Topic: BOLD fMRI

The complement system is an innate immune pathway that responds to pathogens and cellular stress. The complement receptor C3aR is expressed on various brain cells, especially microglia. C3a, the ligand of C3aR, is elevated in several psychiatric disorders, such as psychosis, schizophrenia, bipolar disorder and depression. Previous studies have shown that mice lacking C3aR exhibit behavioural abnormalities, including anxiety, hyperactivity, and working memory deficit. These findings indicate that C3aR is involved in the development and/or function of brain circuits. We performed a brain imaging

In the brain, neuronal activity triggers an increase of oxygenated blood flowvia neurovascular coupling, a process underlying BOLD fMRI and which roleis unclear for the white matter. Here, we used two-photon imaging in extremedepth, functional ultrasound imaging and high-resolution BOLD fMRI (17.2T)to investigate neurovascular coupling along the whole optic nerve, from theretina up to the first relays of vision, in sedated and awake rodents. We findthat visual stimulation increases blood flow in the optic nerve head and atthe level of the synaptic terminals, i.e. the lateral geniculate nucleus