Temporal patterning of neural synchrony in the basal ganglia in Parkinson’s disease

Front. Comput. Neurosci.

Rubchinsky

2017

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Neural synchronization is believed to play an important role in different brain functions. Synchrony in cortical and subcortical circuits is frequently variable in time and not perfect. Few long intervals of desynchronized dynamics may be functionally different from many short desynchronized intervals although the average synchrony may be the same. Recent analysis of imperfect synchrony in different neural systems reported one common feature: neural oscillations may go out of synchrony frequently, but primarily for a short time interval. This study explores potential mechanisms and functional advantages of this short desynchronizations dynamics using computational neuroscience techniques. We show that short desynchronizations are exhibited in coupled neurons if their delayed rectifier potassium current has relatively large values of the voltage-dependent activation time-constant. The delayed activation of potassium current is associated with generation of quickly-rising action potential. This “spikiness” is a very general property of neurons. This may explain why very different neural systems exhibit short desynchronization dynamics. We also show how the distribution of desynchronization durations may be independent of the synchronization strength. Finally, we show that short desynchronization dynamics requires weaker synaptic input to reach a pre-set synchrony level. Thus, this dynamics allows for efficient regulation of synchrony and may promote efficient formation of synchronous neural assemblies.

Section: Methodssupporting

confidence: 78%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Potential Mechanisms and Functions of Intermittent Neural Synchronization

Front. Comput. Neurosci.

Rubchinsky

2017

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“…Synchronous dynamics at rest is very intermittent in both basal ganglia (Park et al, 2010; Ratnadurai-Giridharan et al, 2016) and cortex (Ahn and Rubchinsky, 2013). Thus, matching synchrony patterns in the model and experiment is an appropriate comparison tool, as was discussed in earlier studies (Ahn et al, 2011; Park et al, 2011; Rubchinsky et al, 2014).…”

Section: Discussionmentioning

confidence: 99%

Synchronized Beta-Band Oscillations in a Model of the Globus Pallidus-Subthalamic Nucleus Network under External Input

Front. Comput. Neurosci.

Zauber

Worth

et al. 2016

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Hypokinetic symptoms of Parkinson's disease are usually associated with excessively strong oscillations and synchrony in the beta frequency band. The origin of this synchronized oscillatory dynamics is being debated. Cortical circuits may be a critical source of excessive beta in Parkinson's disease. However, subthalamo-pallidal circuits were also suggested to be a substantial component in generation and/or maintenance of Parkinsonian beta activity. Here we study how the subthalamo-pallidal circuits interact with input signals in the beta frequency band, representing cortical input. We use conductance-based models of the subthalamo-pallidal network and two types of input signals: artificially-generated inputs and input signals obtained from recordings in Parkinsonian patients. The resulting model network dynamics is compared with the dynamics of the experimental recordings from patient's basal ganglia. Our results indicate that the subthalamo-pallidal model network exhibits multiple resonances in response to inputs in the beta band. For a relatively broad range of network parameters, there is always a certain input strength, which will induce patterns of synchrony similar to the experimentally observed ones. This ability of the subthalamo-pallidal network to exhibit realistic patterns of synchronous oscillatory activity under broad conditions may indicate that these basal ganglia circuits are directly involved in the expression of Parkinsonian synchronized beta oscillations. Thus, Parkinsonian synchronized beta oscillations may be promoted by the simultaneous action of both cortical (or some other) and subthalamo-pallidal network mechanisms. Hence, these mechanisms are not necessarily mutually exclusive.

“…We have recently developed time-series analysis techniques to characterize temporal patterning of synchronous dynamics (Ahn et al, 2011;Rubchinsky et al, 2014) and applied them to several biological oscillators (mostly neural oscillators, e.g. Park et al, 2010;Rubchinsky, 2013, 2017;Ahn et al, 2014a,b;Ratnadurai-Giridharan et al, 2016). The data analysis employed here follows these works very closely and is summarized below.…”

Section: Analysis Of the Temporal Patterns Of Synchronymentioning

confidence: 99%

Temporal patterns of dispersal-induced synchronization in population dynamics

Journal of Theoretical Biology

Rubchinsky

2020

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Highlights• Predator-prey oscillating populations with weak dispersal exhibit intermittent synchrony • Temporal patterns of this synchrony depend on the properties of predator-prey interactions in individual patches and may be independent of synchrony strength • The study identifies the properties of the predator-prey oscillators responsible for dynamics with numerous short desynchronizations vs. few long desynchronizations AbstractThe mechanisms and properties of synchronization of oscillating ecological populations attract attention because it is a fairly common phenomenon and because spatial synchrony may elevate a risk of extinction and may lead to other environmental impacts. Conditions for stable synchronization in a system of linearly coupled predator-prey oscillators have been considered in the past. However, the spatial dispersion coupling may be relatively weak and may not necessarily lead to a stable, complete synchrony. If the coupling between oscillators is too weak to induce a stable synchrony, oscillators may be engaged into intermittent synchrony, when episodes of synchronized dynamics are interspersed with the episodes of desynchronized dynamics. In the present study we consider the temporal patterning of this kind of intermittent synchronized dynamics in a system of two dispersal-coupled Rosenzweig-MacArthur predator-prey oscillators. We consider the properties of the distributions of durations of desynchronized intervals and their dependence on the model parameters. We show that the temporal patterning of synchronous dynamics (an ecological network phenomenon) may depend on the properties of individual predator-prey patch (individual oscillator) and may vary independently of the strength of dispersal. We also show that if the dynamics of predator is slow relative to the dynamics of the prey (a situation that may promote brief but large outbreaks), dispersal-coupled predator-prey oscillating populations exhibit numerous short desynchronizations (as opposed to few long desynchronizations) and may require weaker dispersal in order to reach strong synchrony.