Reflex Mechanisms Research Articles

An Improved Modeling of Parkinson’s Tremor and Investigation of Some Approaches to Remove this Symptom

In this research, an improved model of Parkinsonian tremor is presented by using a mathematical and computational approach. In Parkinson’s disease (PD), an abnormal signal is produced by basal ganglia (BG). This signal goes to the thalamus, then enters cortex and after interaction with peripheral system goes to muscle and finally appears as tremor. In the presented model, all of the mentioned process are simulated. Also, the skeletal muscle model as well as the central nervous system (basal ganglia, thalamus, cortex and supplementary motor area) and peripheral nervous system (spinal reflex) mechanisms are considered. In addition, two methods for tremor suppression are applied in this paper, 1) deep brain stimulation (DBS) which affects dopamine level in BG and 2) a mechanical method which is based on a negative feedback. The accuracy and efficiency of the presented simulation are demonstrated by comparison of the obtained results with those obtained by clinical tests.

Development of Bipedal Robot for Immediate Adaption Mechanism by Reflex

Reflexes contribute to many motor functions of humans. In order to understand the reflex mechanisms in posture control of humans, we develop a bipedal robot platform that can reproduce muscle properties and reflexes. This robot with BLDC motors has high back-drivability and torque output ability to reproduce these two characteristics. In this study, to quantitatively investigate the contribution of various types of posture reflexes with different sensory information (muscle length, force, and no input), we compared the settling time and steady-state deviations of the posture response under disturbances.

Efeitos do treinamento muscular respiratório em pacientes após acidente vascular cerebral: uma revisão sistemática

INTRODUÇÃO: O Acidente Vascular Cerebral (AVC) é o resultado da interrupção aguda do suprimento sanguíneo ao cérebro por meio de entupimento ou rompimento dos vasos podendo provocar lesões celulares e alterações nas funções neurológicas. Essas alterações são relevantes para a ineficiência dos mecanismos orofaríngeos da deglutição, respiração, fonação e reflexos protetores das vias aéreas inferiores culminando em alta incidência de pneumonia por aspiração. O Treinamento Muscular Respiratório tem como função restabelecer a função muscular que esteja comprometida, treinar tanta a força quanto à endurance muscular, melhor a eficácia na desobstrução das vias aéreas, condicionar e adaptar ao exercício e prevenir a fadiga muscular respiratória. OBJETIVO: O objetivo desse estudo é sistematizar o efeito do treinamento muscular respiratório sobre os volumes e capacidades pulmonares em indivíduos que sofreram acidente vascular cerebral. MATERIAIS E MÉTODOS: Esta revisão sistemática foi realizada pela busca nas bases de dados BVS (Scielo, Lilacs, IBECS, Medline), PubMed e análise das referências. RESULTADOS: Um total de 4834 estudos foram rastreados e analisados, onde fizeram parte desta revisão 17 estudos publicados entre 2010 e 2019. CONCLUSÃO: Estudos comprovaram que o uso de TMR em pacientes pós-AVC gera efeitos positivos nos volumes e capacidades pulmonares, apesar de terem um tamanho amostral pequeno. A busca por criar novos estudos que possam auxiliar na prescrição e padronização dos treinamentos desses indivíduos em diversos ambientes deve ser um caminho a se pensar.

Les réflexes urétraux : revue de la littérature

The urethrosphincter complex is involved not only in maintaining urinary continence, particularly during effort, but also for the achievement of a complete and effective micturition. Indeed, the urethra is not a simple passive channel for the evacuation of urine from the bladder to the urethral meatus, since its resistive capacities and its possibilities of modulation of the micturition reflex depend on its reflex role either as a sensory afferent or as a neuro-muscular effector. It also participates in many genito-sexual and ano-rectal réflexes. This review of the literature describes the various reflexes of the urethra as a sensory stimulus or a neuromuscular effector. All articles referenced in this review were obtained from articles indexed on Pubmed-Medline, using the keywords: "urethral reflexes; "reflex bladder"; "urination reflex"; "intravaginal; vaginal"; "anorectal; sphincter"; "Storage and voiding"; "reflexes sneezing"; "cough reflex". Other articles were selected through references of the articles issued from the first research. Only articles in English and French have been selected. The articles concerned animal and human experiments. Eight hundred and sixty-four referenced articles were founded and a total of 75articles were included, describing the various reflexes mediated by the urethra acting as a sensory afferent or mechanical effector. We differentiated the known data in humans and animals. The urethra is a complex anatomical structure ensuring, through numerous reflex mechanisms, urinary continence. Urethral resistances are modulated during efforts and depends on the bladder capacity and the intensity of the efforts. During micturition, the coordination between the bladder and the urethra is mediated by reflex pathways organized at the cerebral, spinal and lumbosacral levels. The modulation of the micturition in term of efficacy and velocity, is due in part, to the re-afferentation of the spinal reflex by continuous stimulus of the urethral canal. Many of these reflexes are imperfectly described. Finally, the urethra is implicated in reflex loops of anal continence and sexual functions.

Extraesophageal syndrome of gastroesophageal reflux: relationships with lung disease and transplantation outcome.

Gastroesophageal reflux disease (GERD) is prevalent and may be associated with both esophageal and extraesophageal syndromes, which include various pulmonary conditions. GERD may lead to pulmonary complications through the "reflux" (aspiration) or "reflex" (refluxate-triggered, vagally mediated airway spasm) mechanisms. While GERD may cause or worsen pulmonary disorders, changes in respiratory mechanics due to lung disease may also increase reflux. Typical esophageal symptoms are frequently absent and objective assessment with reflux monitoring is often needed for diagnosis. Impedance monitoring should be considered in addition to traditional pH study due to the involvement of both acidic and weakly acidic/nonacidic reflux. Antireflux therapy may improve outcomes of some pulmonary complications of GERD, although careful selection of a candidate is paramount to successful outcomes. Further research is needed to identify the optimal testing strategy and patient phenotypes that would benefit from antireflux therapy to improve pulmonary outcomes.

The Application of Conditioned Reflex Mechanism in Cybernetics is Studied Based on Computer Aided Technology

Through the introduction of cybernetics, this paper introduces in detail the course of cybernetics in the development of society and science, and briefly expounds the dispute over the status of cybernetics in the development of science and technology, which leads to the inseparable relationship between cybernetics and modern intelligent machines.Finally, based on the computer-aided discussion of the simulation of biological conditioned reflex mechanism by industrial machinery under the background of cybernetics, the irreplaceable position of cybernetics in the development of technology is obtained, and the application of the conditioned reflex mechanism in the future is made a bold assumption according to the prospect of the development of computer.

Pathways of neuro-immune communication: past and present time, clinical application

Fundamental studies in neuroimmunophysiology are the keystone for development of new therapeutic approaches to the treatment of infectious, allergic, oncologic and autoimmune diseases. The achievements in this field allowed approving new treatment methods based on irritation of afferent and efferent fibers of autonomic nerves. That became possible due to numerous studies of pathways between the immune and nervous systems performed over last two decades. The milestones in the history of neuroimmune communication research are represented here. The immune system organs – bone marrow, thymus and spleen are coupled to central nervous system (CNS) via sympathetic nerves. Information about LPS and bacteria emergence in peritoneum, intestine and parenchymal organs reaches the brain via parasympathetic pathways. After vagotomy, the brain neurons do not respond to this kind of antigens. The pattern of brain responses to different applied antigens (the EEG changes and the quantity of c-Fos-positive neurons) is specific for definite antigen, like as algorithms of electroneurogram after exposure to different cytokines. Activation of parasympathetic nerves causes the inhibition of inflammation. The entry of any antigens into the body initiates production of cytokines (IL-1, TNFα, IL-6, IFNγ etc.), via specific receptors which are present on peripheral neurons and terminals of vagus nerve, i.e. the vagal afferent terminals and neurons respond to cytokine action, and these signals are transmitted to CNS neurons. The afferent vagal fibers end on the dorsal vagal complex neurons in the caudal part of medulla oblongata. The information about bacterial antigens, LPS and inflammation is transmitted to the brain via afferent autonomic neural pathways. The speed of this process is high and significantly depends on the rates of cytokine production that are transmitters of signals upon the antigen exposure. It is important to emphasize that this events occur within minutes, and the response to the received information proceeds by reflex mechanisms, i.e., within fraction of a second, as exemplified by inflammation (“inflammation reflex”). This is a fundamentally new and revolutionary discovery in the functional studies of immune system regulation. Clinical efficiency of n. vagus stimulation by pulsed ultrasound was shown, being used for the treatment of inflammatory, allergic and autoimmune diseases, e.g., multiple sclerosis, rheumatoid arthritis, renal inflammatory diseases. Electrical stimulation of the vagus nerve reduces the death of animals in septic shock by 80%. The mentioned data have made a revolution in understanding the functional arrangement of immune system in the body. A hypothesis is represented, which suggests how the information on the antigen exposure is transmitted to the brain.

Quick compensatory mechanisms for tongue posture stabilization during speech production

The human tongue is atypical as a motor system since its movement is determined by deforming its soft tissues via muscles that are in large part embedded in it (muscular hydrostats). However, the neurophysiological mechanisms enabling fine tongue motor control are not well understood. We investigated sensorimotor control mechanisms of the tongue through a perturbation experiment. A mechanical perturbation was applied to the tongue during the articulation of three vowels (/i/, /e/, /ε/) under conditions of voicing, whispering, and posturing. Tongue movements were measured at three surface locations in the sagittal plane using electromagnetic articulography. We found that the displacement induced by the external force was quickly compensated for. Individual sensors did not return to their original positions but went toward a position on the original tongue contour for that vowel. The amplitude of compensatory response at each tongue site varied systematically according to the articulatory condition. A mathematical simulation that included reflex mechanisms suggested that the observed compensatory response can be attributed to a reflex mechanism, rather than passive tissue properties. The results provide evidence for the existence of quick compensatory mechanisms in the tongue that may be dependent on tunable reflexes. The tongue posture for vowels could be regulated in relation to the shape of the tongue contour, rather than to specific positions for individual tissue points.NEW & NOTEWORTHY This study presents evidence of quick compensatory mechanisms in tongue motor control for speech production. The tongue posture is controlled not in relation to a specific tongue position, but to the shape of the tongue contour to achieve specific speech sounds. Modulation of compensatory responses due to task demands and mathematical simulations support the idea that the quick compensatory response is driven by a reflex mechanism.

Bilateral and asymmetrical contributions of passive and active ankle plantar flexors stiffness to spasticity in humans with spinal cord injury.

Spasticity is one of the most common symptoms present in humans with spinal cord injury (SCI); however, its clinical assessment remains underdeveloped. The purpose of the study was to examine the contribution of passive muscle stiffness and active spinal reflex mechanisms to clinical outcomes of spasticity after SCI. It is important that passive and active contributions to increased muscle stiffness are distinguished to make appropriate decisions about antispastic treatments and to monitor its effectiveness. To address this question, we combined biomechanical and electrophysiological assessments of ankle plantarflexor muscles bilaterally in individuals with and without chronic SCI. Spasticity was assessed using the Modified Ashworth Scale (MAS) and a self-reported questionnaire. We performed slow and fast dorsiflexion stretches of the ankle joint to measure passive muscle stiffness and reflex-induced torque using a dynamometer and the soleus H reflex using electrical stimulation over the posterior tibial nerve. All SCI participants reported the presence of spasticity. While 96% of them reported higher spasticity on one side compared with the other, the MAS detected differences across sides in only 25% of the them. Passive muscle stiffness and the reflex-induced torque were larger in SCI compared with controls more on one side compared with the other. The soleus stretch reflex, but not the H reflex, was larger in SCI compared with controls and showed differences across sides, with a larger reflex in the side showing a higher reflex-induced torque. MAS scores were not correlated with biomechanical and electrophysiological outcomes. These findings provide evidence for bilateral and asymmetric contributions of passive and active ankle plantar flexors stiffness to spasticity in humans with chronic SCI and highlight a poor agreement between a self-reported questionnaire and the MAS for detecting asymmetries in spasticity across sides.NEW & NOTEWORTHY Spasticity affects a number of people with spinal cord injury (SCI). Using biomechanical, electrophysiological, and clinical assessments, we found that passive muscle properties and active spinal reflex mechanisms contribute bilaterally and asymmetrically to spasticity in ankle plantarflexor muscles in humans with chronic SCI. A self-reported questionnaire had poor agreement with the Modified Ashworth Scale in detecting asymmetries in spasticity. The nature of these changes might contribute to the poor sensitivity of clinical exams.

HUMAN INTELLIGENCE OPERATED BY INNATE SIGN REFLEX LOGIC OF DICHOTOMY AND DUALISM AND POST-NATALLY ACQUIRED LOGIC OF “GROUP” AND “FORWARD ERROR CORRECTION (FEC)” - DIGITAL LINGUISTICS

It is plausible that language is processed by the innate spinal sign reflex mechanism. Human speech sound contains logical properties of phoneme and mora, which interact with in-brain antigen/antibody molecular structures and networking memories in the postnatally developed logical circuits optimized for signals of syllables, a character set (long lasting syllables) and electronic form (interactive and ubiquitous syllables). For grammatical decoding, sound localization function at the brainstem auditory nuclei is converted to process sound vectors of grammatical syllables. For axiomatic scientific concepts, sign reflex logic of “If A then B” must be upgraded by mathematical group logic to be acquired by learning, so that the results of interdisciplinary conceptual operations should become meaningful and productive. As electronic data is interactive, we can discover as many relevant linguistic information as possible with keyword search on the internet within a few seconds. As a result, we obtain multi-disciplinary and voluminous linguistic information but with uncertain reliability. To inherit collective human intelligence and correct any errors in linguistic information of the past, regenerative reading might be appropriate for individual ontogenesis to repeat intellectual and conceptual phylogeny. Errors cannot be corrected by the original authors posthumously but only by those who are alive now and equipped with error correction techniques for linguistic information.

Design of Muscle Reflex Control for Upright Standing Push-Recovery Based on a Series Elastic Robot Ankle Joint.

In physical human–robot interaction environment, ankle joint muscle reflex control remains significant and promising in human bipedal stance. The reflex control mechanism contains rich information of human joint dynamic behavior, which is valuable in the application of real-time decoding motion intention. Thus, investigating the human muscle reflex mechanism is not only meaningful in human physiology study but also useful for the robotic system design in the field of human–robot physical interaction. In this paper, a specialized ankle joint muscle reflex control algorithm for human upright standing push-recovery is proposed. The proposed control algorithm is composed of a proportional-derivative (PD)-like controller and a positive force controller, which are employed to mimic the human muscle stretch reflex and muscle tendon force reflex, respectively. Reflex gains are regulated by muscle activation levels of contralateral ankle muscles. The proposed method was implemented on a self-designed series elastic robot ankle joint (SERAJ), where the series elastic actuator (SEA) has the potential to mimic human muscle–tendon unit (MTU). During the push-recovery experimental study, the surface electromyography (sEMG), ankle torque, body sway angle, and velocity of each subject were recorded in the case where the SERAJ was unilaterally kneed on each subject. The experimental results indicate that the proposed muscle reflex control method can easily realize upright standing push-recovery behavior, which is analogous to the original human behavior.

The Three Stage Digital Evolution of Linguistic Humans

Digital Linguistics (DL) is an interdisciplinary study that identifies human language as a digital evolution of mammal analog vocal sign communications, founded on the vertebrate spinal sign reflex mechanism [Tokumaru 2017 a/b, 2018 a/b/c/d]. Analog signs are unique with their physical sound waveforms but limited in number, whilst human digital word signs are infinite by permutation of their logical property, phonemes. The first digital evolution took place 66,000 years ago with South African Neolithic industries, Howiesons Poort, when linguistic humans acquired a hypertrophied mandibular bone to house a descended larynx for vowel accented syllables containing logical properties of phonemes and morae. Morae made each syllable distinctive in the time axis and enabled grammatical modulation by alternately transmitting conceptual and grammatical syllables. The sign reflex mechanism is an unconscious self-protection and life-support mechanism, operated by immune cell networks inside the ventricle system. DL identified cellular and molecular structures for the sign (=concept) device as a B lymphocyte (or, in other words, Mobile Ad-Hoc Networking Neuron), connects to sensory, conceptual and networking memories, which consist of its meanings [Table 1]. Its antibodies can network with antigens of CSF-Contacting Neurons at the brainstem reticular formation and of Microglia cells at the neocortex [Figure 1]. It is plausible that the 3D structure of the antigen molecule takes the shape of word sound waveform multiplexing intensity and pitch, and that specifically pairing the antibody molecule consists of three CDRs (Complementality Defining Regions) in the Antibody Variable Region network with the logic of dichotomy and dualism. As sign reflex deals with survival issues such as food, safety and reproduction, it is stubborn, passive and inflexible: It does not spontaneously look for something new, and it is not designed to revise itself. These characteristics are not desirable for the development of human intelligence, and thus are to be overcome. All the word, sensory and network memories in the brain must be acquired postnatally through individual learning and thought. The reason and intelligence of humans depend on how correctly and efficiently humans learn new words and acquire appropriate meanings for them.

Contrasting Reflex Neural Modulation of Muscle Sympathetic Nerve Activity at Rest and During One‐leg Dynamic Exercise in Subjects with and without Heart Failure

We previously showed that muscle sympathetic nerve activity (MSNA) is augmented at rest in patients with heart failure due to reduced ejection fraction (HFrEF), and rises further during mild and moderate dynamic 1‐leg exercise in stark contrast to the drop observed in healthy controls at similar exercise intensities. The reflex mechanisms responsible for this unique response are unknown. We hypothesized that MSNA may be reduced at rest and during exercise in HFrEF by either: 1) stimulating the sympatho‐inhibitory cardiopulmonary baroreceptors by exercising supine rather than upright; or 2) inhibiting the sympatho‐excitatory peripheral chemoreceptors by breathing 32% oxygen (O2). We studied 6 stable, non‐diabetic, medicated HFrEF men ( mean age 58 ± 3 SE [range 46 to 65] years; mean left ventricular ejection fraction 29 ± 4% [range 15–38]); of either ischemic (n=5) or non‐ischemic (n=1) etiology; plus 6 healthy, age matched, medication‐free volunteers (3 women; mean age 58 ± 3 [range 49 to 72]). We assessed peak oxygen uptake (VO2peak ) by open‐circuit spirometry. On a separate day, fibular MSNA (microneurography) was measured at rest and during upright 1‐leg cycling (2 min each unloaded and at 50% of VO2peak). The identical cycling protocol was then repeated during supine exercise (n=5 HFrEF) and again during upright cycling while breathing 32% O2 (n=4 HFrEF). Heart rate and diastolic blood pressure were similar across interventions in both groups but systolic blood pressure was significantly lower in HFrEF vs controls (main effect P=0.01). MSNA was reduced at rest only while supine in control subjects (main effect P=0.01; P=0.01 vs upright). Whereas in HFrEF, both supine posture and supplemental O2 attenuated MSNA burst frequency at rest (main effect P=0.01; P=0.02 vs upright). During exercise, MSNA burst frequency progressively decreased in healthy controls particularly during unloaded cycling (main effect of time P<0.001), and tended to be lower throughout supine cycling (P=0.06 vs upright). By contrast, in HFrEF patients, there was no significant change in MSNA burst frequency during exercise while supine nor with supplemental oxygen (main effect of intervention P=0.51; time P=0.34). Thus, both at rest and during mild cycling exercise, supine posture augments the sympathoinhibitory response in control subjects. However in HFrEF patients, sympathoexcitation at rest can be reduced to a similar extent by either triggering the inhibitory cardiopulmonary baroreflex or abolishing arterial chemoreceptor activation with no further effect during exercise.Support or Funding InformationSupported by Heart and Stroke Foundation of Ontario and Canadian Institutes for Health Research

Presynaptic inhibition in restless legs syndrome

Introduction: Restless legs syndrome (RLS) is a condition that particularly urges at night in resting and causes the need to move the legs. Although the pathophysiology has not yet been clarified, dopamine and iron metabolism and spinal cord pathologies are blamed for causing the condition. There are few studies on spinal reflex mechanisms on RLS. In the present study, we aimed to investigate the role of presynaptic inhibition (PreI) in the spinal cord in RLS.Methods: Fourteen patients with RLS and 14 controls with similar demographic characteristics were included in the study. Soleus muscle H-reflex (Ht) investigation was performed for subjects whose electrophysiologic investigation was normal. The Ht response was conditioned to the stimulation of the common peroneal nerve (CPN) (Hc). The test and conditioned stimulation intervals were kept between 10 ms, 20 ms, 30 ms, 40 ms, 50 ms, 75 ms, 100 ms, 150 ms and 200 ms. In each inter-stimulus interval, nonparametric repeat measurement evaluations were conducted with the percentage value of Hc/Ht. The Hc/Ht values of the study and control groups in the same intervals were compared separately.Results: A significant decrease was detected in Hc values in the control group in the repeat measurement values at 20 ms and 100 ms inter-stimulus intervals; however, there was not decrease in any intervals in the patient’s group.Conclusion: The absence of any decrease in Hc reflexes for 20–100 ms intervals revealed that discernible PreI was vanished in RLS patients.

Problèmes posés par la verticalité de l’enfant paralysé cérébral et rééducation selon l’approche Bobath

During normal development a baby progressively learns to function against gravity eventually resulting in a postural control in an upright position. This was described by Doctor K. Bobath as the normal postural reflex mechanism. Due to the presence of diverse motor disorders in children with cerebral palsy this process is modified. Here we will explain the different disorders in relation to their classification and describe their treatment using the Bobath Approach.

Hypothetically virtual approaches to the analysis of the mechanisms of neuropsychic activity

The main ideas of the book «the Call and all the rest» [1] and of the separately published «the Unexplored and Unexamined» chapters [2] on non-standard and not always well grounded approaches to the understanding of neuro-mental activity. «Staged» questions are considered and their solution cannot be completed without careful research study. It is proposed to use the following hypothetically formulated postulates: 1. Life processes that provide neuropsychic activity cannot be explained only by traditionally understood reflex mechanisms. 2. Any living structure has the biological ability not only to passively absorb information, but also to actively seek it out. 3. The conductor system uses muscle energy in every reflex action. Higher mental activity is formed by other energetic, both exogenous and endogenous flows. 4. Conscious (and perhaps not conscious) life events and behavioral experiences do not disappear from the functional «memory library». 5. Evolutionary unification, despite situational confrontations, is a vital necessity of the interaction process. Its neblinensis parts fall out of the further development cycle. This pattern determines the general theory of unification and development for biology and sociology.

Затрудненное носовое дыхание в практике оториноларинголога: чем помочь?

The article discusses the most common causes of diseases that cause difficulty in nasal breathing. According to the analysis of medical documentation, diseases accompanied by nasal obstruction and rhinorrhea are the most common human diseases. The priority role in the development of the clinical symptoms of rhinitis is played by the release of inflammatory mediators – histamine and bradykinin. Histamine in rhinitis mediates a cascade of pathological reactions, as a result of which local vasodilation develops, accompanied by swelling of the mucous membranes; nasal congestion; increased permeability of the vascular wall; exudation of blood plasma; irritation of nerve endings; triggering reflex mechanisms by stimulating trigeminal histamine receptors. Peculiarities of the course of intermittent and persistent forms of allergic rhinitis, the pathogenesis of allergic inflammation are considered. To reliably eliminate abundant rhinorrhea, combined with nasal congestion, the authors recommend the use of a combined nasal spray, which contains phenylephrine and cetirizine (Phenylephrine + Cetirizine). Based on the analysis of literature data, the effectiveness and safety of the use of the topical form of cetirizine are substantiated. Aspects of the clinical use of the combination of phenylephrine and cetirizine in inflammatory and allergic diseases of the nasal cavity and paranasal sinuses, in the pathogenesis of which the key role is played by swelling of the mucous membrane of the nasal cavity, are examined. It is proved that the new combined nasal spray of domestic production is an effective and safe method for treating patients with manifestations of various forms of rhinitis and nasal obstruction.

Effect of Intestinal Microbiota on Brain Activity: ANN Analysis of Functional Magnetic Resonance Imaging

Modern biotope genomics has been able to determine the characteristics of each individual. The intestinal microbiota has a direct effect on the brain and behavioral activity of the individual. Any change in it modifies the mechanisms of emotional signaling, behavioral and visceral nociceptive reflexes. The resulting signaling mechanisms of the gut microbiota and probiotics including variations in microbiota production influence brain activity. Studies on rodents with reported vagal signaling in response to intestinal and probiotic pathogens. Diet, genetic factors, environmental factors may play a role in these alterations. The result is that is proven by functional brain imaging. The resulting effect of this interaction can be recorded in specific areas in the brain using functional magnetic resonance imaging. Depending on different biotopes in different people, levels of stress or relaxation are recorded. The analysis of these variations allows having an idea of the effect carried by each alteration in biotope and drugs administered to soothe stress for example. However, these effects are far from accurate. Human physiology is much more complex to draw hasty conclusions. If the effect is much more pronounced in women is that they are more emotional, sex is a factor to consider. In this study, we propose an intelligent system for analyzing these variables. The analysis of the MRI image is very complex due to it is a question of defining the exact contours of the activated brain zones. Given the complexity of the system, an artificial neural network analysis with deep learning is proposed. The constructed system is supervised learning. Input variables are (Biotope classification, genetic factor, diet factor, sex) and an output variable that expresses the degree of effect on activation of brain areas in relation to the centers of emotions recorded in functional fMRI. The established algorithm randomly introduces values ​​to the input factors of the system to read predict the emotional effect on the individual.

Robert Graves, Marshall Hall, and reflex action in 1837

ABSTRACTIn several issues of the London Medical Gazette during June–July of 1837 there was an interchange of letters between Robert Graves, Regius Professor of the Institutes of Medicine at Trinity College, Dublin, and the London physician and experimental physiologist Marshall Hall, often considered the discoverer of the phenomenon of reflex activity. Graves asserted that he, rather than Hall, was the originator of the idea of reflex action as a disease mechanism. Hall rejected that assertion and, after exchange of some verbal “pleasantries,” began a tirade about a somewhat different, although not unrelated issue into which the journal editor interjected some not exactly dispassionate comments. Graves soon let the matter of priority lapse, and Hall continued his war with the Council of the Royal Society, but examination of the contemporary and earlier literature suggests that Graves probably was correct, by a narrow time margin, in relation of his claim for priority in using the concept of reflex action in explaining neurological disease mechanisms (not a claim for discovering reflex action), that Hall had used the phrase “reflex action” earlier than Graves, and that others before Hall had gone a long way in studying reflex mechanisms, although Hall’s writings had familiarized the medical profession with the concept.

Pheochromocytoma as a Clinical Model of Peripheral Sympathetic Overdrive: Old and New Findings.

The present paper will review the results of experimental and clinical studies aimed at defining the functional behavior of the central and peripheral nervous system in adrenal pheochromocytoma. The contribution of sympathetic neural influences to the development of high blood pressure values in pheochromocytoma is complex. Studies performed in experimental animal models have shown that hypertension and the concomitant high circulating levels of catecholamines can lead to inhibition of central sympathetic neural outflow by reflex mechanisms and direct stimulation of central adrenergic receptors, respectively. However, these studies have also shown that high circulating levels of catecholamines favor a downregulation of alpha- and beta-adrenergic receptors, lessening their response to endogenous and exogenous adrenergic stimulation. The present paper reviews results of human studies performed by our group and others on the behavior of the central and peripheral nervous system in human pheochromocytoma. We discuss data collected in patients with different levels of peripheral sympathetic drive, i.e., before and after surgical removal of the adrenal pheochromocytoma. In the presence of elevated plasma catecholamine level, such as that characterizing adrenal pheochromocytoma, microneurography shows that central sympathetic neural activity is normal or even inhibited. At the peripheral vascular level, pheochromocytoma is characterized by a reduced vascular reactivity to exogenous sympathetic stimulation but a normal response by the vessels to endogenous adrenergic stimulation.