Basavaraju
G. Sanganahalli1, Peter Herman1,2, Hal Blumenfeld3,
Fahmeed Hyder4
1Diagnostic Radiology, Yale University,
New Haven, CT, United States; 2Human Physiology, Semmelweis
University, Budapest, Hungary; 3Neurology, Neurosurgery and
Neuroscience, Yale University, New Haven, CT, United States; 4Diagnostic
Radiology and Biomedical Engineering, Yale University, New Haven, CT, United
States
BOLD
impulse response functions (IRFs) show variability (i.e, presence/absence of
a delayed undershoot) across different conditions (e.g., stimuli, regions).
Could these BOLD-IRF differences be due to the systems variable adaptive
properties, which are known to differ with baseline? Extracellular data were
compared with BOLD signal (11.7T) during forepaw stimulation under domitor
and α-chloralose anesthesia in rats. BOLD-IRFs were nearly identical in
the early phase but different in the late phase. Domitor, where responses are
more adapted, featured a long time-constant undershoot. These results suggest
that the late phase could potentially represent differences in adaptive
properties across baseline states.