Intrinsic subthreshold oscillations extend the influence of inhibitory synaptic inputs on cortical pyramidal neurons.
Fast inhibitory synaptic inputs, which cause conductance changes that typically last for 10-100 ms, participate in the generation and maintenance of cortical rhythms. We show here that these fast events can have influences that outlast the duration of the synaptic potentials by interacting with subthreshold membrane potential oscillations. Inhibitory postsynaptic potentials (IPSPs) in cortical neurons in vitro shifted the oscillatory phase for several seconds. The phase shift caused by two IPSPs or two current pulses summed non-linearly. Cholinergic neuromodulation increased the power of the oscillations and decreased the magnitude of the phase shifts. These results show that the intrinsic conductances of cortical pyramidal neurons can carry information about inhibitory inputs and can extend the integration window for synaptic input.
Stiefel
Klaus M
KM
Howard Hughes Medical Institute, Computational Neurobiology Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA. stiefel@salk.edu
Fellous
Jean-Marc
JM
Thomas
Peter J
PJ
Sejnowski
Terrence J
TJ
D000818:Animals; D000831:Animals, Newborn; D002540:Cerebral Cortex / Q000166:cytology*; D004558:Electric Stimulation / Q000379:methods; D066298:In Vitro Techniques; D053444:Inhibitory Postsynaptic Potentials / Q000502:physiology; D051379:Mice; D008959:Models, Neurological; D009431:Neural Conduction / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D017711:Nonlinear Dynamics; D018408:Patch-Clamp Techniques; D010507:Periodicity; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D013569:Synapses / Q000502:physiology*