Cerebellar Functions Beyond Movement and Learning

Cerebellar Roles in Motor and Social Functions and Implications for ASD

The cerebellum, traditionally linked to voluntary motor coordination, is now recognized for its role in nonmotor functions, including cognitive and social behaviors. This expanded understanding is vital for identifying neurodevelopmental disorders such as autism spectrum disorder (ASD), where cerebellar abnormalities are common. Recent research has identified specific cerebellar circuits contributing to these diverse functions, revealing interconnected pathways that regulate both motor and social behaviors. The cerebellum communicates extensively with the cerebral cortex, thalamus, and limbic structures through converging and diverging pathways, integrating sensory and motor information to fine-tune outputs and influence higher-order functions. Mouse models have been instrumental in dissecting cerebellar functions, with studies using genetic and neuroanatomical techniques to manipulate specific circuits and observe behavioral outcomes. Disruptions in cerebellar pathways can lead to motor deficits and social impairments, mirroring human neurodevelopmental disorders. This review explores the anatomical and functional organization of cerebellar pathways in mice, their role in behavior, and the implications of cerebellar dysfunction in disorders such as ASD. Understanding these pathways enhances knowledge of cerebellar contributions to behavior and informs therapeutic strategies for cerebellar and neurodevelopmental disorders, emphasizing the integral role of the cerebellum in motor and social functions.

Cerebellar deep brain stimulation as a dual-function therapeutic for restoring movement and sleep in dystonic mice

Dystonia arises with cerebellar dysfunction, which plays a key role in the emergence of multiple pathophysiological deficits that range from abnormal movements and postures to disrupted sleep. Current therapeutic interventions typically do not simultaneously address both the motor and non-motor symptoms of dystonia, underscoring the necessity for a multi-functional therapeutic strategy. Deep brain stimulation (DBS) is effectively used to reduce motor symptoms in dystonia, with existing parallel evidence arguing for its potential to correct sleep disturbances. However, the simultaneous efficacy of DBS for improving sleep and motor dysfunction, specifically by targeting the cerebellum, remains underexplored. Here, we test the effect of cerebellar DBS in two genetic mouse models with dystonia that exhibit sleep defects-Ptf1aCre;Vglut2fx/fx and Pdx1Cre;Vglut2fx/fx-which have overlapping cerebellar circuit miswiring defects but differing severity in motor phenotypes. By targeting DBS to the fiber tracts located between the cerebellar fastigial and the interposed nuclei (FN ​+ ​INT-DBS), we modulated sleep dysfunction by enhancing sleep quality and timing. This DBS paradigm improved wakefulness and rapid eye movement sleep in both mutants. Additionally, the latency to reach REM sleep, a deficit observed in human dystonia patients, was reduced in both models. Cerebellar DBS also induced alterations in the electrocorticogram (ECoG) patterns that define sleep states. As expected, DBS reduced the severe dystonic twisting motor symptoms that are observed in the Ptf1aCre;Vglut2fx/fx mice. These findings highlight the potential for using cerebellar DBS to simultaneously improve sleep and reduce motor dysfunction in dystonia and uncover its potential as a dual-effect in vivo therapeutic strategy.

Neural effects of acupuncture on stroke patients with motor dysfunction: an activation likelihood estimation meta-analysis

Background

Functional magnetic resonance imaging has been used in many studies to explore the neural mechanism of acupuncture in patients with post-stroke motor dysfunction. Inconsistent results have been found in these studies, however. This activation likelihood estimation (ALE) meta-analysis was designed to quantitatively integrate changes in brain activity and the neurological effects of acupuncture on patients with motor dysfunction after stroke.

Methods

We searched PubMed, Embase, Web of Science, the Cochrane Library, China Science and Technology Journal Database, the China Biology Medicine, the China National Knowledge Infrastructure, and Wanfang Data Knowledge Service Platform for literature from the establishment of the database until March 21, 2024. Research papers were selected, data extracted, and quality assessment was done independently by two researchers. The GingerALE software was used for meta-analysis, and Jackknife sensitivity analysis was employed to assess result robustness.

Results

We ended up analyzing 14 studies that included 235 patients and 100 healthy people. ALE meta-analysis showed that Compared with healthy people, the enhanced brain region in poststroke patients with motor dysfunction was located in the left posterior lobe of the cerebellum, the left inferior frontal gyrus, and the left precuneus (p < 0.001). After acupuncture, the activated regions were mainly located in the left posterior lobe of the cerebellum, the right lentiform nucleus putamen, the right medial frontal gyrus, the right inferior frontal gyrus, the left precuneus, the right middle temporal gyrus, the left claustrum, the left cerebellar tonsil, the right superior marginal gyrus, the inactivated area is located in the right medial frontal gyrus the left precentral gyrus and the right precuneus (p < 0.001).

Conclusion

Acupuncture can reestablish motor function by causing extensive changes in the brain function of patients with stroke, which may be the neurological effect of acupuncture therapy on stroke patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024526263.