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Objective. To evaluate the effect of retrobulbar block during orbital exenteration on heart rate variability (HRV). Materials and methods. Fourteen adult cows with ocular squamous cell carcinoma were used. Ocular exenteration is performed under multimodal anesthesia. The cows were sedated (xylazine 2%) and the auriculopalpebral nerve was blocked (lidocaine 2%). They were randomly assigned to two groups, one with a four-point block (n=7) and the second with a retrobulbar block (n=7). Electrocardiograms were recorded during two hours of the surgery in six moments by means of a Holter monitor (Cardio Trak Digital Holter Recorder, Model CT-085, BENEWARE). The data obtained were analyzed using linear methods in the frequency and time domain. Mean heart rate (HR) and mean beat-to-beat interval (RR) duration were evaluated in the time domain. In domain frequency included low (LF), high frequency (HF) and sympathovagal balance (LF/HF) of HRV. Results. In both groups there was a significant increase in heart rate during ocular traction. There were no significant changes in HRV between the different moments of the procedure. Conclusions. During manipulation and exenteration of the eyeball, no decrease in HR associated with the oculocardiac reflex was detected, but sympathetic activation was detected as a result of painful surgical stimuli. No central nervous system (CNS) toxicity from local anesthetics occurred in the animals. [ABSTRACT FROM AUTHOR]

The spinal stretch reflex is a fundamental building block of motor function, with a sensitivity that varies continuously during movement and when changing between movement and posture. Many have investigated task-dependent reflex sensitivity, but few have provided simple, quantitative analyses of the relationship between the volitional control and stretch reflex sensitivity throughout tasks that require coordinated activity of several muscles. Here, we develop such an analysis and use it to test the hypothesis that modulation of reflex sensitivity during movement can be explained by the balance of activity within agonist and antagonist muscles better than by activity only in the muscle homonymous with the reflex. Subjects completed hundreds of flexion and extension movements as small, pseudorandom perturbations of elbow angle were applied to obtain estimates of stretch reflex amplitude throughout the movement. A subset of subjects performed a postural control task with muscle activities matched to those during movement. We found that reflex modulation during movement can be described by background activity in antagonist muscles about the elbow much better than by activity only in the muscle homonymous to the reflex (P < 0.001). Agonist muscle activity enhanced reflex sensitivity, whereas antagonist activity suppressed it. Surprisingly, the magnitude of these effects was similar, suggesting a balance of control between agonists and antagonists very different from the dominance of sensitivity to homonymous activity during posture. This balance is due to a large decrease in sensitivity to homonymous muscle activity during movement rather than substantial changes in the influence of antagonistic muscle activity. [ABSTRACT FROM AUTHOR]

Purpose. The aim of this review was to systematically summarize the current literature on corticospinal excitation and muscle activity in restless legs syndrome (RLS) patients during daytime and diurnal activities. Three models of muscle activation in RLS directed this review: (i) evoked neuromuscular activation; (ii) sensory reflex responsiveness; (iii) voluntary muscle activation. Methods. A literature search was conducted in PubMed and Google Scholar, and 51 articles met the primary inclusion criteria. After a quality analysis, a total 13 articles were deemed of sufficient quality for data extraction. Results. Three studies on evoked neuromuscular activation demonstrated increased motor excitability associated with RLS. Sensory reflex responsiveness studies in RLS patients revealed increased reflex responsiveness, indicating increased spinal excitability and a possible dysfunction in afferent inhibition. Voluntary muscle activation studies showed both diurnal muscle electromyography abnormalities and an increased circadian variation in the musculature of the lower leg in RLS patients. Conclusions. Although a number of mechanisms have been evaluated increasing the understanding of RLS, few studies have evaluated RLS during daytime and diurnal muscle activity in patients with RLS. Furthermore, potential associations with the circadian rhythm have not been thoroughly investigated, nor have methodologies been combined. Future research should aim to establish differences in muscle activity of RLS patients and associate these differences with the duration and severity of symptoms. Suggestions for further studies are provided. [ABSTRACT FROM AUTHOR]

Copyright of Argentinian Journal of Respiratory & Physical Therapy (AJRPT) is the property of Asociacion Civil Cientifica de Difusion y Promocion de la Kinesiologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives: This study aims to find and compare the effects of primal reflex release technique and stretching exercises on pain intensity, functional performance, and pain-free sitting duration in patients with coccydynia. Methods: This is a randomized clinical trial. A total of 46 individuals were chosen for the sample based on the inclusion criteria, and they were divided into groups A and B. Pretreatment values of patients for pain assessment were taken by the Numerical pain rating scale (NPRS), Dallas pain questionnaire (DPQ), and pain-free sitting duration (PFSD). Group A received treatment with a hot pack and primal reflex release technique. Group B received treatment with a hot pack and stretching exercises. Each patient received a total of 12 sessions over the course of 4 weeks, 3 sessions per week. After 4 weeks of therapy, both groups were evaluated again. The obtained data were analyzed using SPSS software, version 21. Results: Findings revealed that within-group differences were statistically significant (P<0.05) for all variables. In the primal reflex release technique group, the average NPRS value reduced from 5.565±1.4086 to 1.7391±1.09617, the average DPQ value from 129.967±33.102 to 38.000±26.691 and the average PFSD duration increased from 43.043±20.323 to 368.478±160.464. In the stretching group, NPRS reduced from 6.087±1.345 to 3.695±1.490, DPQ from 116.032±35.054 to 60.608±22.186 and PFSD increased from 28.260±11.928 to 94.130±102.154. The between-group analysis also indicated statistically significant differences in NPRS, DPQ, and pain-free sitting duration with P=0.001, 0.003, and =0.001, respectively Discussion: The study concluded that both the primal reflex release technique and stretching exercises were effective in reducing pain and improving functional status with a marked increase in pain-free sitting duration. However, the primal reflex release technique was found to be more useful than stretching exercises in terms of mentioned outcome measures on basis of their mean differences. [ABSTRACT FROM AUTHOR]

Purpose The aim of this review was to systematically summarize the current literature on corticospinal excitation and muscle activity in restless legs syndrome (RLS) patients during daytime and diurnal activities. Three models of muscle activation in RLS directed this review: (i) evoked neuromuscular activation; (ii) sensory reflex responsiveness; (iii) voluntary muscle activation. Methods A literature search was conducted in PubMed and Google Scholar, and 51 articles met the primary inclusion criteria. After a quality analysis, a total 13 articles were deemed of sufficient quality for data extraction. Results Three studies on evoked neuromuscular activation demonstrated increased motor excitability associated with RLS. Sensory reflex responsiveness studies in RLS patients revealed increased reflex responsiveness, indicating increased spinal excitability and a possible dysfunction in afferent inhibition. Voluntary muscle activation studies showed both diurnal muscle electromyography abnormalities and an increased circadian variation in the musculature of the lower leg in RLS patients. Conclusions Although a number of mechanisms have been evaluated increasing the understanding of RLS, few studies have evaluated RLS during daytime and diurnal muscle activity in patients with RLS. Furthermore, potential associations with the circadian rhythm have not been thoroughly investigated, nor have methodologies been combined. Future research should aim to establish differences in muscle activity of RLS patients and associate these differences with the duration and severity of symptoms. Suggestions for further studies are provided.

Globally, millions of people are rapidly infected with COVID-19 and it has spread worldwide from January 2020 to till date. Coronavirus mostly affects the respiratory system; it can also result in several multisystem complications. This is a case series of four patients admitted in the department of medicine with post-COVID-19 Guillain–Barre syndrome (GBS). SARS-CoV-2 mainly affects the respiratory system but multiple organ damage is being reported recently, neurologic damage is one of them. SARS-CoV-2 causes neurologic damage including, by direct attack the nervous system through angiotensin-converting enzyme receptor, secondary to an immune reaction against SARS-CoV-2, retrograde transport, cytokine, and hypoxia-related injury. However, pathogenesis is not fully understood. It is hypothesized that the cause of GBS in covid patients is due to immune-mediated. It is hypothesized that inflammatory cytokines may play a role in an immune-mediated neuropathy. In this era of pandemic, we are concern about the involvement of respiratory and gastrointestinal systems only, involvement of other systems is underestimated. It is very important to be aware of association of GBS with COVID-19. Although neurological involvement in COVID-19 is rare, early diagnosis and treatment can reduce morbidity and mortality. We should always think about COVID-19 infection in a patients presented with GBS after respiratory or gastrointestinal involvement.

Reflex epilepsies are a unique and heterogeneous group of epilepsies characterized by recurrent seizure activity evoked by a specific external sensory stimulus or internal cognitive process. Reflex seizures can be part of other epilepsy syndromes including focal and generalized syndromes and have a growing spectrum of presentations. We report a further subtype of reflex seizures associated with towel exposure.We give an account of a case of drug-refractory focal epilepsy admitted to the Epilepsy Monitoring Unit for presurgical assessment with 50% of seizures triggered in response to the touch, feel, smell and thoughts around towels. We reviewed the literature regarding the broad phenotype of reflex epilepsies and seizures.

Posttraumatic stress disorder (PTSD) is associated with fear response system dysregulation. Research has shown that the anterior cingulate cortex (ACC) may modulate the fear response and that individuals with PTSD have abnormalities in ACC structure and functioning. Our objective was to assess whether ACC volume moderates the relationship between PTSD and fear-potentiated psychophysiological response in a sample of Gulf War Veterans. 142 Veteran participants who were associated with a larger study associated with Gulf War Illness were exposed to no threat, ambiguous threat, and high threat conditions in a fear conditioned startle response paradigm and also provided MRI imaging data. PTSD was assessed using the Clinician Administered PTSD Scale (CAPS). Decreased caudal ACC volume predicted greater psychophysiological responses with a slower habituation of psychophysiological magnitudes across trials (p

In the current study, we explored exaggerated physiological startle responses in posttraumatic stress disorder (PTSD) and examined startle reactivity as a biomarker of PTSD in a large veteran sample. We assessed heart rate (HR), skin conductance (SC), and electromyographic (EMG) startle responses to acoustic stimuli under low-, ambiguous-, and high-threat conditions in Gulf War veterans with current (n = 48), past (n = 42), and no history of PTSD (control group; n = 152). We evaluated PTSD status using the Clinician-Administered PTSD Scale and trauma exposure using the Trauma History Questionnaire. Participants with current PTSD had higher HR, ds = 0.28-0.53; SC, d = 0.37; and startle responses than those with past or no history of PTSD. The HR startle response under ambiguous threat best differentiated current PTSD; however, sensitivity and specificity analyses revealed it to be an imprecise indicator of PTSD status, ROC AUC = .66. Participants with high levels of trauma exposure only showed elevated HR and SC startle reactivity if they had current PTSD. Results indicate that startle is particularly elevated in PTSD when safety signals are available but a possibility of danger remains and when trauma exposure is high. However, startle reactivity alone is unlikely to be a sufficient biomarker of PTSD.

Transcutaneous stimulation of the auricular branch of the vagus nerve (tVNS) may accelerate fear extinction in healthy humans. Here, we aimed to investigate this hypothesis in healthy young participants in a prepared learning paradigm, using spider pictures as conditioned stimuli. After a fear conditioning phase, participants were randomly allocated to receive tVNS (final N = 42) or sham stimulation (final N = 43) during an extinction phase. Conditioned fear was assessed using US expectancy ratings, skin conductance and fear potentiated startle responses. After successful fear acquisition, participants in both groups showed a reduction of fear over the course of the extinction phase. There were no between-group differences in extinction rates for physiological indices of fear. Contrary to previous findings, participants in the tVNS condition also did not show accelerated declarative extinction learning. Participants in the tVNS condition did have lower initial US expectancy ratings for the CS- trials than those who received sham stimulation, which may indicate an enhanced processing of safety cues due to tVNS. In conclusion, the expected accelerated extinction due to tVNS was not observed. The results from this study call for more research on the optimal tVNS stimulation intensity settings.

Recent research has identified the lateral habenula (LHb) as a brain region playing an important role in the production of stressful and anxiogenic states. Additionally, norepinephrine (NE) has long been known to be involved in arousal, stress and anxiety, and NE projections to the LHb have been identified emanating from the locus coeruleus (LC). The current research was devised to test the hypothesis that NE release within the LHb contributes to the occurrence of anxiogenic behaviors. Male rats were implanted with bilateral guide cannula aimed at the LHb and subsequently treated with intracranial (IC) infusions of the selective α2 adrenergic autoreceptor agonist, dexmedetomidine (DEX) (0, 0.5, 1.0 μg/side), prior to assessment of ambulatory and anxiogenic behavior in tests of spontaneous locomotion, open field behavior, and acoustic startle-response. Results demonstrated that DEX administration significantly reduced the overall locomotor behavior of subjects at both doses indicating that infusion of even small doses of this α2 agonist into the LHb can have profound effects on the subjects' general levels of alertness and activity. DEX was also found to attenuate anxiety as evidenced by a reduction in the magnitude of a startle-response to an acoustic 110 dB stimulus. Taken together, these results identify a role for NE release within the LHb in both arousal and anxiety.

BACKGROUND:Post-traumatic stress disorder (PTSD) and obesity are highly prevalent in adolescents. Emerging findings from our laboratory and others are consistent with the novel hypothesis that obese individuals may be predisposed to developing PTSD. Given that aberrant fear responses are pivotal in the pathogenesis of PTSD, the objective of this study was to determine the impact of an obesogenic Western-like high-fat diet (WD) on neural substrates associated with fear. METHODS:Adolescent Lewis rats (n = 72) were fed with either the experimental WD (41.4% kcal from fat) or the control diet. The fear-potentiated startle paradigm was used to determine sustained and phasic fear responses. Diffusion tensor imaging metrics and T2 relaxation times were used to determine the structural integrity of the fear circuitry including the medial prefrontal cortex (mPFC) and the basolateral complex of the amygdala (BLA). RESULTS:The rats that consumed the WD exhibited attenuated fear learning and fear extinction. These behavioral impairments were associated with oversaturation of the fear circuitry and astrogliosis. The BLA T2 relaxation times were significantly decreased in the WD rats relative to the controls. We found elevated fractional anisotropy in the mPFC of the rats that consumed the WD. We show that consumption of a WD may lead to long-lasting damage to components of the fear circuitry. CONCLUSIONS:Our findings demonstrate that consumption of an obesogenic diet during adolescence has a profound impact in the maturation of the fear neurocircuitry. The implications of this research are significant as they identify potential biomarkers of risk for psychopathology in the growing obese population.

We have shown that acupuncture, including manual and electroacupuncture (MA and EA), at the P5-6 acupoints stimulates afferent fibers in the median nerve (MN) to modulate sympathoexcitatory cardiovascular reflexes through central regulation of autonomic function. However, the mechanisms underlying acupuncture activation of these sensory afferent nerves and their cell bodies in the dorsal root ganglia (DRG) are unclear. Transient receptor potential vanilloid type 1 (TRPV1) is present in sensory nerve fibers distributed in the general region of acupoints like ST36 and BL 40 located in the hindlimb. However, the contribution of TRPV1 to activation of sensory nerves by acupuncture, leading to modulation of pressor responses, has not been studied. We hypothesized that TRPV1 participates in acupuncture's activation of sensory afferents and their associated cell bodies in the DRG to modulate pressor reflexes. Local injection of iodoresiniferatoxin (Iodo-RTX; a selective TRPV1 antagonist), but not 5% DMSO (vehicle), into the P6 acupoint on the forelimb reversed the MA's inhibition of pressor reflexes induced by gastric distension (GD). Conversely, inhibition of GD-induced sympathoexcitatory responses by EA at P5-6 was unchanged after administration of Iodo-RTX into P5-6. Single-unit activity of Group III or IV bimodal afferents sensitive to both mechanical and capsaicin stimuli responded to MA stimulation at P6. MA-evoked activity was attenuated significantly ( P < 0.05) by local administration of Iodo-RTX ( n = 12) but not by 5% DMSO ( n = 12) into the region of the P6 acupoint in rats. Administration of Iodo-RTX into P5-6 did not reduce bimodal afferent activity evoked by EA stimulation ( n = 8). Finally, MA at P6 and EA at P5-6 induced phosphorylation of extracellular signal-regulated kinases (ERK; an intracellular signaling messenger involved in cellular excitation) in DRG neurons located at C7-8 spinal levels receiving MN inputs. After TRPV1 was knocked down in the DRG at these spinal levels with intrathecal injection of TRPV1-siRNA, expression of phosphorylated ERK in the DRG neuron was reduced in MA-treated, but not EA-treated animals. These data suggest that TRPV1 in Group III and IV bimodal sensory afferent nerves contributes to acupuncture inhibition of reflex increases in blood pressure and specifically plays an important role during MA but not EA.

PTSD has been associated consistently with abnormalities in fear acquisition and extinction learning and retention. Fear acquisition refers to learning to discriminate between threat and safety cues. Extinction learning reflects the formation of a new inhibitory-memory that competes with a previously learned threat-related memory. Adjudicating the competition between threat memory and the new inhibitory memory during extinction may rely, in part, on cognitive processes such as working memory (WM). Despite significant shared neural circuits and signaling pathways the relationship between WM, fear acquisition, and extinction is poorly understood. Here, we analyzed data from a large sample of healthy Marines who underwent an assessment battery including tests of fear acquisition, extinction learning, and WM (N-back). Fear potentiated startle (FPS), fear expectancy ratings, and self-reported anxiety served as the primary dependent variables. High WM ability (N = 192) was associated with greater CS + fear inhibition during the late block of extinction and greater US expectancy change during extinction learning compared to individuals with low WM ability (N = 204). WM ability was not associated with magnitude of fear conditioning/expression. Attention ability was unrelated to fear acquisition or extinction supporting specificity of WM associations with extinction. These results support the conclusion that individual differences in WM may contribute to regulating fear responses.

Prepulse inhibition (PPI) of startle is being explored both as an indicator of target engagement for, and a biomarker predicting the sensitivity to, procognitive effects of drugs. We now report the effects of the pro-attentional drug, d-amphetamine, on PPI and neurocognition in antipsychotic-medicated schizophrenia patients and healthy subjects (HS) who were also tested in a targeted cognitive training (TCT) module. 44 HS and 38 schizophrenia patients completed a double-blind, placebo-controlled crossover study of the effects of a single dose of amphetamine (10 mg po) on PPI and MATRICS Consensus Cognitive Battery (MCCB) performance; TCT results were previously reported from 60 of these subjects. Moderators predicting AMPH sensitivity were assessed, including the rs4680 single-nucleotide polymorphism for catechol-O-methyltransferase (COMT). After placebo, patients exhibited PPI deficits with 60 ms prepulse intervals; these deficits were 'rescued' by amphetamine. The magnitude of amphetamine-enhanced PPI was greater in patients than in HS (p

During threat of shock, the startle reflex is potentiated, suggesting modulation by defensive mobilization. To determine whether startle potentiation is specific to aversive anticipation, startle reflexes were measured in the context of either aversive or appetitive anticipation in a between-subject study. Participants wore a device on the wrist that could deliver electrical shock (n = 49), or vibrotactile stimulation indicating monetary reward (n = 48). Cues signaling threat or safe periods were presented alone, or accompanied by presentation of affective and neutral pictures on half of the trials. Results indicated that the startle reflex was significantly potentiated when anticipating either shock or reward, compared to safe periods, both when no picture was presented, as well as during picture viewing. The difference between threat and safety in both reflex magnitude and skin conductance changes was larger for those anticipating shock, suggesting that the aversive context was more motivationally engaging. The pattern of reflex modulation as a function of picture valence varied under threat and safety, but was identical in the shock and reward groups, consistent with a hypothesis that anticipation of either aversive or appetitive events prompts heightened perceptual vigilance, potentiating the acoustic startle reflex.

Stimulation of vagal afferent endings with intravenous phenylbiguanide (PBG) causes both bradycardia and vasodepression, simulating neurally mediated syncope. Activation of µ-opioid receptors in the nucleus tractus solitarius (NTS) increases blood pressure. Electroacupuncture (EA) stimulation of somatosensory nerves underneath acupoints P5-6, ST36-37, LI6-7 or G37-39 selectively but differentially modulates sympathoexcitatory responses. We therefore hypothesized that EA-stimulation at P5-6 or ST36-37, but not LI6-7 or G37-39 acupoints, inhibits the bradycardia and vasodepression through a µ-opioid receptor mechanism in the NTS. We observed that stimulation at acupoints P5-6 and ST36-37 overlying the deep somatosensory nerves and LI6-7 and G37-39 overlying cutaneous nerves differentially evoked NTS neural activity in anesthetized and ventilated animals. Thirty-min of EA-stimulation at P5-6 or ST36-37 reduced the depressor and bradycardia responses to PBG while EA at LI6-7 or G37-39 did not. Congruent with the hemodynamic responses, EA at P5-6 and ST36-37, but not at LI6-7 and G37-39, reduced vagally evoked activity of cardiovascular NTS cells. Finally, opioid receptor blockade in the NTS with naloxone or a specific μ-receptor antagonist reversed P5-6 EA-inhibition of the depressor, bradycardia and vagally evoked NTS activity. These data suggest that point specific EA stimulation inhibits PBG-induced vasodepression and bradycardia responses through a μ-opioid mechanism in the NTS.

Macrophage cytokine production is regulated by neural signals, for example in the inflammatory reflex. Signals in the vagus and splenic nerves are relayed by choline acetyltransferase+ T cells that release acetylcholine, the cognate ligand for alpha7 nicotinic acetylcholine subunit-containing receptors (α7nAChR), and suppress TNF release in macrophages. Here, we observed that electrical vagus nerve stimulation with a duration of 0.1-60 s significantly reduced systemic TNF release in experimental endotoxemia. This suppression of TNF was sustained for more than 24 h, but abolished in mice deficient in the α7nAChR subunit. Exposure of primary human macrophages and murine RAW 264.7 macrophage-like cells to selective ligands for α7nAChR for 1 h in vitro attenuated TNF production for up to 24 h in response to endotoxin. Pharmacological inhibition of adenylyl cyclase (AC) and knockdown of adenylyl cyclase 6 (AC6) or c-FOS abolished cholinergic suppression of endotoxin-induced TNF release. These findings indicate that action potentials in the inflammatory reflex trigger a change in macrophage behavior that requires AC and phosphorylation of the cAMP response element binding protein (CREB). These observations further our mechanistic understanding of neural regulation of inflammation and may have implications for development of bioelectronic medicine treatment of inflammatory diseases.

The efferent branches of the splanchnic sympathetic nerves that enhance interleukin‐10 (IL‐10) and suppress tumour necrosis factor‐α (TNF) levels in the reflex response to systemic immune challenge were investigated in anaesthetized, ventilated rats. Plasma levels of TNF and IL‐10 were measured 90 min after intravenous lipopolysaccharide (LPS, 60 µg/kg). Splanchnic nerve section, ganglionic blockade with pentolinium tartrate or β2 adrenoreceptor antagonism with ICI 118551 all blocked IL‐10 responses. Restoring plasma adrenaline after splanchnic denervation rescued IL‐10 responses. TNF responses were disinhibited by splanchnic denervation or pentolinium treatment, but not by ICI 118551. Splanchnic nerve branches were cut individually or in combination in vagotomized rats, ruling out any vagal influence on results. Distal splanchnic denervation, sparing the adrenal nerves, disinhibited TNF but did not reduce IL‐10 responses. Selective adrenal denervation depressed IL‐10 but did not disinhibit TNF responses. Selective denervation of either spleen or liver did not affect IL‐10 or TNF responses, but combined splenic and adrenal denervation did so. Finally, combined section of the cervical and lumbar sympathetic nerves did not affect cytokine responses to LPS. Together, these results show that the endogenous anti‐inflammatory reflex is mediated by sympathetic efferent fibres that run in the splanchnic, but not other sympathetic nerves, nor the vagus. Within the splanchnic nerves, divergent pathways control these two cytokine responses: neurally driven adrenaline, acting via β2 adrenoreceptors, regulates IL‐10, while TNF is restrained by sympathetic nerves to abdominal organs including the spleen, where non‐β2 adrenoreceptor mechanisms are dominant. Key points: An endogenous neural reflex, mediated by the splanchnic, but not other sympathetic nerves, moderates the cytokine response to systemic inflammatory challenge. This reflex suppresses the pro‐inflammatory cytokine tumour necrosis factor‐α (TNF), while enhancing levels of the anti‐inflammatory cytokine interleukin‐10 (IL‐10).The reflex enhancement of IL‐10 depends on the splanchnic nerve supply to the adrenal gland and on β2 adrenoreceptors, consistent with mediation by circulating adrenaline. After splanchnic nerve section it can be rescued by restoring circulating adrenaline.The reflex suppression of TNF depends on splanchnic nerve branches that innervate abdominal tissues including, but not restricted to, spleen: it is not blocked by adrenal denervation or β2 adrenoreceptor antagonism.Distinct sympathetic efferent pathways are thus responsible for pro‐ and anti‐inflammatory cytokine components of the reflex regulating inflammation. [ABSTRACT FROM AUTHOR]

The synthesis of new NSAIDs with improved efficacy and selectivity towards COX2, which encouraged by 1,2,4-triazoles and 1,3,4-thiadiazoles with their various biological activities. In this experiment, the production of 1,2,4-triazolothiadiazoles derivatives from Ibuprofen. We have enhanced anti-inflammatory and analgesic activities by conventional method and microwave-assisted technique, and then compare the time consuming by reaction and yield percent of the product in both way, besides anti-inflammatory activity evaluation of targeted compounds by pharmacological test with predictable selectivity towards COX-2 enzyme. A successful synthesis of the target compounds has been achieved by checking purity, characterization, also identification of the synthetic compounds which detected by estimation of physical properties, FT-IR and 1H-NMR spectroscopy. The anti-inflammatory properties of the ending compounds in vivo are being evaluated using egg-white-induced edema models. The experienced compounds (1 MIC., 1 CON.) and the reference drug (Ibuprofen) produced significant reduction in paw edema in compare to the effect of control group. Wholly tested compounds produced considerable decrease of paw edema in contrast to control group. However, final synthesis compounds have considerable more paw edema declining than Ibuprofen. Intermediate and target compounds are synthesis by microwave method have better result by time, purity and yield in compare with conventional way. The synthesized compounds (1 or 2 or 3 MIC.,1 or 2 or 3 or CON.) may exhibit expected selectivity towards COX-2 enzyme properly due to their large size than its parent Ibuprofen. [ABSTRACT FROM AUTHOR]

Medical interest in the knee-jerk reflex began in about 1875 with simultaneous and independent publications by Wilhelm Heinrich Erb (1840–1921) and Carl Friedrich Otto Westphal (1833–1890) contending that the knee jerk was absent (and the ankle clonus was present) in all clear cases of locomotor ataxia (tabes dorsalis). Physicians in the medical communities of Europe, Great Britain, and North America responded with case and large group studies that tested this contention. These studies revealed the usefulness of the knee jerk and other myotatic reflexes, but also unexpected characteristics. The knee jerk, apparently so simple, proved to be a complex phenomenon depending the strength of the strike on the patella, induced muscle tension, and inhibition from the brain. Was it a reflex with afferent and efferent nerves and an intervening process in the spinal cord, or was it a local phenomenon confined to the muscle itself? Experimental studies directed at the reflex issue investigated latencies from patella strike to leg extension or muscle contraction and compared them with latencies from direct muscle strikes and theoretical calculations based on reflex components. Such studies were unable to resolve the reflex issue during the nineteenth century. The physicians were shown to be limited, like all scientific explorers of the unknown, by their knowledge, methodology, and technology. [ABSTRACT FROM AUTHOR]

Wrist position is known to affect the grip strength. We focused on the spinal reflex arc, which would support the movement, and investigated the effects of low‐threshold afferents from the extensor carpi radialis (ECR) on the excitability of the flexor digitorum superficialis (FDS) motoneurons using the post‐stimulus time‐histogram (PSTH) and electromyogram‐averaging (EMG‐A) methods. Electrical conditioning stimulation of an intensity below the motor threshold was applied to the radial nerve branch innervating the ECR. In the PSTH study, changes in the firing probability of single motor units after electrical conditioning stimulation were investigated in seven subjects. An early and significant peak (increase in the firing probability: facilitation) was recorded for 36/60 FDS motor units. The remaining 24 motor units did not show any effects. Weak mechanical conditioning stimulation of the ECR muscle belly induced a similar peak. The central latency of the facilitation was equivalent to that of the homonymous monosynaptic facilitation. In the EMG‐A study, changes in the rectified and averaged electromyograms of FDS induced by conditioning stimulation were examined in 12 subjects. An early and significant peak (facilitation) was induced by both electrical and mechanical conditioning stimulations. The facilitation decreased after withdrawal of the vibration to the ECR muscle belly. The facilitation was never induced by cutaneous nerve stimulation in the PSTH and EMG‐A studies. These findings suggest that Group Ia afferents from the ECR increase the excitability of FDS motoneurons through a monosynaptic path in the spinal cord. These reflex arcs likely facilitate hand grasping movements. [ABSTRACT FROM AUTHOR]

Copyright of Istanbul Gelisim University Journal of Health Sciences / İstanbul Gelişim Üniversitesi Sağlık Bilimleri Dergisi is the property of Istanbul Gelisim Universitesi Saglik Bilimleri Yuksekokulu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The middle-ear muscle reflex (MEMR) and medial olivocochlear reflex (MOCR) modify peripheral auditory function, which may reduce masking and improve speech-in-noise (SIN) recognition. Previous work and our pilot data suggest that the two reflexes respond differently to static versus dynamic noise elicitors. However, little is known about how the two reflexes work in tandem to contribute to SIN recognition. We hypothesized that SIN recognition would be significantly correlated with the strength of the MEMR and with the strength of the MOCR. Additionally, we hypothesized that SIN recognition would be best when both reflexes were activated. A total of 43 healthy, normal-hearing adults met the inclusion/exclusion criteria (35 females, age range: 19-29 years). MEMR strength was assessed using wideband absorbance. MOCR strength was assessed using transient-evoked otoacoustic emissions. SIN recognition was assessed using a modified version of the QuickSIN. All measurements were made with and without two types of contralateral noise elicitors (steady and pulsed) at two levels (50 and 65 dB SPL). Steady noise was used to primarily elicit the MOCR and pulsed noise was used to elicit both reflexes. Two baseline conditions without a contralateral elicitor were also obtained. Results revealed differences in how the MEMR and MOCR responded to elicitor type and level. Contrary to hypotheses, SIN recognition was not significantly improved in the presence of any contralateral elicitors relative to the baseline conditions. Additionally, there were no significant correlations between MEMR strength and SIN recognition, or between MOCR strength and SIN recognition. MEMR and MOCR strength were significantly correlated for pulsed noise elicitors but not steady noise elicitors. Results suggest no association between SIN recognition and the MEMR or MOCR, at least as measured and analyzed in this study. SIN recognition may have been influenced by factors not accounted for in this study, such as contextual cues, warranting further study., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The dive response involves three main components - breath holding, reduced heart rate and increased peripheral vasoconstriction - and is ubiquitous during forced dives in air-breathing vertebrates; however, numerous studies in free-diving animals have shown that the heart rate response to diving varies considerably in a manner that suggests cognitive control. Furthermore, studies on free-diving animals and controlled experiments in trained animals both indicate that the dive response can be conditioned, such that the reduction in heart rate begins before submergence and the extent of the reduction is set early in the dive. In addition, numerous species also experience an increase in heart rate and blood flow during ascent at the end of a dive, a phenomenon commonly called 'ascent tachycardia'. Collectively, these data suggest that although the dive response is under autonomic control, many species can vary its magnitude depending on the length and type of the planned dive - an indication of a role for cognition in the overall physiological responses associated with diving. Here, we provide examples of the conditioned cardiac responses - including anticipatory changes in heart rate - in several diving species and propose potential underlying mechanisms. We also discuss how the anticipatory cardiovascular responses not only improve diving capacity, but also prevent diving-related problems, such as decompression sickness or barotrauma, through a mechanism described by the selective gas exchange hypothesis., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2024. Published by The Company of Biologists Ltd.)

Oral contraceptive (OC) use can increase resting blood pressure (BP) in females as well as contribute to greater activation of group III/IV afferents during upper body exercise. It is unknown, however, whether an exaggerated BP response occurs during lower limb exercise in OC users. We sought to elucidate the group III/IV afferent activity-mediated BP and heart rate responses while performing lower extremity tasks during early and late follicular phases in young, healthy females. Females not taking OCs (NOC: n = 8; age: 25 ± 4 yr) and those taking OCs (OC: n = 10; age: 23 ± 2 yr) completed a continuous knee extension/flexion passive stretch (mechanoreflex) and cycling exercise with subsystolic cuff occlusion (exercise pressor reflex), which was followed by a 2-min postexercise circulatory occlusion (PECO) (metaboreflex). Data collection occurred on two occasions: once during the early follicular phase ( days 1-4 ) and once during the late follicular phase ( days 10-14 ) of their menstrual cycle (NOC) or during the placebo and active pill phases (OC). Resting mean arterial BP and heart rate were not different between phases in NOC and OC participants ( P > 0.05). Hemodynamic responses to metaboreflex, mechanoreflex, and collective exercise pressor reflex activation were not different between phases in both groups ( P > 0.05). In conclusion, although OCs are known to increase BP at rest, our findings indicate that neither endogenous nor exogenous (OC) sex hormones modulate BP during large, lower limb muscle exercise with or without group III/IV afferent activation in young, healthy females. NEW & NOTEWORTHY Sex differences in the cardiovascular response to exercise have been demonstrated and may be dependent on sex hormone levels. Furthermore, oral contraceptives (OCs) have been shown to exaggerate the blood pressure response to upper extremity exercise. The results of this study indicate that neither endogenous nor exogenous (OC) sex hormones modulate BP during lower extremity dynamic exercise or with group III/IV afferent activation in young, healthy females.

Rare epithelial cells in our airways initiate reflexes to guard against harmful stimuli.

Electrophysiological studies of the larynx expose the mechanisms by which voice production is controlled. Previous studies have revealed certain phenomena during laryngeal oscillations that suggest a complex control mechanism. Starting from the principle of agonist-antagonist muscular pairing, the aim of this study was to gain a deeper insight into the function of the cricothyroid (CT) and thyroarytenoid (TA) muscles, both central to voice production. Electromyographic recordings were used to determine the response of the two muscles to different stimulation situations in an ex vivo animal model of the denervated larynx of pigs (n=26). Using a set of different experiments, it was shown that when one muscle (CT or TA muscle) was electrically stimulated, a response was observed in the other muscle, which in the otherwise-denervated larynx, was caused only by the applied stimulation and exhibited the characteristics of compound action potentials. This response was reproducible in all larynxes examined and was present bidirectionally. No response was registered in the absence of stimulation. The results show the existence of coactivation of the CT and TA muscles in the absence of external innervation hinting at the presence of a localized neuronal network of the larynx that has not been described previously. Further morphological investigation is needed to determine the presence of this internal laryngeal neuronal network., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

The red reflex test, performed using a direct ophthalmoscope, serves as a critical diagnostic tool in identifying various ocular conditions. These conditions encompass retinal anomalies (such as retinoblastoma, Coats disease, retinopathy of prematurity, familial exudative vitreoretinopathy, myelinated nerve fibers, ocular toxocariasis, ocular toxoplasmosis, retinochoroidal coloboma, astrocytic, and combined hamartoma), vitreous abnormalities (including persistent fetal vasculature), lens issues (like cataract), anterior chamber and corneal conditions (comprising dysgenesis of the anterior segment, congenital glaucoma, birth trauma), and tear film disturbances. During this examination, the presence of leukocoria, characterized by a white pupillary reflex, can suggest the presence of underlying conditions. Any suspicion of an abnormal red reflex test warrants immediate evaluation by a qualified ophthalmologist. This article primarily underscores the paramount importance of the red reflex examination, not only to identify potential sight-threateningbut also life-threatening conditions. It delves into the most common causes of leukocoria in childhood and offers insights into a comprehensive diagnostic approach. The target audience for this article includes pediatricians, primary care clinicians, and ophthalmologists, all of whom play a pivotal role in the early detection and intervention of these critical eye disorders.

Objectives: To investigate associations between the rectoanal inhibitory reflex (RAIR), type of congenital anorectal malformations (ARMs), type of operation that patients with ARM had undergone, and objectively measured fecal incontinence and defecation problems., Methods: We retrospectively included 69 pediatric patients with ARM. All underwent anorectal function tests at the University Medical Center of Groningen during the last 10 years. We assessed anorectal physiology using the Rome IV criteria and anorectal function tests., Results: We found the reflex in 67% of patients and all types of ARMs. All patients who had not been operated on, and those who had undergone less extensive surgery possessed the reflex. In contrast, patients who underwent posterior sagittal anorectoplasty, 44% possessed it. We found no difference between mean rectal volumes in patients with and without the reflex (251  vs. 325 mL, respectively, p = 0.266). We found that over time, patients without the reflex seemed to develop significantly higher rectal volumes than patients who had it. We did not find a significant difference between the reflex and fecal incontinence; however, it seems that the absence of the reflex, resting anal sphincter pressure, and fecal incontinence are related., Conclusion: The RAIR seems present in patients with ARM irrespective of their malformation type. Corrective surgery, however, may impair this reflex. Seemingly, its absence results in constipation with enlarged rectal volumes and fecal incontinence. Every effort should be made to preserve this reflex during surgery and to use extensive surgical procedures as sparingly as possible., (© 2024 The Author(s). Journal of Pediatric Gastroenterology and Nutrition published by Wiley Periodicals LLC on behalf of European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition.)

Objective: The goal of this study was to determine open field stapedius reflex thresholds (oSRTs) in CI patients with fittings based on subjective loudness ratings. A further objective was to compare these oSRTs and those of eSRT-based fittings that are similar to the oSRTs of normal hearing., Design: Impedance measurements of the ear drum were taken while subjects were wearing their audio processors. The stapedius reflex was elicited by electrical stimulation transmitted through the activated CI system in response to an acoustic stimulus presented in the free sound field., Study Sample: Subjects were 50 experienced CI users ( n  = 57 ears) with CI fittings based on subjective loudness scaling., Results: A reference range for the oSRTs was defined that was identified in CI patients with eSRT-based fittings. Sound levels for stapedius reflex detection were inside the reference target range in 70% of the cases, below the reference range (i.e. down to 40 dB HL) in 20% of the cases, and above the reference range in 10% of the cases., Conclusion: Stapedius reflex detection in a free sound field may help detect fittings with too high or too low stimulation levels that might reduce audiological performance.

BACKGROUND: To date, the focus of pelvic floor muscle training for women suffering from stress urinary incontinence has been on voluntary contractions although involuntary pelvic floor muscle contractions are crucial to guarantee continence in high-impact situations typically triggering this condition. The authors developed 2 pelvic floor muscle home training programs, one including standard voluntary pelvic floor muscle training and one including involuntary reflexive pelvic floor muscle training. OBJECTIVE: This study aimed to test 2 pelvic floor muscle home training programs regarding maintenance of effects of a previous 16-week intervention in terms of stress urinary incontinence symptoms (International Consultation on Incontinence Modular Questionnaire—Urinary Incontinence short form, modified 20-minute pad test), impact on quality of life (Lower Urinary Tract Symptoms Quality of Life module), and digitally assessed pelvic floor muscle strength. STUDY DESIGN: This trial was a continuation of a previously published triple-blind prospective randomized controlled trial with a 6-month evaluation endpoint with 2 intervention groups (experimental group with involuntary reflexive home pelvic floor muscle training and control group with standard voluntary home pelvic floor muscle training). RESULTS: From the originally included 96 randomized and allocated participants (experimental group=46, control group=46), 33 control and 27 experimental participants completed the 6-month follow-up. From post–16-week physiotherapy intervention to 6-month follow-up (home pelvic floor muscle training), there were statistically significant improvements in pelvic floor muscle strength (control and experimental group), and no difference in the International Consultation on Incontinence Modular Questionnaire—Urinary Incontinence short form and pad test, or the Lower Urinary Tract Symptoms Quality of Life module Part B (control and experimental group) and Part A (control group). However, there was a statistically significant improvement in the Lower Urinary Tract Symptoms Quality of Life module Part A (experimental group). At no point in time (pre, post, follow-up) was there any statistically significant difference between the groups. CONCLUSION: Both groups could maintain their intervention training effects. This trial investigated involuntary reflexive pelvic floor muscle training alone, which proved to be an effective alternative to standard voluntary pelvic floor muscle training for maintenance of training effects among women suffering from stress urinary incontinence.

The contribution to balance of spinal and transcortical processes including the long-latency reflex is well known. The control of balance has been modelled previously as a continuous, state feedback controller representing, long-latency reflexes. However, the contribution of slower, variable delay processes has not been quantified. Compared with fixed delay processes (spinal, transcortical), we hypothesize that variable delay processes provide the largest contribution to balance and are sensitive to historical context as well as current states. Twenty-two healthy participants used a myoelectric control signal from their leg muscles to maintain balance of their own body while strapped to an actuated, inverted pendulum. We study the myoelectric control signal (u) in relation to the independent disturbance (d) comprising paired, discrete perturbations of varying inter-stimulus-interval (ISI). We fit the closed loop response, u from d, using one linear and two non-linear non-parametric (many parameter) models. Model M1 (ARX) is a generalized, high-order linear-time-invariant (LTI) process with fixed delay. Model M1 is equivalent to any parametric, closed-loop, continuous, linear-time-invariant (LTI), state feedback model. Model M2, a single non-linear process (fixed delay, time-varying amplitude), adds an optimized response amplitude to each stimulus. Model M3, two non-linear processes (one fixed delay, one variable delay, each of time-varying amplitude), add a second process of optimized delay and optimized response amplitude to each stimulus. At short ISI, the myoelectric control signals deviated systematically both from the fixed delay LTI process (M1), and also from the fixed delay, time-varying amplitude process (M2) and not from the two-process model (M3). Analysis of M3 (all fixed delay and variable delay response amplitudes) showed the variable (compared with fixed) delay process 1) made the largest contribution to the response, 2) exhibited refractoriness (increased delay related to short ISI) and 3) was sensitive to stimulus history (stimulus direction 2 relative to stimulus 1). For this whole-body balance task and for these impulsive stimuli, non-linear processes at variable delay are central to control of balance. Compared with fixed delay processes (spinal, transcortical), variable delay processes provided the largest contribution to balance and were sensitive to historical context as well as current states.

The projection pattern of low‐threshold afferents from the extensor carpi radialis (ECR) to motoneurons supplying intrinsic hand muscles was investigated using the post‐stimulus time‐histogram (PSTH) and electromyogram‐averaging (EMG‐A) methods. Electrical conditioning stimulation was applied to the radial nerve branch innervating the ECR. In the PSTH study, changes in the firing probability of single motor units following the stimulation were examined. An early and significant peak (facilitation) was induced in the motoneurons innervating the muscles, but the facilitation was induced infrequently. The central latency of the facilitation was equivalent to that of homonymous facilitation through monosynaptic path in the spinal cord. In the EMG‐A study, changes in the rectified and averaged electromyograms following the conditioning stimulation were examined. An early and significant peak (facilitation) was also induced. The facilitation disappeared after withdrawal of the vibration to the ECR muscle belly. Cutaneous nerve stimulation overlaying ECR never induced such facilitation in the PSTH and EMG‐A studies. These findings suggest that monosynaptic facilitation mediated by group Ia afferents of ECR to the motoneurons supplying intrinsic hand muscles exists in humans, but the connection seems to be weak. This weakness might allow manipulatory movements of the hand. [ABSTRACT FROM AUTHOR]

Solving the issue of implementation complexity due to the increase in wiring and peripheral circuits is crucial to implement highly autonomous decentralized systems, such as the reflex system of an animal. Our study reports a novel implementation method of electronic-free reflex systems for musculoskeletal robots. The main aim of our research is to build a continuous-valued feedback system of muscle force using only mechanical pneumatic devices without bulky and expensive electrical sensors, computers, or peripheral circuits. Our system, the pneumatic reflex device, requires only a single energy line from the center to perform the control function. In this study, experiments were performed using a single-joint musculoskeletal arm to evaluate the reflex device. [ABSTRACT FROM AUTHOR]

In judo, an anterior cruciate ligament (ACL) injury is the most severe injury an athlete could experience. Most ACL ruptures occur when defending against an osoto-gari attack. This study aims to identify ACL risk factors during osoto-gari defence and implement a modified osoto-gari defence reaction, which is assumed to improve myoelectric patterns and ameliorate critical biomechanical risk factors for ACL injuries. Twenty-six elite judokas were enrolled in the cross-over trial (female: 6; male: 20). 3D kinematics and force dynamometrics were combined with electromyographical recordings to assess the effects of the common and the modified osoto-gari defence reaction. Compared to the common osoto-gari defence reaction (maximal knee flexion: 29 ± 12°; maximal valgus: 10 ± 5°; maximal valgus moment: 58 ± 17 Nm; peak internal rotation: 9 ± 5°), the modified osoto-gari defence reaction showed significantly reduced knee angles (31 ± 10° p < 0.05; 1 ± 0° p < 0.05; 31 ± 9 Nm p < 0.05; 3 ± 0° p < 0.05). The myoelectric activity of the hamstring increased (+5±% to +27±%, p < 0.05) in the modified compared to common defence reaction. The modified osoto-gari defence reaction reduced critical biomechanical risk factors and increased hamstring myoelectric activity. We recommend the implementation of the modified osoto-gari defence reaction in judo practice and seek to evaluate its long-term effectiveness in decreasing ACL injury incidences in elite judo. [ABSTRACT FROM AUTHOR]