A suite of neurophotonic tools to underpin the contribution of internal brain states in fMRI

Recent developments in optical microscopy, applicable for large-scale and longitudinal imaging of cortical activity in behaving animals, open unprecedented opportunities to gain a deeper understanding of neurovascular and neurometabolic coupling during different brain states. Future studies will leverage these tools to deliver foundational knowledge about brain state-dependent regulation of cerebral blood flow and metabolism, as well as regulation as a function of brain maturation and aging. This knowledge is of critical importance to interpret hemodynamic signals observed with functional magnetic resonance imaging (fMRI). •Optical probes for neuromodulation may allow direct measurements of cortical states.•Relative contribution of oxidative and glycolytic metabolism to hemodynamics may be state-dependent.•Loss of aerobic glycolysis in aging may be related to weakening of neuromodulation.•Neuromodulation can alter vasomotion oscillations, a measure of brain state observed through fMRI.