The use of DCEEG to estimate functional and metabolic state of nervous tissue of the brain at hyper- and hypoventilation

Sergey Murik

doi:10.4236/wjns.2012.23027

Abstract

A pilot study has been made of the simultaneous DC potential and total slow electrical activity changes during modeling various metabolic and functional states of the human brain. The multi-electrode DCEEG recordings have been performed during the hyperventilation (frequent deep one-minute long breathing motions) and the hypoventilation (voluntary breath holding). It has been shown that the ischemic state occurring in hyperventilation is accompanied by the negative shift of DC potential and increase in the EEG rhythms amplitude. A distention of brain vessels during hypoventilation (voluntary breath-hold) and an improvement of blood supply and thus improvement of vital and functional state of neurons gave rise to an increase in the EEG rhythm amplitude too, though against a background of a positive DC-potential shift. Obtained results are considered with context the generation of the qualitatively different functional states of brain cells during hyper- and hypoventilation which is reflected in their resting potential and activity. The conducted study show the prospects for DCEEG and the method we used for DCEEG data processing to understand the character of functional and metabolic changes in the nervous tissue.

Highlights

In the first half of the last decade, there appeared a number of publications [1,2] considering full-band EEG as a promising method that could succeed the classical EEG
It is seen that hyperventilation has caused a negative shift of the DC potential and an increase of EEG rhythm amplitudes in the delta and beta ranges
Hyperventilation is considered as a model of weak ischemia [29]

Summary

Introduction

In the first half of the last decade, there appeared a number of publications [1,2] considering full-band EEG (fbEEG) as a promising method that could succeed the classical EEG. FbEEG implies macro-electrode recording of brain potentials in a wide frequency range from 0 to 100 Hz and higher. Very few electrophysiological studies using this method have been reported in recent years This can be partly attributed to the fact that the nature of DC potential is still unclear. The negative DC potential shift was considered as a reflection of depolarization processes in the neuroglial complex [4,5,11,12,13,14,15,16,17] Such understanding implied that the positive DC potential shift was responsible for re- or hyperpolarization of nervous tissue cells occurring under an active electrode

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