Adaptation of Orientation Vectors of Otolith-Related Central Vestibular Neurons to Gravity

Behavioral experiments indicate that central pathways that process otolith-ocular and perceptual information have adaptive capabilities. Because polarization vectors of otolith afferents are directly related to the electro-mechanical properties of the hair cell bundle, it is unlikely that they change their direction of excitation. This indicates that the adaptation must take place in central pathways. Here we demonstrate for the first time that otolith polarization vectors of canal-otolith convergent neurons in the vestibular nuclei have adaptive capability. A total of 10 vestibular-only and vestibular-plus-saccade neurons were recorded extracellularly in two monkeys before and after they were in side-down positions for 2 h. The spatial characteristics of the otolith input were determined from the response vector orientation (RVO), which is the projection of the otolith polarization vector, onto the head horizontal plane. The RVOs had no specific orientation before animals were in side-down positions but moved toward the gravitational axis after the animals were tilted for extended periods. Vector reorientations varied from 0 to 109° and were linearly related to the original deviation of the RVOs from gravity in the position of adaptation. Such reorientation of central polarization vectors could provide the basis for changes in perception and eye movements related to prolonged head tilts relative to gravity or in microgravity.

Download Full-text

Response of vestibular neurons to head rotations in vertical planes. I. Response to vestibular stimulation

Journal of Neurophysiology ◽

10.1152/jn.1988.60.5.1753 ◽

1988 ◽

Vol 60 (5) ◽

pp. 1753-1764 ◽

Cited By ~ 66

Author(s):

J. Kasper ◽

R. H. Schor ◽

V. J. Wilson

Keyword(s):

Vestibular Nucleus ◽

Semicircular Canals ◽

Vestibular Nuclei ◽

Vestibular Stimulation ◽

Excitatory Input ◽

Whole Body ◽

Otolith Organs ◽

Vertical Semicircular Canal ◽

Vector Orientation ◽

Response Vector

1. We have studied, in decerebrate cats, the responses of neurons in the lateral and descending vestibular nuclei to whole-body rotations in vertical planes that activated vertical semicircular canal and utricular receptors. Some neurons were identified as vestibulospinal by antidromic stimulation with floating electrodes placed in C4. 2. The direction of tilt that caused maximal excitation (response vector orientation) of each neuron was determined. Neuron dynamics were then studied with sinusoidal stimuli closely aligned with the response vector orientation, in the range 0.02-1 Hz. A few cells, for which we could not identify a response vector, probably had spatial-temporal convergence. 3. On the basis of dynamics, neurons were classified as receiving their input primarily from vertical semicircular canals, primarily from the otolith organs, or from canal+otolith convergence. 4. Response vector orientations of canal-driven neurons were often near +45 degrees or -45 degrees with respect to the transverse (roll) plane, suggesting these neurons received excitatory input from the ipsilateral anterior or posterior canal, respectively. Some neurons had canal-related dynamics but vector orientations near roll, presumably because they received convergent input from the ipsilateral anterior and posterior canals. Few neurons had their vectors near pitch. 5. In the lateral vestibular nucleus, neurons with otolith organ input (pure otolith or otolith+canal) tended to have vector orientations closer to roll than to pitch. In the descending nucleus the responses were evenly divided between the roll and pitch quadrants. 6. We conclude that most of our neurons have dynamics and response vector orientations that make them good candidates to participate in vestibulospinal reflexes acting on the limbs, but not those acting on the neck.

Download Full-text

Response of commissural and other upper cervical ventral horn neurons to vestibular stimuli in vertical planes

Journal of Neurophysiology ◽

10.1152/jn.1994.71.1.11 ◽

1994 ◽

Vol 71 (1) ◽

pp. 11-16 ◽

Cited By ~ 9

Author(s):

K. Endo ◽

J. Kasper ◽

V. J. Wilson ◽

B. J. Yates

Keyword(s):

Vestibular Nuclei ◽

Vestibular Stimulation ◽

Ventral Horn ◽

Neuron Activity ◽

Vestibulocollic Reflex ◽

Commissural Neurons ◽

Upper Cervical ◽

Neck Motoneurons ◽

Vector Orientation ◽

Response Vector

1. To study their contribution to the vestibulocollic reflex, we have studied, in decerebrate paralyzed cats, the effect of sinusoidal vestibular stimulation in multiple vertical planes on the spontaneous activity of neurons in the C3 ventral horn. Antidromic microstimulation was used to identify 17/42 neurons as commissural; 10 of these were confirmed to have a projection to the contralateral ventral horn. 2. Dynamics of the responses of spontaneously firing neurons were studied with 0.05–1 Hz sinusoidal stimuli delivered near the plane of rotation that produced maximal modulation of neuron activity (response vector orientation). On the basis of their responses, we classified 38 neurons as receiving otolith, semicircular canal, or otolith + canal input. All three response types were found among commissure and nonantidromic neurons. 3. Two-thirds of neuron response vector orientations pointed contralaterally. They were either near the anterior or posterior canal planes or in the roll quadrant. In the case of neurons with input from canals, the latter indicates convergence from the vertical canals on the same side. There were almost no vectors in the pitch quadrants. The distribution of response vector orientations resembles that seen in the vestibular nuclei and pontomedullary reticular formation, suggesting that commissural neurons may not make a new contribution to spatial processing in the vertical vestibulocollic reflex. 4. It is presumed that commissural neurons are premotor. If so, some have the properties to be in the pathway between the contralateral utricle and neck motoneurons. More generally, their actions could modify the effectiveness of vestibulospinal and reticulospinal fibers that have similar spatial properties and make synapses with neck motoneurons.

Download Full-text

Untersuchungen zur Quantifizierung der Änderung der Skelettmuskeldurchblutung nach Gefäßrevaskularisationen mit einem 99mTechnetiummarkierten Tracer

Nuklearmedizin ◽

10.1055/s-0038-1629534 ◽

1990 ◽

Vol 29 (05) ◽

pp. 215-220 ◽

Cited By ~ 1

Author(s):

R. Benning ◽

K. Nagel ◽

M. Jugenheimer ◽

S. Fischer ◽

S. Worthmann ◽

...

Keyword(s):

Transluminal Angioplasty ◽

Lower Limbs ◽

Surgical Patients ◽

Treadmill Test ◽

Negative Results ◽

Clinical Observations ◽

Before And After ◽

Comparative Results ◽

First Time ◽

Percutaneous Transluminal

A new 99mTc-labelled tracer (99mTc-Sestanriibi) was used for the first time to demonstrate the perfusion of the skeletal muscle. In 16 patients with obstructive atherosclerosis of the lower limbs the change of perfusion of thigh and lower leg was studied with SPECT before and after vascular surgery (n = 11) or percutaneous transluminal angioplasty (n = 5). Comparative results of scintigraphic measurements and clinical observations (ancle-arm pressure, treadmill test) in 10 surgical patients (14 operated legs) showed correct positive or negative results in 86% (12/14).

Download Full-text

Trombodynamics Method in the Assessment of Coagulation Parameters in Psychopharmacotherapy of Endogenous Mental Disorders

Psychiatry ◽

10.30629/2618-6667-2020-18-4-16-25 ◽

2020 ◽

Vol 18 (4) ◽

pp. 16-25

Author(s):

N. S. Karpova ◽

O. S. Brusov ◽

I. V. Oleichik ◽

M. I. Faktor ◽

N. S. Levchenko ◽

...

Keyword(s):

Mental Disorders ◽

Response To Therapy ◽

Procoagulant Activity ◽

Coagulation Activity ◽

Continuous Type ◽

Chronic Neuroinflammation ◽

Psychopharmacological Treatment ◽

Before And After ◽

First Time ◽

Schizotypal Disorder

Background: currently, it has been proven that the pathogenesis of endogenous mental disorders is associated with the process of neuroinflammation in the brain of patients. It is also known that chronic neuroinflammation, accompanied by a violation the permeability of the blood-brain barrier. It is accompanied by the activation of platelets that generate procoagulant microparticles, which leads to a disturbance of the hemostasis system, causing an increase in blood clotting in patients. Objective: to investigate the dynamics of procoagulant activity of blood in patients with endogenous mental disorders before and after psychopharmacotherapy.Patients and methods: the study included 185 patients aged 16 to 64 years with the following mental disorders: schizophrenia with attack-like/attack-progressive/continuous type of course (F20.00–2), affective disease (F31.1–5; F32.0–3; F33.0–3), schizotypal disorder with affective fluctuations (F21.3–4). The thrombodynamic test (TD) was performed on T-2 Trombodynamis device according to the manufacturer’s instructions (Hemacore LLC, Moscow, Russia). All patients received standard pharmacotherapy according to their condition.Results: a significant decrease of procoagulant activity of spontaneous clots in the patients’ blood after psychopharmacological treatment is observed. Our data on the positive dynamics of changes in the values of TD test’s indicators in most of the examined patients suggest that a decrease in the coagulation activity of the patients’ blood as a result of treatment may be associated with the anti- inflammatory effect of antipsychotics and antidepressants.Conclusion: for the first time, it was shown that there is a positive dynamic in changing the values of the main parameters of the TD test in most patients with endogenous mental diseases. The results of TD tests can be the basis for monitoring the response to therapy.

Download Full-text

Influences of the selected additives on the weight loss and organoleptic properties of marinated mussels and squids

Acta Veterinaria Brno ◽

10.2754/avb201281030263 ◽

2012 ◽

Vol 81 (3) ◽

pp. 263-267 ◽

Cited By ~ 2

Author(s):

Metin Guldas ◽

Canan Hecer

Keyword(s):

Weight Loss ◽

Salt Content ◽

Meat Products ◽

Organoleptic Properties ◽

Highest Weight ◽

Konjac Flour ◽

Weight Gains ◽

Before And After ◽

Mouth Feel ◽

First Time

Effects of seven different solutions prepared from various additives (carrageenan, konjac flour, phosphate, yeast extract, xanthan gum and maltodextrin) were used to test for the first time in the marination of experimental seafood. The additives were added into the marination solutions and the samples were analyzed before and after marination. Statistically, the experimental solutions did not cause significant changes in pH, acidity and salt content of the samples (P < 0.05). The highest weight gains were obtained from the solution which contained 0.1% of konjac flour (E425 I) as 4.01, 5.21, 4.61 and 4.88 % in the mussels, big squids, diced squids and small squids, respectively. However, this solution was not preferred by the panellists because of its sticky texture. Inversely to red meat products, the solution containing phosphate caused weight loss during marination. The results indicate that the solution containing 0.2% carrageenan LM (low methoxyl) was the best solution in the marination process. Dipping into this solution caused weight gains of 4.69, 2.98, 4.04 and 2.78% in the big squids, the mussels, the small squids and the diced squids, respectively (P < 0.01). The organoleptic properties (mouth feel, flavour and softness) of mussels and squids were also improved by carrageenan LM addition.

Download Full-text

The effects of dehydration and local soil on parasite recovery: A preliminary paleoparasitological evaluation on experimental coprolites

The Holocene ◽

10.1177/09596836211049981 ◽

2021 ◽

pp. 095968362110499

Author(s):

Darío Alejandro Ramirez ◽

Mariana Fabra ◽

Samanta Xavier ◽

Alena Mayo Iñiguez

Keyword(s):

Equal Mass ◽

Central Argentina ◽

Soil Sediment ◽

Local Soil ◽

Before And After ◽

Fresh Feces ◽

Flotation Technique ◽

First Time ◽

Taphonomic Processes

Experimental paleoparasitological approaches have been used in order to optimize the methodology previously to the application in archeological samples. In this study we evaluated the action of dehydration and local soil (Central Argentina) on the loss of parasite eggs in experimental coprolites, using two parasitological techniques: spontaneous sedimentation and sucrose-flotation. Experimental coprolites comprised fresh human feces, positive for Hymenolepis nana, Ascaris sp., and Enterobius vermicularis, submitted to controlled artificial dehydration. Experimental coprolites with soil addition were prepared by mixing archeological sediment with equal mass of fresh feces. Helminth eggs were counted and eggs per gram were estimated in each subsample. Statistical analyses were applied to compare subsamples before and after desiccation and with and without addition of soil sediment. The performance of parasitological methods statistically differed, the sucrose flotation technique being the less effective when fresh feces and experimental coprolites were analyzed. Partial deformation of eggs was observed via both techniques only in subsamples containing H. nana eggs. However, this was not seen in Ascaris sp. subsamples, possibly due to eggshell composition. We found that sample desiccation significantly decreased the number of eggs in the experimental coprolites. Mixing archeological sediment with the fecal material also resulted in significantly fewer eggs surviving, independent of desiccation. This shows that climate and soil in which archeological fecal samples are found can strongly influence the survival of parasite eggs from past populations. The small amount of parasite evidence often found in paleoparasitological analyses, including Central Argentina, could be attributed to the action of taphonomic processes rather than to the real absence of infection in these ancient populations. Importantly, the study highlights the role of local soil, confirmed for the first time by empirical data. The research provides valuable insights into the understanding of the paleoparasitological results of the region and of general paleoparasitology.

Download Full-text

“Girls Are Like Flowers; Boys Are Like footballs”

Boyhood Studies ◽

10.3167/bhs.2020.140104 ◽

2021 ◽

Vol 14 (1) ◽

pp. 45-62

Author(s):

Florencia Herrera

Keyword(s):

Longitudinal Study ◽

Hegemonic Masculinity ◽

Before And After ◽

Gender Practices ◽

First Time ◽

Masculine Gender

To contribute to the discussion about how masculinity—understood as a configuration of gender practices (Connell 2000)—is reproduced, this paper analyzes fathers’ discourse about the gender of their sons and daughters. I carried out a qualitative longitudinal study in Chile during which 28 first-time fathers were interviewed before and after their child’s birth or arrival (adoption). I suggest that these fathers see gender in essentialist, dichotomous, and hierarchical terms. They expect to shape their sons’ gender practices according to hegemonic masculinity (discouraging gender practices associated with femininity or homosexuality). In the study, no attempt to reformulate masculine gender practices was observed but, rather, an interest on the fathers’ part in maintaining the patriarchal gender order.

Download Full-text

Research on Number of High-Pressure Grouting of Hierarchical Multiple for Slope Based on Reliability Analysis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.716-717.363 ◽

2014 ◽

Vol 716-717 ◽

pp. 363-369

Author(s):

Zhen Hua Xie ◽

Dong Yang ◽

Sha Sha Liang ◽

Zhi Yun Jia

Keyword(s):

High Pressure ◽

Rock Mass ◽

System Analysis ◽

Rock Surface ◽

Rock Permeability ◽

Iron Mine ◽

Probability Calculation ◽

Before And After ◽

Pressure Grouting ◽

First Time

The technology of hierarchical multiple high-pressure grouting is an effective approach to manage high and steep slope of broken rock mass. The number of grouting is one of the key parameters of this technology. By the analysis of mechanics and grouting theory, the anchoring effect mainly is affected by anchor slurry vein and the contact area with rock mass. Based on the system analysis of slurry vein development for first time and many times high-pressure grouting, the process flow for hierarchical multiple high-pressure grouting is put forward. Serve the rock permeability changes before and after grouting as an indicator measuring slurry and rock surface area, the method of determining grouting number based on the reliable probability is got. Combined with the engineering example of Shouyun Iron Mine, this paper puts forward the reliability criteria of working state of hierarchical multiple high-pressure grouting. Through the probability calculation, the best number of grouting is 4 times. The tests of permeability of rock mass and drawing force verify the accuracy of this determination method.

Download Full-text

Effects of alternating blood flow restricted training and heavy-load resistance training on myofiber morphology and mechanical muscle function

Journal of Applied Physiology ◽

10.1152/japplphysiol.00015.2020 ◽

2020 ◽

Vol 128 (6) ◽

pp. 1523-1532 ◽

Cited By ~ 1

Author(s):

S. K. Hansen ◽

J. Ratzer ◽

J. L. Nielsen ◽

C. Suetta ◽

A. Karlsen ◽

...

Keyword(s):

Blood Flow ◽

Resistance Training ◽

Domain Size ◽

Load Resistance ◽

Heavy Load ◽

Low Load ◽

Fiber Size ◽

Before And After ◽

Myonuclear Domain ◽

First Time

The present data demonstrate that periodically substituting heavy-load resistance training (HL-RT) with low-load blood flow restricted resistance training (BFR-RT) leads to similar gains in type II myofiber CSA and muscle strength as achieved by HL-RT alone. Furthermore, we have for the first time evaluated myonuclear content and myonuclear domain size before and after training intervention across separate fiber size clusters and found no within-cluster changes for these parameters with training.

Download Full-text

«Raccogliere, pubblicare, illustrare carte». Editori ed edizioni di documenti medievali in Lombardia tra Otto e Novecento

10.36253/978-88-6453-499-2 ◽

2017 ◽

Cited By ~ 2

Author(s):

Gianmarco De Angelis

Keyword(s):

Medieval Studies ◽

State Identity ◽

Legal Documents ◽

Before And After ◽

Long Eighteenth Century ◽

Local Traditions ◽

Italian Unification ◽

First Time ◽

The Great War ◽

Shed Light

A long Eighteenth Century, in continuity with the erudite tradition and the editorial method of Muratori, and a very brief Nineteenth Century, between the first decade after Italian Unification and the eve of the Great War, when a new and (at last) professional generation of scholars (Bonelli, Vittani, Torelli, Manaresi) brought a sweeping change in the field of palaeographic and diplomatic researches and of publications of medieval legal documents: these two are the coordinates (conceptual earlier than chronological) of the present monography, that for the first time deals in a historiographical perspective with a crucial season of Medieval studies in Lombardy, concentrating upon careers, projects and works of its protagonists. The focus is on the editors and editions of charters, but around them we find many other individuals and institutions of the regional and national cultural scene. The Leitmotiv is the delineation of a modern philogical method in the editions of Lombard sources, but the wider context is represented by more general (and stronger, and ideologically characterised) themes of Medieval Studies before and after the national Unification of Italy: the problems of Lombard legacy, the myth of communal age in the Risorgimento culture, the Visconti-Sforza state identity. Finally, this study about editors and editions of medieval charters in Lombardy allows to shed light on the organization of regional historical research, within an intense (and not always simple) dialogue between the hegemonic Milanese capital and the proud local traditions of the other towns and provinces.

Download Full-text