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Motor circuit disorder

Mina Ansari, Sahand Adib Moradi, Farzaneh Ghazi Sherbaf, Abozar Hedayatnia, Mohammad Hadi Aarabi
OBJECTIVE: Research on psychobiological markers of Parkinson's disease (PD) remains a hot topic. Non-motor symptoms such as depression and REM sleep behavior disorder (RBD) each attribute to a particular neurodegenerative cluster in PD, and might enlighten the way for early prediction/detection of PD. The neuropathology of mood disturbances remains unclear. In fact, a few studies have investigated depression using diffusion magnetic resonance imaging (diffusion MRI). METHOD: Diffusion MRI of PD patients without comorbid RBD was used to assess whether microstructural abnormalities are detectable in the brain of 40 PD patients with depression compared to 19 patients without depression...
March 21, 2018: International Psychogeriatrics
Natascia De Lucia, Silvio Peluso, Alessandro Roca, Cinzia Valeria Russo, Marco Massarelli, Giovanna De Michele, Luigi Di Maio, Elena Salvatore, Giuseppe De Michele
Objective: In visuo-constructional tasks, patients may reproduce drawings near-to or superimposed on a model, showing the so-called "Closing-in" (CI), often ascribed to a defect in inhibitory control. CI has been described in neurological conditions, but no studies have explored CI in Huntington's disease (HD), a neurodegenerative disorder often involving the frontal cortical-subcortical circuits. We searched for the occurrence of CI in HD patients and systematically investigated its correlates to find a clinical marker of the frontal/executive dysfunctions in the early examination of HD patients...
March 15, 2018: Archives of Clinical Neuropsychology: the Official Journal of the National Academy of Neuropsychologists
Omid Abbasi, Jan Hirschmann, Lena Storzer, Tolga Esat Özkurt, Saskia Elben, Jan Vesper, Lars Wojtecki, Georg Schmitz, Alfons Schnitzler, Markus Butz
Deep brain stimulation (DBS) is an established therapy to treat motor symptoms in movement disorders such as Parkinson's disease (PD). The mechanisms leading to the high therapeutic effectiveness of DBS are poorly understood so far, but modulation of oscillatory activity is likely to play an important role. Thus, investigating the effect of DBS on cortical oscillatory activity can help clarifying the neurophysiological mechanisms of DBS. Here, we aimed at scrutinizing changes of cortical oscillatory activity by DBS at different frequencies using magnetoencephalography (MEG)...
March 15, 2018: NeuroImage
Nadia Bolognini, Carlo Miniussi
Transcranial magnetic stimulation (TMS) and transcranial electric stimulation (tES) are noninvasive brain stimulation (NIBS) tools that are now widely used in neuroscientific research in humans. The fact that both TMS and tES are able to modulate brain plasticity and, in turn, affect behavior is opening up new horizons in the treatment of brain circuit and plasticity disorders. In the present chapter, we will first provide the reader with a brief background on the basic principles of NIBS, describing the electromagnetic and physical foundations of TMS and tES, as well as the current knowledge of the neurophysiologic basis of their effects on brain activity and plasticity...
2018: Handbook of Clinical Neurology
Syam Krishnan, Krishnakumar Kesava Pisharady, K P Divya, Kuldeep Shetty, Asha Kishore
Deep Brain Stimulation (DBS) was introduced into clinical practice nearly four decades ago and is currently the standard of care for patients with Parkinson's disease experiencing motor complications. Apart from this, it has several other established and emerging applications in movement disorders. The exact mechanisms by which DBS provides relief in movement disorders are still unclear; disruption of pathological neuronal synchrony and abnormal information flow through the neuronal circuits involved, are the most likely underlying mechanisms...
March 2018: Neurology India
Véronique Sgambato, Léon Tremblay
The MPTP monkey model of Parkinson's disease (PD) has allowed huge advances regarding the understanding of the pathological mechanisms of PD and L-DOPA-induced adverse effects. Among the main findings were the imbalance between the efferent striatal pathways in opposite directions between the hypokinetic and hyperkinetic states of PD. In both normal and parkinsonian monkeys, the combination of behavioral and anatomical studies has allowed the deciphering of the cortico-basal ganglia circuits involved in both movement and behavioral disorders...
March 3, 2018: Journal of Neural Transmission
M Angela Cenci, Alan R Crossman
Understanding the biological mechanisms of l-dopa-induced motor complications is dependent on our ability to investigate these phenomena in animal models of Parkinson's disease. The most common motor complications consist in wearing-off fluctuations and abnormal involuntary movements appearing when plasma levels of l-dopa are high, commonly referred to as peak-dose l-dopa-induced dyskinesia. Parkinsonian models exhibiting these features have been well-characterized in both rodent and nonhuman primate species...
February 28, 2018: Movement Disorders: Official Journal of the Movement Disorder Society
Vincenzo G Fiore, Tobias Nolte, Francesco Rigoli, Peter Smittenaar, Xiaosi Gu, Raymond J Dolan
The external part of the globus pallidus (GPe) is a core nucleus of the basal ganglia (BG) whose activity is disrupted under conditions of low dopamine release, as in Parkinson's disease. Current models assume decreased dopamine release in the dorsal striatum results in deactivation of dorsal GPe, which in turn affects motor expression via a regulatory effect on other nuclei of the BG. However, recent studies in healthy and pathological animal models have reported neural dynamics that do not match with this view of the GPe as a relay in the BG circuit...
February 23, 2018: NeuroImage
Marco Rossi, Luca Fornia, Guglielmo Puglisi, Antonella Leonetti, Gianmarco Zuccon, Enrica Fava, Daniela Milani, Alessandra Casarotti, Marco Riva, Federico Pessina, Gabriella Cerri, Lorenzo Bello
OBJECTIVE Apraxia is a cognitive-motor deficit affecting the execution of skilled movements, termed praxis gestures, in the absence of primary sensory or motor disorders. In patients affected by stroke, apraxia is associated with lesions of the lateral parietofrontal stream, connecting the posterior parietal areas with the ventrolateral premotor area and subserving sensory-motor integration for the hand movements. In the neurosurgical literature to date, there are few reports regarding the incidence of apraxia after glioma surgery...
February 23, 2018: Journal of Neurosurgery
Soizic Argaud, Marc Vérin, Paul Sauleau, Didier Grandjean
Parkinson's disease is a neurodegenerative disorder classically characterized by motor symptoms. Among them, hypomimia affects facial expressiveness and social communication and has a highly negative impact on patients' and relatives' quality of life. Patients also frequently experience nonmotor symptoms, including emotional-processing impairments, leading to difficulty in recognizing emotions from faces. Aside from its theoretical importance, understanding the disruption of facial emotion recognition in PD is crucial for improving quality of life for both patients and caregivers, as this impairment is associated with heightened interpersonal difficulties...
February 23, 2018: Movement Disorders: Official Journal of the Movement Disorder Society
Antonino Naro, Antonino Chillura, Simona Portaro, Alessia Bramanti, Rosaria De Luca, Placido Bramanti, Rocco Salvatore Calabrò
The assessment of behavioral responsiveness in patients suffering from chronic disorders of consciousness (DoC), including Unresponsive Wakefulness Syndrome (UWS) and Minimally Conscious State (MCS), is challenging. Even if a patient is unresponsive, he/she may be covertly aware in reason of a cognitive-motor dissociation, i.e., a preservation of cognitive functions despite a solely reflexive behavioral responsiveness. The approach of an external stimulus to the peripersonal space (PPS) modifies some biological measures (e...
2018: Frontiers in Neurology
P R A Heckman, A Blokland, E P P Bollen, J Prickaerts
The corticostriatal and hippocampal circuits contribute to the neurobiological underpinnings of several neuropsychiatric disorders, including Alzheimer's disease, Parkinson's disease and schizophrenia. Based on biological function, these circuits can be clustered into motor circuits, associative/cognitive circuits and limbic circuits. Together, dysfunctions in these circuits produce the wide range of symptoms observed in related neuropsychiatric disorders. Intracellular signaling in these circuits is largely mediated through the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) pathway with an additional role for the cyclic guanosine monophosphate (cGMP)/ protein kinase G (PKG) pathway, both of which can be regulated by phosphodiesterase inhibitors (PDE inhibitors)...
February 15, 2018: Neuroscience and Biobehavioral Reviews
Martesa Tantra, Lanboling Guo, Jinsook Kim, Norliyana Zainolabidin, George J Augustine, Volker Eulenburg, Albert I Chen
Inhibitory interneurons mediate the gating of synaptic transmission and modulate the activities of neural circuits. Disruption of the function of inhibitory networks in the forebrain is linked to impairment of social and cognitive behaviors, but the involvement of inhibitory interneurons in the cerebellum has not been assessed. We found that Cadherin 13 (Cdh13), a gene implicated in autism spectrum disorder and attention-deficit hyperactivity disorder, is specifically expressed in Golgi cells within the cerebelluar cortex...
February 15, 2018: Genes, Brain, and Behavior
Ahmad Raza Khan, Christopher D Kroenke, Ove Wiborg, Andrey Chuhutin, Jens R Nyengaard, Brian Hansen, Sune Nørhøj Jespersen
Chronic mild stress leads to depression in many cases and is linked to several debilitating diseases including mental disorders. Recently, neuronal tracing techniques, stereology, and immunohistochemistry have revealed persistent and significant microstructural alterations in the hippocampus, hypothalamus, prefrontal cortex, and amygdala, which form an interconnected system known as the stress circuit. Most studies have focused only on this circuit, however, some studies indicate that manipulation of sensory and motor systems may impact genesis and therapy of mood disorders and therefore these areas should not be neglected in the study of brain microstructure alterations in response to stress and depression...
2018: PloS One
Michael S Sidorov, Matthew C Judson, Hyojin Kim, Marie Rougie, Alejandra I Ferrer, Viktoriya D Nikolova, Natallia V Riddick, Sheryl S Moy, Benjamin D Philpot
Angelman syndrome (AS), a neurodevelopmental disorder associated with intellectual disability, is caused by loss of maternal allele expression of UBE3A in neurons. Mouse models of AS faithfully recapitulate disease phenotypes across multiple domains, including behavior. Yet in AS, there has been only limited study of behaviors encoded by the prefrontal cortex, a region broadly involved in executive function and cognition. Because cognitive impairment is a core feature of AS, it is critical to develop behavioral readouts of prefrontal circuit function in AS mouse models...
February 5, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Georgios Naros, Florian Grimm, Daniel Weiss, Alireza Gharabaghi
BACKGROUND: Both the cerebello-thalamo-cortical circuit and the basal ganglia/cortical motor loop have been postulated to be generators of tremor in PD. The recent suggestion that the basal ganglia trigger tremor episodes and the cerebello-thalamo-cortical circuitry modulates tremor amplitude combines both competing hypotheses. However, the role of the STN in tremor generation and the impact of proprioceptive feedback on tremor suppression during voluntary movements have not been considered in this model yet...
February 2018: Movement Disorders: Official Journal of the Movement Disorder Society
Michaela Edmond, Olivia Hanley, Polyxeni Philippidou
Vital motor functions, such as respiration and locomotion, rely on the ability of spinal motor neurons (MNs) to acquire stereotypical positions in the ventral spinal cord and to project with high precision to their peripheral targets. These key properties of MNs emerge during development through transcriptional programs that dictate their subtype identity and connectivity; however, the molecular mechanisms that establish the transcriptional landscape necessary for MN specification are not fully understood. Here, we show that the enzyme topoisomerase IIβ (Top2β) controls MN migration and connectivity...
November 2017: ENeuro
Matthew R Bailey, Olivia Goldman, Estefanía P Bello, Muhammad O Chohan, Nuri Jeong, Vanessa Winiger, Eileen Chun, Elke Schipani, Abigail Kalmbach, Joseph F Cheer, Peter D Balsam, Eleanor H Simpson
The functionally selective 5HT-2C receptor ligand SB242084 can increase motivation and have rapid onset anti-depressant like effects. We sought to identify the specific behavioural effects of SB242084 treatment and elucidate the mechanism in female and male mice. Using a quantitative behavioural approach we determined that SB242084 increases the vigor and persistence of goal-directed activity across different types of physical work, particularly when work requirements are demanding. We found this influence of SB242084 on effort, rather than reward to be reflected in striatal dopamine measured during behavior...
January 24, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Chih-Ju Chang, Ming-Yuan Chang, Szu-Yi Chou, Chi-Chen Huang, Jian-Ying Chuang, Tsung-I Hsu, Hsing-Fang Chang, Yi-Hsin Wu, Chung-Che Wu, Daniel Morales, Artur Kania, Tzu-Jen Kao
The precise assembly of a functional nervous system relies on the guided migration of axonal growth cones, which is made possible by signals transmitted to the cytoskeleton by cell surface-expressed guidance receptors. We investigated the function of ephexin1, a Rho guanine nucleotide exchange factor, as an essential growth cone guidance intermediary in the context of spinal lateral motor column (LMC) motor axon trajectory selection in the limb mesenchyme. Using in situ mRNA detection, we first show that ephexin1 is expressed in LMC neurons of chick and mouse embryos at the time of spinal motor axon extension into the limb...
January 23, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Irene E Harmsen, Nathan C Rowland, Richard A Wennberg, Andres M Lozano
BACKGROUND: Deep brain stimulation (DBS) is an important form of neuromodulation that is being applied to patients with motor, mood, or cognitive circuit disorders. Despite the efficacy and widespread use of DBS, the precise mechanisms by which it works remain unknown. Over the last decade, magnetoencephalography (MEG) has become an important functional neuroimaging technique used to study DBS. OBJECTIVE: This review summarizes the literature related to the use of MEG to characterize the effects of DBS...
January 4, 2018: Brain Stimulation
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