Enhancement of resting-state fcMRI networks by prior sensory stimulation.
It is important to consider the effect of a previous experimental condition when analyzing resting-state functional connectivity magnetic resonance imaging (fcMRI) data. In this work, a simple sensory stimulation functional MRI (fMRI) experiment was conducted between two resting-state fcMRI acquisitions in anesthetized rats using a high-field small-animal MR scanner. Previous human studies have reported fcMRI network alteration by prior task/stimulus utilizing similar experimental paradigms. An anesthetized rat preparation was used to test whether brain regions with higher level functions are involved in post-task/stimulus fcMRI network alteration. We demonstrate significant fcMRI enhancement poststimulation in the sensory cortical, limbic, and insular brain regions in rats. These brain regions have been previously implicated in vigilance and anesthetic arousal networks. We tested their experimental paradigm in several inbred strains of rats with known phenotypic differences in anesthetic susceptibility and cerebral vascular function. Brown Norway (BN), Dahl Salt-Sensitive (SS), and consomic SSBN13 strains were tested. We have previously shown significant differences in blood oxygen level-dependent fMRI activity and fcMRI networks across these strains. Here we report statistically significant interstrain differences in regional fcMRI poststimulation enhancement. In the SS strain, poststimulation enhancement occurred in posterior sensory and limbic cortical brain regions. In the BN strain, poststimulation enhancement appeared in anterior cingulate and subcortical limbic brain regions. These results imply that a prior condition has a significant impact on fcMRI networks that depend on intersubject difference in genetics and physiology.
1 Department of Plastic Surgery, Medical College of Wisconsin , Milwaukee, Wisconsin.
Chenxuan
C
Li
Zhixin
Z
Li
B Douglas
BD
Ward
Melinda R
MR
Dwinell
Julian H
JH
Lombard
Anthony G
AG
Hudetz
Christopher P
CP
Pawela
D000344:Afferent Pathways / Q000098:blood supply* / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000098:blood supply*; D001931:Brain Mapping; D017352:Echo-Planar Imaging; D004727:Endothelium / Q000294:innervation; D005121:Extremities / Q000294:innervation; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010812:Physical Stimulation; D051381:Rats; D011914:Rats, Inbred BN; D020303:Rats, Inbred Dahl; D012146:Rest; D013045:Species Specificity
D010100:Oxygen
blood oxygen level-dependent contrast; brain networks; limbic system; neurovascular coupling; rat brain; resting-state functional connectivity magnetic resonance imaging; sensory system; vigilance and arousal networks