Influence of Isoflurane Concentration and Hypoxia on Functional Magnetic Resonance Imaging for the Detection of Bicuculline-Induced Neuronal Activation

• Published in: Neuro-Signals Vol. 13; no. 3; pp. 144 - 149
• Main Authors: Abo, Masahiro, Suzuki, Masahiko, Senoo, Atushi, Miyano, Satoshi, Yamauchi, Hideki, Yonemoto, Kyozo, Watanabe, Shu, Edström, Lars
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland 01.01.2004
• Subjects: Anesthetics, Inhalation - pharmacology; Animals; Bicuculline - pharmacology; Blood Pressure - drug effects; Body Temperature - drug effects; Brain - blood supply; Brain - drug effects; Brain - physiology; Cerebrovascular Circulation - drug effects; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Interactions; GABA Antagonists - pharmacology; Hypoxia - diagnosis; Hypoxia - physiopathology; Isoflurane - pharmacology; Magnetic Resonance Imaging; Male; Neurons - drug effects; Neurons - physiology; Original Paper; Rats; Rats, Sprague-Dawley; Pharmacological stimulation; Hypoxia; Cerebral blood volume; Epileptic seizures; Functional MRI; Intravascular contrast agent; Bicuculline
• ISSN: 1424-862X; 1424-8638
• DOI: 10.1159/000076568

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°C are probably suitable for further fMRI studies.