Na+-mediated coupling between AMPA receptors and KNa channels shapes synaptic transmission.
Na(+)-activated K(+) (K(Na)) channels are expressed in neurons and are activated by Na(+) influx through voltage-dependent channels or ionotropic receptors, yet their function remains unclear. Here we show that K(Na) channels are associated with AMPA receptors and that their activation depresses synaptic responses. Synaptic activation of K(Na) channels by Na(+) transients via AMPA receptors shapes the decay of AMPA-mediated current as well as the amplitude of the synaptic potential. Thus, the coupling between K(Na) channels and AMPA receptors by synaptically induced Na(+) transients represents an inherent negative feedback mechanism that scales down the magnitude of excitatory synaptic responses.
Nanou
Evanthia
E
Nobel Institute for Neurophysiology, Department of Neuroscience, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
Kyriakatos
Alexandros
A
Bhattacharjee
Arin
A
Kaczmarek
Leonard K
LK
Paratcha
Gustavo
G
El Manira
Abdeljabbar
A
D000818:Animals; D007798:Lampreys; D008564:Membrane Potentials / Q000502:physiology*; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D018091:Receptors, AMPA / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism*; D009435:Synaptic Transmission / Q000502:physiology*
D018091:Receptors, AMPA; D028021:Sodium-Potassium-Chloride Symporters