title: Simultaneous fMRI and local field potential measurements during epileptic seizures in medetomidine-sedated rats using raser pulse sequence.
abstract: Simultaneous electrophysiological and functional magnetic resonance imaging measurements of animal models of epilepsy are methodologically challenging, but essential to better understand abnormal brain activity and hemodynamics during seizures. In this study, functional magnetic resonance imaging of medetomidine-sedated rats was performed using novel rapid acquisition by sequential excitation and refocusing (RASER) fast imaging pulse sequence and simultaneous local field potential measurements during kainic acid-induced seizures. The image distortion caused by the hippocampal-measuring electrode was clearly seen in echo planar imaging images, whereas no artifact was seen in RASER images. Robust blood oxygenation level-dependent responses were observed in the hippocampus during kainic acid-induced seizures. The recurrent epileptic seizures were detected in the local field potential signal after kainic acid injection. The presented combination of deep electrode local field potential measurements and functional magnetic resonance imaging under medetomidine anesthesia, which does not significantly suppress kainic acid-induced seizures, provides a unique tool for studying abnormal brain activity in rats.
authors: Department of Neurobiology, A. I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland.
authors: Antti M
authors: AM
authors: Airaksinen
authors: Juha-Pekka
authors: JP
authors: Niskanen
authors: Ryan
authors: R
authors: Chamberlain
authors: Joanna K
authors: JK
authors: Huttunen
authors: Jari
authors: J
authors: Nissinen
authors: Michael
authors: M
authors: Garwood
authors: Asla
authors: A
authors: Pitkänen
authors: Olli
authors: O
authors: Gröhn
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D004562:Electrocardiography / Q000187:drug effects / Q000379:methods*; D006993:Hypnotics and Sedatives / Q000008:administration & dosage; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D020926:Medetomidine / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D012640:Seizures / Q000503:physiopathology*; D012815:Signal Processing, Computer-Assisted
chemical_list: D006993:Hypnotics and Sedatives; D020926:Medetomidine