scholarly journals A dynamical model for the basal ganglia-thalamo-cortical oscillatory activity and its implications in Parkinson’s disease

Author(s):  
Eva M. Navarro-López ◽  
Utku Çelikok ◽  
Neslihan S. Şengör

AbstractWe propose to investigate brain electrophysiological alterations associated with Parkinson’s disease through a novel adaptive dynamical model of the network of the basal ganglia, the cortex and the thalamus. The model uniquely unifies the influence of dopamine in the regulation of the activity of all basal ganglia nuclei, the self-organised neuronal interdependent activity of basal ganglia-thalamo-cortical circuits and the generation of subcortical background oscillations. Variations in the amount of dopamine produced in the neurons of the substantia nigra pars compacta are key both in the onset of Parkinson’s disease and in the basal ganglia action selection. We model these dopamine-induced relationships, and Parkinsonian states are interpreted as spontaneous emergent behaviours associated with different rhythms of oscillatory activity patterns of the basal ganglia-thalamo-cortical network. These results are significant because: (1) the neural populations are built upon single-neuron models that have been robustly designed to have eletrophysiologically-realistic responses, and (2) our model distinctively links changes in the oscillatory activity in subcortical structures, dopamine levels in the basal ganglia and pathological synchronisation neuronal patterns compatible with Parkinsonian states, this still remains an open problem and is crucial to better understand the progression of the disease.

2004 ◽  
Vol 18 (2/3) ◽  
pp. 130-139 ◽  
Author(s):  
Guillermo Paradiso ◽  
Danny Cunic ◽  
Robert Chen

Abstract Although it has long been suggested that the basal ganglia and thalamus are involved in movement planning and preparation, there was little direct evidence in humans to support this hypothesis. Deep brain stimulation (DBS) is a well-established treatment for movement disorders such as Parkinson's disease, tremor, and dystonia. In patients undergoing DBS surgery, we recorded simultaneously from scalp contacts and from electrodes surgically implanted in the subthalamic nucleus (STN) of 13 patients with Parkinson's disease and in the “cerebellar” thalamus of 5 patients with tremor. The aim of our studies was to assess the role of the cortico-basal ganglia-thalamocortical loop through the STN and the cerebello-thalamocortical circuit through the “cerebellar” thalamus in movement preparation. The patients were asked to perform self-paced wrist extension movements. All subjects showed a cortical readiness potential (RP) with onset ranging between 1.5 to 2s before the onset of movement. Subcortical RPs were recorded in 11 of 13 with electrodes in the STN and in 4 of 5 patients with electrodes in the thalamus. The onset time of the STN and thalamic RPs were not significantly different from the onset time of the scalp RP. The STN and thalamic RPs were present before both contralateral and ipsilateral hand movements. Postoperative MRI studies showed that contacts with maximum RP amplitude generally were inside the target nucleus. These findings indicate that both the basal ganglia and the cerebellar circuits participate in movement preparation in parallel with the cortex.


2018 ◽  
Vol 115 (48) ◽  
pp. 12283-12288 ◽  
Author(s):  
Assaf Breska ◽  
Richard B. Ivry

Predicting the timing of upcoming events is critical for successful interaction in a dynamic world, and is recognized as a key computation for attentional orienting. Temporal predictions can be formed when recent events define a rhythmic structure, as well as in aperiodic streams or even in isolation, when a specified interval is known from previous exposure. However, whether predictions in these two contexts are mediated by a common mechanism, or by distinct, context-dependent mechanisms, is highly controversial. Moreover, although the basal ganglia and cerebellum have been linked to temporal processing, the role of these subcortical structures in temporal orienting of attention is unclear. To address these issues, we tested individuals with cerebellar degeneration or Parkinson’s disease, with the latter serving as a model of basal ganglia dysfunction, on temporal prediction tasks in the subsecond range. The participants performed a visual detection task in which the onset of the target was predictable, based on either a rhythmic stream of stimuli, or a single interval, specified by two events that occurred within an aperiodic stream. Patients with cerebellar degeneration showed no benefit from single-interval cuing but preserved benefit from rhythm cuing, whereas patients with Parkinson’s disease showed no benefit from rhythm cuing but preserved benefit from single-interval cuing. This double dissociation provides causal evidence for functionally nonoverlapping mechanisms of rhythm- and interval-based temporal prediction for attentional orienting, and establishes the separable contributions of the cerebellum and basal ganglia to these functions, suggesting a mechanistic specialization across timing domains.


Basal Ganglia ◽  
2014 ◽  
Vol 3 (4) ◽  
pp. 221-227 ◽  
Author(s):  
Claire Delaville ◽  
Ana V. Cruz ◽  
Alex J. McCoy ◽  
Elena Brazhnik ◽  
Irene Avila ◽  
...  

2020 ◽  
Vol 91 (8) ◽  
pp. e6.1-e6
Author(s):  
Peter Brown

Professor Peter Brown is Professor of Experimental Neurology and Director of the Medical Research Council Brain Network Dynamics Unit at the University of Oxford. Prior to 2010 he was a Professor of Neurology at University College London.For decades we have had cardiac pacemakers that adjust their pacing according to demand and yet therapeutic adaptive stimulation approaches for the central nervous system are still not clinically available. Instead, to treat patients with advanced Parkinson’s disease we stimulate the basal ganglia with fixed regimes, unvarying in frequency or intensity. Although effective, this comes with side-effects and in terms of sophistication this treatment approach could be compared to having central heating system on all the time, regardless of temperature. This talk will describe recent steps being taken to define the underlying circuit dysfunction in Parkinson’s and to improve deep brain stimulation by controlling its delivery according to the state of pathological activity.Evidence is growing that motor symptoms in Parkinson’s disease are due, at least in part, to excessive synchronisation between oscillating neurons. Recordings confirm bursts of oscillatory synchronisation in the basal ganglia centred around 20 Hz. The bursts of 20 Hz activity are prolonged in patients withdrawn from their usual medication and the dominance of these long duration bursts negatively correlates with motor impairment. Longer bursts attain higher amplitudes, indicative of more pervasive oscillatory synchronisation within the neural circuit. In contrast, in heathy primates and in treated Parkinson’s disease bursts tend to be short. Accordingly, it might be best to use closed-loop controlled deep brain stimulation to selectively terminate longer, bigger, pathological beta bursts to both save power and to spare the ability of underlying neural circuits to engage in more physiological processing between long bursts. It is now possible to record and characterise bursts on-line during stimulation of the same site and trial adaptive stimulation. Thus far, this has demonstrated improvements in efficiency and side-effects over conventional continuous stimulation, with at least as good symptom control in Parkinsonian patients.


2007 ◽  
Vol 98 (5) ◽  
pp. 2848-2857 ◽  
Author(s):  
Peter Praamstra ◽  
Paul Pope

Performance in behavioral tasks is influenced by temporal expectations shaped by the temporal structure of the task. Such implicit temporal preparation is reflected in slow brain potentials and electroencephalographic oscillations and is attributed to interval timing mechanisms that probably depend on intact basal ganglia function. We investigated implicit timing in Parkinson's disease using a choice reaction task with two temporally regular stimulus presentation regimes, both including occasional deviant interstimulus intervals. Control subjects, but not patients, demonstrated temporal preparation in the form of an adjustment in time course of slow brain potentials to the duration of the interstimulus interval. However, in both groups, timing perturbations were accompanied by a slow brain potential amplitude drop at the time of expected stimulus occurrence, demonstrating intact representation of time in patients. In patients, oscillatory activity in beta and alpha bands showed attenuated preparatory desynchronization and reduced postmovement event-related synchronization, reflecting abnormal engagement and disengagement of sensorimotor and parietal areas. The results demonstrate profoundly deficient temporal preparation with preserved encoding of temporal information, a dissociation that may be explained by impaired dopamine-dependent motor learning. The results are discussed in the context of recent work on oscillatory activity in the basal ganglia.


2014 ◽  
Vol 112 (7) ◽  
pp. 1739-1747 ◽  
Author(s):  
Elizabeth Heinrichs-Graham ◽  
Max J. Kurz ◽  
Katherine M. Becker ◽  
Pamela M. Santamaria ◽  
Howard E. Gendelman ◽  
...  

Parkinson's disease (PD) is a progressive debilitating neurodegenerative disorder clinically manifest by motor, posture and gait abnormalities. Human neurophysiological studies recording local field potentials within the subthalamic nucleus and scalp-based electroencephalography have shown pathological beta synchrony throughout the basal ganglia-thalamic-cortical motor network in PD. Notably, suppression of this pathological beta synchrony by dopamine replacement therapy or deep-brain stimulation has been associated with improved motor function. However, due to the invasive nature of these studies, it remains unknown whether this “pathological beta” is actually stronger than that observed in healthy demographically matched controls. We used magnetoencephalography to investigate neuronal synchrony and oscillatory amplitude in the beta range and lower frequencies during the resting state in patients with PD and a matched group of patients without neurological disease. Patients with PD were studied both in the practically defined drug “OFF” state, and after administration of dopamine replacements. We found that beta oscillatory amplitude was reduced bilaterally in the primary motor regions of unmedicated patients with PD compared with controls. Administration of dopaminergic medications significantly increased beta oscillatory activity, thus having a normalizing effect. Interestingly, we also found significantly stronger beta synchrony (i.e., hypersynchrony) between the primary motor regions in unmedicated patients with PD compared with controls, and that medication reduced this coupling which is in agreement with the intraoperative studies. These results are consistent with the known functionality of the basal ganglia-thalamic-cortical motor circuit and the likely consequences of beta hypersynchrony in the subthalamic nucleus of patients with PD.


Author(s):  
Shivam Kumar ◽  
Lav Goyal ◽  
Shamsher Singh

: Parkinson's disease (PD) is the second most prominent neurodegenerative movement disorder after Alzheimer’s disease, involving 2-3% of the population aged above 65 years. This is mainly triggered by the depletion of dopaminergic neurons located in substantia nigra pars compacta (SNpc) in the region of basal ganglia. At present, diagnosis for symptoms of PD is clinical, contextual, unspecified and therapeutically incomprehensive. Analysis of various causes of PD is essential for an accurate examination of the disease. Among the different causes, tremors, and rigidity unresponsive to the current treatment approach contributing to mortality. In the present review article, we described various key factors of pathogenesis and physiology associated with tremors and rigidity necessary for the treatment of PI (postural instability) in patients with PD. Additionally, several reports showing early tremor and rigidity causes, particularly age, cortex lesions, basal ganglia lesions, genetic abnormalities, weakened reflexes, nutrition, fear of fall, and altered biomechanics, are explored. By summarizing the factors that contribute, we intend to help prospective study activities that comprise histopathological studies to assess rigidity and tremor in PD. With a clear understanding of the contributing factors, various prospective studies can be done to access the incidence of rigidity and tremors.


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