Inputs from the Cerebellar Nuclei to the Forelimb Area of the Motor Cortex

1992 ◽  
pp. 65-84 ◽  
Author(s):  
Y. Shinoda ◽  
T. Futami ◽  
S. Kakei
Keyword(s):  
Motor Cortex ◽  
Cerebellar Nuclei

Differential Effects of Deep Cerebellar Nuclei Inactivation on Reaching and Adaptive Control

2000 ◽  
Vol 83 (4) ◽  
pp. 1886-1899 ◽  
Author(s):  
John H. Martin ◽  
Scott E. Cooper ◽  
Antony Hacking ◽  
Claude Ghez
Keyword(s):  
Motor Cortex ◽  
Cerebellar Nuclei ◽  
Trajectory Control ◽  
Trunk Control ◽  
Temporal And Spatial Variability ◽  
Severe Impairment ◽  
Limb Kinematics ◽  
Path Curvature ◽  
Sensory Evoked ◽  
Proprioceptive Inputs

This study examined the effects of selective inactivation of the cerebellar nuclei in the cat on the control of multijoint trajectories and trajectory adaptation to avoid obstacles. Animals were restrained in a hammock and trained to perform a prehension task in which they reached to grasp a small cube of meat from a narrow food well. To examine trajectory adaptation, reaching was obstructed by placing a horizontal bar in the limb's path. Inactivation was produced by microinjection of the GABA agonist muscimol (0.25–1.0 μg in 1 μL saline). Fastigial nucleus inactivation produced a severe impairment in balance and in head and trunk control but no effect on reaching and grasping. Dentate inactivation slowed movements significantly and produced a significant increase in tip path curvature but did not impair reaching and grasping. Selective inactivation of the anterior and posterior interpositus nuclei did not impair grasping but severely decreased the accuracy of reaching movements and produced different biases in wrist and paw paths. Anterior interpositus inactivation produced movement slowing (wrist speed) and under-reaching to the food well. Wrist and tip paths showed anterior biases and became more curved. Also animals could no longer make anticipatory adjustments in limb kinematics to avoid obstructions but sensory-evoked corrective responses were preserved. Posterior interpositus inactivation produced a significant increase in wrist speed and overreaching. Wrist and tip paths showed a posterior bias and became more curved, although in a different way than during anterior interpositus inactivation. Posterior interpositus inactivation did not impair trajectory adaptation to reach over the obstacle. During inactivation of either interpositus nucleus, all measures of kinematic temporal and spatial variability increased with somewhat greater effects being produced by anterior interpositus inactivation. We discuss our results in relation to the hypothesis that anterior and posterior interpositus have different roles in trajectory control, related possibly to feed-forward use of cutaneous and proprioceptive inputs, respectively. The loss of adaptive reprogramming during anterior interpositus inactivation further suggests a role in motor learning. Comparison with results from our earlier motor cortical study shows that the distinctive impairments produced by inactivation of these two nuclei are similar to those produced by selective inactivation of different zones in the forelimb area of rostral motor cortex. Our findings are consistent with the hypothesis that there are separate functional output channels from the anterior and posterior interpositus nuclei to rostral motor cortex for distinct aspects of trajectory control and, from anterior interpositus alone, for trajectory adaptation.

Cortico-Cerebellar Coherence During a Precision Grip Task in the Monkey

2006 ◽  
Vol 95 (2) ◽  
pp. 1194-1206 ◽  
Author(s):  
Demetris S. Soteropoulos ◽  
Stuart N. Baker
Keyword(s):  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Precision Grip ◽  
Cerebellar Nuclei ◽  
Correlation Peak ◽  
Sensorimotor Processing ◽  
Underlying Mechanisms ◽  
Unit Unit ◽  
Average Coherence ◽  
40 Hz

We studied the synchronization of single units in macaque deep cerebellar nuclei (DCN) with local field potentials (LFPs) in primary motor cortex (M1) bilaterally during performance of a precision grip task. Analysis was restricted to periods of steady holding, during which M1 oscillations are known to be strongest. Significant coherence between DCN units and M1 LFP oscillations bilaterally was seen at ∼10–40 Hz (contralateral M1: 25/87 units; ipsilateral: 9/87 units). Averaged coherence between DCN units and contralateral M1 LFP showed a prominent ∼17-Hz coherence peak and an average phase of approximately −π/2 radians, implying that the DCN units fired around the time of maximal depolarization of M1 cells. The lack of a time delay between DCN and M1 activity suggests that the cerebellum and cortex may form a pair of phase coupled oscillators. Although coherence values were low (mean peak coherence, 0.018), we used a computational model to show that this probably resulted from the nonlinearity of spike generating mechanisms within the DCN. DCN unit discharge and DCN LFPs also showed significant coherence at ∼10–40 Hz, with similarly low magnitude (mean peak coherence, 0.012). The average coherence phase was −2.5 radians for the 6- to 14-Hz range and −1.1 radians for the 17- to 41-Hz range, suggesting different frequency-specific underlying mechanisms. Finally, 4/40 pairs of simultaneously recorded DCN units showed a significant cross-correlation peak, and 16/40 pairs showed significant unit-unit coherence. The extensive oscillatory synchronization observed between cerebellum and motor cortex may have functional importance in sensorimotor processing.

Activity of muscle spindles, motor cortex and cerebellar nuclei during action tremor

1984 ◽  
Vol 323 (2) ◽  
pp. 330-334 ◽  
Author(s):  
Rodger J. Elble ◽  
Marc H. Schieber ◽  
W. Thomas Thach
Keyword(s):  
Motor Cortex ◽  
Muscle Spindles ◽  
Cerebellar Nuclei ◽  
Action Tremor

scholarly journals Functional abnormalities in the cerebello-thalamic pathways in an animal model of dystonia

2020 ◽  
Author(s):  
Elena Laura Margarint ◽  
Hind Baba Aïssa ◽  
Andrés Pablo Varani ◽  
Romain Sala ◽  
Fabien Menardy ◽  
...  
Keyword(s):  
Animal Model ◽  
Motor Cortex ◽  
Mouse Model ◽  
Motor Function ◽  
Cerebellar Nuclei ◽  
Motor Symptoms ◽  
Motor Impairments ◽  
Firing Patterns ◽  
Striatal Function ◽  
Theta Burst

ABSTRACTDystonia is often associated with functional alterations in the cerebello-thalamic pathways, which have been proposed to contribute to the disorder by propagating pathological firing patterns to the forebrain. Here, we examined the function of the cerebello-thalamic pathways in a model of DYT25 dystonia, mice carrying a heterozygous invalidation of Gnal gene which notably disrupts striatal function, exhibiting dystonic movements and postures following systemic or striatal administration of oxotremorine. Theta-burst optogenetic stimulations of the cerebellar nuclei evoked a potentiation of the responses to cerebellar stimulations in the thalamus and motor cortex in WT mice, without evident motor function disruption. In contrast, theta burst stimulations evoked a depression of these responses only in dystonia-manifesting Gnal+/− mice after oxotremorine administration, decreased the disabling dystonia attacks, and increased normal active wake behaviour in Gnal+/− mice. The cerebellum could thus offer a gateway for a corrective treatment of motor impairments in dystonia including striatal dysfunction.One sentence summaryA mouse model of DYT25 dystonia, carrying a Gnal mutation disrupting striatal neurotransmission, exhibits anomalous cerebello-thalamic plasticity in the non-manifesting state, but theta-burst cerebellar stimulations during cholinergic-induced dystonia depress the cerebello-thalamic transmission and reduce the severity of the motor symptoms.

scholarly journals Cerebellar stimulations prevent Levodopa-induced dyskinesia in mice and normalize brain activity

2021 ◽  
Author(s):  
Bérénice Coutant ◽  
Jimena Laura Frontera ◽  
Elodie Perrin ◽  
Adèle Combes ◽  
Thibault Tarpin ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Motor Cortex ◽  
Gold Standard ◽  
Standard Treatment ◽  
Brain Activity ◽  
Symptomatic Relief ◽  
Cerebellar Nuclei ◽  
Striatal Neurons ◽  
Motor Network ◽  
Freely Moving

SUMMARYChronic Levodopa therapy, the gold-standard treatment of Parkinson’s Disease (PD), leads to the emergence of involuntary movements, called levodopa-induced dyskinesia (LID). Cerebellar stimulations have been shown to decrease LID severity in PD patients. Here, in order to determine how cerebellar stimulations induce LID alleviation, we performed daily short trains of optogenetic stimulations of Purkinje cells (PC) in freely moving mice. We demonstrated that these stimulations are sufficient to suppress LID or even prevent their development. This symptomatic relief is accompanied by the normalization of aberrant neuronal discharge in the cerebellar nuclei, the motor cortex and the parafascicular thalamus. Inhibition of the cerebello-parafascicular pathway counteracted the beneficial effect of cerebellar stimulations. Moreover, cerebellar stimulations reversed plasticity in D1 striatal neurons and normalized the overexpression of FosB, a transcription factor causally linked to LID. These findings demonstrate LID alleviation and prevention by daily PC stimulations, which restore the function of a wide brain motor network, and may be valuable for LID treatment.

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