Upper facial muscle activity and survival after hypoxic insult in rats

• Published in: Behavioural brain research Vol. 35; no. 1; p. 81
• Main Author: Paloheimo, M P
• Format: Journal Article
• Language: English
• Published: Netherlands 01.10.1989
• Subjects: Animals; Brain Death - physiopathology; Brain Stem - physiopathology; Electroencephalography; Electromyography; Evoked Potentials; Facial Muscles - innervation; Facial Nerve - physiopathology; Hypoxia, Brain - physiopathology; Male; Rats; Rats, Inbred Strains; Signal Processing, Computer-Assisted
• ISSN: 0166-4328
• DOI: 10.1016/S0166-4328(89)80011-7

Spontaneous cerebral biopotentials were monitored during and after hypoxic insults in 30 ketamine-anesthetized rats. Upper facial electromyographic (EMG, mean integrated amplitude) and electroencephalographic (mean zero cross frequency (ZXF) and mean integrated amplitude (MIA] data were recorded within 30 min after reoxygenation and cardiopulmonary resuscitation. The animals were separated into 2 groups based on 24 h survival. EMG in Survivors (n = 16) recovered regularly to pre-insult levels by 30 min after resuscitation. At this time, EMG activity was consistently low in Non-survivors. In contrast, ZXF and MIA, albeit sensitive hypoxia detectors, did not totally discriminate between Survivors and Non-survivors. Absent EMG in Non-survivors may have reflected irreversible hypoxic damage at the brainstem level.