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Neural reflex

Radek P Kindl, Krunal Patel, Rikin A Trivedi
Brachial plexus tumors are uncommon lesions in young adults. The majority of these are benign peripheral sheath tumors. In this 3-dimensional video, we present a case of a 19-yr-old female who presented to the neurosurgical outpatients with an anterior neck lump. It has been present for months, causing occasional numbness and paraesthesia in the distribution of the left ring finger. There was no objective weakness in finger flexion with normal long flexors reflexes. The cervical spine and supraclavicular brachial plexus were investigated with a magnetic resonance imaging (Gadolinium) scan (Figure 1)...
August 8, 2018: Operative Neurosurgery (Hagerstown, Md.)
Harumitsu Hirata, Valentina Dallacasagrande, Kamila Mizerska, Evguenia Ivakhnitskaia, Mark I Rosenblatt
Purpose: Previously we found two types of corneal neurons that we hypothesized to play an important role in tearing. One type is called low threshold-cold sensitive plus dry sensitive (LT-CS + DS), and the other is termed high threshold-cold sensitive plus dry sensitive (HT-CS + DS). The present study examined critical stimuli influencing the activity of these neurons to elucidate environmental factors that may trigger this ocular reflex. Methods: Single corneal neurons were extracellularly recorded from the trigeminal ganglia in response to ocular stimuli that mimic environmental conditions one encounters in daily life...
August 1, 2018: Investigative Ophthalmology & Visual Science
Ken Johkura, Yosuke Kudo, Eriko Sugawara, Kosuke Watanabe, Tomoki Nakamizo, Masahiro Yamamoto, Kazumitsu Amari, Koji Takahashi, Osamu Tanaka
BACKGROUND AND PURPOSE: Lateral medullary infarction (LMI) sometimes causes long-lasting dizziness. Although the precise mechanism of chronic post-LMI dizziness is unknown, a cerebellar control disorder of the vestibulo-ocular reflex (VOR) has been reported in such patients. We conducted a proof-of-principle cohort study to assess the potential efficacy of cerebellar repetitive transcranial magnetic stimulation (rTMS) as treatment for chronic post-LMI dizziness. METHODS: We first applied cerebellar rTMS in healthy volunteers (n = 11) and showed that cerebellar intermittent theta burst stimulation (iTBS) affected vestibulocerebellar neural activity...
September 15, 2018: Journal of the Neurological Sciences
Stephanie A Martinez, Nhuquynh D Nguyen, Eric Bailey, Denis Doyle-Green, Henry A Hauser, John P Handrakis, Steven Knezevic, Casey Marett, Jennifer Weinman, Angelica F Romero, Tiffany M Santiago, Ajax H Yang, Lok Yung, Pierre K Asselin, Joseph P Weir, Stephen D Kornfeld, William A Bauman, Ann M Spungen, Noam Y Harel
BACKGROUND AND PURPOSE: Spared fibers after spinal cord injury (SCI) tend to consist predominantly of subcortical circuits that are not under volitional (cortical) control. We aim to improve function after SCI by using targeted physical exercises designed to simultaneously stimulate cortical and spared subcortical neural circuits. METHODS: Participants with chronic motor-incomplete SCI enrolled in a single-center, prospective interventional crossover study. Participants underwent 48 sessions each of weight-supported robotic-assisted treadmill training and a novel combination of balance and fine hand exercises, in randomized order, with a 6-week washout period...
2018: PloS One
Yoshinori Kawai
To integrate and broadcast neural information, local microcircuits and global macrocircuits interact within certain specific nuclei of the central nervous system. The structural and functional architecture of this interaction was determined for the caudal nucleus of the tractus solitarius (NTS) at the level of the area postrema (AP), a relay station of peripheral viscerosensory information that is processed and conveyed to brain regions concerned with autonomic-affective and other interoceptive reflexive functions...
2018: Frontiers in Neuroanatomy
Yunbing Ma, Qian Wang, Debria Joe, Manqi Wang, Matthew D Whim
Hypoglycemia activates the counterregulatory response (CRR), a neural-endocrine reflex that restores euglycemia. Although effective if occasionally activated, repeated induction of the CRR leads to a decline in responsiveness and prolonged exposure to hypoglycemia. The mechanism underlying this impairment is not known. We found that the reduction in epinephrine release that characterizes a suppressed CRR involves a long-lasting form of sympatho-adrenal synaptic plasticity. Using optogenetically evoked catecholamine release, we show that recurrent hypoglycemia reduced the secretory capacity of mouse adrenal chromaffin cells...
August 6, 2018: Journal of Clinical Investigation
Nobuo Yanagisawa
Involuntary movements and parkinsonism have been interesting and important topics in neurology since the last century. The development of anatomical and physiological studies of the neural circuitry of motor systems has encouraged the study of movement disorders by means of pathophysiology and brain imaging.Multichannel electromyography from affected muscles has generated objective and analytical data on chorea, ballism, athetosis, and dystonia. Studies using floor reaction forces revealed the pathophysiology of freezing of gait in parkinsonism...
2018: Proceedings of the Japan Academy. Series B, Physical and Biological Sciences
T M Scharfenberger, M Schrafl-Altermatt, V Dietz
OBJECTIVES: To evaluate whether the task-specific neural coupling mechanism during the performance of cooperative hand movements is preserved in tetraplegic subjects. METHODS: Recordings of ipsilateral and contralateral electromyographic reflex responses in activated forearm muscles and bilateral somatosensory potentials (SSEP) to unilateral ulnar nerve stimulations during rest, cooperative and non-cooperative hand movements. RESULTS: Contralateral reflex responses were present in almost all patients during cooperative hand movements but small in amplitude when hand function was severely impaired...
August 1, 2018: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
Kishan J Padalia, Arjun J Padalia, Milind G Parikh
There have been over 80 documented cases of swallow syncope-a rare form of reflex or neurally mediated syncope-with most cases associated with an underlying esophageal disorder. Here, we describe the first reported case of swallow syncope or presyncope caused by an infectious esophagitis. Our 65-year-old patient initially developed dysphagia, odynophagia, and presyncope with swallowing. This lead to nutrition and medication avoidance behavior, which was followed by the development of diabetic ketoacidosis. The diagnosis of swallow presyncope was confirmed with a provocative swallow study demonstrating 8 s sinus arrest, and an underlying cause of Candida esophagitis was found by upper endoscopy...
July 30, 2018: Dysphagia
Lauren B Burhans, Bernard G Schreurs
Conditioning-specific reflex modification (CRM) of the rabbit eyeblink response is an associative phenomenon characterized by increases in the frequency, size, and peak latency of the reflexive unconditioned eyeblink response (UR) when the periorbital shock unconditioned stimulus (US) is presented alone following conditioning, particularly to lower intensity USs that produced minimal responding prior to conditioning. Previous work has shown that CRM shares many commonalities with the conditioned eyeblink response (CR) including a similar response topography, suggesting the two may share similar neural substrates...
July 24, 2018: Neurobiology of Learning and Memory
Luis E Boero, Valeria C Castagna, Mariano N Di Guilmi, Juan D Goutman, Ana Belén Elgoyhen, María Eugenia Gómez-Casati
Cochlear synaptopathy produced by exposure to noise levels which only cause transient auditory threshold elevations is a condition that affects many people and is believed to contribute to poor speech discrimination in noisy environments. These functional deficits in hearing, without changes in sensitivity, have been called hidden hearing loss (HHL). It has been proposed that activity of the medial olivocochlear (MOC) system can ameliorate acoustic trauma effects. Here we explore the role of the MOC system in HHL by comparing the performance of two different mouse models: an α9 nicotinic receptor subunit knock-out ( Chrna9 KO) which lacks cholinergic transmission between efferent neurons and hair cells, and a gain of function knock-in ( Chrna9L9'T KI) carrying an α9 point mutation that leads to enhanced cholinergic activity...
July 20, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Ya-Chen Huang, Zung Fan Yuan, Chang-Huan Yang, Yan-Jhih Shen, Jyun-Yi Lin, Ching Jung Lai
Obstructive sleep apnea is mainly characterized by intermittent hypoxia (IH), which is associated with hyperreactive airway diseases and lung inflammation. Sensitization of lung vagal C fibers (LVCFs) induced by inflammatory mediators may play a central role in the pathogenesis of airway hypersensitivity. In females, estrogen interferes with inflammatory signaling pathways that may modulate airway hyperreactivity. In this study, we investigated the effects of IH on the reflex and afferent responses of LVCFs to chemical stimulants and lung inflammation in adult female rats, as well as the role of estrogen in these responses...
2018: Frontiers in Physiology
Luigi Taranto-Montemurro, Scott A Sands, Kevin P Grace, Ali Azarbarzin, Ludovico Messineo, Rebecca Salant, David P White, D Andrew Wellman
RATIONALE: Several studies have shown that obstructive sleep apnea (OSA) improves during slow wave sleep (SWS) for reasons that remain unclear. Recent studies have identified forms of neural memory such as short-term potentiation or after-discharge that can occur in response to upper airway obstruction. Neural memory may play a role in the development of stable breathing during SWS by increasing upper airway muscles activity in this sleep stage. We hypothesize that the after-discharge of the genioglossus muscle following upper airway obstruction is enhanced during SWS compared to non-REM stage 2 (N2)...
July 18, 2018: Journal of Physiology
Gino Seravalle, Fosca Quarti-Trevano, Raffaella Dell'Oro, Edoardo Gronda, Domenico Spaziani, Rita Facchetti, Cesare Cuspidi, Giuseppe Mancia, Guido Grassi
AIM: Although abnormalities in reflex sympathetic neural function represent a hallmark of heart failure, no information is available on the neuroadrenergic and baroreflex function in heart failure with preserved, midrange and reduced ejection fraction. The current study was designed to assess muscle sympathetic nerve traffic (MSNA) and baroreflex function in the clinical classes of heart failure defined by the new European Society of Cardiology/American College of Cardiology Foundation/American Heart Association guidelines...
July 16, 2018: Journal of Hypertension
Christine N Metz, Valentin A Pavlov
Improved understanding of neuroimmune communication and the neural regulation of immunity and inflammation has recently led to proposing the concept of the neuroimmune communicatome. This advance is based on experimental evidence for an organized and brain integrated reflex-like relationship and dialogue between the nervous and the immune systems. A key circuitry in this communicatome is provided by efferent vagus nerve fibers and cholinergic signaling. Inflammation and metabolic alterations co-exist in many disorders affecting the liver and the gastrointestinal (GI) tract, including obesity, metabolic syndrome, fatty liver disease, liver injury and liver failure, as well as inflammatory bowel disease...
July 12, 2018: American Journal of Physiology. Gastrointestinal and Liver Physiology
K Leggett, V Mendis, Wham Mulders
Animal models of tinnitus rely on interpretation of behavioural or reflexive tests to determine the presence of this phantom perception. A commonly used test is the gap prepulse inhibition of acoustic startle (GPIAS), which is often combined with prepulse inhibition (PPI) to ensure that reduced GPIAS suppression is not due to hearing loss caused by the acoustic trauma commonly used to trigger tinnitus development. In our laboratory GPIAS and PPI are routinely used on two colonies of outbred tri-colour guinea pigs...
June 1, 2018: International Tinnitus Journal
Romain Tisserand, Christopher J Dakin, Machiel Hf Van der Loos, Elizabeth A Croft, Timothy J Inglis, Jean-Sébastien Blouin
The neural control of transition between posture and movement encompasses the regulation of reflex-stabilizing mechanisms to enable motion. Optimal feedback theory suggests that such transitions require the disengagement of one motor control policy before the implementation of another. To test this possibility, we investigated the continuity of the vestibular control of balance during transitions between quiet standing and locomotion and between two standing postures. Healthy subjects initiated and terminated locomotion or shifted the distribution of their weight between their feet, while exposed to electrical vestibular stimuli (EVS)...
July 10, 2018: ELife
Khadijeh Haji Naghi Tehrani
BACKGROUND: Neuropathy is one of the most common complications of diabetes mellitus. Neuropathy can cause the sensory deficit, neurological disorder, limb ulcers, osteomyelitis, and amputation. Therefore, neurological examinations, determining the nerve conduction velocity and performing sensory and motor tests are important for timely diagnosis and treatment. AIM: The present study aimed to investigate the nerve conduction velocity in diabetic patients and its relationship with tendon reflexes...
June 20, 2018: Open Access Macedonian Journal of Medical Sciences
M M Iversen, H Zhu, W Zhou, C C Della Santina, J P Carey, R D Rabbitt
Individuals suffering from Tullio phenomena experience dizziness, vertigo, and reflexive eye movements (nystagmus) when exposed to seemingly benign acoustic stimuli. The most common cause is a defect in the bone enclosing the vestibular semicircular canals of the inner ear. Surgical repair often corrects the problem, but the precise mechanisms underlying Tullio phenomenon are not known. In the present work we quantified the phenomenon in an animal model of the condition by recording fluid motion in the semicircular canals and neural activity evoked by auditory-frequency stimulation...
July 6, 2018: Scientific Reports
Lisa Quadt, Hugo D Critchley, Sarah N Garfinkel
Interoception is the sensing of internal bodily sensations. Interoception is an umbrella term that encompasses (1) the afferent (body-to-brain) signaling through distinct neural and humoral (including immune and endocrine) channels; (2) the neural encoding, representation, and integration of this information concerning internal bodily state; (3) the influence of such information on other perceptions, cognitions, and behaviors; (4) and the psychological expression of these representations as consciously accessible physical sensations and feelings...
July 5, 2018: Annals of the New York Academy of Sciences
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