TY - JOUR
T1 - Dynamic correlations between hemodynamic, metabolic, and neuronal responses to acute whole-brain ischemia
AU - Taylor, Jennifer M.
AU - Zhu, Xiao Hong
AU - Zhang, Yi
AU - Chen, Wei
N1 - Publisher Copyright:
© 2015 John Wiley & Sons, Ltd.
PY - 2015/11
Y1 - 2015/11
N2 - Cerebral ischemia sets off a cascade of neuronal and metabolic responses to preserve brain viability. An understanding of the temporal evolution of these changes during and after ischemia, and their correlation with hemodynamic changes, is essential. In this study, a 12-min whole-brain ischemia based on the four-blood-vessel occlusion model was employed in rats. Using a high-temporal-resolution simultaneous 1H-31P MRS acquisition sequence at 9.4T, we investigated dynamic occlusion and reperfusion responses in cerebral lactate (Lac), phosphocreatine (PCr), adenosine triphosphate (ATP), pH, and blood oxygenation level dependence (BOLD), together with changes in neuronal field potential activity. We reveal tightly coupled dynamics between hemodynamic, metabolic, and neuronal responses to ischemia. Neuronal activity, BOLD, PCr, Lac, and pH changed immediately following occlusion, indicating reduced energy substrates and consumption, and increased glycolysis to maintain cellular ATP levels, which started to decrease 2.2min after the onset of occlusion. ATP stores were then gradually consumed to maintain a minimum housekeeping neuronal activity level. By correlating dynamic changes of brain activity, BOLD, and energy metabolism, new insights into the brain's survival ability and mechanisms during an acute ischemic attack from the perspectives of cerebral metabolism, neuroenergetics, and neuronal activity were gained.
AB - Cerebral ischemia sets off a cascade of neuronal and metabolic responses to preserve brain viability. An understanding of the temporal evolution of these changes during and after ischemia, and their correlation with hemodynamic changes, is essential. In this study, a 12-min whole-brain ischemia based on the four-blood-vessel occlusion model was employed in rats. Using a high-temporal-resolution simultaneous 1H-31P MRS acquisition sequence at 9.4T, we investigated dynamic occlusion and reperfusion responses in cerebral lactate (Lac), phosphocreatine (PCr), adenosine triphosphate (ATP), pH, and blood oxygenation level dependence (BOLD), together with changes in neuronal field potential activity. We reveal tightly coupled dynamics between hemodynamic, metabolic, and neuronal responses to ischemia. Neuronal activity, BOLD, PCr, Lac, and pH changed immediately following occlusion, indicating reduced energy substrates and consumption, and increased glycolysis to maintain cellular ATP levels, which started to decrease 2.2min after the onset of occlusion. ATP stores were then gradually consumed to maintain a minimum housekeeping neuronal activity level. By correlating dynamic changes of brain activity, BOLD, and energy metabolism, new insights into the brain's survival ability and mechanisms during an acute ischemic attack from the perspectives of cerebral metabolism, neuroenergetics, and neuronal activity were gained.
KW - Brain hemodynamics
KW - Brain ischemia
KW - Brain metabolism
KW - Electrophysiology
KW - MRS
KW - Simultaneous acquisition
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U2 - 10.1002/nbm.3408
DO - 10.1002/nbm.3408
M3 - Article
C2 - 26373461
AN - SCOPUS:84945465083
SN - 0952-3480
VL - 28
SP - 1357
EP - 1365
JO - NMR in biomedicine
JF - NMR in biomedicine
IS - 11
ER -