Efferent and afferent vagal actions on cortical blood flow and kainic acid-induced seizure activity in urethane anesthetized rats.
Autonomic dysfunction during seizures can induce bradyarrhythmia via efferent vagal overactivity. We studied cardiovascular, brain blood flow, and electroencephalographic consequences of vagal stimulation during seizures in rats. Efferent vagal stimulation reduced seizure activity, completely suppressing it at high frequencies, by reducing heart rate, arterial pressure, and cortical blood flow. Afferent vagal activation was more variable, and the highest stimulation frequencies also appeared to reduce cortical blood flow. We conclude that efferent vagal activity can arrest ongoing seizure activity by ultimately decreasing hippocampal blood flow. Afferent vagal activity (which does not occur during seizures) may have a similar action.
Department of the Autonomic Nervous System, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan.
Harumi
H
Hotta
Nobuhiro
N
Watanabe
Rena
R
Orman
Mark
M
Stewart
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects / Q000502:physiology; D002540:Cerebral Cortex / Q000098:blood supply / Q000187:drug effects / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D007608:Kainic Acid / Q000633:toxicity; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects / Q000502:physiology*; D009476:Neurons, Efferent / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000139:chemically induced / Q000503:physiopathology*; D014520:Urethane / Q000494:pharmacology; D014630:Vagus Nerve / Q000187:drug effects / Q000502:physiology*
D014520:Urethane; D007608:Kainic Acid