Journal of neuroscience methods
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J. Neurosci. Methods · Jul 2001
Removal of ECG interference from the EEG recordings in small animals using independent component analysis.
In experiments involving small animals, the electroencephalogram (EEG) recorded during severe injury and accompanying resuscitation exhibit the strong presence of electrocardiogram (ECG). For improved quantitative EEG (qEEG) analysis, it is therefore imperative to remove ECG interference from EEG. In this paper, we validate the use of independent component analysis (ICA) to effectively suppress the interference of ECG from EEG recordings during normal activity, asphyxia and recovery following asphyxia. ⋯ The improvement in normalized power spectrum of EEG obtained for all animals was 7.71+/-3.63 db at the 3rd minute of recovery and dropped to 1.15+/-0.60 db at 63rd minute. The application of ICA has been particularly useful when the power of EEG is low, such as that observed during early brain hypoxic-asphyxic injury. The method is also useful in situations where accurate indications of EEG signal power and frequency content are needed.
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J. Neurosci. Methods · Jul 2001
Visualization of rat pial microcirculation using the novel orthogonal polarized spectral (OPS) imaging after brain injury.
Recently, the novel optical system, orthogonal polarized spectral (OPS) imaging was developed to visualize microcirculation. Investigation of changes in microcirculation is essential for physiological, pathophysiological, and pharmacological studies. In the present study applicability of OPS imaging was assessed to study pial microcirculation in normal and traumatized rat brain. ⋯ In venules, mean flow velocity of 0.68+/-0.08 mm/s was significantly decreased by 50% at 30 min after trauma. OPS imaging is an easy to use optical system allowing to generate high quality images and to reliably investigate pial microcirculation without having to remove the dura. This technique opens the possibility to perform longitudinal studies investigating changes in pial microcirculation.