%0 Journal Article
%A Spyropoulos, Georgios
%A Dowdall, Jarrod Robert
%A SchÃ¶lvinck, Marieke Louise
%A Bosman, Conrado Arturo
%A Lima, Bruss
%A Peter, Alina
%A Onorato, Irene
%A Klon-Lipok, Johanna
%A Roese, Rasmus
%A Neuenschwander, Sergio
%A Singer, Wolf
%A Vinck, Martin
%A Fries, Pascal
%T Spontaneous variability in gamma dynamics described by a linear harmonic oscillator driven by noise
%D 2020
%R 10.1101/793729
%J bioRxiv
%P 793729
%X Circuits of excitatory and inhibitory neurons can generate rhythmic activity in the gamma frequency-range (30-80Hz). Individual gamma-cycles show spontaneous variability in amplitude and duration. The mechanisms underlying this variability are not fully understood. We recorded local-field-potentials (LFPs) and spikes from awake macaque V1, and developed a noise-robust method to detect gamma-cycle amplitudes and durations. Amplitudes and durations showed a weak but positive correlation. This correlation, and the joint amplitude-duration distribution, is well reproduced by a dampened harmonic oscillator driven by stochastic noise. We show that this model accurately fits LFP power spectra and is equivalent to a linear PING (Pyramidal Interneuron Network Gamma) circuit. The model recapitulates two additional features of V1 gamma: (1) Amplitude-duration correlations decrease with oscillation strength; (2) Amplitudes and durations exhibit strong and weak autocorrelations, respectively, depending on oscillation strength. Finally, longer gamma-cycles are associated with stronger spike-synchrony, but lower spike-rates in both (putative) excitatory and inhibitory neurons. In sum, V1 gamma-dynamics are well described by the simplest possible model of gamma: A linear harmonic oscillator driven by noise.Competing Interest StatementThe authors have declared no competing interest.
%U https://www.biorxiv.org/content/biorxiv/early/2020/05/20/793729.full.pdf