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https://www.readbyqxmd.com/read/28192274/activity-and-connectivity-of-the-cerebellum-in-trigeminal-nociception
#1
Jan Mehnert, Laura Schulte, Dagmar Timmann, Arne May
The role of the cerebellum in pathologies of the trigeminal nervous system is still unknown although recently gathered evidence point to a modulatory rather than a passive role. Here we provide evidence for the activation of specific cerebellar areas during nociceptive trigeminal input in the left nostril in a large number of volunteers (54 subjects) and an additional independent group (18 subjects) as measured by functional magnetic resonance imaging (fMRI). Peak voxel activity ipsilateral to the stimulated side can be seen in cerebellar lobules VI, VIIIa and Crus I, and vermal lobule VIIIa, although some activations are also seen in the contralateral side...
February 10, 2017: NeuroImage
https://www.readbyqxmd.com/read/28168279/positive-and-negative-somatotopic-bold-responses-in-contralateral-versus-ipsilateral-penfield-homunculus
#2
Zohar Tal, Ran Geva, Amir Amedi
No abstract text is available yet for this article.
February 7, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/28161314/groupwise-structural-parcellation-of-the-whole-cortex-a-logistic-random-effects-model-based-approach
#3
Guillermo Gallardo, William Wells Iii, Rachid Deriche, Demian Wassermann
Current theories hold that brain function is highly related to long-range physical connections through axonal bundles, namely extrinsic connectivity. However, obtaining a groupwise cortical parcellation based on extrinsic connectivity remains challenging. Current parcellation methods are computationally expensive; need tuning of several parameters or rely on ad-hoc constraints. Furthermore, none of these methods present a model for the cortical extrinsic connectivity of the cortex. To tackle these problems, we propose a parsimonious model for the extrinsic connectivity and an efficient parceling technique based on clustering of tractograms...
February 1, 2017: NeuroImage
https://www.readbyqxmd.com/read/28119344/dermatomal-organization-of-si-leg-representation-in-humans-revising-the-somatosensory-homunculus
#4
Caroline Dietrich, Kathrin R Blume, Marcel Franz, Ralph Huonker, Maria Carl, Sandra Preißler, Gunther O Hofmann, Wolfgang H R Miltner, Thomas Weiss
Penfield and Rasmussen's homunculus is the valid map of the neural body representation of nearly each textbook of biology, physiology, and neuroscience. The somatosensory homunculus places the foot representation on the mesial surface of the postcentral gyrus followed by the representations of the lower leg and the thigh in superio-lateral direction. However, this strong homuncular organization contradicts the "dermatomal" organization of spinal nerves. We used somatosensory-evoked magnetic fields and source analysis to study the leg's neural representation in the primary somatosensory cortex (SI)...
January 23, 2017: Cerebral Cortex
https://www.readbyqxmd.com/read/27915070/vicarious-ratings-of-social-touch-reflect-the-anatomical-distribution-velocity-tuning-of-c-tactile-afferents-a-hedonic-homunculus
#5
Susannah C Walker, Paula D Trotter, Andy Woods, Francis McGlone
A subclass of C-fibres, C-tactile afferents (CTs), have been discovered which respond preferentially to low force/velocity stroking touch, that is typically perceived as pleasant. Molecular genetic visualization of these low-threshold mechanosensitive C-fibres (CLTMs) in mice revealed a denser distribution in dorsal than ventral thoracic sites, scattered distal limb innervation and a complete absence from glabrous paw skin (Liu et al., 2007). Here we used third-party ratings to examine whether affective responses to social touch reflect the anatomical distribution and velocity tuning of CTs...
November 30, 2016: Behavioural Brain Research
https://www.readbyqxmd.com/read/27811749/use-of-dna-barcoding-to-distinguish-the-malaria-vector-anopheles-neivai-in-colombia
#6
Andrés López-Rubio, Juan Suaza-Vasco, Paula L Marcet, Natalia Ruíz-Molina, Lorenzo Cáceres, Charles Porter, Sandra Uribe
A reference 535 bp barcode sequence from a fragment of the mitochondrial gene cytochrome oxidase I (COI), acquired from specimens of An. neivai Howard, Dyar & Knab, 1913 from its type locality in Panama, was used as a tool for distinguishing this species from others in the subgenus Kerteszia. Comparisons with corresponding regions of COI between An. neivai and other species in the subgenus (An. bellator Dyar & Knab 1906, An. homunculus Komp 1937, An cruzii Dyar & Knab, 1908 and An. laneanus Corrêa & Cerqueira, 1944) produced K2P genetic distances of 8...
October 17, 2016: Zootaxa
https://www.readbyqxmd.com/read/27765146/stem-members-of-platyrrhini-are-distinct-from-catarrhines-in-at-least-one-derived-cranial-feature
#7
Ethan L Fulwood, Doug M Boyer, Richard F Kay
The pterion, on the lateral aspect of the cranium, is where the zygomatic, frontal, sphenoid, squamosal, and parietal bones approach and contact. The configuration of these bones distinguishes New and Old World anthropoids: most extant platyrrhines exhibit contact between the parietal and zygomatic bones, while all known catarrhines exhibit frontal-alisphenoid contact. However, it is thought that early stem-platyrrhines retained the apparently primitive catarrhine condition. Here we re-evaluate the condition of key fossil taxa using μCT (micro-computed tomography) imaging...
November 2016: Journal of Human Evolution
https://www.readbyqxmd.com/read/27639500/impaired-communication-between-the-motor-and-somatosensory-homunculus-is-associated-with-poor-manual-dexterity-in-autism-spectrum-disorder
#8
Abigail Thompson, Declan Murphy, Flavio Dell'Acqua, Christine Ecker, Grainne McAlonan, Henrietta Howells, Simon Baron-Cohen, Meng-Chuan Lai, Michael V Lombardo
BACKGROUND: Fine motor skill impairments are common in autism spectrum disorder (ASD), significantly affecting quality of life. Sensory inputs reaching the primary motor cortex (M1) from the somatosensory cortex (S1) are likely involved in fine motor skill and specifically motor learning. However, the role of these connections has not been directly investigated in humans. This study aimed to investigate, for the first time, the role of the S1-M1 connections in healthy subjects in vivo and whether microstructural alterations are associated with motor impairment in ASD...
February 1, 2017: Biological Psychiatry
https://www.readbyqxmd.com/read/27636245/knee-pain-severity-rather-than-structural-damage-is-a-risk-factor-for-incident-widespread-pain-the-multicenter-osteoarthritis-most-study
#9
Lisa C Carlesso, Neil Segal, Jeffrey R Curtis, Barton L Wise, Laura Frey Law, Michael Nevitt, Tuhina Neogi
OBJECTIVES: To examine the longitudinal relation of knee pain, radiographic osteoarthritis (ROA), symptomatic knee OA (SxOA) and knee pain severity to incident widespread pain (WSP). METHODS: The Multicenter Osteoarthritis Study is a longitudinal cohort of persons with or at risk of knee OA. Participants were characterized with regards to consistent frequent knee pain (CFKP), ROA (Kellgren & Lawrence grade ≥2), SxOA, and knee pain severity at the 60-month visit (baseline)...
September 16, 2016: Arthritis Care & Research
https://www.readbyqxmd.com/read/27546883/systemic-inflammation-and-painful-joint-burden-in-osteoarthritis-a-matter-of-sex
#10
A V Perruccio, V Chandran, J D Power, M Kapoor, N N Mahomed, R Gandhi
OBJECTIVE: We investigated the association between serum levels of C-reactive protein (CRP) and the extent of multijoint pain among individuals with hip/knee osteoarthritis (OA) and determined whether the association differs by sex. DESIGN: Serum CRP and cartilage oligomeric matrix protein (COMP) were determined by enzyme-linked immunosorbent assay (ELISA) in 189 individuals (101 female, 88 male) scheduled for total hip/knee arthroplasty for OA. Patients indicated on a homunculus all painful joints; a summed count was derived...
January 2017: Osteoarthritis and Cartilage
https://www.readbyqxmd.com/read/27497839/mollusc-models-i-the-snail-ilyanassa
#11
REVIEW
Morgan Q Goulding, J David Lambert
Ilyanassa obsoleta has been a model system for experimental embryology for over a century. Here we highlight new insight into early cell lineage specification in Ilyanassa. As in all molluscs and other spiralians, stereotyped cleavage patterns establish a homunculus of regional founder cells. Ongoing studies are beginning to dissect mechanisms of asymmetric cell division that specify these cells' fates. This is only part of the story: overlaid on intrinsic cell identities is a graded 'organizer' signal, and emerging evidence suggests wider roles for short-range intercellular signaling...
August 2016: Current Opinion in Genetics & Development
https://www.readbyqxmd.com/read/27472549/remodeling-of-cortical-activity-for-motor-control-following-upper-limb-loss
#12
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
https://www.readbyqxmd.com/read/27457552/neotropics-provide-insights-into-the-emergence-of-new-world-monkeys-new-dental-evidence-from-the-late-oligocene-of-peruvian-amazonia
#13
Laurent Marivaux, Sylvain Adnet, Ali J Altamirano-Sierra, Myriam Boivin, François Pujos, Anusha Ramdarshan, Rodolfo Salas-Gismondi, Julia V Tejada-Lara, Pierre-Olivier Antoine
Recent field efforts in Peruvian Amazonia (Contamana area, Loreto Department) have resulted in the discovery of a late Oligocene (ca. 26.5 Ma; Chambira Formation) fossil primate-bearing locality (CTA-61). In this paper, we analyze the primate material consisting of two isolated upper molars, the peculiar morphology of which allows us to describe a new medium-sized platyrrhine monkey: Canaanimico amazonensis gen. et sp. nov. In addition to the recent discovery of Perupithecus ucayaliensis, a primitive anthropoid taxon of African affinities from the alleged latest Eocene Santa Rosa locality (Peruvian Amazonia), the discovery of Canaanimico adds to the evidence that primates were well-established in the Amazonian Basin during the Paleogene...
August 2016: Journal of Human Evolution
https://www.readbyqxmd.com/read/27282300/faciolingual-hemiparesis-with-mild-limb-weakness-of-cortical-origin
#14
Aintzine Ruisanchez-Nieva, Jone Bocos-Portillo, Rakel Vazquez-Picon, David Anguizola Tamayo, Lara Pardina-Vilella, Marian Gomez-Beldarrain, Juan Carlos Garcia-Monco
The clinical combination of unilateral facial and hypoglossal palsy with upper limb weakness is known as the capsular genu syndrome and responds most often to an ischemic infarct in the internal capsule. We here describe a patient with this peculiar combination, in whom the responsible lesion was located in the contralateral prefrontal cortex, involving the corresponding areas of the Penfield's homunculus. Contralateral cortical frontal lesions should be considered in patients with facial and hypoglossal palsy with upper limb weakness...
September 2016: Journal of Stroke and Cerebrovascular Diseases: the Official Journal of National Stroke Association
https://www.readbyqxmd.com/read/27207250/the-segmental-diffusivity-profile-of-amyotrophic-lateral-sclerosis-associated-white-matter-degeneration
#15
C Schuster, M Elamin, O Hardiman, P Bede
BACKGROUND AND PURPOSE: Magnetic resonance diffusivity indices have been repeatedly proposed as biomarkers of neurodegeneration in amyotrophic lateral sclerosis (ALS), but no consensus exists as to which diffusivity parameter is the most sensitive to identify early degenerative changes. Despite numerous studies, surprisingly little is known of the segmental vulnerability of the corticospinal tracts and corpus callosum. Our objective was to characterize the core three-dimensional white matter signature of ALS, to describe phenotype-specific patterns of white matter degeneration and to evaluate the diffusivity profile of individual patients and controls in specific white matter segments...
August 2016: European Journal of Neurology: the Official Journal of the European Federation of Neurological Societies
https://www.readbyqxmd.com/read/27199874/the-central-governor-model-of-exercise-regulation-teaches-us-precious-little-about-the-nature-of-mental-fatigue-and-self-control-failure
#16
REVIEW
Michael Inzlicht, Samuele M Marcora
Self-control is considered broadly important for many domains of life. One of its unfortunate features, however, is that it tends to wane over time, with little agreement about why this is the case. Recently, there has been a push to address this problem by looking to the literature in exercise physiology, specifically the work on the central governor model of physical fatigue. Trying to explain how and why mental performance wanes over time, the central governor model suggests that exertion is throttled by some central nervous system mechanism that receives information about energetic bodily needs and motivational drives to regulate exertion and, ultimately, to prevent homeostatic breakdown, chiefly energy depletion...
2016: Frontiers in Psychology
https://www.readbyqxmd.com/read/27146682/mitochondrial-genomes-of-anopheles-kerteszia-diptera-culicidae-from-the-atlantic-forest-brazil
#17
T M P Oliveira, P G Foster, E S Bergo, S S Nagaki, S S Sanabani, O Marinotti, P N Marinotti, M A M Sallum
Mitochondrial genome sequences are widely used as molecular markers for phylogenetic studies of mosquito species complexes, such as the Anopheles albitarsis complex. Except for a few studies that employed a limited number of nuclear or mitochondrial loci to address the genetic structure and species status of Anopheles cruzii, Anopheles bellator, and Anopheles homunculus, little is known about genetic markers that can be employed in studies focusing on Kerteszia species. The complete mitochondrial genomes of seven specimens of An...
July 2016: Journal of Medical Entomology
https://www.readbyqxmd.com/read/27000722/the-double-homunculus-model-of-self-reflective-systems
#18
Koji Sawa, Abir U Igamberdiev
Vladimir Lefebvre introduced the principles of self-reflective systems and proposed the model to describe consciousness based on these principles (Lefebvre V.A., 1992, J. Math. Psychol. 36, 100-128). The main feature of the model is an assumption of "the image of the self in the image of the self", that is, "a Double Homunculus". In this study, we further formalize the Lefebvre's formulation by using difference equations for the description of self-reflection. In addition, we also implement a dialogue model between the two homunculus agents...
June 2016: Bio Systems
https://www.readbyqxmd.com/read/26898371/the-attentive-homunculus-erp-evidence-for-somatotopic-allocation-of-attention-in-tactile-search
#19
Bettina Forster, Maria Tziraki, Alexander Jones
Our brain constantly receives tactile information from the body's surface. We often only become aware of this information when directing our attention towards the body. Here, we report a study investigating the behavioural and neural response when selecting a target amongst distractor vibrations presented simultaneously to several locations either across the hands or body. Comparable visual search studies have revealed the N2pc as the neural correlate of visual selective attention. Analogously, we describe an enhanced negativity contralateral to the tactile target side...
April 2016: Neuropsychologia
https://www.readbyqxmd.com/read/26817727/a-working-memory-system-with-distributed-executive-control
#20
André Vandierendonck
Working memory consists of domain-specific storage facilities and domain-general executive control processes. In some working memory theories, these control processes are accounted for via a homunculus, the central executive. In the present article, the author defends a mechanistic view of executive control by adopting the position that executive control is situated in the context of goal-directed behavior to maintain and protect the goal and to select an action to attain the goal. On the basis of findings in task switching and dual tasking, he proposes an adapted multicomponent working memory model in which the central executive is replaced by three interacting components: an executive memory that maintains the task set, a collection of acquired procedural rules, and an engine that executes the procedural rules that match the ensemble of working memory contents...
January 2016: Perspectives on Psychological Science: a Journal of the Association for Psychological Science
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