A Biased Diffusion Approach to Sleep Dynamics Reveals Neuronal Characteristics

Long-range temporal organisation of limb movement kinematics in human neonates

“…The shorter cycles apparent within this 1-hour cycle ( Fig. 2 ) possibly indicate further heterogeneity within behavioural states ( Peirano et al, 1986 , Dvir et al, 2019 , Whitehead et al, 2019c ). While the same subcortical structures generate motor activity across sleep-wake states in neonatal animals, movement-initiating neural activity differs by state, potentially explaining the variance in motor phenotype putatively associated with state here ( Rio-Bermudez et al, 2015 , Inácio et al, 2016 ).…”

Random walk model simulates the increased drowsiness of children with obstructive sleep apnea

“…Analyzing healthy and sleep apnea data through a random walk model both groups (for more details, see [16]). The exponent τ sleep is obtained from the probability distribution of sleep bouts of each child [12].…”

“…2). The standard deviation of the neuronal voltage fluctuations σ can be thus calculated by using the characteristic time constant τ from all sleep bout durations: σ = Δ/ √ τ with Δ = 25 mV for children and Δ = 23 mV for adults (for details on how to derive σ and Δ, see [16]). 8)) that can be calculated using the maximum likelihood estimation (MLE) [12,39].…”

“…The upper panel illustrates the dynamics of the model: the neuronal voltage of WPN shows unbiased diffusion for negative values of V (corresponding to sleep), whereas for positive values of V arousals occur and diffusion is biased towards sleep due to a sleep restoring current [1,12]. In our model, sleep is further divided into three stages according to the neuronal voltage: light sleep stages N1 (for 0 ≤ V < −L) and N2 (for −L ≤ V < −D) as well as deep sleep N3 (for −D ≤ V ≤ −Δ) [16]. The lower panel shows the derived hypnogram from the simulated neuronal voltage dynamics.…”

“…Recently, a model has been developed to simulate brief arousals from sleep [12,16]. The model is based on a physiological mechanism that takes into account the intrinsic noise ("sub-threshold voltage fluctuations") of wake-promoting neurons (WPN) in the brain stem.…”