Electrocortical activity in the near-term ovine fetus: Automated analysis using amplitude frequency components

• Published in: Brain research 2011-07, Vol.1402, p.30-37
• Main Authors: Keen, Ashley E, Frasch, Martin G, Sheehan, Melissa A, Matushewski, Brad J, Richardson, Bryan S
• Format: Article
• Language: English
• Subjects: Animals; Behavioural state; Biological and medical sciences; brain; Brain development; Brain Waves - physiology; Central nervous system; Cerebral Cortex - embryology; Cerebral Cortex - physiology; Electroencephalography - instrumentation; Electroencephalography - methods; Electrophysiology; Female; Fetal Monitoring - instrumentation; Fetal Monitoring - methods; Fetus; Fetus - physiology; Fundamental and applied biological sciences. Psychology; Neurology; Pregnancy; Reaction Time - physiology; Sheep; Signal Processing, Computer-Assisted - instrumentation; Time Factors; Vertebrates: nervous system and sense organs
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/j.brainres.2011.05.044

Abstract We have designed an automated method for analyzing electrocortical (ECoG) activity in the near-term ovine fetus to process and quantitatively classify large amounts of data rapidly and objectively. Seven chronically catheterized fetal sheep were studied for 8 h each at ~ 0.9 of gestation with continuous recording of ECoG activity using a computerized data acquisition system. Multiple ECoG amplitude and frequency parameters were scored from which we established animal specific parameter cut-off values as well as population based duration cut-off values to distinguish low-voltage/high frequency (LV/HF) and high-voltage/low frequency (HV/LF) state epochs, and indeterminate voltage/frequency (IV/F) and transition period activities. We have shown that the incidence of the predominant LV/HF and HV/LF activity states at 45% and 36% of the time, respectively, is comparable to that previously reported using semi-quantitative techniques with visual analysis. However, the duration of these state epochs is considerably shorter due to the detection of brief periods of IV/F activity which would be difficult to capture using visual analysis. Importantly, our findings in the healthy ovine fetus near-term using this automated ECoG scoring methodology now provide a framework from which to study maturational events in younger animals, and under adverse pregnancy conditions.