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1.
Otol Neurotol ; 44(2): 191, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36624602
2.
Mol Med ; 29(1): 4, 2023 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-36650454

RESUMO

BACKGROUND: Inflammation, the physiological response to infection and injury, is coordinated by the immune and nervous systems. Interleukin-1ß (IL-1ß) and other cytokines produced during inflammatory responses activate sensory neurons (nociceptors) to mediate the onset of pain, sickness behavior, and metabolic responses. Although nociceptors expressing Transient Receptor Potential Ankyrin-1 (TRPA1) can initiate inflammation, comparatively little is known about the role of TRPA1 nociceptors in the physiological responses to specific cytokines. METHODS: To monitor body temperature in conscious and unrestrained mice, telemetry probes were implanted into peritoneal cavity of mice. Using transgenic and tissue specific knockouts and chemogenetic techniques, we recorded temperature responses to the potent pro-inflammatory cytokine IL-1ß. Using calcium imaging, whole cell patch clamping and whole nerve recordings, we investigated the role of TRPA1 during IL-1ß-mediated neuronal activation. Mouse models of acute endotoxemia and sepsis were used to elucidate how specific activation, with optogenetics and chemogenetics, or ablation of TRPA1 neurons can affect the outcomes of inflammatory insults. All statistical tests were performed with GraphPad Prism 9 software and for all analyses, P ≤ 0.05 was considered statistically significant. RESULTS: Here, we describe a previously unrecognized mechanism by which IL-1ß activates afferent vagus nerve fibers to trigger hypothermia, a response which is abolished by selective silencing of neuronal TRPA1. Afferent vagus nerve TRPA1 signaling also inhibits endotoxin-stimulated cytokine storm and significantly reduces the lethality of bacterial sepsis. CONCLUSION: Thus, IL-1ß activates TRPA1 vagus nerve signaling in the afferent arm of a reflex anti-inflammatory response which inhibits cytokine release, induces hypothermia, and reduces the mortality of infection. This discovery establishes that TRPA1, an ion channel known previously as a pro-inflammatory detector of cold, pain, itch, and a wide variety of noxious molecules, also plays a specific anti-inflammatory role via activating reflex anti-inflammatory activity.


Assuntos
Hipotermia Induzida , Hipotermia , Interleucina-1beta , Canais de Potencial de Receptor Transitório , Animais , Camundongos , Anquirinas/metabolismo , Citocinas/metabolismo , Hipotermia/metabolismo , Inflamação/metabolismo , Interleucina-1beta/metabolismo , Fibras Nervosas/metabolismo , Dor/metabolismo , Reflexo , Células Receptoras Sensoriais/metabolismo , Canais de Potencial de Receptor Transitório/genética , Canais de Potencial de Receptor Transitório/metabolismo , Canal de Cátion TRPA1/genética , Canal de Cátion TRPA1/metabolismo , Nervo Vago/metabolismo
3.
JAMA Ophthalmol ; 141(1): e225106, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36656294

RESUMO

This case report describes a diagnosis of Oguchi disease in a girl aged 12 years with a history of high myopia and golden-metallic tapetal sheen noted on bilateral retinal examination.


Assuntos
Reflexo , Retina , Feminino , Humanos , Criança
4.
BMJ Open Respir Res ; 10(1)2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36697033

RESUMO

INTRODUCTION: Patients with chronic obstructive pulmonary disease (COPD) are often hospitalised due to severe acute exacerbation (AE) or community-acquired pneumonia (CAP). Previous studies revealed the association of cough reflex sensitivity with the pathophysiology of COPD and pneumonia. We hypothesised that cough reflex sensitivity may be associated with severe AE or CAP requiring hospitalisation in patients with COPD. METHODS: We prospectively recruited 68 patients with COPD between June 2018 and January 2020. Patient characteristics, lung and cardiac functions, and biomarkers, including capsaicin cough reflex sensitivity and blood eosinophil count, were evaluated at enrolment. All participants were monitored for AE or CAP requiring hospitalisation for 12 months. We determined the risk factors and ORs for hospitalisation in patients with COPD using a multivariate analysis. RESULTS: Eight patients experienced AE (n=3) or CAP (n=5) and required hospitalisation during follow-up. Patients in the hospitalisation+ group had higher modified Medical Research Council scores and blood eosinophil counts (≥300 µL) than those in the hospitalisation- group. Capsaicin cough reflex sensitivity tended to decrease in the hospitalisation+ group compared with that in the hospitalisation- group. Multivariate analysis revealed that a decreased capsaicin cough reflex and high eosinophil count (≥300 µL) were predictive risk factors for future hospitalisation due to AE-COPD or CAP. CONCLUSION: In addition to eosinophils, decreased capsaicin cough reflex sensitivity was associated with hospitalisation due to AE-COPD or CAP. Capsaicin cough reflex sensitivity in patients with COPD may play a role in the prevention of severe AE or pneumonia requiring hospitalisation. TRIAL REGISTRATION NUMBER: UMIN000032497.


Assuntos
Pneumonia , Doença Pulmonar Obstrutiva Crônica , Humanos , Capsaicina/efeitos adversos , Tosse/etiologia , Hospitalização , Pneumonia/complicações , Reflexo/fisiologia
5.
Physiol Rep ; 11(1): e15567, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36636780

RESUMO

The speed of pellet propulsion through the isolated guinea pig distal colon in vitro significantly exceeds in vivo measurements, suggesting a role for inhibitory mechanisms from sources outside the gut. The aim of this study was to investigate the effects of sympathetic nerve stimulation on three different neurogenic motor behaviors of the distal colon: transient neural events (TNEs), colonic motor complexes (CMCs), and pellet propulsion. To do this, segments of guinea pig distal colon with intact connections to the inferior mesenteric ganglion (IMG) were set up in organ baths allowing for simultaneous extracellular suction electrode recordings from smooth muscle, video recordings for diameter mapping, and intraluminal manometry. Electrical stimulation (1-20 Hz) of colonic nerves surrounding the inferior mesenteric artery caused a statistically significant, frequency-dependent inhibition of TNEs, as well as single pellet propulsion, from frequencies of 5 Hz and greater. Significant inhibition of CMCs required stimulation frequencies of 10 Hz and greater. Phentolamine (3.6 µM) abolished effects of colonic nerve stimulation, consistent with a sympathetic noradrenergic mechanism. Sympathetic inhibition was constrained to regions with intact extrinsic nerve pathways, allowing normal motor behaviors to continue without modulation in adjacent extrinsically denervated regions of the same colonic segments. The results demonstrate differential sensitivities to sympathetic input among distinct neurogenic motor behaviors of the colon. Together with findings indicating CMCs activate colo-colonic sympathetic reflexes through the IMG, these results raise the possibility that CMCs may paradoxically facilitate suppression of pellet movement in vivo, through peripheral sympathetic reflex circuits.


Assuntos
Gânglios Simpáticos , Sistema Nervoso Simpático , Cobaias , Animais , Gânglios Simpáticos/fisiologia , Reflexo/fisiologia , Colo/inervação , Atividade Motora , Estimulação Elétrica
6.
BJOG ; 130(2): 184-191, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-35993438

RESUMO

OBJECTIVE: Cytology performed directly on hrHPV-positive self-samples (reflex cytology) is feasible and for women with abnormal cytology, an additional cytology test at the general practitioner could be omitted. The aim of this study is to assess the added value of digital imaging (ThinPrep® Imaging System) on the clinical utility of reflex cytology by reducing screening error. DESIGN: A secondary analysis of a prospective cohort study. SETTING: One of five Dutch screening laboratories. POPULATION: Women tested hrHPV-positive on self-samples between December 2018 and August 2019. METHODS: Self-samples were used for reflex cytology with and without digital imaging. The follow-up data (cytological and histological results within 1 year of follow-up) were obtained through the Dutch Pathology Registry (PALGA). MAIN OUTCOME MEASURES: Test performance of the reflex cytology was determined by comparing it with physician-collected follow-up results. RESULTS: The sensitivity for detecting abnormal cells by reflex cytology on self-samples increased significantly from 26.3% (42/160; 95% confidence interval [CI] 19.6-33.8) without digital imaging to 35.4% (56/158; 95% CI 28-43.4) with digital imaging (P < 0.05) without compromising specificity. Importantly, 41.7% of women with ≥CIN2 (35/84) and 45.6% with ≥CIN3 (26/57) were detected by reflex cytology with digital imaging on hrHPV-positive self-samples. CONCLUSION: Digital imaging is of added value to reflex cytology on hrHPV-positive self-samples with a 9% increase in sensitivity. If reflex cytology on self-samples analysed with digital imaging had been implemented in the screening programme, 35.4% of the hrHPV-positive women with abnormal cytology on additional physician-collected samples could have been referred directly for colposcopy.


Assuntos
Alphapapillomavirus , Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Gravidez , Neoplasias do Colo do Útero/diagnóstico por imagem , Detecção Precoce de Câncer/métodos , Papillomaviridae , Triagem/métodos , Infecções por Papillomavirus/complicações , Estudos Prospectivos , Colposcopia , Reflexo , Displasia do Colo do Útero/diagnóstico por imagem
7.
J Hypertens ; 41(2): 233-245, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36583351

RESUMO

BACKGROUND: Hypothalamic paraventricular nucleus (PVN) is an important central site for the control of the adipose afferent reflex (AAR) that increases sympathetic outflow and blood pressure in obesity-related hypertension (OH). METHOD: In this study, we investigated the effects of nitric oxide (NO) and cardiovascular bioactive polypeptide adrenomedullin (ADM) in the PVN on AAR and sympathetic nerve activity (SNA) in OH rats induced by a high-fat diet. RESULTS: The results showed that ADM, total neuronal NO synthase (nNOS) and phosphorylated-nNOS protein expression levels in the PVN of the OH rats were down-regulated compared to the control rats. The enhanced AAR in OH rats was attenuated by PVN acute application of NO donor sodium nitroprusside (SNP), but was strengthened by the nNOS inhibitor nNOS-I, guanylyl cyclase inhibitor (1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one, ODQ) and gamma-aminobutyric acid A type receptor (GABAA) antagonist Bicuculline. Moreover, PVN ADM microinjection not only decreased basal SNA but also attenuated the enhanced AAR in OH rats, which were effectively inhibited by ADM receptor antagonist ADM22-52, nNOS-I, ODQ or Bicuculline pretreatment. Bilateral PVN acute microinjection of ADM also caused greater increases in NO and cyclic guanosine monophosphate (cGMP) levels, and nNOS phosphorylation. Adeno-associated virus vectors encoding ADM (AAV-ADM) transfection in the PVN of OH rats not only decreased the elevated AAR, basal SNA and blood pressure (BP), but also increased the expression and activation of nNOS. Furthermore, AAV-ADM transfection improved vascular remodeling in OH rats. CONCLUSION: Taken together, our data highlight the roles of ADM in improving sympathetic overactivation, enhanced AAR and hypertension, and its related mechanisms associated with receptors mediated NO-cGMP-GABAA pathway in OH condition.


Assuntos
Hipertensão , Núcleo Hipotalâmico Paraventricular , Ratos , Animais , Núcleo Hipotalâmico Paraventricular/metabolismo , Adrenomedulina , Óxido Nítrico/metabolismo , Ratos Sprague-Dawley , Receptores de GABA/metabolismo , Bicuculina/metabolismo , Bicuculina/farmacologia , Obesidade/complicações , Reflexo/fisiologia , Pressão Sanguínea/fisiologia , Óxido Nítrico Sintase Tipo I/metabolismo , Óxido Nítrico Sintase Tipo I/farmacologia , Ácido gama-Aminobutírico/metabolismo , Ácido gama-Aminobutírico/farmacologia , Sistema Nervoso Simpático
8.
Hear Res ; 427: 108663, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36502543

RESUMO

Noise exposure may damage the synapses that connect inner hair cells with auditory nerve fibers, before outer hair cells are lost. In humans, this cochlear synaptopathy (CS) is thought to decrease the fidelity of peripheral auditory temporal coding. In the current study, the primary hypothesis was that higher middle ear muscle reflex (MEMR) thresholds, as a proxy measure of CS, would be associated with smaller values of the binaural intelligibility level difference (BILD). The BILD, which is a measure of binaural temporal coding, is defined here as the difference in thresholds between the diotic and the antiphasic versions of the digits in noise (DIN) test. This DIN BILD may control for factors unrelated to binaural temporal coding such as linguistic, central auditory, and cognitive factors. Fifty-six audiometrically normal adults (34 females) aged 18 - 30 were tested. The test battery included standard pure tone audiometry, tympanometry, MEMR using a 2 kHz elicitor and 226 Hz and 1 kHz probes, the Noise Exposure Structured Interview, forward digit span test, extended high frequency (EHF) audiometry, and diotic and antiphasic DIN tests. The study protocol was pre-registered prior to data collection. MEMR thresholds did not predict the DIN BILD. Secondary analyses showed no association between MEMR thresholds and the individual diotic and antiphasic DIN thresholds. Greater lifetime noise exposure was non-significantly associated with higher MEMR thresholds, larger DIN BILD values, and lower (better) antiphasic DIN thresholds, but not with diotic DIN thresholds, nor with EHF thresholds. EHF thresholds were associated with neither MEMR thresholds nor any of the DIN outcomes, including the DIN BILD. Results provide no evidence that young, audiometrically normal people incur CS with impacts on binaural temporal processing.


Assuntos
Orelha Média , Reflexo , Feminino , Humanos , Adulto Jovem , Estimulação Acústica , Limiar Auditivo , Músculos , Audiometria de Tons Puros
9.
Neurosci Lett ; 794: 136998, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-36496035

RESUMO

Morphological studies have demonstrated that the lateral reticular nucleus (LRt) receives fibers projected from sites that are related to control of the swallowing reflex. Although the LRt may therefore be related to control of the swallowing reflex, the functional role of the LRt in the swallowing reflex remains unknown. The present study examined whether the swallowing reflex is modulated by stimulation of the LRt. These experiments were performed on rats anesthetized by urethane. The swallowing reflex was evoked by repetitive electrical stimulation of the superior laryngeal nerve (SLN) and was identified by electromyographic activities from the mylohyoid muscle. Electrical stimulation was applied to the LRt or glutamate was injected into the LRt. The number of swallows was reduced, and the latency of the onset of the first swallow was increased during electrical stimulation near the middle of the rostrocaudal direction of the LRt. The number of swallows was reduced, and the latency of onset of the first swallow increased after microinjection of glutamate near the rostrocaudal center of the LRt. The present study suggests that the LRt is involved in control of the swallowing reflex.


Assuntos
Deglutição , Formação Reticular , Ratos , Animais , Deglutição/fisiologia , Núcleos da Rafe , Ácido Glutâmico , Estimulação Elétrica , Reflexo/fisiologia
10.
Am J Physiol Regul Integr Comp Physiol ; 324(2): R183-R195, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36534589

RESUMO

We investigated the role played by bradykinin 2 (B2) receptors in the exaggerated exercise pressor reflex in rats with a femoral artery ligated for 72 h to induce simulated peripheral artery disease (PAD). We hypothesized that in decerebrate, unanesthetized rats with a ligated femoral artery, hindlimb arterial injection of HOE-140 (100 ng, B2 receptor antagonist) would reduce the pressor response to 30 s of electrically induced 1 Hz hindlimb skeletal muscle contraction, and 30 s of 1 Hz hindlimb skeletal muscle stretch (a model of mechanoreflex activation isolated from contraction-induced metabolite production). We hypothesized no effect of HOE-140 in sham-operated "freely perfused" rats. In both freely perfused (n = 4) and "ligated" (n = 4) rats, we first confirmed efficacious B2 receptor blockade by demonstrating that HOE-140 injection significantly reduced (P < 0.05) the peak increase in mean arterial pressure (peak ΔMAP) in response to hindlimb arterial injection of bradykinin. In subsequent experiments, we found that HOE-140 reduced the peak ΔMAP response to muscle contraction in ligated (n = 14; control: 23 ± 2; HOE-140: 17 ± 2 mmHg; P = 0.03) but not freely perfused rats (n = 7; control: 17 ± 3; HOE-140: 18 ± 4 mmHg; P = 0.65). Furthermore, HOE-140 had no effect on the peak ΔMAP response to stretch in ligated rats (n = 14; control: 37 ± 4; HOE-140: 32 ± 5 mmHg; P = 0.13) but reduced the integrated area under the blood pressure signal over the final ∼20 s of the maneuver. The data suggest that B2 receptors contribute to the exaggerated exercise pressor reflex in rats with simulated PAD, and that contribution includes a modest role in the chronic sensitization of the mechanically activated channels/afferents that underlie mechanoreflex activation.


Assuntos
Doença Arterial Periférica , Reflexo , Ratos , Animais , Reflexo/fisiologia , Músculo Esquelético/metabolismo , Receptores da Bradicinina/metabolismo , Ratos Sprague-Dawley , Bradicinina/farmacologia , Contração Muscular/fisiologia , Pressão Sanguínea/fisiologia , Artéria Femoral , Membro Posterior/metabolismo
11.
BMJ ; 379: o2992, 2022 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-36535674

Assuntos
Reflexo , Humanos
12.
PLoS One ; 17(12): e0279477, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36548285

RESUMO

During submaximal isometric contraction, there are two different load types: maintenance of a constant limb angle while supporting an inertial load (position task) and maintenance of a constant force by pushing against a rigid restraint (force task). Previous studies demonstrated that performing the position task requires more proprioceptive information. The purpose of this study was to investigate whether there would be a difference in cutaneous information processing between the position and force tasks by assessing the gating effect, which is reduction of amplitude of somatosensory evoked potentials (SEPs), and cutaneomuscular reflex (CMR). Eighteen healthy adults participated in this study. They contracted their right first dorsal interosseous muscle by abducting their index finger to produce a constant force against a rigid restraint that was 20% maximum voluntary contraction (force task), or to maintain a target position corresponding to 10° abduction of the metacarpophalangeal joint while supporting a load equivalent to 20% maximum voluntary contraction (position task). During each task, electrical stimulation was applied to the digital nerves of the right index finger, and SEPs and CMR were recorded from C3' of the International 10-20 system and the right first dorsal interosseous muscle, respectively. Reduction of the amplitude of N33 component of SEPs was significantly larger during the force than position task. In addition, the E2 amplitude of CMR was significantly greater for the force than position task. These findings suggest that cutaneous information processing differs with load type during static muscle contraction.


Assuntos
Dedos , Músculo Esquelético , Adulto , Humanos , Músculo Esquelético/fisiologia , Dedos/fisiologia , Contração Muscular/fisiologia , Reflexo/fisiologia , Pele/inervação , Contração Isométrica/fisiologia , Eletromiografia
13.
Arq Neuropsiquiatr ; 80(10): 1075-1076, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36535292

RESUMO

In this paper, we present a historical review of the whistle-smile reflex, a semiological sign missed in the literature and clinical practice.


Apresentamos neste artigo uma revisão histórica do reflexo do assovio-sorriso, um sinal semiológico esquecido na literatura e na prática clínica.


Assuntos
Reflexo , Humanos
14.
J Neural Eng ; 19(6)2022 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-36583387

RESUMO

Objective:recently, pupil oscillations synchronized with steady visual stimuli were used as input for an interface. The proposed system, inspired by a brain-computer interface based on steady-state visual evoked potentials, does not require contact with the participant. However, the pupil oscillation mechanism limits the stimulus frequency to 2.5 Hz or less, making it hard to enhance the information transfer rate (ITR).Approach:here, we compared multiple conditions for stimulation to increase the ITR of the pupil vibration-based interface, which were called monocular-single, monocular-superposed, and binocular-independent conditions. The binocular-independent condition stimulates each eye at different frequencies respectively and mixes them by using the visual stereoscopic perception of users. The monocular-superposed condition stimulates both eyes by a mixed signal of two different frequencies. We selected the shape of the stimulation signal, evaluated the amount of spectral leakage in the monocular-superposed and binocular-independent conditions, and compared the power spectrum density at the stimulation frequency. Moreover, 5, 10, and 15 patterns of stimuli were classified in each condition.Main results:a square wave, which causes an efficient pupil response, was used as the stimulus. Spectral leakage at the beat frequency was higher in the monocular-superposed condition than in the binocular-independent one. The power spectral density of stimulus frequencies was greatest in the monocular-single condition. Finally, we could classify the 15-stimulus pattern, with ITRs of 14.4 (binocular-independent, using five frequencies), 14.5 (monocular-superimposed, using five frequencies), and 23.7 bits min-1(monocular-single, using 15 frequencies). There were no significant differences for the binocular-independent and monocular-superposed conditions.Significance:this paper shows a way to increase the number of stimuli that can be simultaneously displayed without decreasing ITR, even when only a small number of frequencies are available. This could lead to the provision of an interface based on pupil oscillation to a wider range of users.


Assuntos
Pupila , Visão Binocular , Humanos , Pupila/fisiologia , Visão Binocular/fisiologia , Potenciais Evocados Visuais , Visão Monocular/fisiologia , Reflexo , Estimulação Luminosa
15.
Proc Natl Acad Sci U S A ; 119(48): e2208353119, 2022 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-36409890

RESUMO

Descending motor drive and somatosensory feedback play important roles in modulating muscle activity. Numerous studies have characterized the organization of neuronal connectivity in which descending motor pathways and somatosensory afferents converge on spinal motor neurons as a final common pathway. However, how inputs from these two pathways are integrated into spinal motor neurons to generate muscle activity during actual motor behavior is unknown. Here, we simultaneously recorded activity in the motor cortices (MCx), somatosensory afferent neurons, and forelimb muscles in monkeys performing reaching and grasping movements. We constructed a linear model to explain the instantaneous muscle activity using the activity of MCx (descending input) and peripheral afferents (afferent input). Decomposition of the reconstructed muscle activity into each subcomponent indicated that muscle activity before movement onset could first be explained by descending input from mainly the primary motor cortex and muscle activity after movement onset by both descending and afferent inputs. Descending input had a facilitative effect on all muscles, whereas afferent input had a facilitative or suppressive effect on each muscle. Such antagonistic effects of afferent input can be explained by reciprocal effects of the spinal reflex. These results suggest that descending input contributes to the initiation of limb movement, and this initial movement subsequently affects muscle activity via the spinal reflex in conjunction with the continuous descending input. Thus, spinal motor neurons are subjected to temporally organized modulation by direct activation through the descending pathway and the lagged action of the spinal reflex during voluntary limb movement.


Assuntos
Córtex Motor , Movimento , Animais , Movimento/fisiologia , Neurônios Motores/fisiologia , Córtex Motor/fisiologia , Reflexo/fisiologia , Extremidade Superior
16.
J Acoust Soc Am ; 152(4): 2398, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36319231

RESUMO

This study investigated whether visual attention affects the reliability (i.e., repeatability) of transiently evoked otoacoustic emission (TEOAE) magnitudes or of medial olivocochlear reflex (MOCR) estimates. TEOAEs were measured during three visual attentional conditions: control (subject were seated with eyes closed); passive (subjects looked at a pattern of squares on a computer screen); and active (subjects silently counted an occasionally inverted pattern). To estimate reliability, the whole recording session was repeated the next day. The results showed that visual attention does not significantly affect TEOAE or MOCR magnitudes-or their reliability. It is therefore possible to employ visual stimuli (e.g., watching a silent movie) during TEOAE experiments, a procedure sometimes used during testing to prevent subjects from falling asleep or to keep children still and quiet.


Assuntos
Emissões Otoacústicas Espontâneas , Reflexo , Criança , Humanos , Reprodutibilidade dos Testes , Estimulação Acústica , Emissões Otoacústicas Espontâneas/fisiologia , Reflexo/fisiologia , Cóclea/fisiologia
17.
J Acoust Soc Am ; 152(4): 2150, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36319248

RESUMO

The medial olivocochlear reflex (MOCR), usually assessed by the inhibition of transiently evoked otoacoustic emissions (TEOAEs) with contralateral noise, is a very small effect. In understanding the origin of the MOCR, it is crucial to obtain data of the highest accuracy, i.e., with a high signal-to-noise ratio (SNR), which in turn largely depends on the number of signal averages. This study investigates how the reliability of MOCR measures is affected by the number of averages. At the same time, the effect of the presence of synchronized spontaneous otoacoustic emissions (SSOAEs) is taken into account, as it is known that this factor significantly affects TEOAE amplitudes and SNRs. Each recording session consisted of two series of four measurements, allowing comparison of MOCR magnitude based on 250, 500, 750, and 1000 averages. Reliability was based on comparing the two series. The results show that, for a good quality MOCR measure (i.e., intraclass correlation above 0.9), the required number of averages is at least double that obtainable from a standard TEOAE test (i.e., 500 compared to 250). Ears without SSOAEs needed a higher number of averages to reach a correlation of 0.9 than ears with SSOAEs.


Assuntos
Emissões Otoacústicas Espontâneas , Reflexo , Reprodutibilidade dos Testes , Razão Sinal-Ruído , Estimulação Acústica , Cóclea
18.
J Neural Eng ; 19(6)2022 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-36343359

RESUMO

Objective.Epidural spinal cord stimulation (SCS) is a potential intervention to improve limb and autonomic functions, with lumbar stimulation improving locomotion and thoracic stimulation regulating blood pressure. Here, we asked whether sacral SCS could be used to target the lower urinary tract (LUT) and used a high-density epidural electrode array to test whether individual electrodes could selectively recruit LUT nerves.Approach. We placed a high-density epidural SCS array on the dorsal surface of the sacral spinal cord and cauda equina of anesthetized cats and recorded the stimulation-evoked activity from nerve cuffs on the pelvic, pudendal and sciatic nerves.Main results. Here we show that sacral SCS evokes responses in nerves innervating the bladder and urethra and that these nerves can be activated selectively. Sacral SCS always recruited the pelvic and pudendal nerves and selectively recruited both of these nerves in all but one animal. Individual branches of the pudendal nerve were always recruited as well. Electrodes that selectively recruited specific peripheral nerves were spatially clustered on the arrays, suggesting anatomically organized sensory pathways.Significance.This selective recruitment demonstrates a mechanism to directly modulate bladder and urethral function through known reflex pathways, which could be used to restore bladder and urethral function after injury or disease.


Assuntos
Nervo Pudendo , Traumatismos da Medula Espinal , Estimulação da Medula Espinal , Animais , Bexiga Urinária/inervação , Uretra/inervação , Uretra/fisiologia , Reflexo/fisiologia , Medula Espinal , Estimulação Elétrica/métodos
19.
Sci Rep ; 12(1): 19480, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376410

RESUMO

The binocular alignment of the eyes involves both voluntary and reflexive mechanisms, but little is known about the visual input and neurological pathway of the reflex component. Our studies examined the role of spatiotemporal frequency and contrast in the control of reflex eye alignment, and compared the contrast sensitivity of the alignment reflex with psychophysical contrast sensitivity. We measured the contrast sensitivity of vertical disparity-driven vergence eye movements in response to bandwidth filtered static or 6 Hz counterphase flickering noise and measured psychophysical detection sensitivity for the same stimuli. Contrast thresholds for producing a detectable vertical alignment change (measured with nonius lines) were determined using a staircase method for 7 spatial frequencies [0.25-16 cycles per degree] and 3 vertical disparities [5, 10, and 30 arcmin] in 7 adults with normal or corrected to normal vision. The main findings of this study are, (1) the vertical alignment reflex had overall relatively high contrast sensitivity, comparable to but somewhat less than visual detection thresholds, (2) the most effective stimulus spatial frequency scaled in inverse proportion to the disparity being stimulated, and (3) unlike psychophysical contrast sensitivity, the eye alignment reflex contrast sensitivity was not improved by flickering low spatial frequencies.


Assuntos
Convergência Ocular , Disparidade Visual , Adulto , Humanos , Sensibilidades de Contraste , Percepção Visual , Transtornos da Visão , Reflexo , Visão Binocular/fisiologia
20.
Zhonghua Yan Ke Za Zhi ; 58(11): 975-978, 2022 Nov 11.
Artigo em Chinês | MEDLINE | ID: mdl-36348544

RESUMO

Ocular cardiac reflex (OCR) usually occurs in ophthalmic surgery, especially in extraocular muscle(s) surgery. OCR generally can cause sinus bradycardia, arrhythmia, reduced atrial pressure, ventricular tachycardia, ventricular fibrillation, ventricular doublet, dizziness, nausea and other symptoms. Severe cases will appear cardiac arrest, respiratory arrest, etc. Recent studies on the mechanism of OCR and the relationship between surgical operation and anaesthesia in extraocular muscle surgery and the occurrence of OCR are reviewed in this paper in order to reduce the occurrence of OCR and treatment of OCR in extraocular muscle surgery.


Assuntos
Reflexo Oculocardíaco , Estrabismo , Humanos , Músculos Oculomotores/cirurgia , Reflexo Oculocardíaco/fisiologia , Estrabismo/cirurgia , Bradicardia/epidemiologia , Bradicardia/etiologia , Reflexo
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