Anticipatory Postural Adjustments (APAs) are a crucial aspect of the voluntary movement organization, being fundamental in stabilizing both the whole-body (inter-limb APAs) and its segments (intra-limb APAs). Until now, only a few works investigated the neural structures involved in APAs programming, by correlating neurological diseases with APAs changes. This approach clarified not only the knowledge regarding these pathologies, but also the relationships between these structures and the APA command. So, to enrich the comprehension about the neural network generating and influencing APAs, this thesis is focused on two aspects. The first part investigated the role of two subcortical structures, basal ganglia and cerebellum, in APAs organization. In particular, it was analyzed (i) how intra-limb APAs stabilize the arm and the forearm, when flexing the index-finger, in patients with basal ganglia dysfunction, as well as (ii) the inter-limb APAs associated to gait initiation in children with cerebellar ataxia. Results showed that basal ganglia seem to be involved in APA control, since the normal pattern of intra-limb APAs is disrupted in parkinsonian patients. On the other hand, the role of the cerebellum as a timing-machine was confirmed, since several alterations were found in the temporal organization of inter-limb APAs in ataxic vs. healthy children. Considering recent studies showing that basal ganglia and cerebellum are reciprocally interconnected and that the cerebellum exerts a functional compensatory activity in parkinsonian patients, it could be interesting to address future studies to inquire a reciprocal compensatory role of basal ganglia in cerebellar disease. The second part dealt with the possible influence of cognitive processes on APA control. To achieve this goal, a cerebellar area with a well-known cognitive role, Crus I-II, was examined. In this context, a protocol of Magnetic Resonance Spectroscopy was developed, able to characterize and quantify metabolites in a cerebellar area of interest. The protocol was validated in healthy subjects and could be used in future investigations of neurological diseases affecting postural and motor control. Finally, the Parietal Operculum (PO) activity was studied. This is a cortical sensory-motor integration center, notably involved in a multimodal network. So, intra-limb APAs associated to index-finger flexion were analyzed in healthy subjects before, during and after modulating the contralateral PO (coPO) excitability by anodal and cathodal transcranial Direct Current Stimulation (tDCS). Since no significant effects were found on intra-limb APAs amplitude and timing, the coPO does not seem to be involved in APA control. However, future studies should address the possible influence of both POs by bilateral tDCS.
CONTRIBUTION OF BASAL GANGLIA, CEREBELLUM AND PARIETAL OPERCULUM TO ANTICIPATORY POSTURAL ADJUSTMENTS / S.m. Marchese ; tutor: P. Cavallari ; coordinatore: C. Sforza. - Milano : Università degli studi di Milano. DIPARTIMENTO DI FISIOPATOLOGIA MEDICO-CHIRURGICA E DEI TRAPIANTI, 2020 Jan 20. ((32. ciclo, Anno Accademico 2019.
|Titolo:||CONTRIBUTION OF BASAL GANGLIA, CEREBELLUM AND PARIETAL OPERCULUM TO ANTICIPATORY POSTURAL ADJUSTMENTS|
|Supervisori e coordinatori interni:||SFORZA, CHIARELLA|
|Data di pubblicazione:||20-gen-2020|
|Parole Chiave:||motor control; postural control; human; neuromodulation; magnetic resonance spectroscopy; gait analysis|
|Settore Scientifico Disciplinare:||Settore BIO/09 - Fisiologia|
|Citazione:||CONTRIBUTION OF BASAL GANGLIA, CEREBELLUM AND PARIETAL OPERCULUM TO ANTICIPATORY POSTURAL ADJUSTMENTS / S.m. Marchese ; tutor: P. Cavallari ; coordinatore: C. Sforza. - Milano : Università degli studi di Milano. DIPARTIMENTO DI FISIOPATOLOGIA MEDICO-CHIRURGICA E DEI TRAPIANTI, 2020 Jan 20. ((32. ciclo, Anno Accademico 2019.|
|Appare nelle tipologie:||Tesi di dottorato|