title: Hemodynamic response in the unanesthetized rat: intrinsic optical imaging and spectroscopy of the barrel cortex.
abstract: Optical imaging spectroscopy was used to measure the hemodynamic response of somatosensory cortex to stimulation of the whiskers. Responses to brief puffs of air were compared in anesthetized and unanesthetized rats. The hemodynamic response was approximately four times larger in the unanesthetized animal than the corresponding anesthetized animal. In unanesthetized animals, a short-latency (approximately 400 milliseconds) short-duration (approximately 300 milliseconds) hemodynamic startle response was observed. General linear model analysis was used to extract this component from the time series, and revealed an underlying short-latency increase in deoxygenated hemoglobin in response to somatosensory stimulation. It is proposed that anesthesia can have a marked affect on the relation between changes in blood volume and blood flow. This work represents a step in the development of an experimental model that can be used to investigate fundamental neurologic processes in the awake-behaving rodent.
authors.affiliation: Department of Psychology and Artificial Intelligence Vision Research Unit, University of Sheffield, Western Bank, Sheffield, UK.
authors.forename: Jason
authors.initials: J
authors.lastname: Berwick
authors.forename: Chris
authors.initials: C
authors.lastname: Martin
authors.forename: John
authors.initials: J
authors.lastname: Martindale
authors.forename: Myles
authors.initials: M
authors.lastname: Jones
authors.forename: Dave
authors.initials: D
authors.lastname: Johnston
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
authors.forename: Peter
authors.initials: P
authors.lastname: Redgrave
authors.forename: John
authors.initials: J
authors.lastname: Mayhew
mesh_terms: D000758:Anesthesia; D000818:Animals; D001143:Arousal / Q000502:physiology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D008954:Models, Biological; D051381:Rats; D011919:Rats, Inbred Strains; D013003:Somatosensory Cortex / Q000098:blood supply*; D013057:Spectrum Analysis