TY - JOUR
T1 - Neurovascular coupling in normal aging
T2 - A combined optical, ERP and fMRI study
AU - Fabiani, Monica
AU - Gordon, Brian A.
AU - Maclin, Edward L.
AU - Pearson, Melanie A.
AU - Brumback-Peltz, Carrie R.
AU - Low, Kathy A.
AU - McAuley, Edward
AU - Sutton, Bradley P.
AU - Kramer, Arthur F.
AU - Gratton, Gabriele
N1 - Funding Information:
The work presented in this paper was supported by NIA grant # AG21887 to M. Fabiani and by NIMH grant # R56MH097973 to G. Gratton. We wish to thank Yukyung Lee, Katherine S. Morris, and Shawna Doerksen for their help with data collection, and Stan Colcombe and Kirk Erickson for their useful advice for the analysis of the fMRI data.
PY - 2014/1/15
Y1 - 2014/1/15
N2 - Brain aging is characterized by changes in both hemodynamic and neuronal responses, which may be influenced by the cardiorespiratory fitness of the individual. To investigate the relationship between neuronal and hemodynamic changes, we studied the brain activity elicited by visual stimulation (checkerboard reversals at different frequencies) in younger adults and in older adults varying in physical fitness. Four functional brain measures were used to compare neuronal and hemodynamic responses obtained from BA17: two reflecting neuronal activity (the event-related optical signal, EROS, and the C1 response of the ERP), and two reflecting functional hemodynamic changes (functional magnetic resonance imaging, fMRI, and near-infrared spectroscopy, NIRS). The results indicated that both younger and older adults exhibited a quadratic relationship between neuronal and hemodynamic effects, with reduced increases of the hemodynamic response at high levels of neuronal activity. Although older adults showed reduced activation, similar neurovascular coupling functions were observed in the two age groups when fMRI and deoxy-hemoglobin measures were used. However, the coupling between oxy- and deoxy-hemoglobin changes decreased with age and increased with increasing fitness. These data indicate that departures from linearity in neurovascular coupling may be present when using hemodynamic measures to study neuronal function.
AB - Brain aging is characterized by changes in both hemodynamic and neuronal responses, which may be influenced by the cardiorespiratory fitness of the individual. To investigate the relationship between neuronal and hemodynamic changes, we studied the brain activity elicited by visual stimulation (checkerboard reversals at different frequencies) in younger adults and in older adults varying in physical fitness. Four functional brain measures were used to compare neuronal and hemodynamic responses obtained from BA17: two reflecting neuronal activity (the event-related optical signal, EROS, and the C1 response of the ERP), and two reflecting functional hemodynamic changes (functional magnetic resonance imaging, fMRI, and near-infrared spectroscopy, NIRS). The results indicated that both younger and older adults exhibited a quadratic relationship between neuronal and hemodynamic effects, with reduced increases of the hemodynamic response at high levels of neuronal activity. Although older adults showed reduced activation, similar neurovascular coupling functions were observed in the two age groups when fMRI and deoxy-hemoglobin measures were used. However, the coupling between oxy- and deoxy-hemoglobin changes decreased with age and increased with increasing fitness. These data indicate that departures from linearity in neurovascular coupling may be present when using hemodynamic measures to study neuronal function.
KW - Aging
KW - Event-related brain potentials (ERPs)
KW - Event-related optical signal (EROS)
KW - Fitness
KW - Functional magnetic resonance imaging (fMRI)
KW - Near-infrared spectroscopy (NIRS)
KW - Neurovascular coupling
UR - http://www.scopus.com/inward/record.url?scp=84889663322&partnerID=8YFLogxK
U2 - 10.1016/j.neuroimage.2013.04.113
DO - 10.1016/j.neuroimage.2013.04.113
M3 - Article
C2 - 23664952
AN - SCOPUS:84889663322
SN - 1053-8119
VL - 85
SP - 592
EP - 607
JO - NeuroImage
JF - NeuroImage
ER -