Tae Kim1, Kazuto Masamoto2, Alberto Vazquez1, Mitsuhiro Fukuda1, Seong-Gi Kim1
1Radiology, University of Pittsburgh, Pittsburgh, PA, United States; 2The University of Electro-communications, Chofugaoka, Japan
Frequency-dependence of neural, CBF, and BOLD fMRI responses on stimulation duration were measured in the isoflurane-anesthetized rats. Higher frequency stimulation produced a larger neural activity per unit time during the early stimulation period, but dramatically decreased for later periods, while lower frequency stimulation induced smaller, but similar field potential amplitude responses maintained over the entire stimulation period. Similar frequency-dependent trends were observed in CBF and BOLD responses. Our findings suggest that the optimal stimulation frequency is dependent on stimulus duration, and it should be aware on the experiment design under isoflurane anesthesia.