Magnetic fields associated with anoxic depolarization in anesthetized rats.
We have performed simultaneous measurements of the DC-magnetoencephalogram (DC-MEG) and DC-electrocorticogram (DC-ECoG) in rats (n = 6) subjected to 90 s of reversible anoxia. The onset of major shifts of electric and magnetic signals occurred at 52 +/- 18 (S.D.) and 68 +/- 14 (S.D.), respectively, and reached a peak at 83 +/- 27 and 102 +/- 19 (S.D.) s, respectively, after termination of mechanical ventilation. DC-ECoG signal deflections were always associated with DC-MEG deflections. The time of onset and peak signals in both DC-MEG and DC-ECoG changes caused by asphyxia were highly correlated (r + 0.83, 0.94; P less than 0.05, 0.001; respectively). Our observations suggest that the non-invasive technique of DC-MEG is reliable and may provide insight into the mechanisms of anoxic cerebral depolarization.
Takanashi
Y
Y
Department of Neurology, Henry Ford Hospital, Detroit, MI 48202.
Chopp
M
M
Levine
S R
SR
Kim
J
J
Moran
J E
JE
Tepley
N
N
Chen
Q
Q
Barkley
G L
GL
Welch
K M
KM
D000768:Anesthesia, General; D000818:Animals; D001237:Asphyxia; D001921:Brain / Q000502:physiology* / Q000503:physiopathology; D004569:Electroencephalography; D000860:Hypoxia / Q000503:physiopathology*; D015225:Magnetoencephalography; D051381:Rats; D011919:Rats, Inbred Strains; D012121:Respiration, Artificial