Skip to main content

Mechanisms of cortical high-gamma activity (60-200 Hz) investigated with computational modeling

High-gamma activity (HGA) at frequencies 60-200 Hz have been observed during task-related cortical activation in humans [1] and in animals [2], and have been used to map normal brain function and to decode commands in brain-computer interfaces. To understand the role that HGA plays in both normal and pathological brain states, deeper insights into its generating mechanisms are essential. Because the neural populations recorded by LFPs and EEG cannot be comprehensively recorded at scales that are likely to be relevant, we used a biologically based computational model of a cortical network to investigate the mechanisms generating HGA. The computational model included excitatory pyramidal regular-spiking and inhibitory fast-spiking neurons described by Hodgkin - Huxley dynamics. We compared activity generated by this model with HGA that was observed in LFP recorded in monkey somatosensory cortex during vibrotactile stimulation. Increase of firing rate and broadband HGA responses in LFP signals generated by the model were in agreement with experimental results (see Figure 1).

Figure 1

Comparison of high-gamma observed in vivo ( AB ) and simulated in the model ( CD ) during sensory stimulation for different stimulus amplitudes denoted G1, G2, G5 and G10. AC: average firing rate of neurons. BD: time - frequency maps of LFP signals.


The HGA appear to be mediated mostly by an excited population of inhibitory fast-spiking interneurons firing at high-gamma frequencies and pacing excitatory regular-spiking pyramidal cells, which fire at lower rates but in phase with the population rhythm. HGA reflects local cortical activation under normal conditions and as such is a good candidate for mapping cortical areas engaged by a specific task. The mechanisms of HGA, in this model of local cortical circuits, appear to be similar to those proposed for hippocampal ripples generated by subset of interneurons that regulate discharge of principal cells.


  1. 1.

    Crone NE, Sinai AS: A Korzeniewska High-frequency gamma oscillations and human brain mapping with electrocorticography. Prog Brain Res. 2006, 159: 275-295.

    PubMed  Article  Google Scholar 

  2. 2.

    Ray S, Hsiao SS, Crone NE, Franaszczuk PJ, Niebur E: Effect of stimulus intensity on the spike-local field potential relationship in the secondary somatosensory cortex. J Neurosci. 2008, 28: 7334-7343.

    PubMed  CAS  PubMed Central  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Piotr Suffczynski.

Rights and permissions

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Suffczynski, P., Crone, N.E. & Franaszczuk, P.J. Mechanisms of cortical high-gamma activity (60-200 Hz) investigated with computational modeling. BMC Neurosci 16, P73 (2015).

Download citation


  • Somatosensory Cortex
  • Cortical Activation
  • Principal Cell
  • Neural Population
  • Cortical Circuit