Predicting spike timing of neocortical pyramidal neurons by simple threshold models.
Neurons generate spikes reliably with millisecond precision if driven by a fluctuating current--is it then possible to predict the spike timing knowing the input? We determined parameters of an adapting threshold model using data recorded in vitro from 24 layer 5 pyramidal neurons from rat somatosensory cortex, stimulated intracellularly by a fluctuating current simulating synaptic bombardment in vivo. The model generates output spikes whenever the membrane voltage (a filtered version of the input current) reaches a dynamic threshold. We find that for input currents with large fluctuation amplitude, up to 75% of the spike times can be predicted with a precision of +/-2 ms. Some of the intrinsic neuronal unreliability can be accounted for by a noisy threshold mechanism. Our results suggest that, under random current injection into the soma, (i) neuronal behavior in the subthreshold regime can be well approximated by a simple linear filter; and (ii) most of the nonlinearities are captured by a simple threshold process.
Jolivet
Renaud
R
Ecol Polytechnique Federale de Lausanne (EPFL), School of Computer and Communication Sciences and Brain Mind Institute, Station 15, CH-1015, Lausanne, Switzerland. renuad.jolivet@epfl.ch
Rauch
Alexander
A
Lüscher
Hans-Rudolf
HR
Gerstner
Wulfram
W
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D004056:Differential Threshold / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008959:Models, Neurological; D009433:Neural Inhibition; D017711:Nonlinear Dynamics; D011237:Predictive Value of Tests; D011336:Probability; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D011930:Reaction Time / Q000502:physiology*; D015203:Reproducibility of Results; D013003:Somatosensory Cortex / Q000166:cytology*; D013997:Time Factors