Irregular firing of isolated cortical interneurons in vitro driven by intrinsic stochastic mechanisms.
Pharmacologically isolated GABAergic irregular spiking and stuttering interneurons in the mouse visual cortex display highly irregular spike times, with high coefficients of variation approximately 0.9-3, in response to a depolarizing, constant current input. This is in marked contrast to cortical pyramidal cells, which spike quite regularly in response to the same current injection. We applied time-series analysis methods to show that the irregular behavior of the interneurons was not a consequence of low-dimensional, deterministic processes. These methods were also applied to the Hindmarsh and Rose neuronal model to confirm that the methods are adequate for the types of data under investigation. This result has important consequences for the origin of fluctuations observed in the cortex in vivo.
Computational Neuroscience Laboratory, Howard Hughes Medical Institute, Salk Institute for Biological Studies, La Jolla, CA 92037, USA. benglitz@salk.edu
Bernhard
B
Englitz
Klaus M
KM
Stiefel
Terrence J
TJ
Sejnowski
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D003198:Computer Simulation; D003344:Cortical Synchronization; D007395:Interneurons / Q000502:physiology*; D051379:Mice; D008959:Models, Neurological; D009433:Neural Inhibition / Q000502:physiology; D017711:Nonlinear Dynamics; D010507:Periodicity; D017966:Pyramidal Cells / Q000502:physiology; D051381:Rats; D013269:Stochastic Processes; D009435:Synaptic Transmission / Q000502:physiology; D013997:Time Factors; D014793:Visual Cortex / Q000502:physiology*