Dataset Information

Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes.

ABSTRACT:

Background

The substantia nigra pars reticulata (SNr) is a major output nucleus of the basal ganglia, delivering inhibitory efferents to the relay nuclei of the thalamus. Pathological hyperactivity of SNr neurons is known to be responsible for some motor disorders e.g. in Parkinson's disease. One way to restore this pathological activity is to electrically stimulate one of the SNr input, the excitatory subthalamic nucleus (STN), which has emerged as an effective treatment for parkinsonian patients. The neuronal network and signal processing of the basal ganglia are well known but, paradoxically, the role of astrocytes in the regulation of SNr activity has never been studied.

Principal findings

In this work, we developed a rat brain slice model to study the influence of spontaneous and induced excitability of afferent nuclei on SNr astrocytes calcium activity. Astrocytes represent the main cellular population in the SNr and display spontaneous calcium activities in basal conditions. Half of this activity is autonomous (i.e. independent of synaptic activity) while the other half is dependent on spontaneous glutamate and GABA release, probably controlled by the pace-maker activity of the pallido-nigral and subthalamo-nigral loops. Modification of the activity of the loops by STN electrical stimulation disrupted this astrocytic calcium excitability through an increase of glutamate and GABA releases. Astrocytic AMPA, mGlu and GABA(A) receptors were involved in this effect.

Significance

Astrocytes are now viewed as active components of neural networks but their role depends on the brain structure concerned. In the SNr, evoked activity prevails and autonomous calcium activity is lower than in the cortex or hippocampus. Our data therefore reflect a specific role of SNr astrocytes in sensing the STN-GPe-SNr loops activity and suggest that SNr astrocytes could potentially feedback on SNr neuronal activity. These findings have major implications given the position of SNr in the basal ganglia network.

SUBMITTER: Barat E

PROVIDER: S-EPMC3407058 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes.

Barat Elodie E Boisseau Sylvie S Bouyssières Céline C Appaix Florence F Savasta Marc M Albrieux Mireille M

PloS one 20120727 7

<h4>Background</h4>The substantia nigra pars reticulata (SNr) is a major output nucleus of the basal ganglia, delivering inhibitory efferents to the relay nuclei of the thalamus. Pathological hyperactivity of SNr neurons is known to be responsible for some motor disorders e.g. in Parkinson's disease. One way to restore this pathological activity is to electrically stimulate one of the SNr input, the excitatory subthalamic nucleus (STN), which has emerged as an effective treatment for parkinsonia ...[more]

PMID: 22848608

Similar Datasets

Project description:ObjectiveCurrent understanding of the neuromodulatory effects of deep brain stimulation (DBS) on large-scale brain networks remains elusive, largely due to the lack of techniques that can reveal DBS-induced activity at the whole-brain level. Using a novel 3T magnetic resonance imaging (MRI)-compatible stimulator, we investigated whole-brain effects of subthalamic nucleus (STN) stimulation in patients with Parkinson disease.MethodsFourteen patients received STN-DBS treatment and participated in a block-design functional MRI (fMRI) experiment, wherein stimulations were delivered during "ON" blocks interleaved with "OFF" blocks. fMRI responses to low-frequency (60Hz) and high-frequency(130Hz) STN-DBS were measured 1, 3, 6, and 12 months postsurgery. To ensure reliability, multiple runs (48 minutes) of fMRI data were acquired at each postsurgical visit. Presurgical resting-state fMRI (30 minutes) data were also acquired.ResultsTwo neurocircuits showed highly replicable, but distinct responses to STN-DBS. A circuit involving the globus pallidus internus (GPi), thalamus, and deep cerebellar nuclei was significantly activated, whereas another circuit involving the primary motor cortex (M1), putamen, and cerebellum showed DBS-induced deactivation. These 2 circuits were dissociable in terms of their DBS-induced responses and resting-state functional connectivity. The GPi circuit was frequency-dependent, selectively responding to high-frequency stimulation, whereas the M1 circuit was responsive in a time-dependent manner, showing enhanced deactivation over time. Finally, activation of the GPi circuit was associated with overall motor improvement, whereas M1 circuit deactivation was related to reduced bradykinesia.InterpretationConcurrent DBS-fMRI using 3T revealed 2 distinct circuits that responded differentially to STN-DBS and were related to divergent symptoms, a finding that may provide novel insights into the neural mechanisms underlying DBS. ANN NEUROL 2020;88:1178-1193.

Project description:There are many documented sex differences in the clinical course, symptom expression profile, and treatment response of Parkinson's disease, creating additional challenges for patient management. Although subthalamic nucleus deep brain stimulation is an established therapy for Parkinson's disease, the effects of sex on treatment outcome are still unclear. The aim of this retrospective observational study, was to examine sex differences in motor symptoms, non-motor symptoms, and quality of life after subthalamic nucleus deep brain stimulation. Outcome measures were evaluated at 1 and 12 months post-operation in 90 patients with Parkinson's disease undergoing subthalamic nucleus deep brain stimulation aged 63.00 ± 8.01 years (55 men and 35 women). Outcomes of clinical evaluations were compared between sexes via a Student's t-test and within sex via a paired-sample t-test, and generalized linear models were established to identify factors associated with treatment efficacy and intensity for each sex. We found that subthalamic nucleus deep brain stimulation could improve motor symptoms in men but not women in the on-medication condition at 1 and 12 months post-operation. Restless legs syndrome was alleviated to a greater extent in men than in women. Women demonstrated poorer quality of life at baseline and achieved less improvement of quality of life than men after subthalamic nucleus deep brain stimulation. Furthermore, Hoehn-Yahr stage was positively correlated with the treatment response in men, while levodopa equivalent dose at 12 months post-operation was negatively correlated with motor improvement in women. In conclusion, women received less benefit from subthalamic nucleus deep brain stimulation than men in terms of motor symptoms, non-motor symptoms, and quality of life. We found sex-specific factors, i.e., Hoehn-Yahr stage and levodopa equivalent dose, that were related to motor improvements. These findings may help to guide subthalamic nucleus deep brain stimulation patient selection, prognosis, and stimulation programming for optimal therapeutic efficacy in Parkinson's disease.

Dataset Information

Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes.

Background

Principal findings

Significance

Publications

Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets