title: Comparison of somatosensory evoked potentials and cerebral blood oxygenation changes in the sensorimotor cortex during activation in the rat.
abstract: The relationship between changes in cerebral blood oxygenation and neuronal activity remains to be fully established. We compared somatosensory evoked potentials (SEP) and evoked cerebral blood oxygenation (CBO) changes in the sensorimotor cortex of the rat. In rats anesthetized with urethane and alpha-chloralose, we measured SEP and CBO using visible light spectroscopy (VLS) during neuronal activity. Increase of stimulus frequency caused a decrease of SEP amplitude, but an increase in concentration changes of deoxy-Hb and oxygen saturation. The difference in frequency responses between SEP and CBO might be caused by activation of inhibitory neurons, which could suppress excitatory neurons at high stimulus frequencies; activation of inhibitory neurons could reduce SEP amplitude, and increase oxygen saturation due to an increase of evoked cerebral blood flow.
authors.affiliation: Division of Neurological Surgery, Department of Neurological Surgery, Nihon University School of Medicine, Tokyo, Japan. yk-mikan@d8.dion.ne.jp
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kondo
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sakatani
authors.forename: Takahiro
authors.initials: T
authors.lastname: Igarashi
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Hoshino
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Murata
authors.forename: Emiri
authors.initials: E
authors.lastname: Tejima
authors.forename: Tsuneo
authors.initials: T
authors.lastname: Kano
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Katayama
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D006454:Hemoglobins / Q000378:metabolism; D010100:Oxygen / Q000097:blood*; D051381:Rats; D011916:Rats, Inbred F344; D013057:Spectrum Analysis
chemical_list: D006454:Hemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen