title: The development of electrocortical activity in the fetal and neonatal guinea pig.
abstract: We have developed techniques for chronic recording of electrocortical activity in the fetal and neonatal guinea pig with subsequent power spectral analysis. Thirty-four unanesthesized, unrestrained pregnant Hartley guinea pigs were studied 1 to 14 days following surgical procedures. Twelve neonatal animals instrumented during the first week of life were studied at 3 to 30 days. Spontaneous, undifferentiated electrocortical activity was recorded from the youngest fetuses studied, with high-voltage slow activity appearing at 50 days' gestation. Cycling electrocortical activity and sleep spindles could be observed in the late-term fetal and neonatal animals, with rapid eye movements and behavioral state defined in the latter. Power spectral analysis demonstrated more predominant delta activity, faster beta frequencies, and better-developed sleep spindles in the neonatal animal as compared to the fetus.
mesh_terms: D000703:Analog-Digital Conversion; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology; D002540:Cerebral Cortex / Q000502:physiology*; D004569:Electroencephalography / Q000379:methods*; D004576:Electromyography; D005260:Female; D005333:Fetus / Q000502:physiology*; D006168:Guinea Pigs / Q000502:physiology*; D008838:Microcomputers; D011247:Pregnancy