Related Experiment Video
Updated: May 20, 2026
Analyzing the Size, Shape, and Directionality of Networks of Coupled Astrocytes
Published on: October 4, 2018
Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes
Elodie Barat1, Sylvie Boisseau, Céline Bouyssières
1Institut National de la Santé et de la Recherche Médicale, U 836, Equipe Dynamique et Physiopathologie des Ganglions de la Base, Grenoble F-38043, France.
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.
More Related Videos
10:52Microelectrode Guided Implantation of Electrodes into the Subthalamic Nucleus of Rats for Long-term Deep Brain Stimulation
Published on: October 2, 2015
12:19Imaging Intracellular Ca2+ Signals in Striatal Astrocytes from Adult Mice Using Genetically-encoded Calcium Indicators
Published on: November 19, 2014
