Influence of the frequency parameter on extracellular glutamate and γ-aminobutyric acid in substantia nigra and globus pallidus during electrical stimulation of subthalamic nucleus in rats

2003 ◽  
Vol 72 (2) ◽  
pp. 259-267 ◽  
Author(s):  
François Windels ◽  
Nicolas Bruet ◽  
Annie Poupard ◽  
Claude Feuerstein ◽  
Anne Bertrand ◽  
...  
1994 ◽  
Vol 14 (1) ◽  
pp. 132-144 ◽  
Author(s):  
Minas Tzagournissakis ◽  
Catherine R. Dermon ◽  
Helen E. Savaki

The alterations in local metabolic activity of several anatomically distinct brain areas were investigated by means of the quantitative autoradiographic 2-deoxy-D-[1-14C]glucose method in awake rats during unilateral electrical stimulation of the subthalamic nucleus (STH). Unilateral electrical stimulation of the STH induced local metabolic activation (by 70% as compared with the control group), as well as distal metabolic activations in the substantia nigra reticulata (by 34%), globus pallidus (by 19%), entopeduncular nucleus (by 18%), deep layers of the superior colliculi (by 15%), and parafascicular thalamic nucleus (by 18%), ipsilaterally to the stimulated side. The ventrolateral motor thalamic nucleus as well as the limbic components, posterior cingulate cortex, and anteroventral thalamic nucleus displayed bilateral metabolic activations (by 20–28%). These results indicate that, in addition to its known ipsilateral motor connections, each STH is functionally related to the limbic system bilaterally. It is suggested that the STH is a site where the central motor information is accessible to the limbic system. Quantitative image analysis of individual serial sections in the STH, substantia nigra, and globus pallidus revealed a consistent dorsoventral pattern of topographic interrelations. Stimulation of either the dorsal or the ventral subdivision of the STH induced always stronger activation in the dorsal compartment of the substantia nigra and in the ventral compartment of the globus pallidus. These results suggest that the earlier-described inversion of the dorsoventral functional correspondence between the substantia nigra and globus pallidus may be partly mediated via the subthalamic nerve cells projecting collateral axons to both these areas.


2004 ◽  
Vol 100 (6) ◽  
pp. 997-1001 ◽  
Author(s):  
Mitsuhiro Ogura ◽  
Naoyuki Nakao ◽  
Ekini Nakai ◽  
Yuji Uematsu ◽  
Toru Itakura

Object. Although chronic electrical stimulation of the globus pallidus (GP) has been shown to ameliorate motor disabilities in Parkinson disease (PD), the underlying mechanism remains to be clarified. In this study the authors explored the mechanism for the effects of deep brain stimulation of the GP by investigating the changes in neurotransmitter levels in the cerebrospinal fluid (CSF) during the stimulation. Methods. Thirty patients received chronic electrical stimulation of the GP internus (GPi). Clinical effects were assessed using the Unified PD Rating Scale (UPDRS) and the Hoehn and Yahr Staging Scale at 1 week before surgery and at 6 and 12 months after surgery. One day after surgery, CSF samples were collected through a ventricular tube before and 1 hour after GPi stimulation. The concentration of neurotransmitters such as γ-aminobutyric acid (GABA), noradrenaline, dopamine, and homovanillic acid (HVA) in the CSF was measured using high-performance liquid chromatography. The treatment was effective for tremors, rigidity, and drug-induced dyskinesia. The concentration of GABA in the CSF increased significantly during stimulation, although there were no significant changes in the level of noradrenaline, dopamine, and HVA. A comparison between an increased rate of GABA concentration and a lower UPDRS score 6 months postimplantation revealed that the increase in the GABA level correlated with the stimulation-induced clinical effects. Conclusions. Stimulation of the GPi substantially benefits patients with PD. The underlying mechanism of the treatment may involve activation of GABAergic afferents in the GP.


1996 ◽  
Vol 66 (4) ◽  
pp. 161-169 ◽  
Author(s):  
Aleksandar Beriç ◽  
Djordje Sterio ◽  
Michael Dogali ◽  
Ron Alterman ◽  
Patrick Kelly

1997 ◽  
Vol 77 (3) ◽  
pp. 1635-1638 ◽  
Author(s):  
M. Clara Sañudo-Peña ◽  
J. Michael Walker

Sañudo-Peña, M. Clara and J. Michael Walker. Role of the subthalamic nucleus in cannabinoid actions in the substantia nigra of the rat. J. Neurophysiol. 77: 1635–1638, 1997. The effect of cannabinoids on the excitatory input to the substantia nigra reticulata (SNr) from the subthalamic nucleus was explored. For this purpose a knife cut was performed rostral to the subthalamic nucleus to isolate the subthalamic nucleus and the SNr from the striatum, a major source of cannabinoid receptors to the SNr. The data showed that the cannabinoid agonist WIN55,212-2 blocked the increase in the firing rate of SNr neurons induced by stimulation of the subthalamic nucleus with bicuculline. Furthermore, the cannabinoid antagonist SR141716A antagonized the effect of the cannabinoid agonist. This study showed that cannabinoids regulate not only the striatonigral pathway, as previously reported, but also the subthalamonigral pathway. The opposite influences of these two inputs to the SNr, inhibitory and excitatory respectively, suggest that endogenous cannabinoids play a major role in the physiological regulation of the SNr.


Author(s):  
Charles J. Wilson

The subthalamo-pallidal system constitutes the second layer of circuitry in the basal ganglia, downstream of the striatum. It consists of four nuclei. Two of them, the external segment of the globus pallidus (GPe) and subthalamic nucleus (STN), make their connections primarily within the basal ganglia. The others, the internal segment of the globus pallidus (GPi) and the substantia nigra pars reticulata (SNr), are the output nuclei of the basal ganglia. Collectively, their axons distribute collaterals to all the targets of the basal ganglia. Rare interneurons have been reported in each of them from studies of Golgi-stained preparations, but they have not so far been confirmed using more modern methods. The circuit as described here is based primarily on studies of the axonal arborizations of neurons stained individually by intracellular or juxtacellular labeling.


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