Abstract
So far, many behavioral and pharmacological experiments on genetically modified mice have been conducted to study the molecular mechanism of the psychiatric or neurological diseases. On the other hand, recent functional MRI studies have revealed close relationship between the psychiatric or neurological diseases and the structure of functional connectivity in the resting-state of the human brain. To make linkage between the human and mouse studies, it is necessary to establish the method to analyze brain-wide spontaneous activity in the mouse. In this study, we simultaneously measured spontaneous cortical EEG and transcranial green-reflected-light (GRL, wavelength of 530 nm) signal to monitor cortical hemodynamics at high-spatial resolution in unanesthetized mice during natural sleep-wake cycle. It is shown that GRF decreases at 3% during theta-dominant period (REM sleep) compared to the delta-dominant periods, suggesting the increase in the blood volume of the cerebral cortex during REM sleep.
