Quantitative Modeling of Sleep Dynamics

Quantitative modelling of sleep dynamics

“…For example, figure 11a shows excellent agreement of predicted and observed EEG spectra over several decades. The features reproduced include alpha and beta peaks and asymptotic low-and high-frequency behaviours; key differences between wake and sleep spectra can also be reproduced, including the strong increase in low-f activity in sleep, where our corticothalamic NFT predicts steepening of the spectrum from 1/f towards 1/f 3 , as seen in figure 11b [5,6,15]. Each feature is related to anatomy and physiology: 1/f or 1/f 3 behaviours are signatures of marginally stable, near-critical dynamics, which allow complex behaviour [4,14], while the high-f fall-off results from low-pass filtering by synaptic and dendritic dynamics.…”

“…Each feature is related to anatomy and physiology: 1/f or 1/f 3 behaviours are signatures of marginally stable, near-critical dynamics, which allow complex behaviour [4,14], while the high-f fall-off results from low-pass filtering by synaptic and dendritic dynamics. Corticothalamic and intrathalamic loop resonances account for the alpha, beta and spindle peaks, and for the correlated changes in spectral peaks between sleep and wake [4][5][6]54]. It has been shown that the state and physical stability of the corticothalamic system can be approximately represented in a three-dimensional space with axes x, y, z that parametrize dimensionless cortical, corticothalamic and intrathalamic gains, respectively [4].…”

“…Sleep-wake dynamics also require the corticothalamic system and its network interactions to be considered, since this system generates the electroencephalographic (EEG) rhythms often used to characterize arousal states [3][4][5][6][7][8][9]. Figure 1 shows key brain structures, connections and feedbacks involved in arousal dynamics.…”

“…Wake and sleep states of the brain are primarily due to the ascending arousal system (AAS) of the dorsal hypothalamus and brainstem, driven by homeostatic influences, circadian rhythms entrained to daily light cycles via the suprachiasmatic nucleus (SCN) and cortical feedbacks [1,2]. Sleep-wake dynamics also require the corticothalamic system and its network interactions to be considered, since this system generates the electroencephalographic (EEG) rhythms often used to characterize arousal states [3][4][5][6][7][8][9]. Figure 1 shows key brain structures, connections and feedbacks involved in arousal dynamics.…”