Project Details

Sleep is crucial for maintaining healthy cognitive function, yet the neurochemical mechanisms underlying its different stages in the human brain remain poorly understood.

This project aims to characterize how brain metabolites fluctuate across various sleep stages using simultaneous magnetic resonance spectroscopy (MRS) and electroencephalography (EEG).

Specifically, we measured thirteen metabolites including GABA, glutamate, lactate, and creatine, in anterior cingulate cortex, hypothesizing distinct

neurochemical signatures may characterize different arousal states.

Utilizing a dataset of 68 subjects who underwent EEG-MRS scans, we segmented EEG data into 8-second windows aligned to MRS acquisition timing.

Each artifact-free 8-second EEG window was classified into one of five sleep states: Awake and Alert, Awake and Drowsy, Transition into Sleep, Sleep, and Arousal from Sleep.

The optimal length of MRS data needed to reliably quantify metabolites remains elusive, therefore we first ran a segmentation analysis to quantify this number.

Our metrics were SNR and coefficient of variation of metabolite concentrations. Our findings will provide foundational insights into the biochemical dynamics of arousal stages,

enhancing our understanding of healthy brain sleep physiology. This study bridges a significant gap by directly linking neurochemical profiles to physiological arousal states.