Single-axon tracing study of neurons of the external segment of the globus pallidus in primate

Sato, Fumi; Lavallée, Philippe; Lévesque, Martin; Parent, André

doi:10.1002/(sici)1096-9861(20000131)417:1<17::aid-cne2>3.0.co;2-i

Cited by 261 publications

(184 citation statements)

References 59 publications

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“…The pairs fulfilled the inclusion criteria (rate stability and refractory period) for 610 -5390 sec (mean Ϯ SD, 1785 Ϯ 1137 sec), and the 60 neurons fired 6531-361,280 spikes (mean Ϯ SD, 79,106 Ϯ 65,223 spikes) during that period. Despite the existence of at least two types of neurons in the pallidum Kita and Kitai, 1994;Sato et al, 2000), all of the recordings were presumed to derive from the high-frequency discharge projection neurons on the basis of their irregular firing pattern, nonbursting discharge, and shortduration action potential (DeLong et al, 1985). In most cases (23 of 33), it was not possible to associate with full confidence one or both members of the pair with the internal or external segments of the pallidum.…”

Section: Autocorrelations and Cross-correlations Of Pallidal Neuronsmentioning

confidence: 70%

“…The main type of neurons in the pallidum is inhibitory, and these neurons have, in addition to their projection to other brain areas, axonal collaterals within the pallidum (Yelnik et al, , 1997Kita and Kitai, 1994;Bevan et al, 1998;Sato et al, 2000;Parent et al, 2001). Such inhibitory collaterals are expected to generate negative correlations in the spiking activity of neighboring neurons.…”

Section: Introductionmentioning

confidence: 99%

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Functional Correlations between Neighboring Neurons in the Primate Globus Pallidus Are Weak or Nonexistent

Bar‐Gad¹,

Heimer²,

Ritov³

et al. 2003

J. Neurosci.

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The anatomical structure of the basal ganglia displays topographical organization and massive funneling of neuronal projections toward the globus pallidus as well as an axonal collateral system within this nucleus. This structure suggests the formation of correlations between the spiking activities of pallidal cells. Nevertheless, previous studies of remote neurons in the pallidum have reported uncorrelated spiking activity. These correlation results may be challenged, because remote pallidal neurons may be located in different pallidal territories. To further test the independence of pallidal activity, we studied the spiking activity of neighboring pairs recorded by the same electrodes. A narrow peak dominated the correlations of all pairs of neurons recorded on the same electrode. This type of peak is classically interpreted as a sign of strong common input. However, recent mathematical analysis shows that such peaks may derive from a technical inability to detect overlapping spikes by spike-sorting techniques. A long-term shallow trough in the correlation of neighboring neurons may also result from the same effect, which we have termed the "shadowing effect." A comparison of the expected shadowing effect with the actual correlations suggests that no real correlations exist between 93.9% of neighboring pallidal pairs. The remaining 6.1% of the pairs display symmetric long-term positive correlations centered on time 0. Thus, functional interactions between neighboring pallidal neurons donotdisplayanysignificantdifferencesfromtheinteractionsbetweenphysicallyremoteneuronsinthisbrainarea.Moreover,thecombination of anatomical data and current physiological results suggests an active decorrelating process performed in the basal ganglia.

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Section: Autocorrelations and Cross-correlations Of Pallidal Neuronsmentioning

confidence: 70%

Section: Introductionmentioning

confidence: 99%

Functional Correlations between Neighboring Neurons in the Primate Globus Pallidus Are Weak or Nonexistent

Bar‐Gad¹,

Heimer²,

Ritov³

et al. 2003

J. Neurosci.

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“…41,56 Additionally, stimulation may have orthodromically activated GPe-STN projection neurons that extend inhibitory collaterals into SNr. 57 These considerations attest to the complex pattern of excitation and inhibition that is likely to emerge in response to stimulation and the importance of incorporating polysynaptic pathways and adjacent fiber tracts into the interpretation of experimental findings.…”

Section: Axonal Output Of the Stimulated Nucleusmentioning

confidence: 99%

“…70 Anatomical tracing studies have found that approximately 40% of GPe cells send projections to the STN through the GPi. 57 Thus, stimulating the GPi may influence the STN directly, by activating GPe GABAergic fibers of passage. In primates, nigrostriatal axons collateralize in both GPe and GPi, forming dense fiber bundles along the medullary laminae en route to the putamen.…”

Section: Activation Of Fiber Tracts Of Passagementioning

confidence: 99%

Mechanisms and Targets of Deep Brain Stimulation in Movement Disorders

et al. 2008

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Summary:Chronic electrical stimulation of the brain, known as deep brain stimulation (DBS), has become a preferred surgical treatment for medication-refractory movement disorders. Despite its remarkable clinical success, the therapeutic mechanisms of DBS are still not completely understood, limiting opportunities to improve treatment efficacy and simplify selection of stimulation parameters. This review addresses three questions essential to understanding the mechanisms of DBS. 1) How does DBS affect neuronal tissue in the vicinity of the active electrode or electrodes? 2) How do these changes translate into therapeutic benefit on motor symptoms? 3) How do these effects depend on the particular site of stimulation? Early hypotheses proposed that stimulation inhibited neuronal activity at the site of stimulation, mimicking the outcome of ablative surgeries. Recent studies have challenged that view, suggesting that although somatic activity near the DBS electrode may exhibit substantial inhibition or complex modulation patterns, the output from the stimulated nucleus follows the DBS pulse train by direct axonal excitation. The intrinsic activity is thus replaced by high-frequency activity that is time-locked to the stimulus and more regular in pattern. These changes in firing pattern are thought to prevent transmission of pathologic bursting and oscillatory activity, resulting in the reduction of disease symptoms through compensatory processing of sensorimotor information. Although promising, this theory does not entirely explain why DBS improves motor symptoms at different latencies. Understanding these processes on a physiological level will be critically important if we are to reach the full potential of this powerful tool.

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“…In both models, the GP e → GP i connection is minimised. On the one hand, this is contradictory with anatomical data pointing out that one third of the projecting GPe neurons target the GPi/SNr [20], implying that the connection from GPe to GPi is not non-existent. On the other hand, electrophysiological data lead to the hypothesis that they might be weak [21].…”

Section: Model Comparisonmentioning

confidence: 99%

Multi-objective Evolutionary Algorithms to Investigate Neurocomputational Issues: The Case Study of Basal Ganglia Models

Liénard

Guillot

Girard

2010

From Animals to Animats 11

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Abstract. The basal ganglia (BG) are a set of subcortical nuclei involved in action selection processes. We explore here the automatic parameterization of two models of the basal ganglia (the GPR and the CBG) using multi-objective evolutionary algorithms. We define two objective functions characterizing the supposed winner-takes-all functionality of the BG and obtain a set of solutions lying on the Pareto front for each model. We show that the CBG architecture leads to solutions dominating the GPR ones, this highlights the usefulness of the CBG additional connections with regards to the GPR. We then identify the most satisfying solutions on the fronts in terms of both functionality and plausibility. We finally define critical and indifferent parameters by analyzing their variations and values on the fronts, helping us to understand the dynamics governing the selection process in the BG models.

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Single-axon tracing study of neurons of the external segment of the globus pallidus in primate

Cited by 261 publications

References 59 publications

Functional Correlations between Neighboring Neurons in the Primate Globus Pallidus Are Weak or Nonexistent

Functional Correlations between Neighboring Neurons in the Primate Globus Pallidus Are Weak or Nonexistent

Mechanisms and Targets of Deep Brain Stimulation in Movement Disorders

Multi-objective Evolutionary Algorithms to Investigate Neurocomputational Issues: The Case Study of Basal Ganglia Models

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