Organization of Motor Cortical Inputs to the Subthalamic Nucleus in the Monkey

Iwamuro, Hirokazu; Tachibana, Yoshihisa; Saito, Nobuhito; Nambu, Atsushi

doi:10.1007/978-1-4419-0340-2_9

Cited by 4 publications

(18 citation statements)

References 22 publications

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“…These predictions resulted from extensive tests with a computational model of the macaque monkey basal ganglia, fitted from over a hundred independent anatomical and physiological experimental data in macaque monkeys (Liénard and Girard, 2014). Furthermore, to ascertain the delays between BG nuclei we also incorporated a set of stimulation studies to our calculations (Yoshida et al, 1993, Turner and DeLong, 2000, Nambu et al, 2000, Kita et al, 2004, 2005, Tachibana et al, 2008, Iwamuro et al, 2009)see section 2. Although this model contains numerous parameters, it is important to notice that these were optimized to fit to healthy non-human primate references.…”

Section: Discussionmentioning

confidence: 99%

“…The two experimental data to which the delays could not be fit to were in fact data that differed across experiments. Indeed, after cortical stimulation, Nambu et al (2000) report a late STN excitation after 32.3 ± 11.8 ms, while Iwamuro et al (2009) report a 16.0 ± 2.8 ms delay. These two numerical delays used in the optimization procedure are thus in contradiction.…”

Section: Transmission Delays In the Primate Basal Gangliamentioning

confidence: 98%

“…A vast number of stimulation studies aimed at characterizing transmission delays across different neuronal groups (Yoshida et al, 1993, Turner and DeLong, 2000, Nambu et al, 2000, Kita et al, 2004, 2005 , Tachibana et al, 2008, Iwamuro et al, 2009. To the best of our knowledge, this work is the first to perform a meta-analysis of these experimental studies by computational means.…”

Section: Axonal Delaysmentioning

confidence: 99%

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Beta-Band Oscillations without Segregated Pathways: the opposing Roles of D2 and D5 Receptors in the Basal Ganglia

Liénard¹,

Aubin²,

Cos³

et al. 2017

Preprint

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Parkinson's disease is characterized by the death of dopaminergic neurons and the emergence of strong β-band oscillations throughout the basal ganglia nuclei. According to the mainstream theory, this synchrony is mediated by a dopamine deficit within the striatum creating a functional imbalance between the D1-expressing medium spiny neurons, which project to the internal segment of the globus pallidus, and D2-expressing one, which target its external segment, and ultimately leads to oscillatory activity. However, anatomical evidence gathered in rodents and primates has shown that striatal neurons are for the most part not organized into independent populations differentially targeting the two segments of the globus pallidus, nor alternatively expressing D1 or D2 receptors, thus calling for an alternative mechanism through which the lack of dopamine may cause oscillations. Here we adopt a computational approach in which we investigate a model whose parameters are fit to an extensive set of anatomical and physiological constraints from non-human primates, including axonal transmission delays gathered from eight experimental studies. Investigating the lack of dopamine in this model revealed that in the absence of segregated pathways, β-band oscillations emerge as a consequence of the extra-striate dopaminergic receptors reduced activity. These oscillations are caused by synchronous activity within the external globus pallidus-subthalamic nucleus loop, and their frequency are modulated by the transmission delays between these nuclei. Our model delivers a parsimonious explanation of oscillations that does not require any external driving influence from cortex, nor specific medium spiny neuron properties.

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Section: Discussionmentioning

confidence: 99%

Section: Transmission Delays In the Primate Basal Gangliamentioning

confidence: 98%

Section: Axonal Delaysmentioning

confidence: 99%

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Beta-Band Oscillations without Segregated Pathways: the opposing Roles of D2 and D5 Receptors in the Basal Ganglia

Liénard¹,

Aubin²,

Cos³

et al. 2017

Preprint

View full text Add to dashboard Cite

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“…Some anatomical experiments showed that the projections from the MI, SMA, and PM partially overlap in the striatum,21,22 and an electrophysiological study revealed that around 20% of putamen neurons receive convergent inputs from the MI and SMA 11. Another experiment showed that around 30% of STN neurons receive convergent inputs from the MI and SMA 13. The functions of these convergences remain unknown.…”

Section: Parallel Organization Of the Cortico-basal Ganglia Loopsmentioning

confidence: 99%

“…Fiber connections can also be studied by electrophysiological methods. Stimulation of the MI induces responses in the corresponding areas in the striatum, STN, GPe, and GPi 11,13,14…”

Section: Somatotopic Organization Of the Basal Gangliamentioning

confidence: 99%

Electrophysiological Evidences of Organization of Cortical Motor Information in the Basal Ganglia

Iwamuro¹

2011

JMD

Self Cite

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During the last two decades, the many developments in the treatment of movement disorders such as Parkinson disease and dystonia have enhanced our understanding on organization of the basal ganglia, and this knowledge has led to other advances in the field. According to many electrophysiological and anatomical findings, it is considered that motor information from different cortical areas is processed through several cortico-basal ganglia loops principally in a parallel fashion and somatotopy from each cortical area is also well preserved in each loop. Moreover, recent studies suggest that not only the parallel processing but also some convergence of information occur through the basal ganglia. Information from cortical areas whose functions are close to each other tends to converge in the basal ganglia. The cortico-basal ganglia loops should be comprehended more as a network rather than as separated subdivisions. However, the functions of this convergence still remain unknown. It is important even for clinical doctors to be well informed about this kind of current knowledge because some symptoms of movement disorders may be explained by disorganization of the information network in the basal ganglia.

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A biologically constrained model of the whole basal ganglia addressing the paradoxes of connections and selection

Liénard

Girard

2013

J Comput Neurosci

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The basal ganglia nuclei form a complex network of nuclei often assumed to perform selection, yet their individual roles and how they influence each other is still largely unclear. In particular, the ties between the external and internal parts of the globus pallidus are paradoxical, as anatomical data suggest a potent inhibitory projection between them while electrophysiological recordings indicate that they have similar activities. Here we introduce a theoretical study that reconciles both views on the intra-pallidal projection, by providing a plausible characterization of the relationship between the external and internal globus pallidus. Specifically, we developed a mean-field model of the whole basal ganglia, whose parameterization is optimized to respect best a collection of numerous anatomical and electrophysiological data. We first obtained models respecting all our constraints, hence anatomical and electrophysiological data on the intrapallidal projection are globally consistent. This model furthermore predicts that both aforementioned views about the intra-pallidal projection may be reconciled when this projection is weakly inhibitory, thus making it possible to support similar neural activity in both nuclei and for the entire basal ganglia to select between actions. Second, we predicts that afferent projections are substantially unbalanced towards the external segment, as it receives the strongest excitation from STN and the weakest inhibition from the striatum. Finally, our study strongly suggest that the intrapallidal connection pattern is not focused but diffuse, as this latter pattern is more efficient for the overall selection performed in the basal ganglia.

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Organization of Motor Cortical Inputs to the Subthalamic Nucleus in the Monkey

Cited by 4 publications

References 22 publications

Beta-Band Oscillations without Segregated Pathways: the opposing Roles of D2 and D5 Receptors in the Basal Ganglia

Beta-Band Oscillations without Segregated Pathways: the opposing Roles of D2 and D5 Receptors in the Basal Ganglia

Electrophysiological Evidences of Organization of Cortical Motor Information in the Basal Ganglia

A biologically constrained model of the whole basal ganglia addressing the paradoxes of connections and selection

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