Influence of isoflurane concentration and hypoxia on functional magnetic resonance imaging for the detection of bicuculline-induced neuronal activation.
Our present study shows that transient changes in relative cerebral blood volume (rCBV) induced by stimulation with bicuculline under six different conditions of anesthesia can be detected with high spatial resolution functional magnetic resonance imaging (fMRI). Bicuculline was administered at a low dose to induce neural activation, and no seizure activity was noted. Of the six conditions, the maximal reaction to bicuculline was observed under 1.5% isoflurane in 60% nitrogen and 40% oxygen. Our results imply that the rCBV changes under this level of isoflurane anesthesia with body temperature maintained at 37.5 degrees C are probably suitable for further fMRI studies.
Abo
Masahiro
M
Department of Rehabilitation Medicine, Jikei University School of Medicine, Tokyo, Japan. abo@jikei.ac.jp
Suzuki
Masahiko
M
Senoo
Atushi
A
Miyano
Satoshi
S
Yamauchi
Hideki
H
Yonemoto
Kyozo
K
Watanabe
Shu
S
Edström
Lars
L
D018685:Anesthetics, Inhalation / Q000494:pharmacology; D000818:Animals; D001640:Bicuculline / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D001921:Brain / Q000098:blood supply / Q000187:drug effects* / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004347:Drug Interactions; D018756:GABA Antagonists / Q000494:pharmacology; D000860:Hypoxia / Q000175:diagnosis / Q000503:physiopathology*; D007530:Isoflurane / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging; D008297:Male; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley
D018685:Anesthetics, Inhalation; D018756:GABA Antagonists; D007530:Isoflurane; D001640:Bicuculline