Optimal time scale for spike-time reliability: theory, simulations, and experiments.
Use of spike timing to encode information requires that neurons respond with high temporal precision and with high reliability. Fast fluctuating stimuli are known to result in highly reproducible spike times across trials, whereas constant stimuli result in variable spike times. Here, we first studied mathematically how spike-time reliability depends on the rapidness of aperiodic stimuli. Then, we tested our theoretical predictions in computer simulations of neuron models (Hodgkin-Huxley and modified quadratic integrate-and-fire), as well as in patch-clamp experiments with real neurons (mitral cells in the olfactory bulb and pyramidal cells in the neocortex). As predicted by our theory, we found that for firing frequencies in the beta/gamma range, spike-time reliability is maximal when the time scale of the input fluctuations (autocorrelation time) is in the range of a few milliseconds (2-5 ms), coinciding with the time scale of fast synapses, and decreases substantially for faster and slower inputs. Finally, we comment how these findings relate to mechanisms causing neuronal synchronization.
Galán
Roberto F
RF
Department of Biological Sciences, Carnegie Mellon University, Mellon Institute, 4400 Fifth Ave., Pittsburgh, Pennsylvania 15213, USA. galan@cnbc.cmu.edu
Ermentrout
G Bard
GB
Urban
Nathaniel N
NN
D000200:Action Potentials / Q000502:physiology*; D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D003344:Cortical Synchronization; D051379:Mice; D008959:Models, Neurological; D019579:Neocortex / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009830:Olfactory Bulb / Q000502:physiology*; D009924:Organ Culture Techniques; D017966:Pyramidal Cells / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000502:physiology*; D013997:Time Factors