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cortical sensory motor areas

Kirsty J Dixon, Jose Mier, Shyam Gajavelli, Alisa Turbic, Ross Bullock, Ann M Turnley, Daniel J Liebl
Traumatic brain injury (TBI) leads to a series of pathological events that can have profound influences on motor, sensory and cognitive functions. Conversely, TBI can also stimulate neural stem/progenitor cell proliferation leading to increased numbers of neuroblasts migrating outside their restrictive neurogenic zone to areas of damage in support of tissue integrity. Unfortunately, the factors that regulate migration are poorly understood. Here, we examine whether ephrinB3 functions to restrict neuroblasts from migrating outside the subventricular zone (SVZ) and rostral migratory stream (RMS)...
September 28, 2016: Stem Cell Research
Yiwen Li Hegner, Axel Lindner, Christoph Braun
The processes underlying perceptual decision making are diverse and typically engage a distributed network of brain areas. It is a particular challenge to establish a sensory-to-motor functional hierarchy in such networks. This is because single-cell recordings mainly study the nodes of decision networks in isolation but seldom simultaneously. Moreover, imaging methods, which allow simultaneously accessing information from overall networks, typically suffer from either the temporal or the spatial resolution necessary to establish a detailed functional hierarchy in terms of a sequential recruitment of areas during a decision process...
October 21, 2016: Human Brain Mapping
Siyu Zhang, Min Xu, Wei-Cheng Chang, Chenyan Ma, Johnny Phong Hoang Do, Daniel Jeong, Tiffany Lei, Jiang Lan Fan, Yang Dan
Long-range projections from the frontal cortex are known to modulate sensory processing in multiple modalities. Although the mouse has become an increasingly important animal model for studying the circuit basis of behavior, the functional organization of its frontal cortical long-range connectivity remains poorly characterized. Here we used virus-assisted circuit mapping to identify the brain networks for top-down modulation of visual, somatosensory and auditory processing. The visual cortex is reciprocally connected to the anterior cingulate area, whereas the somatosensory and auditory cortices are connected to the primary and secondary motor cortices...
October 17, 2016: Nature Neuroscience
David C Cappadocia, Simona Monaco, Ying Chen, Gunnar Blohm, J Douglas Crawford
The cortical mechanisms for reach have been studied extensively, but directionally selective mechanisms for visuospatial target memory, movement planning, and movement execution have not been clearly differentiated in the human. We used an event-related fMRI design with a visuospatial memory delay, followed by a pro-/anti-reach instruction, a planning delay, and finally a "go" instruction for movement. This sequence yielded temporally separable preparatory responses that expanded from modest parieto-frontal activation for visual target memory to broad occipital-parietal-frontal activation during planning and execution...
October 15, 2016: Cerebral Cortex
Bao-Hua Liu, Andrew D Huberman, Massimo Scanziani
The mammalian visual cortex massively innervates the brainstem, a phylogenetically older structure, via cortico-fugal axonal projections. Many cortico-fugal projections target brainstem nuclei that mediate innate motor behaviours, but the function of these projections remains poorly understood. A prime example of such behaviours is the optokinetic reflex (OKR), an innate eye movement mediated by the brainstem accessory optic system, that stabilizes images on the retina as the animal moves through the environment and is thus crucial for vision...
October 12, 2016: Nature
Alexei L Vyssotski, Anna E Stepien, Georg B Keller, Richard H R Hahnloser
What cortical inputs are provided to motor control areas while they drive complex learned behaviors? We study this question in the nucleus interface of the nidopallium (NIf), which is required for normal birdsong production and provides the main source of auditory input to HVC, the driver of adult song. In juvenile and adult zebra finches, we find that spikes in NIf projection neurons precede vocalizations by several tens of milliseconds and are insensitive to distortions of auditory feedback. We identify a local isometry between NIf output and vocalizations: quasi-identical notes produced in different syllables are preceded by highly similar NIf spike patterns...
October 2016: PLoS Biology
Francisco L Colino, Ji-Hang Lee, Gordon Binsted
A multitude of events bombard our sensory systems at every moment of our lives. Thus, it is important for the sensory and motor cortices to gate unimportant events. Tactile suppression is a well-known phenomenon defined as a reduced ability to detect tactile events on the skin before and during movement. Previous experiments (Buckingham et al. in Exp Brain Res 201(3):411-419, 2010; Colino et al. in Physiol Rep 2(3):e00267, 2014) found detection rates decrease just prior to and during finger abduction and decrease according to the proximity of the moving effector...
October 8, 2016: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Nobuo Kunori, Ichiro Takashima
The motor cortex of rats contains two forelimb motor areas; the caudal forelimb area (CFA) and the rostral forelimb area (RFA). Although the RFA is thought to correspond to the premotor and/or supplementary motor cortices of primates, which are higher-order motor areas that receive somatosensory inputs, it is unknown whether the RFA of rats receives somatosensory inputs in the same manner. To investigate this issue, voltage-sensitive dye (VSD) imaging was used to assess the motor cortex in rats following a brief electrical stimulation of the forelimb...
October 7, 2016: European Journal of Neuroscience
Catherine Mercier, Martin Gagné, Karen T Reilly, Laurent J Bouyer
Sensorimotor integration is altered in people with chronic pain. While there is substantial evidence that pain interferes with neural activity in primary sensory and motor cortices, much less is known about its impact on integrative sensorimotor processes. Here, the short latency afferent inhibition (SAI) paradigm was used to assess sensorimotor integration in the presence and absence of experimental cutaneous heat pain applied to the hand. Ulnar nerve stimulation was combined with transcranial magnetic stimulation to condition motor evoked potentials (MEPs) in the first dorsal interosseous muscle...
2016: Brain Sciences
Lijun Chen, Chuanfu Li, Jian Zhai, Anqin Wang, Qin Song, Ying Liu, Ru Ma, Long Han, Yamikani Ndasauka, Xiaoming Li, Hai Li, Xiaochu Zhang
Previous studies have suggested that cortical functional reorganization is associated with motor recovery after stroke and that normal afferent sensory information is very important in that process. In this study, we selected patients who had a stroke in or under the thalamus, with potentially impaired afferent sensory information and analyzed the differences between these patients and healthy controls at three levels: brain regions, the functional connectivity between brain areas, and the whole-brain functional network...
September 23, 2016: Neuroscience Bulletin
Christos Papadelis, Carola Arfeller, Silvia Erla, Giandomenico Nollo, Luigi Cattaneo, Christoph Braun
Coordination between vision and action relies on a fronto-parietal network that receives visual and proprioceptive sensory input in order to compute motor control signals. Here, we investigated with magnetoencephalography (MEG) which cortical areas are functionally coupled on the basis of synchronization during visuomotor integration. MEG signals were recorded from twelve healthy adults while performing a unimanual visuomotor (VM) task and control conditions. The VM task required the integration of pinch motor commands with visual sensory feedback...
November 1, 2016: Brain Research
Nasim F Mehrabi, Henry J Waldvogel, Lynette J Tippett, Virginia M Hogg, Beth J Synek, Richard L M Faull
BACKGROUND: Huntington's disease (HD) is characterised by variable symptoms and neuropathology of the basal ganglia and cortex. Previously, we have shown that the pattern of pyramidal cell loss in 8 different cortical regions correlates with the phenotypic variability in HD. In the primary motor and anterior cingulate cortices, the pattern of interneuron degeneration correlates with pyramidal cell death and variable HD symptom profiles. OBJECTIVES: This study aimed to examine the pattern of interneuron degeneration in 3 further regions of the HD cortex (primary sensory, superior frontal, superior parietal cortices) to determine whether HD neuropathogenesis was characterised by a general fundamental pattern of cortical interneuron loss, and explore the relationship between cortical interneuron loss with previously determined pyramidal cell loss and clinical heterogeneity...
August 25, 2016: Neurobiology of Disease
Diego A R Zorio, Christine M Jackson, Yong Liu, Edwin W Rubel, Yuan Wang
The fragile X mental retardation protein (FMRP) plays an important role in normal brain development. Absence of FMRP results in abnormal neuronal morphologies in a selected manner throughout the brain, leading to intellectual deficits and sensory dysfunction in the fragile X syndrome (FXS). Despite FMRP importance for proper brain function, its overall expression pattern in the mammalian brain at the resolution of individual neuronal cell groups is not known. In this study we used FMR1 knockout and isogenic wildtype mice to systematically map the distribution of FMRP expression in the entire mouse brain...
August 19, 2016: Journal of Comparative Neurology
Francesca Anzellotti, Marco Onofrj, Laura Bonanni, Antonio Saracino, Raffaella Franciotti
Enlarged cortical components of somatosensory evoked potentials (giant SEPs) recorded by electroencephalography (EEG) and abnormal somatosensory evoked magnetic fields (SEFs) recorded by magnetoencephalography (MEG) are observed in the majority of patients with cortical myoclonus (CM). Studies on simultaneous recordings of SEPs and SEFs showed that generator mechanism of giant SEPs involves both primary sensory and motor cortices. However the generator sources of giant SEPs have not been fully understood as only one report describes clearly giant SEPs following lower limb stimulation...
2016: NeuroImage: Clinical
Rachel W Mulheren, Erin Kamarunas, Christy L Ludlow
Sour stimuli have been shown to upregulate swallowing in patients and in healthy volunteers. However, such changes may be dependent on taste-induced increases in salivary flow. Other mechanisms include genetic taster status (Bartoshuk et al., 2004) and differences between sour and other tastes. We investigated the effects of taste on swallowing frequency and cortical activation in the swallowing network and whether taster status affected responses. 3ml boluses of sour, sour with slow infusion, sweet, water, and water with infusion were compared on swallowing frequency and hemodynamic responses...
August 3, 2016: Journal of Neurophysiology
Edward F Ester, David W Sutterer, John T Serences, Edward Awh
UNLABELLED: Control over visual selection has long been framed in terms of a dichotomy between "source" and "site," where top-down feedback signals originating in frontoparietal cortical areas modulate or bias sensory processing in posterior visual areas. This distinction is motivated in part by observations that frontoparietal cortical areas encode task-level variables (e.g., what stimulus is currently relevant or what motor outputs are appropriate), while posterior sensory areas encode continuous or analog feature representations...
August 3, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
N M Ipekchyan, S A Badalyan
The peculiarities of localization and distribution of cortico-thalamic efferents of different somatotopical representations of primary motor (MI) and sensory (SI) cortex were studied in cat brain. MI efferent fibers (4y, 6ab areas) preferentially projected to ventral posterolateral and medial (VPL, VPM), ventrolateral (VL), and reticular (R) nuclei, localized in rostral part of the thalamus (T), as opposed to SI (areas 1, 2, 3a, 3b), which projected preferentially to caudal part of T, VPL, VPM and R nuclei...
2016: Morfologi︠a︡
Laura Williams, Nikta Pirouz, J C Mizelle, William Cusack, Rob Kistenberg, Lewis A Wheaton
OBJECTIVE: Upper extremity loss presents immediate and lasting challenges for motor control. While sensory and motor representations of the amputated limb undergo plasticity to adjacent areas of the sensorimotor homunculus, it remains unclear whether laterality of motor-related activity is affected by neural reorganization following amputation. METHODS: Using electroencephalography, we evaluated neural activation patterns of formerly right hand dominant persons with upper limb loss (amputees) performing a motor task with their residual right limb, then their sound left limb...
September 2016: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Laura Ortiz-Terán, Tomás Ortiz, David L Perez, Jose Ignacio Aragón, Ibai Diez, Alvaro Pascual-Leone, Jorge Sepulcre
It is well established that the human brain reorganizes following sensory deprivations. In blind individuals, visual processing regions including the lateral occipital cortex (LOC) are activated by auditory and tactile stimuli as demonstrated by neurophysiological and neuroimaging investigations. The mechanisms for such plasticity remain unclear, but shifts in connectivity across existing neural networks appear to play a critical role. The majority of research efforts to date have focused on neuroplastic changes within visual unimodal regions, however we hypothesized that neuroplastic alterations may also occur in brain networks beyond the visual cortices including involvement of multimodal integration regions and heteromodal cortices...
2016: Frontiers in Systems Neuroscience
Joaquim P Brasil-Neto
Both invasive and non-invasive motor cortex stimulation techniques have been successfully employed in the treatment of chronic pain, but the precise mechanism of action of such treatments is not fully understood. It has been hypothesized that a mismatch of normal interaction between motor intention and sensory feedback may result in central pain. Sensory feedback may come from peripheral nerves, vision and also from corollary discharges originating from the motor cortex itself. Therefore, a possible mechanism of action of motor cortex stimulation might be corollary discharge reinforcement, which could counterbalance sensory feedback deficiency...
2016: Frontiers in Human Neuroscience
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