Pyramidal cell-to-inhibitory cell spike transduction explicable by active dendritic conductances in inhibitory cell.
In the guinea-pig hippocampal CA3 region, the synaptic connection from pyramidal neurons to stratum pyramidale inhibitory neurons is remarkable. Anatomically, the connection usually consists of a single release site on an interneuronal dendrite, sometimes 200 microns or more from the soma. Nevertheless, the connection is physiologically powerful, in that a single presynaptic action potential can evoke, with probability 0.1 to 0.6, a postsynaptic action potential with latency 2 to 6 ms. We construct a model interneuron and show that the anatomical and physiological observations can be reconciled if the interneuron dendrites are electrically excitable. Excitable dendrites could also account for depolarization-induced amplification of the pyramidal cell-interneuron EPSP in the voltage range subthreshold for spike generation.
Traub
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RD
IBM Research Division, T.J. Watson Research Center, Yorktown Heights, NY 10598, USA.
Miles
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R
D000200:Action Potentials; D000818:Animals; D001369:Axons / Q000502:physiology; D002450:Cell Communication; D003712:Dendrites / Q000502:physiology*; D004553:Electric Conductivity; D005071:Evoked Potentials; D006168:Guinea Pigs; D006624:Hippocampus / Q000502:physiology*; D066298:In Vitro Techniques; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D017966:Pyramidal Cells / Q000502:physiology*; D015398:Signal Transduction; D013569:Synapses / Q000502:physiology*; D013997:Time Factors