Characterization of the functional MRI response temporal linearity via optical control of neocortical pyramidal neurons.

摘要: The blood oxygenation level-dependent (BOLD) signal serves as the basis for human functional MRI (fMRI). Knowledge of properties BOLD signal, such how linear its response is to sensory stimuli, essential design and interpretation fMRI experiments. Here, we combined cell-type site-specific causal control provided by optogenetics (opto-fMRI) in mice test linearity signals driven locally induced excitatory activity. We employed high-resolution mouse at 9.4 tesla measure response, extracellular electrophysiological recordings effects stimulation on single unit, multiunit, local field potential Optically layer V neocortical pyramidal neurons resulted a positive stimulated site. Consistent with transform model, this summated closely spaced trains stimulation. These were equivalent responses generated through multisynaptic method driving activity tactile stimulation, paralleled changes measures. results illustrate opto-fMRI reinforce critical assumption neuroimaging that—to first approximation—the tracks neural levels.