Shmuel Na'aman1, Sebastien Thomas1,
Mirza Baig1, Peter O'Connor1, Amir Shmuel1,2
1MNI, Dept. of Neurology and
Neurosurgery, McGill University, Montreal, QC, Canada; 2Center for
MR Research, U. of Minnesota, Minneapolis, MN, United States
Recent
studies have demonstrated large amplitude spontaneous slow (< 0.1 Hz)
fluctuations in functional-MRI (fMRI) signals in humans in the resting state.
Despite the large body of human imaging literature on spontaneous activity
and functional-connectivity in the resting state, the link to underlying
neural activity remains tenuous. We show that spontaneous neurophysiological
activity in rat S1FL includes events in which changes in local field
potentials across cortical layers resemble the corresponding changes in
response to sensory stimulation. These spontaneous neurophysiological events
are accompanied by increases in blood oxygenation that peak approximately 5 s
following the events.