K+ channel regulation of signal propagation in dendrites of hippocampal pyramidal neurons.
Pyramidal neurons receive tens of thousands of synaptic inputs on their dendrites. The dendrites dynamically alter the strengths of these synapses and coordinate them to produce an output in ways that are not well understood. Surprisingly, there turns out to be a very high density of transient A-type potassium ion channels in dendrites of hippocampal CA1 pyramidal neurons. These channels prevent initiation of an action potential in the dendrites, limit the back-propagation of action potentials into the dendrites, and reduce excitatory synaptic events. The channels act to prevent large, rapid dendritic depolarizations, thereby regulating orthograde and retrograde propagation of dendritic potentials.
Hoffman
D A
DA
Division of Neuroscience, Baylor College of Medicine, Houston, Texas 77030, USA.
Magee
J C
JC
Colbert
C M
CM
Johnston
D
D
D000200:Action Potentials; D000818:Animals; D002452:Cell Count; D003712:Dendrites / Q000378:metabolism*; D005071:Evoked Potentials; D006624:Hippocampus / Q000166:cytology; D066298:In Vitro Techniques; D018408:Patch-Clamp Techniques; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000378:metabolism*; D017966:Pyramidal Cells / Q000378:metabolism* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction
D026902:Potassium Channel Blockers; D015221:Potassium Channels