Network remodeling induced by transcranial brain stimulation: A computational model of tDCS-triggered cell assembly formation

Han, Lu; Gallinaro, Júlia V.; Rotter, Stefan

doi:10.1162/netn_a_00097

Cited by 35 publications

(41 citation statements)

References 51 publications

(86 reference statements)

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“…What we show here is that network activity may have also constrained this enhancing effect. Known homeostatic plasticity mechanisms depend on neuronal firing [45], and conceivably the effects of tDCS on neuronal excitability can in principle recruit these mechanisms [46]. Regardless, network effects are likely to be less specific than the pathway specific mechanisms studied with classic plasticity induction mechanisms [12] We conclude that the specific effects of DCS will depend strongly on the endogenous network activity, which motivates future research with more realistic preparations.…”

Section: Discussionmentioning

confidence: 88%

Effects of direct current stimulation on synaptic plasticity in a single neuron

et al. 2021

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Background: Transcranial direct current stimulation (DCS) has lasting effects that may be explained by a boost in synaptic long-term potentiation (LTP). We hypothesized that this boost is the result of a modulation of somatic spiking in the postsynaptic neuron, as opposed to indirect network effects. To test this directly we record somatic spiking in a postsynaptic neuron during LTP induction with concurrent DCS. Methods: We performed rodent in-vitro patch-clamp recordings at the soma of individual CA1 pyramidal neurons. LTP was induced with theta-burst stimulation (TBS) applied concurrently with DCS. To test the causal role of somatic polarization, we manipulated polarization via current injections. We also used a computational multi-compartment neuron model that captures the effect of electric fields on membrane polarization and activity-dependent synaptic plasticity. Results: TBS-induced LTP was enhanced when paired with anodal DCS as well as depolarizing current injections. In both cases, somatic spiking during the TBS was increased, suggesting that evoked somatic activity is the primary factor affecting LTP modulation. However, the boost of LTP with DCS was less than expected given the increase in spiking activity alone. In some cells, we also observed DCS-induced spiking, suggesting DCS also modulates LTP via induced network activity. The computational model reproduces these results and suggests that they are driven by both direct changes in postsynaptic spiking and indirect changes due to network activity. Conclusion: DCS enhances synaptic plasticity by increasing postsynaptic somatic spiking, but we also find that an increase in network activity may boost but also limit this enhancement.

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Section: Discussionmentioning

confidence: 88%

Effects of direct current stimulation on synaptic plasticity in a single neuron

et al. 2021

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“…They may include immediate and in-cascade, short- and medium-term network, synaptic, cellular, and molecular processes, including multiple plasticity processes [ 30 , 48 , 55 , 56 , 57 ]. A computational study predicts that focal stimulation can trigger new functional large-scale neural connections [ 58 ]. The effects of tDCS also depend on the state of the brain and neural systems [ 52 , 59 , 60 , 61 , 62 , 63 , 64 ].…”

Section: Discussionmentioning

confidence: 99%

Frontoparietal anodal tDCS reduces ketamine-induced oscillopathies

Lahogue

Pinault

2021

Translational Neuroscience

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During the prodromal phase of schizophrenia with its complex and insidious clinical picture, electroencephalographic recordings detect widespread oscillation disturbances (or oscillopathies) during the wake–sleep cycle. Neural oscillations are electrobiomarkers of the connectivity state within systems. A single-systemic administration of ketamine, a non-competitive NMDA glutamate receptor antagonist, transiently reproduces the oscillopathies with a clinical picture reminiscent of the psychosis prodrome. This acute pharmacological model may help the research and development of innovative treatments against psychotic transition. Transcranial electrical stimulation is recognized as an appropriate non-invasive therapeutic modality since it can increase cognitive performance and modulate neural oscillations with little or no side effects. Therefore, our objective was to set up, in the sedated adult rat, a stimulation method that is able to normalize ketamine-induced increase in gamma-frequency (30–80 Hz) oscillations and decrease in sigma-frequency (10–17 Hz) oscillations. Unilateral and bipolar frontoparietal (FP), transcranial anodal stimulation by direct current (<+1 mA) was applied in ketamine-treated rats. A concomitant bilateral electroencephalographic recording of the parietal cortex measured the stimulation effects on its spontaneously occurring oscillations. A 5 min FP anodal tDCS immediately and quickly reduced, significantly with an intensity-effect relationship, the ketamine-induced gamma hyperactivity, and sigma hypoactivity at least in the bilateral parietal cortex. A duration effect was also recorded. The tDCS also tended to diminish the ketamine-induced delta hypoactivity. These preliminary neurophysiological findings are promising for developing a therapeutic proof-of-concept against neuropsychiatric disorders.

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“…Efficient induction of such assemblies can provide a powerful means to trigger or suppress a specific behavior (8,11), and can potentially guide us in understanding brain diseases (12) and to design more efficient brain machine interfaces (13). As with other perturbation techniques (14)(15)(16)(17), it is crucial to understand how parameters of stimulation, including the pattern of activation of specific neurons and the general state of the network dynamics, can be optimized for an efficient induction. This optimization can, however, be complicated, given the complex connectivity and dynamics of cortical networks.…”

Section: Introductionmentioning

confidence: 99%

Excitatory-inhibitory balance modulates the formation and dynamics of neuronal assemblies in cortical networks

Sadeh

Clopath

2021

Preprint

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Repetitive activation of subpopulation of neurons in cortical networks leads to the formation of neuronal assemblies, which can guide learning and behavior. Recent technological advances have made the artificial induction of such assemblies feasible, yet how various patterns of activation can shape their emergence in different operating regimes is not clear. Here we studied this question in large-scale cortical networks composed of excitatory (E) and inhibitory (I) neurons. We found that the dynamics of the network in which neuronal assemblies are embedded is important for their induction. In networks with strong E-E coupling at the border of E-I balance, increasing the number of perturbed neurons enhanced the potentiation of ensembles. This was, however, accompanied by off-target potentiation of connections from unperturbed neurons. When strong E-E connectivity was combined with dominant E-I interactions, formation of ensembles became specific. Counter-intuitively, increasing the number of perturbed neurons in this regime decreased the average potentiation of individual synapses, leading to an optimal assembly formation at intermediate sizes. This was due to potent lateral inhibition in this regime, which also slowed down the formation of neuronal assemblies, resulting in a speed-accuracy trade-off in the performance of the networks in pattern completion and behavioral discrimination. Our results therefore suggest that the two regimes might be suited for different cognitive tasks, with fast regimes enabling crude detections and slow but specific regimes favoring finer discriminations. Functional connectivity inferred from recent experiments in mouse cortical networks seems to be consistent with the latter regime, but we show that recurrent and top-down mechanisms can dynamically modulate the networks to switch between different states. Our work provides a framework to study how neuronal perturbations can lead to network-wide plasticity under biologically realistic conditions, and sheds light on the design of future experiments to optimally induce behaviorally relevant neuronal assemblies.

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Network remodeling induced by transcranial brain stimulation: A computational model of tDCS-triggered cell assembly formation

Cited by 35 publications

References 51 publications

Effects of direct current stimulation on synaptic plasticity in a single neuron

Effects of direct current stimulation on synaptic plasticity in a single neuron

Frontoparietal anodal tDCS reduces ketamine-induced oscillopathies

Excitatory-inhibitory balance modulates the formation and dynamics of neuronal assemblies in cortical networks

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