Bridging Single Neuron Dynamics to Global Brain States

Abstract

Biological neural networks produce information backgrounds of multi-scale spontaneous activity that become more complex in brain states displaying higher capacities for cognition, for instance, attentive awake versus asleep or anesthetized states. Here, we review brain state-dependent mechanisms spanning ion channel currents (microscale) to the dynamics of brain-wide, distributed, transient functional assemblies (macroscale). Not unlike how microscopic interactions between molecules underlie structures formed in macroscopic states of matter, using statistical physics, the dynamics of microscopic neural phenomena can be linked to macroscopic brain dynamics through mesoscopic scales. Beyond spontaneous dynamics, it is observed that stimuli evoke collapses of complexity, most remarkable over high dimensional, asynchronous, irregular background dynamics during consciousness. In contrast, complexity may not be further collapsed beyond synchrony and regularity characteristic of unconscious spontaneous activity. We propose that increased dimensionality of spontaneous dynamics during conscious states supports responsiveness, enhancing neural networks' emergent capacity to robustly encode information over multiple scales.

Light/Clock Influences Membrane Potential Dynamics to Regulate Sleep States

“…This model is based on the prediction that neural network signals flow along well-behaved axonal rails and pass the activity baton at synapses. Regardless of whether spiking activity is used for information representation, the "membrane potential dynamics" of neurons is the essence of neuronal information representation (32,33). In this review, we define membrane potential dynamics as the stochastically/deterministically shaped temporal structure of membrane potential (34,35) (Figure 1).…”

Modelos de redes de neurônios para o neocórtex e fenômenos emergentes observados

“…Dado que as evidências experimentais indicam que existe correlação entre o grau de sincronia da atividade de disparos de populações de neurônios corticais e o estado de consciência do indivíduo [30,96], modelos de redes de neurônios de disparo como os descritos nesta revisão oferecem uma oportunidade de que se possa começar a entender mecanisticamente [97] a relação entre a dinâmica de neurônios individuais e estados comportamentais complexos.…”

“…Conjectura-se que a atividade assíncrona característica dos estados de vigília reflita a disponibilidade de um repertório maior e mais diversificado de padrões neurais, possibilitando a existência de ricos estados de consciência, enquanto que o repertório reduzido de padrões neurais durante regimes de atividade coletiva síncrona cerceia ou restringe a consciência [28][29][30].…”

Modeling the Synchronization of Multimodal Perceptions as a Basis for the Emergence of Deterministic Behaviors

“…The introduction of a time dimension projects into the domain of dynamical systems e.g., monitoring (or behavioral) consciousness, in which associations between percepts are replaced by causality rules (Freeman, 1999) that can involve contextual and/or multimodal perceptions. The complexity of the corresponding neural phenomena has so far prevented the definition of models directly relating single neuron dynamics to global brain states (see e.g., Goldman et al, 2019). As an example, whereas neurological measurements (Tomov et al, 2018) have validated a computational Bayesian model positing a dedicated neural mechanism for causal learning (Gershman, 2017), nothing is known about the corresponding basic neuronal processes that could be reproduced in a bio-inspired robot.…”