Abstract #1095

Hsieh J, Kuo W, Ho L, Cheng C, Yeh T

The characteristic tripod resting rhythm has been identified with very low frequency signal fluctuation (VLF, 0.01~0.03 Hz) using 3T fMRI studies. Physiological cardio-respiratory aliasing signals and spontaneous vasomotor reactivity have been proposed for the origins of resting rhythms. In this blood-oxygen-level-dependence (BOLD)-based fMRI study of normal subjects, verification of cerebral resting tripod signal was obtained when cerebral blood flow (CBF) was independently modulated by the inhaling graded carbogens (0.003~5% CO2, 20% O2 and 80~75% N2). Tripod resting rhythm was concluded to represent the true neural activities during awake resting state.