Fmri Of Rat Brain Functional Network Connection

Functional magnetic resonance imaging (fMRI) is an imaging technology based on the blood oxygenation change during neural activity. At present, the investigation of the brain connectivity during resting state has been an important field using fMRI techniques.This paper focused on the study of connectivity of the rat brain based on fMRI. Some aspects of this dissertation have been put forward:1. Study of the brain activation of forepaw stimulation rat. Independent components analysis (ICA) was employed to analyze forepaw stimulation fMRI data, and the activation regions were found. The results showed during forepaw stimulation, the primary somatosensory cortex (S1) and thalamus were significant positively activated, the CPu(caudate putamen nucleus) was significant negatively activated. There were three rats showed positive activation in the secondary somatosensory cortex (S2), and no significant BOLD response in S1 and thalamus of the same hemisphere, which meant these regions were related to somatosensory system.2. Study of the connectivity of brain inside motor-sensory system during resting state and stimulus state. Based on the rat brain in stereotaxic coordinates and the activation regions mentioned above, regions of interest (ROI) were selected. We used correlation analysis method to find the correlation coefficient matrix between regions, and build the network to explore the brain network properties of rat's motor-sensory system. The results showed that during the resting state, the strong intracotical connectivity and LFF between bilateral hemisphere motor-sensory cortex were found. Besides, the significant connectivity between bilateral hemisphere putamen, hippocampus and cingulate was found, but the connectivity was weak intrathalamic and between cortex and thalamic. It's interesting that the motor-sensory system showed significant hemisphere predominance during resting state. Comparing to resting state, the global connectivity between brain regions decreased during stimulus state. The brain network of motor-sensory system showed small-world property during resting state, but random network during forepaw stimulation. It suggested that rat has some similar properties to human in functional separation and integration during brain information processing.