current, active at subthreshold potentials. Although some studies have suggested that Kv7/M-channels may affect subthreshold resonance in SCs, others have found no Kv7/M-current in these cells, so the expression and roles of Kv7/M-channels in SCs are still debated. Using whole-cell voltage-clamp, we have identified a typical M-current with pharmacological properties characteristic of Kv7/M-channels in rat MEC SCs. Current-clamp experiments showed that the specific Kv7/M-channel blocker XE991 increased SCs excitability, and reduced spike frequency adaptation. Our results demonstrate that Kv7/M-channels are expressed in SCs and contribute substantially to regulation of excitability in these cells.
Department of Physiology at the Institute of Basal Medical Sciences, University of Oslo, 0317 Oslo, Norway.
Maximiliano Jose
MJ
Nigro
Department of Physiology at the Institute of Basal Medical Sciences, University of Oslo, 0317 Oslo, Norway.
Pedro
P
Mateos-Aparicio
Department of Physiology at the Institute of Basal Medical Sciences, University of Oslo, 0317 Oslo, Norway j.s.storm@medisin.uio.no.
Johan F
JF
Storm
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D018728:Entorhinal Cortex / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015640:Ion Channel Gating / Q000187:drug effects / Q000502:physiology; D051656:KCNQ Potassium Channels / Q000378:metabolism*; D008297:Male; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
C112297:10,10-bis(4-pyridinylmethyl)-9(10H)-anthracenone; D000873:Anthracenes; D051656:KCNQ Potassium Channels; D026902:Potassium Channel Blockers