title: Effect of midazolam on memory: a study of process dissociation procedure and functional magnetic resonance imaging.
abstract: To assess the effects of midazolam on explicit and implicit memories, 12 volunteers were randomly divided into the two groups: one with an Observer's Assessment of Alertness/Sedation score of 3 (mild sedation) and one with a score of 1 (deep sedation). Blood oxygen-level-dependent functional magnetic resonance imaging was measured before and during an auditory stimulus, then with midazolam sedation, and then during a second auditory stimulus with continuous midazolam sedation. After 4 h, explicit and implicit memories were assessed. There was no evidence of explicit memory at the two levels of midazolam sedation. Implicit memory was retained at a mild level of midazolam sedation but absent at a deep level of midazolam sedation. At a mild level of midazolam sedation, activation of all brain areas by auditory stimulus (as measured by functional magnetic resonance imaging) was uninhibited. However, a deep level of midazolam sedation depressed activation of the superior temporal gyrus by auditory stimulus. We conclude that midazolam does not abolish implicit memory at a mild sedation level, but can abolish both explicit and implicit memories at a deep sedation level. The superior temporal gyrus may be one of the target areas.
authors.affiliation:  Visiting Anaesthetist.
authors.forename: S Y
authors.initials: SY
authors.lastname: Tian
authors.affiliation:  Vice Professor.
authors.forename: L
authors.initials: L
authors.lastname: Zou
authors.affiliation:  Resident.
authors.forename: X
authors.initials: X
authors.lastname: Quan
authors.affiliation:  Resident.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation:  Professor, Department of Anaesthesiology, Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China.
authors.forename: F S
authors.initials: FS
authors.lastname: Xue
authors.affiliation:  Professor, Department of Anaesthesiology, Peking Union Medical College Hospital.
authors.forename: T H
authors.initials: TH
authors.lastname: Ye
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods; D000328:Adult; D001307:Auditory Perception / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D001931:Brain Mapping / Q000379:methods; D016292:Procedural Sedation / Q000379:methods; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000187:drug effects*; D008874:Midazolam / Q000494:pharmacology*; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D013702:Temporal Lobe / Q000187:drug effects / Q000502:physiology; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D008874:Midazolam; D010100:Oxygen
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