CC BY
11B-PS-3
Resting-state functional connectivity revealed by optical neural and hemodynamic signals
J. Lu1, B. Li1, P. Li1
1Huazhong University of Science and Technology,
Wuhan National Laboratory for Optoelectronics, Wuhan, China
Coherent low-frequency (<0.1 Hz) hemodynamic fluctuations have been shown to reflect resting-state functional connectivity (RSFC) [1], and the patterns of the RSFC closely resemble the signals observed during functional tasks [2-3]. the RSFC integrity appears to be essential for the maintenance of normal brain functions [4] and changes in RSFC are often associated with neuropsychiatry disorders, such as Alzheimer's disease and depression. The RSFC obtained by spontaneous hemodynamic signals is used to indirectly characterize the neural functional connectivity based on neurovascular mechanisms. However, the neurovascular uncoupling may occur under some pathological conditions [5] and whether the RSFC evaluated by spontaneous hemodynamic fluctuations is still a reliable indicator of neural functional connectivity needs to be investigated. The objective of the present study was to compare the hemodynamic RSFC with the neural RSFC under the condition of neurovascular uncoupling produced by cortical spreading depression (CSD) in mice. The hemodynamic RSFC was obtained by using optical intrinsic signal imaging and the neural RSFC was accessed by using voltage-sensitive dye imaging. Seven recordings of resting-state VSD imaging were performed for each mouse (n = 8). One recording was performed before CSD, and others were performed 10 min after CSD to eliminate the interference from the propagation dynamics of CSD. Each recording (t0-t6) lasted for 180 s to ensure the emergence of stable functional networks, and the time interval between the recordings was 10 min. In addition, among five of these mice, functional activations were studied by the electrical stimulation of the hindlimbs. Another four mice (n = 4) were taken as the VSD control group to explore the effects of bleaching on the VSD signals. The experimental operations were the same as the resting-state VSD imaging, but no CSD was elicited. The results showed that during the periods of neurovascular uncoupling after CSD, although reduced correlations between the bilateral cortexes and the increased correlations within the unilateral cortex were found both in the neural and the hemodynamic RSFC, the neural RSFC was altered to a lesser extent and recovered much faster. This study helps to understand the effects of neurovascular uncoupling on the neural and the hemodynamic RSFC and may provide a reference for analyzing the hemodynamic RSFC of diseases associated with neurovascular uncoupling.
References
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