Real-time electrochemical monitoring of brain tissue oxygen: a surrogate for functional magnetic resonance imaging in rodents

TY - JOUR

T1 - Real-time electrochemical monitoring of brain tissue oxygen

T2 - a surrogate for functional magnetic resonance imaging in rodents

AU - Lowry, John P

AU - Griffin, Karen

AU - McHugh, Stephen B

AU - Lowe, Andrew S

AU - Tricklebank, Mark

AU - Sibson, Nicola R

N1 - Copyright (c) 2010 Elsevier Inc. All rights reserved.

PY - 2010/8/15

Y1 - 2010/8/15

N2 - Long-term in-vivo electrochemistry (LIVE) enables real-time monitoring and measurement of brain metabolites. In this study we have simultaneously obtained blood oxygenation level dependent (BOLD) fMRI and amperometric tissue O(2) data from rat cerebral cortex, during both increases and decreases in inspired O(2) content. BOLD and tissue O(2) measurements demonstrated close correlation (r=0.7898) during complete (0%) O(2) removal, with marked negative responses occurring ca. 30s after the onset of O(2) removal. Conversely, when the inspired O(2) was increased (50, 70 and 100% O(2) for 1min) similar positive rapid changes (ca. 15s) in both the BOLD and tissue O(2) signals were observed. These findings demonstrate, for the first time, the practical feasibility of obtaining real-time metabolite information during fMRI acquisition, and that tissue O(2) concentration monitored using an O(2) sensor can serve as an index of changes in the magnitude of the BOLD response. As LIVE O(2) sensors can be used in awake animals performing specific behavioural tasks the technique provides a viable animal surrogate of human fMRI experimentation.

AB - Long-term in-vivo electrochemistry (LIVE) enables real-time monitoring and measurement of brain metabolites. In this study we have simultaneously obtained blood oxygenation level dependent (BOLD) fMRI and amperometric tissue O(2) data from rat cerebral cortex, during both increases and decreases in inspired O(2) content. BOLD and tissue O(2) measurements demonstrated close correlation (r=0.7898) during complete (0%) O(2) removal, with marked negative responses occurring ca. 30s after the onset of O(2) removal. Conversely, when the inspired O(2) was increased (50, 70 and 100% O(2) for 1min) similar positive rapid changes (ca. 15s) in both the BOLD and tissue O(2) signals were observed. These findings demonstrate, for the first time, the practical feasibility of obtaining real-time metabolite information during fMRI acquisition, and that tissue O(2) concentration monitored using an O(2) sensor can serve as an index of changes in the magnitude of the BOLD response. As LIVE O(2) sensors can be used in awake animals performing specific behavioural tasks the technique provides a viable animal surrogate of human fMRI experimentation.

KW - Magnetic Resonance Imaging

KW - Animals

KW - Electrodes, Implanted

KW - Brain Chemistry

KW - Brain

KW - Cerebrovascular Circulation

KW - Rats

KW - Oxygen

KW - Brain Mapping

KW - Feasibility Studies

KW - Rats, Sprague-Dawley

KW - Time Factors

KW - Electrochemical Techniques

KW - Male

U2 - 10.1016/j.neuroimage.2010.04.187

DO - 10.1016/j.neuroimage.2010.04.187

M3 - Article

C2 - 20417284

SN - 1095-9572

VL - 52

SP - 549

EP - 555

JO - NeuroImage

JF - NeuroImage

IS - 2

ER -