scholarly journals Subthalamic, not striatal, activity correlates with basal ganglia downstream activity in normal and parkinsonian monkeys

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Marc Deffains ◽  
Liliya Iskhakova ◽  
Shiran Katabi ◽  
Suzanne N Haber ◽  
Zvi Israel ◽  
...  

The striatum and the subthalamic nucleus (STN) constitute the input stage of the basal ganglia (BG) network and together innervate BG downstream structures using GABA and glutamate, respectively. Comparison of the neuronal activity in BG input and downstream structures reveals that subthalamic, not striatal, activity fluctuations correlate with modulations in the increase/decrease discharge balance of BG downstream neurons during temporal discounting classical condition task. After induction of parkinsonism with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), abnormal low beta (8-15 Hz) spiking and local field potential (LFP) oscillations resonate across the BG network. Nevertheless, LFP beta oscillations entrain spiking activity of STN, striatal cholinergic interneurons and BG downstream structures, but do not entrain spiking activity of striatal projection neurons. Our results highlight the pivotal role of STN divergent projections in BG physiology and pathophysiology and may explain why STN is such an effective site for invasive treatment of advanced Parkinson's disease and other BG-related disorders.

2020 ◽  
Author(s):  
Maria-Daniela Cirnaru ◽  
Sicheng Song ◽  
Kizito-Tshitoko Tshilenge ◽  
Chuhyon Corwin ◽  
Justyna Mleczko ◽  
...  

AbstractThe basal ganglia, best known for processing information required for multiple aspects of movement, is also part of a network which regulates reward and cognition. The major output nucleus of the basal ganglia is the striatum, and its functions are dependent on neuronal compartmentation, including striosomes and matrix, which are selectively affected in disease. Striatal projection neurons are GABAergic medium spiny neurons (MSNs), all of which share basic molecular signatures but are subtyped by selective expression of receptors, neuropeptides, and other gene families. Neurogenesis of the striosome and matrix occurs in separate waves, but the factors regulating terminal neuronal differentiation following migration are largely unidentified. We performed RNA- and ATAC-seq on sorted murine striosome and matrix cells at postnatal day 3. Focusing on the striosomal compartment, we validated the localization and role of transcription factors and their regulator(s), previously not known to be associated with striatal development, including Irx1, Foxf2, Olig2 and Stat1/2. In addition, we validated the enhancer function of a striosome-specific open chromatin region located 15Kb downstream of the Olig2 gene. These data and data bases provide novel tools to dissect and manipulate the networks regulating MSN compartmentation and differentiation and thus provide new approaches to establishing MSN subtypes from human iPSCs for disease modeling and drug discovery.


Synapse ◽  
2018 ◽  
Vol 73 (4) ◽  
pp. e22079 ◽  
Author(s):  
Brisa García-Vilchis ◽  
Paola Suárez ◽  
Miguel Serrano-Reyes ◽  
Mario Arias-García ◽  
Dagoberto Tapia ◽  
...  

2020 ◽  
Author(s):  
Krishnakanth Kondabolu ◽  
Natalie M. Doig ◽  
Olaoluwa Ayeko ◽  
Bakhtawer Khan ◽  
Alexandra Torres ◽  
...  

AbstractThe striatum and subthalamic nucleus (STN) are considered to be the primary input nuclei of the basal ganglia. Projection neurons of both striatum and STN can extensively interact with other basal ganglia nuclei, and there is growing anatomical evidence of direct axonal connections from the STN to striatum. There remains, however, a pressing need to elucidate the organization and impact of these subthalamostriatal projections in the context of the diverse cell types constituting the striatum. To address this, we carried out monosynaptic retrograde tracing from genetically-defined populations of dorsal striatal neurons in adult male and female mice, quantifying the connectivity from STN neurons to spiny projection neurons, GABAergic interneurons, and cholinergic interneurons. In parallel, we used a combination of ex vivo electrophysiology and optogenetics to characterize the responses of a complementary range of dorsal striatal neuron types to activation of STN axons. Our tracing studies showed that the connectivity from STN neurons to striatal parvalbumin-expressing interneurons is significantly higher (~ four-to eight-fold) than that from STN to any of the four other striatal cell types examined. In agreement, our recording experiments showed that parvalbumin-expressing interneurons, but not the other cell types tested, commonly exhibited robust monosynaptic excitatory responses to subthalamostriatal inputs. Taken together, our data collectively demonstrate that the subthalamostriatal projection is highly selective for target cell type. We conclude that glutamatergic STN neurons are positioned to directly and powerfully influence striatal activity dynamics by virtue of their enriched innervation of GABAergic parvalbumin-expressing interneurons.


2015 ◽  
Vol 113 (3) ◽  
pp. 796-807 ◽  
Author(s):  
Ricardo Hernández-Martínez ◽  
José J. Aceves ◽  
Pavel E. Rueda-Orozco ◽  
Teresa Hernández-Flores ◽  
Omar Hernández-González ◽  
...  

The external globus pallidus (GPe) is central for basal ganglia processing. It expresses muscarinic cholinergic receptors and receives cholinergic afferents from the pedunculopontine nuclei (PPN) and other regions. The role of these receptors and afferents is unknown. Muscarinic M1-type receptors are expressed by synapses from striatal projection neurons (SPNs). Because axons from SPNs project to the GPe, one hypothesis is that striatopallidal GABAergic terminals may be modulated by M1 receptors. Alternatively, some M1 receptors may be postsynaptic in some pallidal neurons. Evidence of muscarinic modulation in any of these elements would suggest that cholinergic afferents from the PPN, or other sources, could modulate the function of the GPe. In this study, we show this evidence using striatopallidal slice preparations: after field stimulation in the striatum, the cholinergic muscarinic receptor agonist muscarine significantly reduced the amplitude of inhibitory postsynaptic currents (IPSCs) from synapses that exhibited short-term synaptic facilitation. This inhibition was associated with significant increases in paired-pulse facilitation, and quantal content was proportional to IPSC amplitude. These actions were blocked by atropine, pirenzepine, and mamba toxin-7, suggesting that receptors involved were M1. In addition, we found that some pallidal neurons have functional postsynaptic M1 receptors. Moreover, some evoked IPSCs exhibited short-term depression and a different kind of modulation: they were indirectly modulated by muscarine via the activation of presynaptic cannabinoid CB1 receptors. Thus pallidal synapses presenting distinct forms of short-term plasticity were modulated differently.


2012 ◽  
Vol 107 (1) ◽  
pp. 424-432 ◽  
Author(s):  
Shin Yanagihara ◽  
Neal A. Hessler

The basal ganglia is thought to be critical for motor control and learning in mammals. In specific basal ganglia regions, gamma frequency oscillations occur during various behavioral states, including sleeping periods. Given the critical role of sleep in regulating vocal plasticity of songbirds, we examined the presence of such oscillations in the basal ganglia. In the song system nucleus Area X, epochs of high-gamma frequency (80–160 Hz) oscillation of local field potential during sleep were associated with phasic increases of neural activity. While birds were awake, activity of the same neurons increased specifically when birds were singing. Furthermore, during sleep there was a clear tendency for phase locking of spikes to these oscillations. Such patterned activity in the sleeping songbird basal ganglia could play a role in off-line processing of song system motor networks.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Katalin Skrapits ◽  
Miklós Sárvári ◽  
Imre Farkas ◽  
Balázs Göcz ◽  
Szabolcs Takács ◽  
...  

Human reproduction is controlled by ~2,000 hypothalamic gonadotropin-releasing hormone (GnRH) neurons. Here we report the discovery and characterization of additional ~150,000-200,000 GnRH-synthesizing cells in the human basal ganglia and basal forebrain. Nearly all extrahypothalamic GnRH neurons expressed the cholinergic marker enzyme choline acetyltransferase. Similarly, hypothalamic GnRH neurons were also cholinergic both in embryonic and adult human brains. Whole-transcriptome analysis of cholinergic interneurons and medium spiny projection neurons laser-microdissected from the human putamen showed selective expression of GNRH1 and GNRHR1 autoreceptors in the cholinergic cell population and uncovered the detailed transcriptome profile and molecular connectome of these two cell types. Higher-order non-reproductive functions regulated by GnRH under physiological conditions in the human basal ganglia and basal forebrain require clarification. The role and changes of GnRH/GnRHR1 signaling in neurodegenerative disorders affecting cholinergic neurocircuitries, including Parkinson's and Alzheimer's diseases, need to be explored.


2020 ◽  
Author(s):  
Qiaoling Cui ◽  
Xixun Du ◽  
Isaac Y. M. Chang ◽  
Arin Pamukcu ◽  
Varoth Lilascharoen ◽  
...  

AbstractThe classic basal ganglia circuit model asserts a complete segregation of the two striatal output pathways. Empirical data argue that, in addition to indirect-pathway striatal projection neurons (iSPNs), direct-pathway striatal projection neurons (dSPNs) innervate the external globus pallidus (GPe). However, the functions of the latter were not known. In this study, we interrogated the organization principles of striatopallidal projections and how they are involved in full-body movement in mice (both males and females). In contrast to the canonical motor-promoting role of dSPNs in the dorsomedial striatum (DMSdSPNs), optogenetic stimulation of dSPNs in the dorsolateral striatum (DLSdSPNs) suppressed locomotion. Circuit analyses revealed that dSPNs selectively target Npas1+ neurons in the GPe. In a chronic 6-hydroxydopamine lesion model of Parkinson’s disease, the dSPN-Npas1+ projection was dramatically strengthened. As DLSdSPN-Npas1+ projection suppresses movement, the enhancement of this projection represents a circuit mechanism for the hypokinetic symptoms of Parkinson’s disease that has not been previously considered.Significance statementIn the classic basal ganglia model, the striatum is described as a divergent structure—it controls motor and adaptive functions through two segregated, opponent output streams. However, the experimental results that show the projection from direct-pathway neurons to the external pallidum have been largely ignored. Here, we showed that this striatopallidal sub-pathway targets a select subset of neurons in the external pallidum and is motor-suppressing. We found that this sub-pathway undergoes plastic changes in a Parkinson’s disease model. In particular, our results suggest that the increase in strength of this sub-pathway contributes to the slowness or reduced movements observed in Parkinson’s disease.


2021 ◽  
Author(s):  
Katalin Skrapits ◽  
Miklós Sárvári ◽  
Imre Farkas ◽  
Balázs Göcz ◽  
Szabolcs Takács ◽  
...  

Human reproduction is controlled by ~2,000 hypothalamic gonadotropin-releasing hormone (GnRH) neurons. Here we report the discovery and characterization of additional 150-200,000 GnRH-synthesizing cells in the human basal ganglia and basal forebrain. Extrahypothalamic GnRH neurons were cholinergic. Though undetectable in adult rodents, the GnRH-GFP transgene was expressed transiently by caudate-putamen cholinergic interneurons in newborn transgenic mice. In slice electrophysiological studies, GnRH inhibited these interneurons via GnRHR1 autoreceptors. Whole-transcriptome analysis of cholinergic interneurons and medium spiny projection neurons laser-microdissected from the human putamen confirmed selective expression of GnRH and GnRHR1 autoreceptors in cholinergic cells and uncovered the detailed transcriptome profile and molecular connectome of these two cell types. Higher-order non-reproductive functions regulated by GnRH under physiological conditions in the human basal ganglia and basal forebrain require clarification. GnRH/GnRHR1 signaling as a potential therapeutic target in the treatment of neurodegenerative disorders affecting cholinergic neurocircuitries, including Parkinson’s and Alzheimer’s diseases, needs to be explored.


2013 ◽  
Vol 109 (12) ◽  
pp. 3025-3040 ◽  
Author(s):  
M. Guthrie ◽  
A. Leblois ◽  
A. Garenne ◽  
T. Boraud

In a previous modeling study, Leblois et al. (2006) demonstrated an action selection mechanism in cortico-basal ganglia loops based on competition between the positive feedback, direct pathway through the striatum and the negative feedback, hyperdirect pathway through the subthalamic nucleus. The present study investigates how multiple level action selection could be performed by the basal ganglia. To do this, the model is extended in a manner consistent with known anatomy and electrophysiology in three main areas. First, two-level decision making has been incorporated, with a cognitive level selecting based on cue shape and a motor level selecting based on cue position. We show that the decision made at the cognitive level can be used to bias the decision at the motor level. We then demonstrate that, for accurate transmission of information between decision-making levels, low excitability of striatal projection neurons is necessary, a generally observed electrophysiological finding. Second, instead of providing a biasing signal between cue choices as an external input to the network, we show that the action selection process can be driven by reasonable levels of noise. Finally, we incorporate dopamine modulated learning at corticostriatal synapses. As learning progresses, the action selection becomes based on learned visual cue values and is not interfered with by the noise that was necessary before learning.


1986 ◽  
Vol 55 (4) ◽  
pp. 826-845 ◽  
Author(s):  
S. Nozaki ◽  
A. Iriki ◽  
Y. Nakamura

The role of the pyramidal tract (PT) in the induction of the rhythmical masticatory activity (RMA) of the anterior digastric motoneurons by repetitive stimulation of the cortical masticatory area (CMA) was studied in the ketamine-anesthetized guinea pig. The coronal section of the medial brain stem at the pontine level did not show any effect on the cortically induced RMA in the digastric EMG, as long as the majority of the PT fibers was spared of the section. In contrast, unilateral section of the PT at the pontine level abolished the RMA in the digastric EMG induced by repetitive stimulation of the ipsilateral CMA, while that induced by the contralateral CMA stimulation was not affected by the PT section. The threshold of repetitive PT stimulation for induction of the RMA of the digastric EMG was much higher at the levels caudal to the facial nucleus than that at more rostral levels, and no RMA was induced by the PT stimulation at the caudal bulbar levels even at the supramaximal intensities for RMA induction of the PT stimulation at more rostral levels. Single shocks applied to the PT at the caudal bulbar levels did not evoke any antidromic field potential in the CMA. Single shocks applied to the CMA evoked a negative field potential in the medial bulbar reticular formation (MBRF) mainly on the contralateral side after a monosynaptic latency, which was largest in amplitude in the region including the most dorsal portion of the nucleus reticularis paragigantocellularis and the area dorsally adjacent to it (dPGC). Stimulation of the oral portion of the nucleus reticularis gigantocellularis (GC) evoked an antidromic negative field potential in the ipsilateral dPGC. Intracellular recording from neurons in the dPGC demonstrated that neurons were located in the dPGC that responded with EPSPs after a monosynaptic latency to single shocks applied to the contralateral CMA and with antidromic spike potentials to stimulation of the oral portion of the ipsilateral GC (GCo). Single shocks applied to the dPGC evoked antidromic field potential in the area in the contralateral cerebral cortex corresponding with the CMA. Injection of horseradish peroxidase (HRP) into the dPGC on one side retrogradely labeled the pyramidal cells with HRP bilaterally in the cerebral cortical area corresponding with the CMA. The number and density of the labeled cells on the contralateral side far exceeded those on the ipsilateral side.(ABSTRACT TRUNCATED AT 400 WORDS)


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