Peduncle

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Peduncle

  • caudal peduncle
  • cerebellar peduncle
  • cerebral peduncle
  • middle cerebellar peduncle
  • superior cerebellar peduncle


  • Selected Abstracts


    Eyeblink conditioning using cochlear nucleus stimulation as a conditioned stimulus in developing rats

    DEVELOPMENTAL PSYCHOBIOLOGY, Issue 7 2008
    John H. Freeman
    Abstract Previous studies demonstrated that the development of auditory conditioned stimulus (CS) input to the cerebellum may be a neural mechanism underlying the ontogenetic emergence of eyeblink conditioning in rats. The current study investigated the role of developmental changes in the projections of the cochlear nucleus (CN) in the ontogeny of eyeblink conditioning using electrical stimulation of the CN as a CS. Rat pups were implanted with a bipolar stimulating electrode in the CN and given six 100-trial training sessions with a 300 ms stimulation train in the CN paired with a 10 ms periorbital shock unconditioned stimulus (US) on postnatal days (P) 17,18 or 24,25. Control groups were given unpaired presentations of the CS and US. Rats in both age groups that received paired training showed significant increases in eyeblink conditioned responses across training relative to the unpaired groups. The rats trained on P24,25, however, showed stronger conditioning relative to the group trained on P17,18. Rats with missed electrodes in the inferior cerebellar peduncle or in the cerebellar cortex did not show conditioning. The findings suggest that developmental changes in the CN projections to the pons, inferior colliculus, or medial auditory thalamus may be a neural mechanism underlying the ontogeny of auditory eyeblink conditioning. © 2008 Wiley Periodicals, Inc. Dev Psychobiol 50: 640-646, 2008. [source]


    Correlation of anatomy and function in medulla oblongata infarction

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 2 2009
    C. Eggers
    Background:, A presentation of all aspects of the dorsolateral medulla oblongata syndrome is clinically very rare to find. In most cases patients present with fragmentary symptoms, e.g. ipsilateral axial lateropulsion, nystagmus, dysarthria, dysphagia or hemiataxia. However, the clinical presentation and lesion anatomy at the level of the medulla oblongata is still unsatisfactory. The aim of this study was to correlate the functional deficit with structural MRI-data. Methods:, We included thirteen patients (eight male, five female, mean age 65.5) with medulla oblongata infarction with clinically predominant ipsilateral axial lateropulsion and correlated clinical with structural deficits. Results:, Magnetic resonance imaging lesion mapping demonstrated ipsilateral axial lateropulsion to result from lesions of the spinocerebellar tract, the inferior cerebellar peduncle or the inferior vestibular nucleus. Nystagmus was associated with lesions of the inferior vestibular nucleus, dissociated sensory loss with the spinothalamic tract and hemiataxia with the spinocerebellar tract. Conclusions:, Correlating dysfunction and lesion anatomy is a promising approach to enhance our knowledge on medulla oblongata topography. [source]


    rFVIIa, for acute rebleeding of a cerebral cavernous malformation

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2007
    K. Engelhardt
    Recurrent bleeding episodes of cavernomas especially in the brainstem can cause progressive neurological deficits. Therefore brainstem cavernomas are still a therapeutic dilemma and a treatment challenge for the neuro critical care community. We report a 39-year-old woman with spontaneous ataxia diplopia and vomiting, who has been treated for multiple intracerebral cavernomas during the last 10 years. A cerebral computed tomography (cCT) revealed a re-bleeding cavernoma in the left cerebral peduncle with consecutive obstructive hydrocephalus. As a result of the difficult anatomical location, no surgical approach was possible. As an off-label treatment, recombinant activated factor VII (rFVIIa) was administered to prevent possible further bleeding and especially further sequelae. The patient recovered well and no adverse events and especially no further bleeding of the cavernoma were observed. To our knowledge, this is the first report of the safe and successful use of rFVIIa to treat re-bleeding episodes in cavernomas. Further clinical studies are needed to specify the future potential of rFVIIa. [source]


    Striatal infarcts mimicking frontotemporal dementia: a case report

    EUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2003
    Y. Nishio
    We described a patient with bilateral striatal infarcts, in whom stereotyped and disinhibited behaviors were insidiously emerged over 2 years mimicking frontotemporal dementia (FTD). A positron emission tomography with 18-fluorodeoxy glucose showed a hypometabolism in the frontal lobes, basal ganglia, and thalami. The peculiar behavioral alterations remained unchanged for the following 7 years, suggesting that the disease is not degenerative but of vascular origin. A disruption of the fronto-subcortical circuits at the level of the striatum or the anterior thalamic peduncle is attributable to the FTD-like behavioral and cognitive syndrome. [source]


    A multiparametric evaluation of regional brain damage in patients with primary progressive multiple sclerosis

    HUMAN BRAIN MAPPING, Issue 9 2009
    Antonia Ceccarelli
    Abstract The purpose of this study is to define the topographical distribution of gray matter (GM) and white matter (WM) damage in patients with primary progressive multiple sclerosis (PPMS), using a multiparametric MR-based approach. Using a 3 Tesla scanner, dual-echo, 3D fast-field echo (FFE), and diffusion tensor (DT) MRI scans were acquired from 18 PPMS patients and 17 matched healthy volunteers. An optimized voxel-based (VB) analysis was used to investigate the patterns of regional GM density changes and to quantify GM and WM diffusivity alterations of the entire brain. In PPMS patients, GM atrophy was found in the thalami and the right insula, while mean diffusivity (MD) changes involved several cortical-subcortical structures in all cerebral lobes and the cerebellum. An overlap between decreased WM fractional anisotropy (FA) and increased WM MD was found in the corpus callosum, the cingulate gyrus, the left short temporal fibers, the right short frontal fibers, the optic radiations, and the middle cerebellar peduncles. Selective MD increase, not associated with FA decrease, was found in the internal capsules, the corticospinal tracts, the superior longitudinal fasciculi, the fronto-occipital fasciculi, and the right cerebral peduncle. A discrepancy was found between regional WM diffusivity changes and focal lesions because several areas had DT MRI abnormalities but did not harbor T2-visible lesions. Our study allowed to detect tissue damage in brain areas associated with motor and cognitive functions, which are known to be impaired in PPMS patients. Combining regional measures derived from different MR modalities may be a valuable tool to improve our understanding of PPMS pathophysiology. Hum Brain Mapp 2009. © 2009 Wiley-Liss, Inc. [source]


    Application of Congo Red agar for detection of Streptococcus dysgalactiae isolated from diseased fish

    JOURNAL OF APPLIED ICHTHYOLOGY, Issue 4 2009
    M. Abdelsalam
    Summary The strong clinical similarity between Lancefield group C Streptococcus dysgalactiae subsp. dysgalactiae (GCSD) and Lactococcus garvieae infections, characterized by development of necrotic lesions in the caudal peduncle of infected fish, has hindered differentiation of these two strains, making rapid and accurate diagnosis of diseased fish in fish farms difficult. GCSD from diseased fish were presumptively identified and isolated using Todd-Hewitt agar containing 30 ,g ml,1 of Congo Red dye (TH-CR). TH-CR agar was also used to detect and presumptively identify the GCSD obtained from artificially or naturally infected fish. Orange GCSD colonies distinct from the L. garvieae colonies were observed on the TH-CR agar; thus, TH-CR agar can be used to detect and identify GCSD isolated from infected fish. [source]


    Morphological differences between two ecologically similar sympatric fishes

    JOURNAL OF FISH BIOLOGY, Issue 10 2009
    I. P. Helland
    Morphological differentiation and microhabitat segregation of two ecologically similar populations of pelagic planktivorous fishes, Coregonus albula and the smaller Coregonus fontanae, were studied in Lake Stechlin (northern Germany). Both populations performed diel vertical migrations, although C. fontanae was always situated in deeper pelagic water than C. albula both during day and night. Landmark-based geometric morphometrics revealed that sympatric C. albula and C. fontanae differ in external morphology, with main differences found in head length and eye position, as well as in length and width of the caudal peduncle. Moreover, while C. albula has a similar morphology over all sizes, the shape of C. fontanae changes with size. Accordingly, the morphology of the two is most different at smaller size. Although the morphological differences may reflect adaptations to the slightly differing microhabitats of the two populations, there is no conclusive evidence that this correspondence between ecology and morphology is the main mechanism behind the coexistence of the closely related coregonids in Lake Stechlin. [source]


    The role of predation in variation in body shape in guppies Poecilia reticulata: a comparison of field and common garden phenotypes

    JOURNAL OF FISH BIOLOGY, Issue 6 2009
    J. G. Burns
    The body shapes of both wild-caught and laboratory-reared male and female Trinidadian guppies Poecilia reticulata from two low-predation and two high-predation populations were studied, but predation regime did not seem to be the most important factor affecting body shape. Instead, complicated patterns of plasticity in body shape among populations and the sexes were found. In particular, populations differed in the depth of the caudal peduncle, which is the muscular region just anterior to the tail fin rays and from which most swimming power is generated. Strikingly, the direction of population differences in caudal peduncle depth observed in wild-caught individuals was reversed when P. reticulata were raised in a common laboratory environment. [source]


    The relationship between caudal differential pressure and activity of Atlantic cod: a potential method to predict oxygen consumption of free-swimming fish

    JOURNAL OF FISH BIOLOGY, Issue 4 2007
    M. F. Steinhausen
    This study reports the first results on telemetry of caudal differential pressure during spontaneous swimming activity in cod Gadus morhua and demonstrates that tail-beat pressure may be used as a predictor of activity and swimming costs of free-swimming cod. Tail-beat pressure was monitored using a differential pressure sensor on the caudal peduncle of cod and spontaneous swimming activity was quantified using a customized video-computer tracking programme. Tail-beat pressure was found to correlate with (1) swimming speed (U) and oxygen consumption during forced swimming and (2) mean U during spontaneous activity. Based on the relationship between and the integrated pressure performed by the tail during forced swimming, it should be possible to predict during spontaneous activity. To gain precise measures of activity and thus predictions of for free-swimming fish, however, individual calibrations are necessary. [source]


    The novel application of an immunological technique reveals the immunosuppressive effect of phytoestrogens in Betta splendens

    JOURNAL OF FISH BIOLOGY, Issue A 2006
    D. R. Ardia
    The novel application of a standard technique to assess cell-mediated immune response to phytohaemagglutinin (PHA) injected in the caudal peduncle in a small fish (<2 g) to test the immunosuppressive effect of three phytoestrogens: genistein, equol and ,-sitosterol is described. Individual Betta splendens exposed to these oestrogenic chemicals produced weaker inflammatory responses to PHA than did control individuals, suggesting that phytoestrogens are immunosuppressive. This technique should enable immune function in fish species, too small to provide sufficient blood for conventional immunological measures, to be assessed. [source]


    Lancefield group C Streptococcus dysgalactiae infection responsible for fish mortalities in Japan

    JOURNAL OF FISH DISEASES, Issue 12 2004
    R Nomoto
    Abstract A Lancefield serological group C Streptococcus sp. was isolated from cultured amberjack, Seriola dumerili Risso, and yellowtail, Seriola quinqueradiata Temminck and Schlegel, immunized with Lactococcus garvieae commercial vaccines in Japan. The isolated bacteria were Gram-positive cocci, auto-aggregating in saline, morphologically long chains in growth medium, catalase negative and , -haemolytic on blood agar. An almost complete gene sequence of the 16S rDNA of two isolates was determined and compared with that of bacterial strains in the database. The isolates were identified as Streptococcus dysgalactiae based on the results of the 16S rDNA sequence, the bacteriological properties and the Lancefield serological grouping. Oligonucleotide primers specifically designed for the 16S,23S rDNA intergenic spacer region of S. dysgalactiae amplified a gene from all the fish isolates, as well as the type strains , -haemolytic S. dysgalactiae subsp. dysgalactiae ATCC430738 and , -haemolytic S. dysgalactiae subsp. equisimilis ATCC35666, but not those of S. equi ATCC33398, Lactococcus garvieae ATCC43921 and L. garvieae KG9408. The severe necrotic lesions of the caudal peduncle seen in experimentally infected fish were similar to those seen in naturally infected fish. [source]


    Quantification of red myotomal muscle volume and geometry in the shortfin mako shark (Isurus oxyrinchus) and the salmon shark (Lamna ditropis) using T1 -weighted magnetic resonance imaging

    JOURNAL OF MORPHOLOGY, Issue 4 2007
    Cameron N. Perry
    Abstract T1 -weighted magnetic resonance imaging (MRI) in conjunction with image and segmentation analysis (i.e., the process of digitally partitioning tissues based on specified MR image characteristics) was evaluated as a noninvasive alternative for differentiating muscle fiber types and quantifying the amounts of slow, red aerobic muscle in the shortfin mako shark (Isurus oxyrinchus) and the salmon shark (Lamna ditropis). MRI-determinations of red muscle quantity and position made for the mid-body sections of three mako sharks (73.5,110 cm fork length, FL) are in close agreement (within the 95% confidence intervals) with data obtained for the same sections by the conventional dissection method involving serial cross-sectioning and volumetric analyses, and with previously reported findings for this species. The overall distribution of salmon shark red muscle as a function of body fork length was also found to be consistent with previously acquired serial dissection data for this species; however, MR imaging revealed an anterior shift in peak red muscle cross-sectional area corresponding to an increase in body mass. Moreover, MRI facilitated visualization of the intact and anatomically correct relationship of tendon linking the red muscle and the caudal peduncle. This study thus demonstrates that MRI is effective in acquiring high-resolution three-dimensional digital data with high contrast between different fish tissue types. Relative to serial dissection, MRI allows more precise quantification of the position, volume, and other details about the types of muscle within the fish myotome, while conserving specimen structural integrity. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source]


    Diffusion Tensor Tractography-based Analysis of the Pyramidal Tract in Patients with Amyotrophic Lateral Sclerosis

    JOURNAL OF NEUROIMAGING, Issue 3 2008
    Yoon-Ho Hong MD
    ABSTRACT BACKGROUND AND PURPOSE We attempted to measure DTI parameters of the brainstem pyramidal tract using two approaches, ie, simple ROI and tract-specific analyses. Results obtained for healthy subjects and ALS patients were compared. METHODS DTI was performed using a single shot SE-EPI with 25 noncollinear diffusion gradient directions (b= 1000 second/mm2) and with no diffusion gradient on a 3.0-T MR system in 10 ALS patients and in 8 age- and sex-matched normal controls. To delineate the brainstem pyramidal tract, tractography was performed using two ROIs, ie, a seed ROI at the cerebral peduncle (ROI-1) and a target ROI at the lower pons (ROI-2). ROI-1 was subsequently restricted to voxels that contained streamlines in the tract reconstruction, thus creating a sub-ROI. RESULTS Mean fractional anisotropy (FA) and mean diffusivity values were highly reproducible by tract specific analysis, whereas simple ROI analysis yielded larger variabilities between operators. FA values were significantly lower in ALS patients than in normal controls in the tractography-derived sub-ROI (P= .01), but not in the seed or target ROIs. CONCLUSIONS These results suggest, compared with simple ROI analysis, that tract-specific analysis using DTI fiber-tracking is more reliable and sensitive for detecting upper motor neuron pathology in ALS. [source]


    ULTRASTRUCTURE OF GYMNODINIUM AUREOLUM (DINOPHYCEAE): TOWARD A FURTHER REDEFINITION OF GYMNODINIUM SENSU STRICTO

    JOURNAL OF PHYCOLOGY, Issue 4 2001
    Gert HansenArticle first published online: 21 DEC 200
    Examination of the ultrastucture of the unarmored dinoflagellate Gymnodinium aureolum (Hulburt) G. Hansen (syn: Gyrodinium aureolum Hulburt) revealed the presence of nuclear chambers, which are specialized differentiations of the nuclear envelope, similar to those described in the type species of Gymnodinium, G. fuscum (Ehrenberg) Stein and certain other Gymnodinium species. The nuclear pores were restricted to these chambers. In the flagellar apparatus a nuclear fibrous connective linked the longitudinal microtubular root and the nucleus. This structure had so far been observed only in Gymnodinium spp. and in the heterotrophic species Actiniscus pentasterias (Ehrenberg) Ehrenberg, Nematodinium armatum (Dogiel) Kofoid et Swezy and Polykrikos kofoidii Chatton. Another unusual feature of G. aureolum was the presence of a striated fiber in the longitudinal flagellum, a feature previously only found in Ceratium furca (Ehrenberg) Claparčde et Lachmann and C. tripos (O.F. Müller) Nitzsch. Gymnodinium aureolum also possessed a prominent ventral protrusion associated with the peduncle and containing electron opaque material. It is concluded that G. aureolum belongs to the Gymnodinium sensu stricto group. This may be a temporary classification, however, because G. aureolum and its allies differ from the type species G. fuscum by the presence of a transverse striated root, striated collars, trichocysts, and a peduncle. [source]


    Brain Microstructure Is Related to Math Ability in Children With Fetal Alcohol Spectrum Disorder

    ALCOHOLISM, Issue 2 2010
    Catherine Lebel
    Background:, Children with fetal alcohol spectrum disorder (FASD) often demonstrate a variety of cognitive deficits, but mathematical ability seems to be particularly affected by prenatal alcohol exposure. Parietal brain regions have been implicated in both functional and structural studies of mathematical ability in healthy individuals, but little is known about the brain structure underlying mathematical deficits in children with FASD. The goal of this study was to use diffusion tensor imaging (DTI) to investigate the relationship between mathematical skill and brain white matter structure in children with FASD. Methods:, Twenty-one children aged 5 to 13 years diagnosed with FASD underwent DTI on a 1.5-T MRI scanner and cognitive assessments including the Woodcock-Johnson Quantitative Concepts test. Voxel-based analysis was conducted by normalizing subject images to a template and correlating fractional anisotropy (FA) values across the brain white matter with age-standardized math scores. Results:, Voxel-based analysis revealed 4 clusters with significant correlations between FA and math scores: 2 positively-correlated clusters in the left parietal region, 1 positively-correlated cluster in the left cerebellum, and 1 negatively-correlated cluster in the bilateral brainstem. Diffusion tractography identified the specific white matter tracts passing through these clusters, namely the left superior longitudinal fasciculus, left corticospinal tract and body of the corpus callosum, middle cerebellar peduncle, and bilateral projection fibers including the anterior and posterior limbs of the internal capsule. Conclusions:, These results identify 4 key regions related to mathematical ability and provide a link between brain microstructure and cognitive skills in children with FASD. Given previous findings in typically developing children and those with other abnormal conditions, our results highlight the consistent importance of the left parietal area for mathematical tasks across various populations, and also demonstrate other regions that may be specific to mathematical processing in children with FASD. [source]


    Modifications of mechanical characteristics and phenolic composition in berry skins and seeds of Mondeuse winegrapes throughout the on-vine drying process,

    JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 11 2009
    Luca Rolle
    Abstract BACKGROUND: Among several common drying systems used in the enological sector the dry-on-vine (DOV) method assumes particular importance because famous wines such as Sauternes, Tokay and Ice Wines are produced by grapes dried using this system. Knowledge about trends in mechanical properties and phenolic composition during on-vine grape drying is scarce. The objective of this current study is therefore to increase the knowledge on these aspects. RESULTS: Berry skin break energy (+0.10 N) and berry skin thickness (+69 µm) values increase during grape dehydration, while the peduncle detach force decreases (,0.86 N). Large reductions in the anthocyanin content have also been observed (,40%), but their profile does not show significant changes. Seed hardness (,7.10 N, ,1.40 mJ) decreases during the withering, and higher seed springiness has been observed. Seed proanthocyanidins (+2050 mg kg berry,1) and flavanols vanillin assay (+670 mg kg berry,1) increase progressively throughout the withering. In contrast, a distinct lowering of these substances in the skins was noted. CONCLUSION: Many modifications in the chemical,physical characteristics of berries of Mondeuse winegrapes throughout the DOV process were found. The mechanical characteristics of grapes, in particular the peduncle detachment force, are important parameters in assessing their suitability for the drying-on-plant process. Copyright © 2009 Society of Chemical Industry [source]


    Apparent diffusion coefficient of the superior cerebellar peduncle differentiates progressive supranuclear palsy from Parkinson's disease,

    MOVEMENT DISORDERS, Issue 16 2008
    Giuseppe Nicoletti MD
    Abstract The early diagnosis of progressive supranuclear palsy (PSP) may be challenging, because of clinical overlapping features with Parkinson's disease (PD) and other parkinsonian syndromes such as the Parkinsonian variant of multiple system atrophy (MSA-P). Conventional MRI can help in differentiating parkinsonian disorders but its diagnostic accuracy is still unsatisfactory. On the basis of the pathological demonstration of superior cerebellar peduncle (SCP) atrophy in patients with PSP, we assessed the SCP apparent diffusion coefficient (ADC) values in patients with PSP, PD, and MSA-P in order to evaluate its differential diagnostic value in vivo. Twenty-eight patients with PSP (14 with possible-PSP and 14 with probable-PSP), 15 PD, 15 MSA-P, and 16 healthy subjects were studied by using diffusion weighted imaging (DWI). ADC was calculated in regions of interest defined in the left and right SCP by two clinically blinded operators. Intrarater (r = 0.98, P < 0.001) and interrater reliability (r = 0.97; P < 0.001) for SCP measurements were high. Patients with PSP had higher SCP rADC values (median 0.98 × 10,3mm2/s) than patients with PD (median 0.79 × 10,3 mm2/s, P < 0.001), MSA-P (median 0.79 × 10,3 mm2/s, P < 0.001), and healthy controls (median 0.80 × 10,3 mm2/s, P < 0.001). DWI discriminated patients with PSP from PD and healthy subjects on the basis of SCP rADC individual values (100% sensitivity and specificity) and from patients with MSA-P (96.4% sensitivity and 93.3% specificity). The higher values of rADC in SCP of patients with PSP correspond with the in vivo microstructural feature of atrophy detected postmortem and provide an additional support for early discrimination between PSP and other neurodegenerative parkinsonisms. © 2008 Movement Disorder Society [source]


    Microstructural white matter changes in primary torsion dystonia

    MOVEMENT DISORDERS, Issue 2 2008
    Maren Carbon MD
    Abstract Primary torsion dystonia (PTD) has been conceptualized as a disorder of the basal ganglia. However, recent data suggest a widespread pathology involving motor control pathways. In this report, we explored whether PTD is associated with abnormal anatomical connectivity within motor control pathways. We used diffusion tensor magnetic resonance imaging (DT-MRI) to assess the microstructure of white matter. We found that fractional anisotropy, a measure of axonal integrity and coherence, was significantly reduced in PTD patients in the pontine brainstem in the vicinity of the left superior cerebellar peduncle and bilaterally in the white matter of the sensorimotor region. Our data thus support the possibility of a disturbance in cerebello-thalamo-cortical pathways as a cause of the clinical manifestations of PTD. © 2007 Movement Disorder Society [source]


    Diffusion-weighted magnetic resonance imaging differentiates Parkinsonian variant of multiple-system atrophy from progressive supranuclear palsy

    MOVEMENT DISORDERS, Issue 1 2007
    Dominic C. Paviour PhD, MRCP
    Abstract Progressive supranuclear palsy (PSP) and the parkinsonian variant of multiple-system atrophy (MSA-P) may present with a similar phenotype. Magnetic resonance diffusion-weighted imaging (DWI) has been shown to be a sensitive discriminator of MSA-P from Parkinson's disease (PD). We studied 20 PSP, 11 MSA-P, 12 PD patients and 7 healthy controls in order to investigate whether regional apparent diffusion coefficients (rADCs) help distinguish PSP and MSA-P; whether rADCs are correlated with clinical disease severity scores; and the relationship between brainstem and cerebellar volumes and rADCs in PSP and MSA-P. The Unified Parkinson's Disease Rating Scale, Hoehn and Yahr score, Mini Mental State Examination, and frontal assessment battery were recorded in all patients. Regional ADCs were measured in the middle cerebellar peduncle (MCP), caudal and rostral pons, midbrain, decussating fibers of the superior cerebellar peduncle, thalamus, putamen, globus pallidus, caudate nucleus, corpus callosum, frontal and parietal white matter, as well as the centrum semiovale. In MSA-P, rADCs in the MCP and rostral pons were significantly greater than in PSP (P < 0.001 and 0.009) and PD (P < 0.001 and = 0.002). Stepwise logistic regression revealed that the MCP rADC distinguishes MSA-P from PSP with a sensitivity of 91% and a specificity of 84%. Increased brainstem rADCs were associated with motor deficit in MSA-P and PSP. Increased rADCs in the pons and MCP were associated with smaller pontine and cerebellar volumes in MSA-P. rADCs distinguish MSA-P from PSP. These have a clinical correlate and are associated with reduced brainstem and cerebellar volumes. © 2006 Movement Disorder Society [source]


    Arm chorea secondary to an unruptured giant aneurysm,

    MOVEMENT DISORDERS, Issue 11 2003
    Luis M. Barreiro De Madariaga MD
    Abstract We describe the case of a 20-year-old male who developed right-arm choreic movements secondary to a giant unruptured aneurysm impinging upon the left thalamus, putamen, globus pallidus, cerebral peduncle, midbrain, and subthalamic nucleus. The aneurysm was treated successfully with coils and a supraclinoid balloon. Abnormal movements initially failed to ameliorate, but within a few months, it was possible to discontinue symptomatic haloperidol therapy, with only mild residual abnormal movements. © 2003 Movement Disorder Society [source]


    Three-dimensional MRI of cerebral projections in rat brain in vivo after intracortical injection of MnCl2

    NMR IN BIOMEDICINE, Issue 5 2003
    Peter R. Allegrini
    Abstract In this study we investigated the potential of in vivo MRI detection of axonal Mn2+ transport for tracing neuronal projections originating in the sensorimotor cortex in healthy and lesioned rat brains. Special attention was given to the potential of visualizing neuronal sprouting of central nervous system across the midline. After injecting unchelated MnCl2 into the forelimb area of sensorimotor cortex of 18 healthy and 10 lesioned rats corticofugal projections could be traced through the internal capsule to the cerebral peduncle and the pyramidal decussation. Although the neuronal tract was visible as early as 6,h after MnCl2 injection, best contrast was achieved after 24,48,h. Beside the cortico-spinal tract, the cortico-thalamic fibres were also visualized by anterograde Mn2+ transport. Cortico-striatal fibres were partially masked by the very high signal near the MnCl2 injection site but could be discerned as well. Slight, diffuse signal enhancement of cortical tissue contralateral to the MnCl2 injection site in healthy rat brains suggests interhemispheric connections or passive diffusion of Mn2+. However, enhanced fibre tract contrast connecting both hemispheres was visible 16 weeks after onset of focal photothrombotic cortical injury. In conclusion our study has shown that we were able to visualize reproducibly the main descending corticofugal projections and interhemispheric connections by non-invasive MRI after localized injection of MnCl2. The appearence of interhemispheric Mn2+ -enhanced fibres after photothrombotic focal injury indicates that the method may bear potential to follow non-invasively gross plastic changes of connectivity in the brain after injury. Copyright © 2001 John Wiley & Sons, Ltd. [source]


    Structural and Functional Features of Choroid Epithelium from Buffalo Brain

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 11 2007
    Gaetano Scala
    Abstract Choroid plexuses (CPs) play pivotal roles in many processes that establish, survey, and maintain the biochemical and cellular status of the central nervous system (CNS). Changes in the anatomy and physiology of CPs have been linked to several CNS diseases. However, CP structure and function are not definitely known. Here, we report structural and functional features of choroid epithelium from buffalo brain never described before. Mixed with common epithelial cells, two novel cell types were identified by scanning and transmission electron microscopies. The first peculiar cells showed a globular apical portion projecting into the ventricular cavities, and a basal peduncle in direct contact with blood capillaries underlying the epithelium. The second type of cells resulted to be formed by a globular body from which depart numerous processes; these cells, localized deeply in the choroid epithelium, strictly contact neighboring epithelial cells. No synaptic contacts were detected between these cell populations and common epithelial cells. To gain some insight into the functional properties of choroid cells, NADPH diaphorase (NADPHd) and neuronal nitric oxide synthase (nNOS) activities were evaluated. Of interest, whereas a strong NADPHd activity was detected in all cell types of choroid epithelium, nNOS was only detected in the first type of peculiar cells. The presence of nNOS in the CPs was confirmed by Western blotting. These results suggest that nitric oxide may serve as a signal for the regulation of CP multiple functions. Anat Rec, 290:1399,1412, 2007. © 2007 Wiley-Liss, Inc. [source]


    Three-dimensional average-shape atlas of the honeybee brain and its applications

    THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 1 2005
    Robert Brandt
    Abstract The anatomical substrates of neural nets are usually composed from reconstructions of neurons that were stained in different preparations. Realistic models of the structural relationships between neurons require a common framework. Here we present 3-D reconstructions of single projection neurons (PN) connecting the antennal lobe (AL) with the mushroom body (MB) and lateral horn, groups of intrinsic mushroom body neurons (type 5 Kenyon cells), and a single mushroom body extrinsic neuron (PE1), aiming to compose components of the olfactory pathway in the honeybee. To do so, we constructed a digital standard atlas of the bee brain. The standard atlas was created as an average-shape atlas of 22 neuropils, calculated from 20 individual immunostained whole-mount bee brains. After correction for global size and positioning differences by repeatedly applying an intensity-based nonrigid registration algorithm, a sequence of average label images was created. The results were qualitatively evaluated by generating average gray-value images corresponding to the average label images and judging the level of detail within the labeled regions. We found that the first affine registration step in the sequence results in a blurred image because of considerable local shape differences. However, already the first nonrigid iteration in the sequence corrected for most of the shape differences among individuals, resulting in images rich in internal detail. A second iteration improved on that somewhat and was selected as the standard. Registering neurons from different preparations into the standard atlas reveals 1) that the m-ACT neuron occupies the entire glomerulus (cortex and core) and overlaps with a local interneuron in the cortical layer; 2) that, in the MB calyces and the lateral horn of the protocerebral lobe, the axon terminals of two identified m-ACT neurons arborize in separate but close areas of the neuropil; and 3) that MB-intrinsic clawed Kenyon cells (type 5), with somata outside the calycal cups, project to the peduncle and lobe output system of the MB and contact (proximate) the dendritic tree of the PE1 neuron at the base of the vertical lobe. Thus the standard atlas and the procedures applied for registration serve the function of creating realistic neuroanatomical models of parts of a neural net. The Honeybee Standard Brain is accessible at www.neurobiologie.fu-berlin.de/beebrain. J. Comp. Neurol. 492:1,19, 2005. © 2005 Wiley-Liss, Inc. [source]


    Organization of tectopontine terminals within the pontine nuclei of the rat and their spatial relationship to terminals from the visual and somatosensory cortex

    THE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 3 2005
    Cornelius Schwarz
    Abstract We investigated the spatial relationship of axonal and dendritic structures in the rat pontine nuclei (PN), which transfer visual signals from the superior colliculus (SC) and visual cortex (A17) to the cerebellum. Double anterograde tracing (DiI and DiAsp) from different sites in the SC showed that the tectal retinotopy of visual signals is largely lost in the PN. Whereas axon terminals from lateral sites in the SC were confined to a single terminal field close to the cerebral peduncle, medial sites in the SC projected to an additional dorsolateral one. On the other hand, axon terminals originating from the two structures occupy close but, nevertheless, totally nonoverlapping terminal fields within the PN. Furthermore, a quantitative analysis of the dendritic trees of intracellularly filled identified pontine projection neurons showed that the dendritic fields were confined to either the SC or the A17 terminal fields and never extended into both. We also investigated the projections carrying cortical somatosensory inputs to the PN as these signals are known to converge with tectal ones in the cerebellum. However, terminals originating in the whisker representation of the primary somatosensory cortex and in the SC were located in segregated pontine compartments as well. Our results, therefore, point to a possible pontocerebellar mapping rule: Functionally related signals, commonly destined for common cerebellar target zones but residing in different afferent locations, may be kept segregated on the level of the PN and converge only later at specific sites in the granular layer of cerebellar cortex. J. Comp. Neurol. 484:283,298, 2005. © 2005 Wiley-Liss, Inc. [source]


    Feeding by the Pfiesteria -Like Heterotrophic Dinoflagellate Luciella masanensis

    THE JOURNAL OF EUKARYOTIC MICROBIOLOGY, Issue 3 2007
    HAE JIN JEONG
    ABSTRACT. To explore the feeding ecology of the Pfiesteria -like dinoflagellate (PLD) Luciella masanensis (GenBank Accession no. AM050344, previously Lucy), we investigated the feeding behavior and the kinds of prey species that L. masanensis fed on and determined its growth and ingestion rates of L. masanensis when it fed on the dinoflagellate Amphidinium carterae and an unidentified cryptophyte species (equivalent spherical diam., ESD=5.6 ,m), which were the dominant phototrophic species when L. masanensis and similar small heterotrophic dinoflagellates were abundant in Masan Bay, Korea in 2005. Additionally, these parameters were also measured for L. masanensis fed on blood cells of the perch Lateolabrax japonicus and the raphidophyte Heterosigma akashiwo in the laboratory. Luciella masanensis fed on prey cells by using a peduncle after anchoring the prey with tow filament, and was able to feed on diverse prey such as cryptophytes, raphidophytes, diatoms, mixotrophic dinoflagellates, and the blood cells of fish and humans. Among the prey species tested in the present study, perch blood cells were observed to be the optimal prey for L. masanensis. Specific growth rates of L. masanensis feeding on perch blood cells, A. carterae, H. akashiwo, and the cryptophyte, either increased continuously or became saturated with increasing the mean prey concentration. The maximum specific growth rate of L. masanensis feeding on perch blood cells (1.46/day) was much greater than that of A. carterae (0.59/day), the cryptophyte (0.24/day), or H. akashiwo (0.20/day). The maximum ingestion rate of L. masanensis on perch blood cells (2.6 ng C/grazer/day) was also much higher than that of A. carterae (0.32 ng C/grazer/day), the cryptophyte (0.44 ng C/grazer/day), or H. akashiwo (0.16 ng C/grazer/day). The kinds of prey species which L. masanensis is able to feed on were the same as those of Pfiesteria piscicida, but very different from those of another PLD Stoeckeria algicida. However, the maximum growth and ingestion rates of L. masanensis on perch blood cells, A. carterae, H. akashiwo, and the cryptophyte were considerably lower than those of P. piscicida. Therefore, these three dinoflagellates may occupy different ecological niches in marine planktonic communities, even though they have a similar size and shape and the same feeding mechanisms. [source]


    Ontogeny of the shi drum Umbrina cirrosa (Linnaeus 1758), a candidate new species for aquaculture

    AQUACULTURE RESEARCH, Issue 13 2005
    Giorgos Koumoundouros
    Abstract The ontogeny of shi drum Umbrina cirrosa (Linnaeus 1758), a candidate new species for aquaculture, was studied throughout the entire larval phase. Geometric morphometric analysis revealed two clear inflection points (7.0 and 12.7 mm total length, TL) in the shape ontogeny of this species, separating the studied period into three phases of different allometric priorities. Spline graphs demonstrated that the major non-uniform shape ontogeny correlated with the development of the fins, the anterior dorsal area of the body, the caudal peduncle, the eye and the mouth. Concerning the morphological features, shi drum larvae are characterized by an upward anterior bending of the notochord. The ontogeny of the fins began with the formation of the pectoral buds (2.9 mm TL), continued with the notochord flexion (4.3 mm TL, associated with the caudal fin development), the appearance of the pelvic buds, the first anal rays (4.5 mm TL) and the first dorsal rays (4.8 mm TL). Shi drum juveniles presented 25 vertebrae and the following dominant fin types: D XI,23, AII,6, VI,5, P17 and C17. [source]


    Analysis of morphological variation of the Acer tschonoskii complex in eastern Asia: implications of inflorescence size and number of flowers within sect.

    BOTANICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2003
    Macrantha
    Flower and fruit specimens of 184 individuals were sampled to investigate patterns of intraspecific variation and to evaluate recognition of taxa within the Acer tschonoskii complex using morphometric analysis. Previous taxonomic treatments have considered A. tschonoskii var. rubripes (= A. komarovii) and A. tschonoskii var. tschonoskii to be separate species. The morphological discontinuity between these two taxa was evident in peduncle and pedicel length, and in number of flowers. In addition, the delimitations of some species within sect. Macrantha were clarified using these diagnostic characters. In view of the geographical distribution of the A. tschonoskii complex, which includes many taxa of sect. Macrantha from China to Japan through Korea, the long raceme with many flowers (A. sikkimense) and unlobed leaf are considered more primitive than the short raceme with a small number of flowers and five-lobed leaf (A. maximowiczii and A. komarovii). However, many intermediate taxa were present. This study also suggests that several Chinese taxa, such as A. metcalfii, A. taronense, A. hookeri and A. grosseri, may be subject to different taxonomic interpretation and should be reinvestigated morphologically. © 2003 The Linnean Society of London. Botanical Journal of the Linnean Society, 2003, 143, 29,42. [source]


    Progressive Supranuclear Palsy: Pathology and Genetics

    BRAIN PATHOLOGY, Issue 1 2007
    Dennis W. Dickson
    Progressive supranuclear palsy (PSP) is an atypical Parkinsonian disorder associated with progressive axial rigidity, vertical gaze palsy, dysarthria and dysphagia. Neuropathologically, the subthalamic nucleus and brainstem, especially the midbrain tectum and the superior cerebellar peduncle, show atrophy. The substantia nigra shows loss of pigment corresponding to nigrostriatal dopaminergic degeneration. Microscopic findings include neuronal loss, gliosis and neurofibrillary tangles in basal ganglia, diencephalon and brainstem. Characteristic tau pathology is also found in glia. The major genetic risk factor for sporadic PSP is a common variant in the gene encoding microtubule-associated protein tau (MAPT) and recent studies have suggested that this may result in the altered expression of specific tau protein isoforms. Imaging studies suggest that there may be sensitive and specific means to differentiate PSP from other parkinsonian disorders, but identification of a diagnostic biomarker is still elusive. [source]


    Quantitative diffusion tensor imaging for evaluation of motor function in patients with brain infarcts

    ACTA NEUROLOGICA SCANDINAVICA, Issue 5 2010
    X. Liu
    Liu X, Li L, Tian W, Zhao C, Dogra V. Quantitative diffusion tensor imaging for evaluation of motor function in patients with brain infarcts. Acta Neurol Scand: 2010: 121: 315,319. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objective,,, To evaluate the quantitative diffusion value in ipsilateral cerebral peduncle of patients with differing motor function abilities and analyse the thresholds discriminating the poor motor function disability. Method,,, Twenty-nine patients who previously suffered stroke underwent diffusion tensor imaging examinations. Motor function was evaluated 8 months after the event. The ipsilateral apparent diffusion coefficient (ADC) and fractional anisotropy (FA) of cerebral peduncle and ADC ratio and FA ratio of patients with different motor function scales were analysed. Results,,, The ipsilateral FA value and FA ratio were distinctly different in patients with different motor function scales, and significantly correlated with the motor function scales. There was no significant difference of ipsilateral ADC and ADC ratio, and neither had correlation with motor function scale. The patients with poor motor function scale could be discriminated by the cutoff value of ipsilateral FA of 0.453 and FA ratio of 0.623 with sensitivity of 90%, 75% and specificity of 88.9%, 88.9% respectively. Conclusions,,, The ipsilateral FA value and FA ratio were feasible and better imaging indices in discriminating patients with poor motor function ability. [source]


    Food or sex; pollinator,prey conflict in carnivorous plants

    ECOLOGY LETTERS, Issue 6 2001
    B. Anderson
    Carnivorous plants potentially trap their own pollinators and it has been argued that considerable spatial separation of flowers and traps has evolved to protect pollinators. We investigated flower-trap separation of Drosera and Utricularia. Short Drosera had a greater element of floral,trap separation than tall Drosera. Such a relationship is unexpected for plants whose peduncles were evolved to protect their pollinators. Utricularia can not trap pollinators but this genus still produces exceptionally long peduncles. We propose that flower-trap separation evolved because carnivorous plants are often short and need to project their flowers well above ground level to make them more attractive to pollinators. [source]