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Comprehensive Physiology Apr 2014Evidence accumulated over 30 years, from experiments on animals and human subjects, has conclusively demonstrated that inputs from the vestibular otolith organs... (Review)
Review
Evidence accumulated over 30 years, from experiments on animals and human subjects, has conclusively demonstrated that inputs from the vestibular otolith organs contribute to the control of blood pressure during movement and changes in posture. This review considers the effects of gravity on the body axis, and the consequences of postural changes on blood distribution in the body. It then separately considers findings collected in experiments on animals and human subjects demonstrating that the vestibular system regulates blood distribution in the body during movement. Vestibulosympathetic reflexes differ from responses triggered by unloading of cardiovascular receptors such as baroreceptors and cardiopulmonary receptors, as they can be elicited before a change in blood distribution occurs in the body. Dissimilarities in the expression of vestibulosympathetic reflexes in humans and animals are also described. In particular, there is evidence from experiments in animals, but not humans, that vestibulosympathetic reflexes are patterned, and differ between body regions. Results from neurophysiological and neuroanatomical studies in animals are discussed that identify the neurons that mediate vestibulosympathetic responses, which include cells in the caudal aspect of the vestibular nucleus complex, interneurons in the lateral medullary reticular formation, and bulbospinal neurons in the rostral ventrolateral medulla. Recent findings showing that cognition can modify the gain of vestibulosympathetic responses are also presented, and neural pathways that could mediate adaptive plasticity in the responses are proposed, including connections of the posterior cerebellar vermis with the vestibular nuclei and brainstem nuclei that regulate blood pressure.
Topics: Animals; Blood Pressure; Homeostasis; Humans; Posture; Reflex; Sympathetic Nervous System; Vestibule, Labyrinth
PubMed: 24715571
DOI: 10.1002/cphy.c130041 -
Journal of Immunology (Baltimore, Md. :... May 2017The field of immunology is principally focused on the molecular mechanisms by which hematopoietic cells initiate and maintain innate and adaptive immunity. That... (Review)
Review
The field of immunology is principally focused on the molecular mechanisms by which hematopoietic cells initiate and maintain innate and adaptive immunity. That cornerstone of attention has been expanded by recent discoveries that neuronal signals occupy a critical regulatory niche in immunity. The discovery is that neuronal circuits operating reflexively regulate innate and adaptive immunity. One particularly well-characterized circuit regulating innate immunity, the inflammatory reflex, is dependent upon action potentials transmitted to the reticuloendothelial system via the vagus and splenic nerves. This field has grown significantly with the identification of several other reflexes regulating discrete immune functions. As outlined in this review, the delineation of these mechanisms revealed a new understanding of immunity, enabled a first-in-class clinical trial using bioelectronic devices to inhibit cytokines and inflammation in rheumatoid arthritis patients, and provided a mosaic view of immunity as the integration of hematopoietic and neural responses to infection and injury.
Topics: Adaptive Immunity; Allergy and Immunology; Animals; Cytokines; Humans; Immunity, Innate; Neurogenic Inflammation; Neuroimmunomodulation; Neurosciences; Reflex; Spleen; Vagus Nerve
PubMed: 28416717
DOI: 10.4049/jimmunol.1601613 -
Neuron Oct 2019The ability to establish behaviorally what psychological capacity an animal is deploying-to discern accurately what an animal is doing-is key to functional analyses of... (Review)
Review
The ability to establish behaviorally what psychological capacity an animal is deploying-to discern accurately what an animal is doing-is key to functional analyses of the brain. Our current understanding of these capacities suggests, however, that this task is complex; there is evidence that multiple capacities are engaged simultaneously and contribute independently to the control of behavior. As such, establishing the contribution of a cell, circuit, or neural system to any one function requires careful dissection of that role from its influence on other functions and, therefore, the careful selection and design of behavioral tasks fit for that purpose. Here I describe recent research that has sought to utilize behavioral tools to investigate the neural bases of instrumental conditioning, particularly the circuits and systems supporting the capacity for goal-directed action, as opposed to conditioned reflexes and habits, and how these sources of action control interact to generate adaptive behavior.
Topics: Adaptation, Psychological; Animals; Behavior Therapy; Behavior, Animal; Brain; Goals; Reflex; Volition
PubMed: 31600515
DOI: 10.1016/j.neuron.2019.09.024 -
Physiological Research Dec 2023Cough is one of the most important airway defensive reflexes aimed at removing foreign particles or endogenously produced materials from the airways and provides... (Review)
Review
Cough is one of the most important airway defensive reflexes aimed at removing foreign particles or endogenously produced materials from the airways and provides protection against aspiration. Generally considered, cough is a vital physiological defensive mechanism for lung health. However, in case of cough dysregulation this reflex can become pathological and leads to an adverse influence on daily life. Therefore, it is necessary to effectively evaluate the severity of cough for its diagnosis and treatment. There are subjective and objective methods for assessing cough. These methods should help describe the heterogeneity of cough phenotypes and may establish better treatment by monitoring response to nonpharmacological or pharmacological therapies. It is important to keep in mind that the clinical assessment of cough should include both tools that measure the amount and severity of the cough. The importance of a combined subjective and objective evaluation for a comprehensive assessment of cough has been advocated in the guidelines of the European Respiratory Society on cough evaluation. This review article provides an overview of subjective and objective methods for assessing and monitoring cough in children and adults comparing to animal models. Key words Cough frequency; Cough intensity; Cough reflex sensitivity; Cough monitors; Cough assessment.
Topics: Animals; Adult; Child; Humans; Cough; Lung; Reflex
PubMed: 38215057
DOI: 10.33549/physiolres.935062 -
Neurotherapeutics : the Journal of the... Jul 2018Neurological disorders, such as spinal cord injury, stroke, traumatic brain injury, cerebral palsy, and multiple sclerosis cause motor impairments that are a huge burden... (Review)
Review
Neurological disorders, such as spinal cord injury, stroke, traumatic brain injury, cerebral palsy, and multiple sclerosis cause motor impairments that are a huge burden at the individual, family, and societal levels. Spinal reflex abnormalities contribute to these impairments. Spinal reflex measurements play important roles in characterizing and monitoring neurological disorders and their associated motor impairments, such as spasticity, which affects nearly half of those with neurological disorders. Spinal reflexes can also serve as therapeutic targets themselves. Operant conditioning protocols can target beneficial plasticity to key reflex pathways; they can thereby trigger wider plasticity that improves impaired motor skills, such as locomotion. These protocols may complement standard therapies such as locomotor training and enhance functional recovery. This paper reviews the value of spinal reflexes and the therapeutic promise of spinal reflex operant conditioning protocols; it also considers the complex process of translating this promise into clinical reality.
Topics: Animals; Conditioning, Operant; Humans; Neuronal Plasticity; Reflex; Spinal Cord Injuries
PubMed: 29987761
DOI: 10.1007/s13311-018-0643-2 -
Otolaryngologic Clinics of North America Aug 2020Animal models have significantly contributed to understanding the pathophysiology of chronic subjective tinnitus. They are useful because they control etiology, which in... (Review)
Review
Animal models have significantly contributed to understanding the pathophysiology of chronic subjective tinnitus. They are useful because they control etiology, which in humans is heterogeneous; employ random group assignment; and often use methods not permissible in human studies. Animal models can be broadly categorized as either operant or reflexive, based on methodology. Operant methods use variants of established psychophysical procedures to reveal what an animal hears. Reflexive methods do the same using elicited behavior, for example, the acoustic startle reflex. All methods contrast the absence of sound and presence of sound, because tinnitus cannot by definition be perceived as silence.
Topics: Acoustic Stimulation; Animals; Behavior, Animal; Disease Models, Animal; Hearing; Hearing Loss; Humans; Reflex; Reflex, Startle; Reproducibility of Results; Sound; Tinnitus
PubMed: 32327193
DOI: 10.1016/j.otc.2020.03.001 -
Spinal Cord Series and Cases 2020Sacral reflexes are important to allow the SCI practitioner to gain information about the state of the sacral spinal cord segments. The presence of the bulbocavernosus... (Review)
Review
Sacral reflexes are important to allow the SCI practitioner to gain information about the state of the sacral spinal cord segments. The presence of the bulbocavernosus and/or the anal wink reflex indicate an intact spinal reflex arc and reflex conal autonomic function (as part of the upper motor neuron syndrome); their absence defines a lower motor neuron syndrome. The assessment of sacral reflexes helps predict the type of bladder, bowel and sexual functions and the related therapeutic interventions. We suggest adding the sacral component of the International Standards for the Assessment of Autonomic Function after SCI (ISAFSCI) to the International Standards for the Neurologic Classification of Spinal Cord Injury (ISNCSCI) examination so there can be a detailed description of these important functions. As an alternative, the performance of sacral reflexes should be routinely required as part of the neurologic examination after SCI. Whether the sacral motor neuron system is classified as upper or lower motor neuron injury is also quite useful and as such should be present in the ISCNSCI.
Topics: Humans; Neurologic Examination; Reflex; Sacrococcygeal Region; Spinal Cord Injuries
PubMed: 31934355
DOI: 10.1038/s41394-019-0252-2 -
Journal of Neurophysiology Jul 2022In this paper, we review the legacy of Gerald (Gerry) Gottlieb in various fields related to the neural control of human movement. His studies on the myotatic (stretch)... (Review)
Review
In this paper, we review the legacy of Gerald (Gerry) Gottlieb in various fields related to the neural control of human movement. His studies on the myotatic (stretch) reflex and postmyotatic responses to ankle joint perturbations paved the way for current explorations of long-loop reflexes and their role in the control of movement. The dual-strategy hypothesis introduced order into a large body of literature on the triphasic muscle activation patterns seen over a variety of voluntary movements in healthy persons. The dual-strategy hypothesis continues to be important for understanding the performance of subjects with disordered motor control. The principle of linear synergy (covariance of joint torques) was an attempt to solve one of the notorious problems of motor redundancy, which remains an important topic in the field. Gerry's attitude toward the equilibrium-point hypothesis varied between rejection and using it to explore patterns of hypothetical control variables and movement variability. The discovery of reciprocal excitation in healthy neonates fostered other studies of changes in spinal cord physiology as motor skills develop. In addition, studies of people with spasticity and the effects of treatment with intrathecal baclofen were crucial in demonstrating the possibility of unmasking voluntary movements after suppression of the hyperreflexia of spasticity. Gerry Gottlieb contributed a significant body of knowledge that formed a solid foundation from which to study a variety of neurological diseases and their treatments, and a more comprehensive and parsimonious foundation to describe the neural control of human movement.
Topics: Electromyography; Humans; Infant, Newborn; Movement; Muscle Contraction; Muscle, Skeletal; Reflex; Reflex, Stretch
PubMed: 35675443
DOI: 10.1152/jn.00141.2022 -
British Journal of Anaesthesia Feb 1993
Topics: Anesthesia; Animals; Cough; Dogs; Humans; Infant; Laryngeal Nerves; Reflex; Respiratory Physiological Phenomena
PubMed: 8031328
DOI: 10.1093/bja/70.2.121 -
Experimental Physiology Jul 2021This article reviews a unique direct injection technique that complements the more conventional right atrial injection and aerosol delivery methods to study sensory and... (Review)
Review
NEW FINDINGS
This article reviews a unique direct injection technique that complements the more conventional right atrial injection and aerosol delivery methods to study sensory and reflex effects of the lung sensors. Used in combination with other methods, this technique should contribute to the pulmonary sensory research.
ABSTRACT
The lungs house sensory receptors (sensors) that mediate a variety of sensory and reflex responses to mechanical or chemical changes. These reflexes are mainly carried through pulmonary sympathetic and vagal afferent pathways. The chemosensors in the lung periphery are especially important in pulmonary diseases and their reflex responses have traditionally been studied either by aerosol delivery, which also activates receptors in the central airways, or by right atrial injection, which also activates receptors lying outside the lung. Thus, these techniques may confound the interpretation of sensory function. Our laboratory has developed a direct injection technique to deliver agents into the lung parenchyma, which complements the conventional techniques with some important advantages. This article reviews the technique.
Topics: Afferent Pathways; Lung; Reflex; Sensory Receptor Cells; Vagus Nerve
PubMed: 33719104
DOI: 10.1113/EP089261