Synaptic activation of voltage-gated channels in the dendrites of hippocampal pyramidal neurons.
Activation of dendritic voltage-gated ion channels by local synaptic input was tested by simultaneous dendrite-attached patch-clamp recordings and whole-cell somatic voltage recordings made from CA1 pyramidal neurons in hippocampal slices. Schaffer collateral stimulation elicited subthreshold excitatory postsynaptic potentials (EPSPs) that opened voltage-gated sodium and calcium channels in the apical dendrites. The EPSP-activated sodium channels opened near the peak of the EPSP, whereas low voltage-activated calcium channels opened near the EPSP peak and during the decay phase. Dendritic high voltage-activated channels required somatic action potential generation or suprathreshold synaptic trains for activation. Dendritic voltage-gated channels are, therefore, likely to participate in dendritic integration of synaptic events.
Magee
J C
JC
Division of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA.
Johnston
D
D
D000200:Action Potentials; D000818:Animals; D015220:Calcium Channels / Q000378:metabolism; D003712:Dendrites / Q000502:physiology*; D015640:Ion Channel Gating; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015222:Sodium Channels / Q000378:metabolism; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission; D013779:Tetrodotoxin / Q000494:pharmacology
D015220:Calcium Channels; D015222:Sodium Channels; D013779:Tetrodotoxin