Abstract
Local field potentials (LFPs) are widely used to study the function of local networks in the brain. They are also closely correlated with the blood-oxygen-level-dependent signal, the predominant contrast mechanism in functional magnetic resonance imaging. We developed a new laminar cortex model (LCM) to simulate the amplitude and frequency of LFPs. Our model combines the laminar architecture of the cerebral cortex and multiple continuum models to simulate the collective activity of cortical neurons. The five cortical layers (layer I, II/III, IV, V, and VI) are simulated as separate continuum models between which there are synaptic connections. The LCM was used to simulate the dynamics of the visual cortex under different conditions of visual stimulation. LFPs are reported for two kinds of visual stimulation: general visual stimulation and intermittent light stimulation. The power spectra of LFPs were calculated and compared with existing empirical data. The LCM was able to produce spontaneous LFPs exhibiting frequency-inverse (1/ƒ) power spectrum behaviour. Laminar profiles of current source density showed similarities to experimental data. General stimulation enhanced the oscillation of LFPs corresponding to gamma frequencies. During simulated intermittent light stimulation, the LCM captured the fundamental as well as high order harmonics as previously reported. The power spectrum expected with a reduction in layer IV neurons, often observed with focal cortical dysplasias associated with epilepsy was also simulated.
Highlights
Neuronal activity changes the distribution of electric potentials in the brain [1,2]
Local field potentials (LFPs) are low-frequency fluctuations of the electric fields produced by the brain
LFPs reflect the activity of neurons within a few square millimeters of the cerebral cortex, an area containing more than 10,000 neurons
Summary
Neuronal activity changes the distribution of electric potentials in the brain [1,2]. Local field potentials (LFPs) are the lowfrequency (,100 Hz) fluctuations in electric potentials in the extracellular space of the brain [2,3]. They represent a weighted average of the potential changes produced by neuronal activity in a small volume around the measuring electrode [4,5]. A major difficulty with this paradigm is that LFPs reflect the activity of more than 10,000 neurons [11] within 250 micrometres of the recording electrode [4,5] Simultaneous measurement of such a large number of neuron activities has not been achieved to date. Multiple concurrent processes contribute to LFPs, including action potentials, synaptic transmission, glial activity, and even extracellular space diffusion [12] and are difficult to disambiguate
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
