Nicolò Meneghetti,
Alberto MazzoniGamma band neuronal oscillations are involved with sensory processing ubiquitously in the central nervous system. They emerge from the coordinated interaction of excitation and inhibition and are a biological marker of local active network computations [1]. Visual features as contrast and orientation are known to modulate broad band gamma activity in the primary visual cortex (V1) of primates [2]. In mouse V1, however, a narrow band within gamma oscillation was found to display specific functional sensitivity to visual features [3].
Here we present a network of recurrent excitatory-inhibitory spiking neurons reproducing the gamma narrow band dynamics in mouse V1 observed in [3], building on previous works of our group [4], [5]. By combining experimental data analysis and simulations, we show that a proper design of the simulated thalamic input results in the network to exhibit both narrow and broad band gamma activity.
We reproduced the spectral and temporal modulations of V1 local field potentials of awake mice presented with gratings of different contrast levels by approximating the thalamic input rate with two linear functions defined over complementary contrast ranges. We propose a theoretical framework in which the external thalamic drive is responsible for inducing the emergence of broad by triggering cortical resonances and narrow band gamma activity by inducing entrainment to an oscillatory drive. Our results support in particular the hypothesis of a subcortical origin of the narrow gamma band [3].
Our network provides a simple and effective model of contrast-induced gamma activity in rodents V1. The model could be easily extended to reproduce the modulation of V1 gamma activity induced by other visual stimulus features. Moreover, the model could help to investigate network dynamics responsible for pathological dysfunctions of physiological visual information processing in mice.
Acknowledgements
This work was supported by the Italian Ministry of Research (MIUR, PRIN2017, PROTECTION, project 20178L7WRS).
References
[1] G. Buzsáki and X.-J. Wang. Mechanisms of Gamma Oscillations. Annu. Rev. Neurosci. 2012, 35(1), 203-225
[2] J. A. Henrie and R. Shapley. LFP Power Spectra in V1 Cortex: The Graded Effect of Stimulus Contrast. Journal of Neurophysiology 2005, 94(1), 479-490
[3] A. B. Saleem et al. Subcortical Source and Modulation of the Narrowband Gamma Oscillation in Mouse Visual Cortex. Neuron 2017, 93(2), 315-322
[4] A. Mazzoni et al. Cortical dynamics during naturalistic sensory stimulations: Experiments and models. Journal of Physiology-Paris 2011, 105(1-3), 2-15
[5] A. Mazzoni et al. Computing the Local Field Potential (LFP) from Integrate-and-Fire Network Models. PLoS Comput Biol 2015,11(12), e1004584
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