The temporal asymmetry of cortical dynamics as a signature of brain states

Scientific Reports, Journal Year: 2024, Volume and Issue: 14(1)

Published: Oct. 16, 2024

The brain is a complex non-equilibrium system capable of expressing many different dynamics as well the transitions between them. We hypothesized that level can serve signature given state, which was quantified using arrow time (the irreversibility). Using this thermodynamic framework, irreversibility emergent cortical activity from local field potential recordings in male Lister-hooded rats at anesthesia levels and during sleep-wake cycle. This measure carried out on five distinct states: slow-wave sleep, awake, deep anesthesia-slow waves, light microarousals. Low were associated with synchronous found both sleep states, suggesting slow waves state closest to equilibrium (maximum symmetry), thus requiring minimum energy. Higher when became more asynchronous, for example, wakefulness. These changes also reflected hierarchy across areas. neural states characterized by degrees hierarchy, acting markers transitions. could open new routes monitoring, controlling, even changing health disease.

Language: Английский

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Laminar evoked responses in mouse somatosensory cortex suggest a special role for deep layers in cortical complexity

European Journal of Neuroscience, Journal Year: 2023, Volume and Issue: 59(5), P. 752 - 770

Published: Aug. 16, 2023

Abstract It has been suggested that consciousness is closely related to the complexity of brain. The perturbational index (PCI) used in humans and rodents distinguish conscious from unconscious states based on global cortical responses (recorded by electroencephalography, EEG) local stimulation (CS). However, it unclear how different layers respond CS contribute resulting intra‐ inter‐areal connectivity PCI. A detailed investigation dynamics needed understand basis for We hypothesized level correlates with layer‐specific activity connectivity. tested this idea measuring somatosensory cortex (S1) mice, combining electrical deep motor cortex, electrocorticography (ECoG) laminar recordings 1–6 S1, during wakefulness general anaesthesia (sevoflurane). found transition wake sevoflurane correlated a drop both PCI (PCI st ) values (complexity). This was accompanied decrease neural firing rate, spike‐field coherence long‐range functional specific (L5, L6). Our results suggest are mechanistically important changes thereby state consciousness.

Language: Английский

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Sleep disrupts complex spiking dynamics in the neocortex and hippocampus

PLoS ONE, Journal Year: 2023, Volume and Issue: 18(8), P. e0290146 - e0290146

Published: Aug. 17, 2023

Neuronal interactions give rise to complex dynamics in cortical networks, often described terms of the diversity activity patterns observed a neural signal. Interestingly, complexity spontaneous electroencephalographic signals decreases during slow-wave sleep (SWS); however, underlying mechanisms remain elusive. Here, we analyse in-vivo recordings from neocortical and hippocampal neuronal populations rats show that decrease is due emergence synchronous DOWN states. Namely, find states SWS force population be more recurrent, deterministic, less random than REM or wakefulness, which, turn, leads field recordings. Importantly, when exclude analysis, wakefulness become indistinguishable: spiking all collapses common scaling. We complement these results by implementing critical branching model cortex, which shows inducing only percentage neurons enough generate replicates SWS.

Language: Английский

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The reduction of sleep-like perilesional cortical dynamics underlies clinical recovery in stroke

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: March 16, 2024

Abstract Introduction Recent studies have shown that, following brain injury, sleep-like cortical dynamics intrude into wakefulness, potentially contributing to network disruption and behavioral deficits. Aim We employ TMS in combination with EEG detect these assess their impact on networks clinical evolution awake stroke patients. Methods Twelve patients subacute unilateral ischemic underwent a longitudinal study two assessments (t0 t1), including evaluation using the National Institutes of Health Stroke Scale (NIHSS) TMS-EEG recordings targeting perilesional contralesional sites. Parameters such as slow wave amplitude (SWa), high-frequency power (HFp) suppression, Perturbational Complexity Index-state transition (PCIst) were analyzed quantify network-level consequences. Results demonstrated significant improvement (NIHSS score: 7.16±0.73 at t0, 4.33±0.74 t1; W=78, P<0.001). Perilesional SWa HFp suppression decreased significantly t1 compared t0 (T(11)=3.05, P=0.01 T(11)=-3.39, P<0.01, respectively), along recovery PCIst values (T(11)=-2.35, P=0.04). Importantly, both dissipation interactions correlated patients’ (Spearman ρ=0.62, P=0.03; ρ=-0.68, P=0.01, respectively). Conclusion These findings underscore potential an objective measure neurological suggest viable strategy for post-stroke neuromodulation rehabilitation.

Language: Английский

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Microstimulation reveals anesthetic state-dependent effective connectivity of neurons in cerebral cortex

Frontiers in Neuroscience, Journal Year: 2024, Volume and Issue: 18

Published: July 5, 2024

Complex neuronal interactions underlie cortical information processing that can be compromised in altered states of consciousness. Here intracortical microstimulation was applied to investigate anesthetic state-dependent effective connectivity neurons rat visual cortex vivo. Extracellular activity recorded at 32 sites layers 5/6 while stimulating with charge-balanced discrete pulses each electrode random order. The same stimulation pattern three levels anesthesia desflurane and wakefulness. Spikes were sorted classified by their waveform features as putative excitatory inhibitory neurons. Network motifs identified graphs constructed from monosynaptic cross-correlograms. Microstimulation caused early (<10 ms) increase followed prolonged (11-100 decrease spiking all throughout the array. response but not decayed rapidly distance site over 1 mm. Effective significant stimulus dense wakefulness sparse under anesthesia. number network motifs, especially those higher order, increased withdrawn indicating a substantial animals woke up. results illuminate impact on functional integrity local circuits affecting state

Language: Английский

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Informational Models of the Phenomenon of Consciousness and the Mechanistic Project in Neuroscience

Erkenntnis, Journal Year: 2024, Volume and Issue: unknown

Published: March 8, 2024

Language: Английский

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Behavioral and cortical arousal from sleep, muscimol-induced coma, and anesthesia by direct optogenetic stimulation of cortical neurons

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: April 25, 2024

Summary The cerebral cortex is widely considered part of the neural substrate consciousness. However, while several studies have demonstrated that stimulation subcortical nuclei can produce EEG activation and restore consciousness, so far no direct causal evidence has been available for itself. Here we tested in mice whether optogenetic cortical neurons posterior parietal (PtA) or medial prefrontal (mPFC) sufficient arousal from three behavioral states characterized by progressively deeper unresponsiveness: sleep, a coma-like state induced muscimol injection midbrain, deep sevoflurane-dexmedetomidine anesthesia. We find always awakens both NREM sleep REM with PtA requiring weaker/shorter light pulses than mPFC. Moreover, most cases (decrease low frequencies) (recovery righting reflex) brainstem coma, as well These findings provide and/or

Language: Английский

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Microstimulation reveals anesthetic state-dependent effective connectivity of neurons in cerebral cortex

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: May 1, 2024

Complex neuronal interactions underlie cortical information processing that can be compromised in altered states of consciousness. Here intracortical microstimulation was applied to investigate the state-dependent effective connectivity neurons rat visual cortex vivo. Extracellular activity recorded at 32 sites layers 5/6 while stimulating with charge-balanced discrete pulses each electrode random order. The same stimulation pattern three levels anesthesia desflurane and wakefulness. Spikes were sorted classified by their waveform features as putative excitatory inhibitory neurons. Microstimulation caused early (<10ms) increase followed prolonged (11-100ms) decrease spiking all throughout array. response but not decayed rapidly distance from site over 1mm. Effective significant stimulus dense wakefulness sparse under anesthesia. Network motifs identified graphs constructed monosynaptic cross-correlograms. number motifs, especially those higher order, increased withdrawn indicating a substantial network animals woke up. results illuminate impact on functional integrity local circuits affecting state

Language: Английский

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Characterising the power spectrum dynamics of the non‐REM to REM sleep transition

Journal of Sleep Research, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 9, 2024

The transition from non-rapid eye movement (NREM) to rapid (REM) sleep is considered a transitional or intermediate stage (IS), characterised by high amplitude spindles in the frontal cortex and theta activity occipital cortex. Early reports rats showed an IS lasting 1 5 s, but recent studies suggested longer duration of this up 20 s. To further characterise IS, we analysed its spectral characteristics on electrocorticogram (ECoG) recordings olfactory bulb (OB), primary motor (M1), somatosensory (S1), secondary visual (V2) 12 Wistar male adult rats. By comparing with consolidated NREM/REM epochs, our results reveal that has specific power patterns fall out NREM REM state distribution. Specifically, main findings were sigma (11-16 Hz) OB, M1, S1, V2 increased during compared sleep, which started first part brain (OB -54 M1 -53 s) prior last spindle occurrence. beta band (17-30 similar pattern band, starting s before occurrence Notably, infraslow coupling (~0.02 occurred at slower frequency (~0.01 sleep. Thus, argue contains own local profile, accordance previous reports, more extended than described previously.

Language: Английский

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