Reduced Interhemispheric Coherence after Cerebellar Vermis Output Perturbation

Abstract

Motor coordination and motor learning are well-known roles of the cerebellum. Recent evidence also supports the contribution of the cerebellum to the oscillatory activity of brain networks involved in a wide range of disorders. Kainate, a potent analog of the excitatory neurotransmitter glutamate, can be used to induce dystonia, a neurological movement disorder syndrome consisting of sustained or repetitive involuntary muscle contractions, when applied on the surface of the cerebellum. This research aims to study the interhemispheric cortical communication between the primary motor cortices after repeated kainate application on cerebellar vermis for five consecutive days, in mice. We recorded left and right primary motor cortices electrocorticograms and neck muscle electromyograms, and quantified the motor behavior abnormalities. The results indicated a reduced coherence between left and right motor cortices in low-frequency bands. In addition, we observed a phenomenon of long-lasting adaptation with a modification of the baseline interhemispheric coherence. Our research provides evidence that the cerebellum can control the flow of information along the cerebello-thalamo-cortical neural pathways and can influence interhemispheric communication. This phenomenon could function as a compensatory mechanism for impaired regional networks.

Infarct‐related structural disconnection and delirium in surgical aortic valve replacement patients

“… 35 Thus, independent of surgery type, vulnerability of the cerebellum to perioperative infarction and the associated risk for subsequent delirium appears to be high. The pathophysiological mechanisms of this association are still relatively obscured, but the role of the cerebellum in brain network oscillatory activity via the cortico‐thalamo‐cerebellar pathway is one hypothesis, as dysfunction in this circuit can have a negative impact on interhemispheric communication and has been suggested as the basis for “dysmetria of thought.” 36 , 37 , 38 Non‐motor deficits arising from lesions damaging the cortico‐cerebellar connection, such as the cognitive abnormalities seen in patients with cerebellar cognitive affective syndrome (aka. Schmahmann's syndrome) 39 are routinely observed during delirium states (e.g., executive dysfunction, affective dysregulation, attention, and working memory impairment).…”

Function and dysfunction of the dystonia network: an exploration of neural circuits that underlie the acquired and isolated dystonias

“…Fremont et al identified that in mice with ouabain-induced lesions the presence of dystonia was accompanied by persistent high-frequency bursts of cerebellar nuclear neurons, and restoration of the ouabain-blocked sodium channels alleviated the symptoms of dystonia as assessed with rotarod and observation assays [ 152 ]. Georgescu Margarint et al created an electromyographical setup that showed lateralized or vermal cerebellar dysfunction (due to kainic acid administration) ultimately triggered dystonia that was associated with a loss of connectivity in the corresponding cortical motor cortices ( Figure 3 ) [ 153 , 154 ], mirroring the human imaging studies in dystonic CP and task specific dystonias. Such studies have highlighted the evolutionary conservation of the dystonia network and shown that anatomic and circuit derived manipulations of the network can inform and confirm findings in the clinical population.…”

Reduced Interhemispheric Coherence in Cerebellar Kainic Acid-Induced Lateralized Dystonia

“…Therapeutic modulation of the cerebellum or its outflow pathway was occasionally found to be effective in the treatment of dystonia (19,20). In animal models, dystonia can be triggered by kainic acid (a glutamate receptor agonist) injection into the cerebellum surface (21)(22)(23). Raike et al showed that focal and generalized dystonia may have similar physiopathology and can be treated with similar strategies (24).…”