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motor cortex

Michael D Guthrie, Donald L Gilbert, David A Huddleston, Ernest V Pedapati, Paul S Horn, Stewart H Mostofsky, Steve W Wu
We describe the development of a reproducible, child-friendly motor response inhibition task suitable for online Transcranial Magnetic Stimulation (TMS) characterization of primary motor cortex (M1) excitability and inhibition. Motor response inhibition prevents unwanted actions and is abnormal in several neuropsychiatric conditions. TMS is a non-invasive technology that can quantify M1 excitability and inhibition using single- and paired-pulse protocols and can be precisely timed to study cortical physiology with high temporal resolution...
February 8, 2018: Journal of Visualized Experiments: JoVE
John E Downey, Nathaniel Schwed, Steven M Chase, Andrew B Schwartz, Jennifer L Collinger
Intracortical brain-computer interfaces (BCIs) are being developed to assist people with motor disabilities in communicating and interacting with the world around them. This technology relies on recordings from the primary motor cortex, which may vary from day to day. 
 Approach: Here we quantify, in two long-term BCI subjects, the length of time that action potentials from the same neuron, or group of neurons, can be recorded from motor cortex. 
 Main Results: These action potentials, are identified by their extracellular waveforms and may change within a single day, although some of these identified units can be identified consistently for weeks and even months...
March 19, 2018: Journal of Neural Engineering
J Michely, L J Volz, F Hoffstaedter, M Tittgemeyer, S B Eickhoff, G R Fink, C Grefkes
Older individuals typically display stronger regional brain activity than younger subjects during motor performance. However, knowledge regarding age-related changes of motor network interactions between brain regions remains scarce. We here investigated the impact of ageing on the interaction of cortical areas during movement selection and initiation using dynamic causal modelling (DCM). We found that age-related psychomotor slowing was accompanied by increases in both regional activity and effective connectivity, especially for 'core' motor coupling targeting primary motor cortex (M1)...
2018: NeuroImage: Clinical
Chia-Hsiung Cheng, Mei-Yin Lin, Shiou-Han Yang
Age-related deficiency in the top-down modulation of cognitive inhibition has been extensively documented, whereas the effects of age on a bottom-up or automatic operation of inhibitory function were less investigated. It is unknown that whether the older adults (OA)' reduced behavioral performance and neural responses are due to the insufficient bottom-up processes. Compared to behavioral assessments which have been widely used to examine the top-down control of response inhibition, electrophysiological recordings are more suitable to probe the early-stage processes of automatic inhibitory function...
2018: Frontiers in Aging Neuroscience
Tanzila Mukhtar, Verdon Taylor
The cerebral cortex is composed of billions of morphologically and functionally distinct neurons. These neurons are produced and organized in a regimental fashion during development. The ability of neurons to encode and elicit complex cognitive and motor functions depends on their precise molecular processes, identity, and connectivity established during development. Elucidating the cellular and molecular mechanisms that regulate development of the neocortex has been a challenge for many years. The cerebral cortical neuronal subtypes are classified based on morphology, function, intrinsic synaptic properties, location, connectivity, and marker gene expression...
2018: Journal of Experimental Neuroscience
Dexter R F Irvine
Perceptual learning, improvement in discriminative ability as a consequence of training, is one of the forms of sensory system plasticity that has driven profound changes in our conceptualization of sensory cortical function. Psychophysical and neurophysiological studies of auditory perceptual learning have indicated that the characteristics of the learning, and by implication the nature of the underlying neural changes, are highly task specific. Some studies in animals have indicated that recruitment of neurons to the population responding to the training stimuli, and hence an increase in the so-called cortical "area of representation" of those stimuli, is the substrate of improved performance, but such changes have not been observed in other studies...
March 12, 2018: Hearing Research
Brian Nils Lundstrom, Christian Meisel, Jamie Van Gompel, Matt Stead, Greg Worrell
OBJECTIVES: To develop quantitative measures for estimating seizure probability, we examine intracranial EEG data from patient groups with three qualitative seizure probabilities: patients with drug resistant focal epilepsy (high), these patients during cortical stimulation (intermediate), and patients who have no history of seizures (low). METHODS: Patients with focal epilepsy were implanted with subdural electrodes during presurgical evaluation. Patients without seizures were implanted during treatment with motor cortex stimulation for atypical facial pain...
February 27, 2018: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Sima Chalavi, Lisa Pauwels, Kirstin-Friederike Heise, Hamed Zivariadab, Celine Maes, Nicolaas A J Puts, Richard A E Edden, Stephan P Swinnen
Efficient practice organization maximizes learning outcome. Although randomization of practice as compared to blocked practice damages training performance, it boosts retention performance, an effect called contextual interference. Motor learning modulates the GABAergic (gamma-aminobutyric acid) system within the sensorimotor cortex (SM); however, it is unclear whether different practice regimes differentially modulate this system and whether this is impacted by aging. Young and older participants were trained on 3 variations of a visuomotor task over 3 days, following either blocked or random practice schedule and retested 6 days later...
February 19, 2018: Neurobiology of Aging
Pascal Röderer, Lara Klatt, Felix John, Verena Theis, Konstanze F Winklhofer, Carsten Theiss, Veronika Matschke
Amyotrophic lateral sclerosis is a devastating motor neuron disease and to this day not curable. While 5-10% of patients inherit the disease (familiar ALS), up to 95% of patients are diagnosed with the sporadic form (sALS). ALS is characterized by the degeneration of upper motor neurons in the cerebral cortex and of lower motor neurons in the brainstem and spinal cord. The wobbler mouse resembles almost all phenotypical hallmarks of human sALS patients and is therefore an excellent motor neuron disease model...
March 16, 2018: Molecular Neurobiology
Max Ward, Joseph Doran, Boris Paskhover, Antonios Mammis
OBJECTIVES: Bibliometric analysis is a commonly used analytic tool for objective determination of the most influential and peer-recognized articles within a given field. This study is the first bibliometric analysis of the literature in the field of invasive neuromodulation, excluding deep brain stimulation. The objectives of this study are to identify the 50 most cited articles in invasive neuromodulation, provide an overview of the literature to assist in clinical education, and evaluate the effect of impact factor on manuscript recognition...
March 13, 2018: World Neurosurgery
Daniella C Parravano, Daniel A Ciampi, Erich T Fonoff, Bernardo Monaco, Jessie Navarro, Lin T Yeng, Manoel J Teixeira, Clement Hamani
BACKGROUND: Motor cortex stimulation (MCS) is routinely used for the treatment of chronic neuropathic pain but its effect on quality of life remains uncertain. OBEJCTIVE: To systematically review the published literature on MCS and quality of life and report the effects of this therapy in a series of patients prospectively followed in our center. METHODS: The systematic literature review was conducted using the search words "motor cortex stimulation and pain and neurosurgery" and "motor cortex stimulation and pain and quality of life...
March 14, 2018: Neurosurgery
Neil E O'Connell, Louise Marston, Sally Spencer, Lorraine H DeSouza, Benedict M Wand
BACKGROUND: This is an updated version of the original Cochrane Review published in 2010, Issue 9, and last updated in 2014, Issue 4. Non-invasive brain stimulation techniques aim to induce an electrical stimulation of the brain in an attempt to reduce chronic pain by directly altering brain activity. They include repetitive transcranial magnetic stimulation (rTMS), cranial electrotherapy stimulation (CES), transcranial direct current stimulation (tDCS), transcranial random noise stimulation (tRNS) and reduced impedance non-invasive cortical electrostimulation (RINCE)...
March 16, 2018: Cochrane Database of Systematic Reviews
Hesham Mostafa Zakaria, Peter Joseph Massa, Richard L Smith, Tarek Hazem Moharram, John Corrigan, Ian Lee, Lonni Schultz, Jianhui Hu, Suresh Patel, Brent Griffith
Preoperative identification of the eloquent brain is important for neurosurgical planning. One common method of finding the motor cortex is by localizing "the Omega sign." No studies have tested the reliability of imaging to identify the Omega sign. We identified 40 recent and consecutive patients who had undergone preoperative functional magnetic resonance imaging for identification of the hand motor area prior to tumor resection. We recruited 11 neurosurgical residents of various levels of training and one board-certified neurosurgeon to identify the hand motor cortex Omega...
January 1, 2018: Neuroradiology Journal
Luqing Wei, Hong Chen, Guo-Rong Wu
The neurovisceral integration model has shown a key role of the amygdala in neural circuits underlying heart rate variability (HRV) modulation, and suggested that reciprocal connections from amygdala to brain regions centered on the central autonomic network (CAN) are associated with HRV. To provide neuroanatomical evidence for these theoretical perspectives, the current study used covariance analysis of MRI-based gray matter volume (GMV) to map structural covariance network of the amygdala, and then determined whether the interregional structural correlations related to individual differences in HRV...
2018: Frontiers in Human Neuroscience
Stefan Elmer, Joëlle Albrecht, Seyed Abolfazl Valizadeh, Clément François, Antoni Rodríguez-Fornells
Word learning constitutes a human faculty which is dependent upon two anatomically distinct processing streams projecting from posterior superior temporal (pST) and inferior parietal (IP) brain regions toward the prefrontal cortex (dorsal stream) and the temporal pole (ventral stream). The ventral stream is involved in mapping sensory and phonological information onto lexical-semantic representations, whereas the dorsal stream contributes to sound-to-motor mapping, articulation, complex sequencing in the verbal domain, and to how verbal information is encoded, stored, and rehearsed from memory...
March 15, 2018: Scientific Reports
Elizabeth A Shay, Quanjing Chen, Frank E Garcea, Bradford Z Mahon
Multivoxel pattern analysis (MVPA) over functional MRI data can distinguish neural representational states that do not differ in their overall amplitude of BOLD contrast. Here we used MVPA to test whether simple intransitive actions can be distinguished in primary motor cortex. Participants rotated and flexed each of their extremities (hands and feet) during fMRI scanning. The primary motor cortex for the hand/wrist was functionally defined in each hemisphere in each subject. Within those subject-specific ROIs, we found that the average amplitude of BOLD contrast for two different movements of the contralateral hand (rotation, flexion) were higher than for the ipsilateral hand, as well as movements by both feet; however, there was no difference in amplitude between the two different types of movements for the contralateral hand...
March 16, 2018: Cognitive Neuroscience
Joery P Molenaar, Nicol C Voermans, Lysanne A de Jong, Dick F Stegeman, Jonne Doorduin, Baziel G van Engelen
Impaired muscle relaxation is a feature of many neuromuscular disorders. However, there are few tests available to quantify muscle relaxation. Transcranial magnetic stimulation (TMS) of the motor cortex can induce muscle relaxation by abruptly inhibiting corticospinal drive. The aim of our study is to investigate if repeatability and reliability of TMS-induced relaxation is greater than voluntary relaxation. Furthermore, effects of sex, cooling and fatigue on muscle relaxation properties were studied. Muscle relaxation of deep finger flexors was assessed in twenty-five healthy subjects (14 M and 11 F, aged 39...
March 15, 2018: Journal of Applied Physiology
B M Fitzgibbon, K E Hoy, L A Knox, E K Guymer, G Littlejohn, D Elliot, L E Wambeek, S McQueen, K A Elford, S J Lee, P G Enticott, P B Fitzgerald
BACKGROUND: Fibromyalgia is a complex chronic disorder with few effective treatments currently available. One promising treatment option is repetitive Transcranial Magnetic Stimulation (rTMS), a non-invasive brain stimulation technique that has shown promise in disorders effecting the central nervous system. METHODS: We assessed the efficacy of a course of high-frequency (10Hz) left-hemisphere dorsolateral prefrontal cortex (DLPFC) rTMS in 26 patients (14 active; 12 sham) with a diagnosis of fibromyalgia...
March 15, 2018: European Journal of Pain: EJP
Edith V Sullivan, Natalie M Zahr, Stephanie A Sassoon, Wesley K Thompson, Dongjin Kwon, Kilian M Pohl, Adolf Pfefferbaum
Importance: The prevalence of alcohol misuse increased substantially over a decade in adults, particularly in those aged 65 years or older. Ramifications for brain structural integrity are significant, especially in older adults. Objectives: To combine cross-sectional, longitudinal data to test age-alcoholism interactions and examine the association between prevalent comorbidities (drug dependence and hepatitis C virus [HCV] infection) and cortical volume deficits in alcohol dependence...
March 14, 2018: JAMA Psychiatry
Adam J Stark, Christopher T Smith, Kalen J Petersen, Paula Trujillo, Nelleke C van Wouwe, Manus J Donahue, Robert M Kessler, Ariel Y Deutch, David H Zald, Daniel O Claassen
Parkinson's disease (PD) is characterized by widespread degeneration of monoaminergic (especially dopaminergic) networks, manifesting with a number of both motor and non-motor symptoms. Regional alterations to dopamine D2/3 receptors in PD patients are documented in striatal and some extrastriatal areas, and medications that target D2/3 receptors can improve motor and non-motor symptoms. However, data regarding the combined pattern of D2/3 receptor binding in both striatal and extrastriatal regions in PD are limited...
2018: NeuroImage: Clinical
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