NMDA receptor-mediated . . .

It was shown recently that the basal dendrites of cortical pyramidal neurons generate NMDA-spikes. In the present study, we made whole-cell recordings from hippocampal CA1 pyramidal neurons and examined whether NMDA receptor activation was involved in synaptic responses. At low input stimulus intens...

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Bibliographic Details
Main Authors: Ryosuke Enoki, Amane Koizumi, Go Sasaki
Other Authors: The Pennsylvania State University CiteSeerX Archives
Format: Text
Language:English
Published: 2004
Subjects:
Hippocampus
Pyramidal neuron
Basal dendrites
NMDA receptor
Depolarizing after-potential
Model simulation
Orca
Online Access:http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.132.5453
http://www.chiur.com/amane/down/enoki_neuroscires2004.pdf
Description
Summary:It was shown recently that the basal dendrites of cortical pyramidal neurons generate NMDA-spikes. In the present study, we made whole-cell recordings from hippocampal CA1 pyramidal neurons and examined whether NMDA receptor activation was involved in synaptic responses. At low input stimulus intensity, EPSPs with a fast decay time were induced. As the intensity of stimulation was increased in the presence of GABA receptor antagonists, a depolarizing after-potential (DAP) was generated in addition to a fast decaying potential. A DAP was never observed when the input was applied to the apical dendrites. The DAP was suppressed by hyperpolarization or by NMDA receptor antagonists, but not by Na +,K +,orCa 2+ channel blockers. One possible mechanism is that the morphology of the basal dendrites favors DAP generation. A compartmental model simulation showed that synaptic inputs to thinner shorter dendrites generated a potential that resembled a DAP. Our study shows that a synaptic input to the basal dendrites of a hippocampal pyramidal neuron can generate a NMDA receptor-mediated potential in the presence of GABA receptor blockade.

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