Topic: total hemoglobin

Aims: Resting-state functional imaging (RSFI) is increasingly used to understand how distinct brain networks modulate and respond to pain. As migraine, a common headache disorder, can be experimentally modeled by triggering cortical spreading depolarizations (CSD) in rodents, it is crucial to understand its impact on network connectivity to find imaging markers for experimental evaluation of headache and trigeminovascular activation. We used wide-field intrinsic optical-signal imaging (IOSI) to investigate the impact of CSDs on bihemispheric RSFI connectivity. Methods: C57BL6-ChR2mice underwen

Ascending neuromodulatory projections from deep brain nuclei generate internal brain states that differentially engage specific neuronal cell types. Because neurovascular coupling is cell-type specific and neuromodulatory transmitters have vasoactive properties, we hypothesized that the impulse response function (IRF) linking spontaneous neuronal activity with hemodynamics would depend on brain state. To test this hypothesis, we used mesoscopic optical imaging to measure (1) release of neuromodulatory transmitters norepinephrine (NE) or acetylcholine (ACh), (2) Ca2+ activity of local cortic