PT - JOURNAL ARTICLE
AU - Spyropoulos, Georgios
AU - Dowdall, Jarrod Robert
AU - SchÃ¶lvinck, Marieke Louise
AU - Bosman, Conrado Arturo
AU - Lima, Bruss
AU - Peter, Alina
AU - Onorato, Irene
AU - Klon-Lipok, Johanna
AU - Roese, Rasmus
AU - Neuenschwander, Sergio
AU - Singer, Wolf
AU - Vinck, Martin
AU - Fries, Pascal
TI - Spontaneous variability in gamma dynamics described by a linear harmonic oscillator driven by noise
AID - 10.1101/793729
DP - 2020 Jan 01
TA - bioRxiv
PG - 793729
4099 - http://biorxiv.org/content/early/2020/05/20/793729.short
4100 - http://biorxiv.org/content/early/2020/05/20/793729.full
AB - 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.