scholarly journals Motor cortex can directly drive the globus pallidus neurons in a projection neuron type-dependent manner in the rat

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Fuyuki Karube ◽  
Susumu Takahashi ◽  
Kenta Kobayashi ◽  
Fumino Fujiyama
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Globus Pallidus ◽  
Projection Neuron ◽  
Excitatory Input ◽  
Morphological Observation ◽  
Dependent Manner ◽  
Motor Behaviors ◽  
Connection Probability ◽  
Motor Loop

The basal ganglia are critical for the control of motor behaviors and for reinforcement learning. Here, we demonstrate in rats that primary and secondary motor areas (M1 and M2) make functional synaptic connections in the globus pallidus (GP), not usually thought of as an input site of the basal ganglia. Morphological observation revealed that the density of axonal boutons from motor cortices in the GP was 47% and 78% of that in the subthalamic nucleus (STN) from M1 and M2, respectively. Cortical excitation of GP neurons was comparable to that of STN neurons in slice preparations. FoxP2-expressing arkypallidal neurons were preferentially innervated by the motor cortex. The connection probability of cortico-pallidal innervation was higher for M2 than M1. These results suggest that cortico-pallidal innervation is an additional excitatory input to the basal ganglia, and that it can affect behaviors via the cortex-basal ganglia-thalamus motor loop.

scholarly journals Motor cortex can directly drive the globus pallidal neurons in a projection neuron type dependent manner in rat

2019 ◽  
Author(s):  
Fuyuki Karube ◽  
Susumu Takahashi ◽  
Kenta Kobayashi ◽  
Fumino Fujiyama
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Morphological Analysis ◽  
Projection Neuron ◽  
Excitatory Input ◽  
Morphological Observation ◽  
Dependent Manner ◽  
Synaptic Connections ◽  
Motor Behaviors ◽  
Cortical Excitation

AbstractThe basal ganglia (BG) are critical for the control of motor behaviors and for reinforcement learning. Here, we demonstrate in rats that primary and secondary motor areas (M1 and M2) make functional synaptic connections in the globus pallidus (GP), not usually thought of as an input site of the BG using optogenetics and morphological analysis. The cortical excitation in the GP was as strong as that in the STN. GP neurons projecting to the striatum were preferentially innervated by the motor cortex. Morphological observation revealed that the density of axonal boutons from motor cortices in the GP was approximately 30% of that in the striatum, but was comparable to that in the STN. M1 and M2 projected differentially to the BG in terms of topography and substructures. These results suggest that cortico-pallidal innervation is an additional excitatory input to the BG, and can affects behaviors via the cortex-basal ganglia-thalamus loop.

326 Characterization of Synchronization Between Globus Pallidus Neurons and Motor Cortex in Parkinson's Disease

Neurosurgery ◽  
2017 ◽  
Vol 64 (CN_suppl_1) ◽  
pp. 271-272
Author(s):  
Doris D Wang ◽  
Nicki Swann ◽  
Coralie de Hemptinne ◽  
Philip A Starr
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Globus Pallidus ◽  
Field Potentials ◽  
Frequency Range ◽  
Neuronal Synchronization ◽  
Motor Loop ◽  
Beta Oscillation ◽  
Insight Into

Abstract INTRODUCTION Excessive oscillatory neuronal synchronization throughout the basal ganglia thalamocortical motor loop is a hallmark of the Parkinsonian state. This may manifest as spike-spike correlations, coherence between field potentials, or spike-field interactions within or between structures in the circuit. Globus pallidus occupies a central role in basal ganglia processing, but neither internal (GPi) nor external (GPe) globus pallidus is monosynaptically connected to motor cortex. Understanding patterns of M1-pallidal synchronization will provide insight into the possible different roles of GPi and GPe stimulation, compared to STN stimulation, in ameliorating the excessive neuronal synchronization in PD. METHODS Using subdural electrodes and high resolution electrocorticography (ECoG) contacts temporarily placed over motor cortex during DBS implantation and microelectrode recordings, we evaluate the strength and topography of synchronization between pallidal neurons and cortical ECoG potentials in 16 PD patients. RESULTS >Recording from 59 GPe and 42 GPi cells with cortical ECoG field potentials demonstrated that 17% of GPe and 12% of GPi neurons showed significant interactions associated with cortical recording sites approximately 25 mm from midline. For those pairs with significant interactions, peak of the spike-triggered average potentials occurred within 100ms prior to spike time. GPe neurons showed maximum coherence with M1 in the beta (13-30 Hz) frequency range while GPi neurons had maximum coherence in the alpha (8-12 Hz) range. CONCLUSION Topography of significant M1-pallidal interactions is consistent with tractography findings showing more mesial areas of M1 to dominate cortical-basal ganglia anatomic connectivity. The observation that GPe stimulation is more “prokinetic” than GPi stimulation may be explained by the finding that GPe is more synchronized to the cortex in beta frequencies than GPi, as disruption of beta oscillation is important in ameliorating akinesia.

scholarly journals Role of Individual Basal Ganglia Nuclei in Force Amplitude Generation

2007 ◽  
Vol 98 (2) ◽  
pp. 821-834 ◽  
Author(s):  
Matthew B. Spraker ◽  
Hong Yu ◽  
Daniel M. Corcos ◽  
David E. Vaillancourt
Keyword(s):  
Basal Ganglia ◽  
Motor Cortex ◽  
Globus Pallidus ◽  
Neural Circuit ◽  
Activation Volume ◽  
Force Amplitude ◽  
Percent Signal Change ◽  
Signal Change ◽  
Increased Activity

The basal ganglia-thalamo-cortical loop is an important neural circuit that regulates motor control. A key parameter that the nervous system regulates is the level of force to exert against an object during tasks such as grasping. Previous studies indicate that the basal ganglia do not exhibit increased activity with increasing amplitude of force, although these conclusions are based mainly on the putamen. The present study used functional magnetic resonance imaging to investigate which regions in the basal ganglia, thalamus, and motor cortex display increased activity when producing pinch-grip contractions of increasing force amplitude. We found that the internal portion of the globus pallidus (GPi) and subthalamic nucleus (STN) had a positive increase in percent signal change with increasing force, whereas the external portion of the globus pallidus, anterior putamen, posterior putamen, and caudate did not. In the thalamus we found that the ventral thalamic regions increase in percent signal change and activation volume with increasing force amplitude. The contralateral and ipsilateral primary motor/somatosensory (M1/S1) cortices had a positive increase in percent signal change and activation volume with increasing force amplitude, and the contralateral M1/S1 had a greater increase in percent signal change and activation volume than the ipsilateral side. We also found that deactivation did not change across force in the motor cortex and basal ganglia, but that the ipsilateral M1/S1 had greater deactivation than the contralateral M1/S1. Our findings provide direct evidence that GPi and STN regulate the amplitude of force output. These findings emphasize the heterogeneous role of individual nuclei of the basal ganglia in regulating specific parameters of motor output.

scholarly journals Testing Basal Ganglia Motor Functions Through Reversible Inactivations in the Posterior Internal Globus Pallidus

2008 ◽  
Vol 99 (3) ◽  
pp. 1057-1076 ◽  
Author(s):  
M. Desmurget ◽  
R. S. Turner
Keyword(s):  
Basal Ganglia ◽  
Globus Pallidus ◽  
Reaction Times ◽  
Movement Direction ◽  
Visually Guided ◽  
Movement Initiation ◽  
Internal Globus Pallidus ◽  
On Line ◽  
Motor Loop ◽  
Target Locations

To test current hypotheses on the contribution of the basal ganglia (BG) to motor control, we examined the effects of muscimol-induced inactivations in the skeletomotor region of the internal globus pallidus (sGPi) on visually directed reaching. Injections were made in two monkeys trained to perform four out-and-back reaching movements in quick succession toward four randomly selected target locations. Following sGPi inactivations the following occurred. 1) Peak velocity and acceleration were decreased in nearly all sessions, whereas movement duration lengthened inconsistently. 2) Reaction times were unaffected on average, although minor changes were observed in several individual sessions. 3) Outward reaches showed a substantial hypometria that correlated closely with bradykinesia, but directional accuracy was unaffected. 4) Endpoint accuracy was preserved for the slow visually guided return movements. 5) No impairments were found in the rapid chaining of out-and-back movements, in the selection or initiation of four independent reaches in quick succession or in the quick on-line correction of initially misdirected reaches. 6) Inactivation-induced reductions in the magnitude of movement-related muscle activity (EMG) correlated with the severity of slowing and hypometria. There was no evidence for inactivation-induced alterations in the relative timing of EMG bursts, excessive cocontraction, or impaired suppression of antagonist EMG. Therefore disconnecting the BG motor pathway consistently produced bradykinesia and hypometria, but seldom affected movement initiation time, feedback-mediated guidance, the capacity to produce iterative reaches, or the ability to abruptly reverse movement direction. These results are discussed with reference to the idea that the BG motor loop may regulate energetic expenditures during movement (i.e., movement “vigor”).

scholarly journals Morphological Abnormalities in the Basal Ganglia of Dystonia Patients

2021 ◽  
pp. 1-12
Author(s):  
Xi Bai ◽  
Peter Vajkoczy ◽  
Katharina Faust
Keyword(s):  
Basal Ganglia ◽  
Globus Pallidus ◽  
Trajectory Planning ◽  
Matched Control ◽  
Young Patients ◽  
Control Population ◽  
Pathogenic Role ◽  
Target Region ◽  
Morphological Abnormalities ◽  
Primary Dystonia

<b><i>Objective:</i></b> The pathophysiology of dystonia is poorly understood. As opposed to secondary forms of dystonia, primary dystonia has long been believed to lack any neuroanatomical substrate. During trajectory planning for DBS, however, conspicuous T2-hyperinstensive signal alterations (SA) were registered within the target region, even in young patients, where ischemia is rare. <b><i>Methods:</i></b> Fifty MRIs of primary dystonia patients scheduled for DBS were analyzed. Total basal ganglia (BG) volumes, as well as proportionate SA volumes, were measured and compared to 50 age-matched control patients. <b><i>Results:</i></b> There was a 10-fold preponderance of percentaged SA within the globus pallidus (GP) in dystonia patients. The greatest disparity was in young patients &#x3c;25 years. Also, total BG volume differences were observed with larger GP and markedly smaller putamen and caudate in the dystonia group. <b><i>Conclusions:</i></b> BG morphology in primary dystonia differed from a control population. Volume reductions of the putamen and caudate may reflect functional degeneration, while volume increases of the GP may indicate overactivity. T2-hyperintensive SA in the GP of young primary dystonia patients, where microvascular lesions are highly unlikely, are striking. Their pathogenic role remains unclear.

The K+-evoked release of [3H]acetylcholine from slices of rat globus pallidus: modulation by δ-opioid receptors

1991 ◽  
Vol 69 (3) ◽  
pp. 414-418 ◽  
Author(s):  
Bianca B. Ruzicka ◽  
Khem Jhamandas
Keyword(s):  
Globus Pallidus ◽  
Opioid Receptor ◽  
Opioid Receptors ◽  
Cholinergic Neurons ◽  
Receptor Activation ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Release Of Acetylcholine ◽  
Δ Opioid Receptor ◽  
Tritium Release

Previous investigations have shown that the activation of δ-opioid receptors depresses the release of acetylcholine (ACh) in the rat caudate putamen. This finding raised the possibility that the release of ACh is similarly modulated in the globus pallidus, a region containing a distinct population of cholinergic neurons and enriched in enkephalinergic nerve terminals. In the present study the pallidal release of ACh was characterized and the effects of δ-opioid receptor activation on this release were examined. The results show that this release is stimulated by high K+ in a concentration- and Ca2+-dependent manner. D-Pen2,L-Pen5-enkephalin (0.1 – 10 μM), a selective δ-opioid receptor agonist, produced a dose-related inhibition of the 25 mM K+-evoked tritium release. The maximal inhibitory effect, representing a 34% decrease in the K+-induced tritium release, was observed at a concentration of 1 μM. This opioid effect was attenuated by the selective δ-opioid receptor antagonist, ICI 174864 (1 μM). These findings support the role of a δ-opioid receptor in the modulation of ACh release in the rat globus pallidus.Key words: globus pallidus, acetylcholine, enkephalin, release.

Regionalization within the mammalian telencephalon is mediated by changes in responsiveness to Sonic Hedgehog

Development ◽  
1998 ◽  
Vol 125 (24) ◽  
pp. 5079-5089 ◽  
Author(s):  
J.D. Kohtz ◽  
D.P. Baker ◽  
G. Corte ◽  
G. Fishell
Keyword(s):  
Basal Ganglia ◽  
Globus Pallidus ◽  
Sonic Hedgehog ◽  
Adult Brain ◽  
Ganglionic Eminence ◽  
Lateral Ganglionic Eminence ◽  
Expression Characteristic ◽  
Sonic Hedgehog Gene ◽  
Embryonic Structure ◽  
Sequential Induction

The cortex and basal ganglia are the major structures of the adult brain derived from the embryonic telencephalon. Two morphologically distinct regions of the basal ganglia are evident within the mature ventral telencephalon, the globus pallidus medially, and the striatum, which is positioned between the globus pallidus and the cortex. Deletion of the Sonic Hedgehog gene in mice indicates that this secreted signaling molecule is vital for the generation of both these ventral telencephalic regions. Previous experiments showed that Sonic Hedgehog induces differentiation of ventral neurons characteristic of the medial ganglionic eminence, the embryonic structure which gives rise to the globus pallidus. In this paper, we show that later in development, Sonic Hedgehog induces ventral neurons with patterns of gene expression characteristic of the lateral ganglionic eminence. This is the embryonic structure from which the striatum is derived. These results suggest that temporally regulated changes in Sonic Hedgehog responsiveness are integral in the sequential induction of basal telencephalic structures.

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