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Lara Eid, Martin Parent
Neurons of the globus pallidus receive massive inputs from the striatum and the subthalamic nucleus, but their activity, as well as those of their striatal and subthalamic inputs, are modulated by brainstem afferents. These include serotonin (5-HT) projections from the dorsal raphe nucleus, cholinergic (ACh) inputs from the pedunculopontine tegmental nucleus, and dopamine (DA) afferents from the substantia nigra pars compacta. This review summarizes our recent findings on the distribution, quantitative and ultrastructural aspects of pallidal 5-HT, ACh and DA innervations...
December 2016: Brain Structure & Function
Xiao-Tao Jin, Jean-Francois Paré, Yoland Smith
The intra-pallidal application of γ-aminobutyric acid (GABA) transporter subtype 1 (GAT-1) or GABA transporter subtype 3 (GAT-3) transporter blockers [1-(4,4-diphenyl-3-butenyl)-3-piperidinecarboxylic acid hydrochloride (SKF 89976A) or 1-[2-[tris(4-methoxyphenyl)methoxy]ethyl]-(S)-3-piperidinecarboxylic acid (SNAP 5114)] reduces the activity of pallidal neurons in monkey. This effect could be mediated through the activation of presynaptic GABA(B) heteroreceptors in glutamatergic terminals by GABA spillover following GABA transporter (GAT) blockade...
August 2012: European Journal of Neuroscience
Jeremy R Edgerton, Jesse E Hanson, Cengiz Günay, Dieter Jaeger
The globus pallidus (GP) predominantly contains GABAergic projection neurons that occupy a central position in the indirect pathway of the basal ganglia. They have long dendrites that can extend through one-half the diameter of the GP in rats, potentially enabling convergence and interaction between segregated basal ganglia circuits. Because of the length and fine diameter of GP dendrites, however, it is unclear how much influence distal synapses have on spiking activity. Dendritic expression of fast voltage-dependent Na(+) channels (NaF channels) can enhance the importance of distal excitatory synapses by allowing for dendritic spike initiation and by subthreshold boosting of EPSPs...
November 10, 2010: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Choongseok Park, David Terman
Excitatory-inhibitory networks arise in many regions throughout the central nervous system and display complex spatiotemporal firing patterns. These neuronal activity patterns (of individual neurons and/or the whole network) are closely related to the functional status of the system and differ between normal and pathological states. For example, neurons within the basal ganglia, a group of subcortical nuclei that are responsible for the generation of movement, display a variety of dynamic behaviors such as correlated oscillatory activity and irregular, uncorrelated spiking...
June 2010: Chaos
Philip J Hahn, Cameron C McIntyre
Deep brain stimulation (DBS) of the subthlamic nucleus (STN) represents an effective treatment for medically refractory Parkinson's disease; however, understanding of its effects on basal ganglia network activity remains limited. We constructed a computational model of the subthalamopallidal network, trained it to fit in vivo recordings from parkinsonian monkeys, and evaluated its response to STN DBS. The network model was created with synaptically connected single compartment biophysical models of STN and pallidal neurons, and stochastically defined inputs driven by cortical beta rhythms...
June 2010: Journal of Computational Neuroscience
Alexandru George Floares
Modeling neural networks with ordinary differential equations systems is a sensible approach, but also very difficult. This paper describes a new algorithm based on linear genetic programming which can be used to reverse engineer neural networks. The RODES algorithm automatically discovers the structure of the network, including neural connections, their signs and strengths, estimates its parameters, and can even be used to identify the biophysical mechanisms involved. The algorithm is tested on simulated time series data, generated using a realistic model of the subthalamopallidal network of basal ganglia...
March 2008: Neural Networks: the Official Journal of the International Neural Network Society
Janet Best, Choongseok Park, David Terman, Charles Wilson
Changes in firing patterns are an important hallmark of the functional status of neuronal networks. We apply dynamical systems methods to understand transitions between irregular and rhythmic firing in an excitatory-inhibitory neuronal network model. Using the geometric theory of singular perturbations, we systematically reduce the full model to a simpler set of equations, one that can be studied analytically. The analytic tools are used to understand how an excitatory-inhibitory network with a fixed architecture can generate both activity patterns for possibly different values of the intrinsic and synaptic parameters...
October 2007: Journal of Computational Neuroscience
Yoichi Katayama, Hideki Oshima, Toshikazu Kano, Kazutaka Kobayashi, Chikashi Fukaya, Takamitsu Yamamoto
We examined the direct effect of deep brain stimulation of the subthalamic nucleus (STN-DBS) on levodopa-induced peak-dose dyskinesia in 45 patients with Parkinson's disease (PD) without reducing the levodopa dosage during the early period after surgery. In 8 patients (18%), the dyskinesia was quickly attenuated by bipolar stimulation in an experimental trial (5 min) with the contacts placed within the area above the STN. In contrast, bipolar stimulation using contacts placed within the STN itself tended to provoke or exacerbate the dyskinesia, indicating that dyskinesia could be inhibited by stimulation of the areas above the STN rather than the STN itself...
2006: Stereotactic and Functional Neurosurgery
Adán Hernández, Osvaldo Ibáñez-Sandoval, Arturo Sierra, René Valdiosera, Dagoberto Tapia, Verónica Anaya, Elvira Galarraga, José Bargas, Jorge Aceves
The effects of activating dopaminergic D(2/3) and D(4) receptors during activation of the subthalamic projection to the globus pallidus (GP) were explored in rat brain slices using the whole cell patch-clamp technique. Byocitin labeling and both orthodromic and antidromic activation demonstrated the integrity of some subthalamopallidal connections in in vitro parasagittal brain slices. Excitatory postsynaptic currents (EPSCs) that could be blocked by CNQX and AP5 were evoked onto pallidal neurons by local field stimulation of the subthalamopallidal pathway in the presence of bicuculline...
December 2006: Journal of Neurophysiology
K Kaneda, Y Tachibana, M Imanishi, H Kita, R Shigemoto, A Nambu, M Takada
Enhanced glutamatergic neurotransmission via the subthalamopallidal or subthalamonigral projection seems crucial for developing parkinsonian motor signs. In the present study, the possible changes in the expression of metabotropic glutamate receptors (mGluRs) were examined in the basal ganglia of a primate model for Parkinson's disease. When the patterns of immunohistochemical localization of mGluRs in monkeys administered systemically with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were analysed in comparison with normal controls, we found that expression of mGluR1alpha, but not of other subtypes, was significantly reduced in the internal and external segments of the globus pallidus and the substantia nigra pars reticulata...
December 2005: European Journal of Neuroscience
Lauren M Billings, John F Marshall
The globus pallidus (GP) consists of two neuron populations, distinguished according to their immunoreactivity for parvalbumin (PV). The PV-immunoreactive (PV+) neurons project preferentially to "downstream" targets such as the subthalamic and entopeduncular nuclei, whereas neurons lacking PV (PV- neurons) project preferentially to the striatum, suggesting a role for PV- cells in feedback to striatal neurons. Although dopamine D2 antagonist administration induces immediate early gene expression preferentially in PV- GP neurons, little is known about long-term regulation of PV- versus PV+ GP neurons...
March 24, 2004: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
D Terman, J E Rubin, A C Yew, C J Wilson
Based on recent experimental data, we have developed a conductance-based computational network model of the subthalamic nucleus and the external segment of the globus pallidus in the indirect pathway of the basal ganglia. Computer simulations and analysis of this model illuminate the roles of the coupling architecture of the network, and associated synaptic conductances, in modulating the activity patterns displayed by this network. Depending on the relationships of these coupling parameters, the network can support three general classes of sustained firing patterns: clustering, propagating waves, and repetitive spiking that may show little regularity or correlation...
April 1, 2002: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
G Linazasoro
Current models about the organization of the basal ganglia have provided a resurgence of the surgical treatment of Parkinson's disease (PD). Surgical experience has served to corroborate many of the predictions supported by the model. For instance, hyperactivity of the subthalamopallidal pathway is the key feature in PD and its suppression is associated with an improvement of the cardinal signs and symptoms of the disease. Parkinsonian rest tremor may be related to the oscillatory activity of the subthalamic and pallidal neurons...
January 2001: Neurología: Publicación Oficial de la Sociedad Española de Neurología
Y Smith, A Charara, J E Hanson, M Paquet, A I Levey
Glutamate and GABA neurotransmission is mediated through various types of ionotropic and metabotropic receptors. In this review, we summarise some of our recent findings on the subcellular and subsynaptic localisation of GABA(B) and group I metabotropic glutamate receptors in the striatopallidal complex of monkeys. Polyclonal antibodies that specifically recognise GABA(B)R1, mGluR1a and mGluR5 receptor subtypes were used for immunoperoxidase and pre-embedding immunogold techniques at the light and electron microscope levels...
May 2000: Journal of Anatomy
F Sato, M Parent, M Levesque, A Parent
Axonal projections arising from the subthalamic nucleus (STN) in cynomolgus monkeys (Macaca fascicularis) were traced after labeling small pools (5-15 cells) of neurons with biotinylated dextran amine. Seventy-five single axons were reconstructed from serial sagittal sections with a camera lucida. Most of the STN labeled cells displayed five to eight long, sparsely spined dendrites that arborized mostly along the main axis of the nucleus. Based on their axonal targets, five distinct types of STN projection neurons have been identified: 1) neurons projecting to the substantia nigra pars reticulata (SNr), the internal (GPi) and external (GPe) segments of the globus pallidus (21...
August 14, 2000: Journal of Comparative Neurology
N Mizuno
Morphological features indicating occurrence of two types of extrasynaptic chemical transmission were observed within rat basal ganglia. (1) Striatonigral neurons containing substance P (SP) sent many axon collaterals equipped with axonal varicosities to the striatum: the varicosities displayed synaptophysin-like immunoreactivity (-LI). However, only 15% of the varicosities appeared to be in close contact with structures showing SP receptor (SPR)-LI. Many of axon terminals of striatonigral neurons were confirmed electron microscopically not to be in synaptic contact with SPR-like immunoreactive structures within the striatum...
December 1998: Rinshō Shinkeigaku, Clinical Neurology
T Hashimoto, N Yanagisawa
Inhibitory control of basal ganglia output to thalamocortical projection plays an important role in normal cortical activity in the current model of the basal ganglia motor circuit. Hypokinetic and hyperkinetic movement disorders of basal ganglia origin can be explained by excess or collapse of the basal ganglia output. An abundance of evidence indicates that parkinsonian akinesia results from hyperactivity of the basal ganglia output. Reversal of akinesia by lesions of the internal division of the globus pallidus (GPi) or its excitatory source, the subthalamic nucleus, agrees with this pathological schema...
May 1997: No to Hattatsu. Brain and Development
V Bernard, A Gardiol, B Faucheux, B Bloch, Y Agid, E C Hirsch
The overactivity of subthalamopallidal and corticostriatal glutamatergic neurons observed in Parkinson's disease (PD) suggests that antagonists of glutamate receptor could be used to alleviate the motor symptoms of the disease. In this study, we analysed two features of the striatopallidal complex: (1) the distribution of alpha-amino-3 hydroxy-5-methyl-4-isoxasol-propionate (AMPA) and kainate receptors and their corresponding mRNA by immunohistochemistry and in situ hybridisation and (2) the effect of dopaminergic denervation on AMPA receptor gene expression in PD patients and rats with 6-hydroxydopamine (6-OHDA)-induced degeneration of the nigrostriatal dopaminergic system...
May 13, 1996: Journal of Comparative Neurology
Y Takiyama, S Oyanagi, S Kawashima, H Sakamoto, K Saito, M Yoshida, S Tsuji, Y Mizuno, M Nishizawa
The gene locus for Machado-Joseph disease (MJD) has been mapped to chromosome 14q by linkage analysis, mainly using a single large Japanese family. We studied the clinical and neuropathologic findings of this family with MJD, comparing them with those of spinocerebellar ataxia 1 (SCA1) and spinocerebellar ataxia 2 (SCA2) families. The pedigree included 30 affected persons in 125 members of five generations. Neurologic examination of 21 patients revealed that dystonia, difficulty in eyelid opening, slowness of movements, bulging eyes, and facial-lingual fasciculation-like movements or myokymia are characteristic of this MJD family, although these three autosomal dominant spinocerebellar degenerations have several neurologic signs and symptoms in common...
July 1994: Neurology
Y Smith, T Wichmann, M R DeLong
In order to better understand the way by which the subthalamic nucleus interacts with the globus pallidus to control the output of the basal ganglia, we carried out a series of experiments to investigate the pattern of synaptic innervation of the pallidal neurones by the subthalamic terminals in the squirrel monkey. To address this problem we used the anterograde transport of biocytin. Following injections of biocytin in the subthalamic nucleus, rich plexuses of labelled fibres and varicosities formed bands that lay along the medullary lamina in both segments of the ipsilateral pallidum...
May 8, 1994: Journal of Comparative Neurology
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