Alcohol-induced tolerance and physical dependence in mice with ethanol insensitive α1 GABAA receptors

PubMed Central

Werner, David F.; Swihart, Andrew R.; Ferguson, Carolyn; Lariviere, William R.; Harrison, Neil L.; Homanics, Gregg E.

2009-01-01

Background Although many people consume alcohol (ethanol), it remains unknown why some become addicted. Elucidating the molecular mechanisms of tolerance and physical dependence (withdrawal) may provide insight into alcohol addiction. While the exact molecular mechanisms of ethanol action are unclear, γ-aminobutyric acid type A receptors (GABAA-Rs) have been extensively implicated in ethanol action. The α1 GABAA-R subunit is associated with tolerance and physical dependence, but its exact role remains unknown. In this report, we tested the hypothesis that α1-GABAA-Rs mediate in part these effects of ethanol. Methods Ethanol-induced behavioral responses related to tolerance and physical dependence were investigated in knockin mice that have ethanol-insensitive α1 GABAA-Rs and wildtype controls. Acute functional tolerance (AFT) was assessed using the stationary dowel and loss of righting reflex assays. Chronic tolerance was assessed on the loss of righting reflex, fixed speed rotarod, hypothermia, and radiant tail flick assays following ten consecutive days of ethanol exposure. Withdrawal-related hyperexcitability was assessed by handling-induced convulsions following 3 cycles of ethanol vapor exposure/withdrawal. Immunoblots were used to assess α1 protein levels. Results Compared to controls, knockin mice displayed decreased AFT and chronic tolerance to ethanol-induced motor ataxia, and also displayed heightened ethanol-withdrawal hyperexcitability. No differences between wildtype and knockin mice were seen in other ethanol-induced behavioral measures. Following chronic exposure to ethanol, control mice displayed reductions in α1 protein levels, but knockins did not. Conclusions We conclude that α1-GABAA-Rs play a role in tolerance to ethanol-induced motor ataxia and withdrawal-related hyperexcitability. However, other aspects of behavioral tolerance and physical dependence do not rely on α1-containing GABAA-Rs. PMID:19032579

Diverse autonomic regulation of pupillary function and the cardiovascular system during alcohol withdrawal.

PubMed

Jochum, Thomas; Hoyme, Johannes; Schulz, Steffen; Weißenfels, Markus; Voss, Andreas; Bär, Karl-Jürgen

2016-02-01

Previous research indicated the complexity of autonomic dysfunction during acute alcohol withdrawal. This study aimed to investigate the pupillary light reflex as an indicator of midbrain and brainstem regulatory systems in relation to cardiovascular autonomic function. Thirty male patients were included in the study. They were investigated during acute alcohol withdrawal syndrome and 24h later during clomethiazole treatment and compared to healthy controls. Parameters of pupillary light reflex of both eyes as well as heart rate variability, blood pressure variability and baroreflex sensitivity (BRS) were studied. We observed significantly reduced sympathetic (small diameter, e.g., left eye: 5.00 in patients vs. 5.91 mm in controls) and vagal modulation (e.g., prolonged latencies, left eye: 0.28 vs. 0.26 ms) regarding both pupils during acute alcohol withdrawal syndrome. Cardiovascular parameters showed reduced vagal modulation (e.g., b-slope of BRS: 7. 57 vs. 13.59 ms/mm Hg) and mixed results for sympathetic influence. After 24h, autonomic dysfunction improved significantly, both for the pupils (e.g., left diameter: 5.38 mm) and the heart (e.g., b-slope of BRS: 9.34 ms/mm Hg). While parameters obtained from the pupil correlated with cardiac autonomic function (e.g, BRS and left diameter: r=0.564) in healthy controls, no such pattern was observed in patients. Results obtained from the pupil during acute alcohol withdrawal do not simply mirror autonomic dysfunction regarding the heart. Pupillary and cardiovascular changes after 24h indicate state dependencies of the results. The findings are discussed with respect to autonomic mechanisms and potentially involved brain regions. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

FMRFamide produces biphasic modulation of the LFS motor neurons in the neural circuit of the siphon withdrawal reflex of Aplysia by activating Na+ and K+ currents.

PubMed

Belkin, K J; Abrams, T W

1993-12-01

The molluscan neuropeptide FMRFamide has an inhibitory effect on transmitter release from the presynaptic sensory neurons in the neural circuit for the siphon withdrawal reflex. We have explored whether FMRFamide also acts postsynaptically in motor neurons in this circuit, focusing on the LFS motor neurons. FMRFamide typically produces a biphasic response in LFS neurons: a fast excitatory response followed by a prolonged inhibitory response. We have analyzed these postsynaptic actions and compared them with the mechanism of FMRFamide's inhibition of the presynaptic sensory neurons. The transient excitatory effect of FMRFamide, which desensitizes rapidly, is due to activation of a TTX-insensitive, Na(+)-dependent inward current. The late hyperpolarizing phase of the FMRFamide response results from activation of at least two K+ currents. One component of the hyperpolarizing response is active at rest and at more hyperpolarized membrane potentials, and is blocked by 5 mM 4-aminopyridine, suggesting that it differs from the previously described FMRFamide-modulated K+ currents in the presynaptic sensory neurons. In addition, FMRFamide increases a 4-aminopyridine-insensitive K+ current. Presynaptically, FMRFamide increases K+ conductance, acting via release of arachidonic acid. In the LFS motor neurons, application of arachidonic acid mimicked the prolonged, hyperpolarizing phase of the FMRFamide response; 4-bromophenacyl bromide, an inhibitor of phospholipase A2, selectively blocked this component of the FMRFamide response. Thus, FMRFamide may act in parallel pre- and post-synaptically to inhibit the output of the siphon withdrawal reflex circuit, producing this inhibitory effect via the same second messenger in the sensory neurons and motor neurons, though a number of the K+ currents modulated in these two types of neurons are different.

Analysis and Synthesis of Adaptive Neural Elements and Assemblies

DTIC Science & Technology

1988-09-22

neuromodulation , has been identified in sensory neurons mediating the gill and tail withdrawal reflexes of Aplysia (Hawkins et al., 1983, Walters and... neuromodulation and predicted a characteristic interstimulus interval (ISI) curve (Gingrich and Byrne, 1987). At the subcellular level, the model’s ISI

Influence of time off feed on broiler viscera weight, diameter, and shear.

PubMed

Buhr, R J; Northcutt, J K; Lyon, C E; Rowland, G N

1998-05-01

The influence of time off feed on broiler viscera weight, intestinal diameter, and shear was studied by subjecting market-age male broilers (42, 44, or 48 d) to incremental feed withdrawal periods (0, 6, 12, 18, or 24 h). Body weight was determined prior to feed withdrawal and at the time of processing. After slaughter, scalding, and defeathering, the abdominal cavity was opened. Diameter and shear of the proventriculus-ventriculus junction, jejunum, and ileum segments were measured, as were gallbladder length and width. Thoracic and abdominal viscera, liver, and ventriculus weights were determined, and liver surface color was measured. Percentage body weight loss increased with longer feed withdrawal periods, as viscera, liver, and ventriculus weights decreased. Gallbladder length increased with time off feed, whereas its width did not change. Diameter of the proventriculus-ventriculus junction, jejunum, and ileum decreased with longer feed withdrawal periods. Shear values for the proventriculus-ventriculus junction, jejunum, and ileum were not influenced by time off feed. Positive correlations (P < 0.05 and r > 0.4) between viscera weight and intestinal diameter were detected. Correlations between all measured parameters and shear values were not significant. Liver color measurements indicated that longer feed withdrawal periods resulted in significant linear decreases in L* (lightness), +a* (redness), and +b* (yellowness). Longer feed withdrawal periods decreased viscera weight and intestinal diameter, which would lower the potential for cutting the intestine during automated evisceration. However, the resulting greater gallbladder length (5 mm) would increase the possibility of bile contamination during evisceration.

Neural Regulation of Cardiovascular Response to Exercise: Role of Central Command and Peripheral Afferents

PubMed Central

Nobrega, Antonio C. L.; O'Leary, Donal; Silva, Bruno Moreira; Piepoli, Massimo F.; Crisafulli, Antonio

2014-01-01

During dynamic exercise, mechanisms controlling the cardiovascular apparatus operate to provide adequate oxygen to fulfill metabolic demand of exercising muscles and to guarantee metabolic end-products washout. Moreover, arterial blood pressure is regulated to maintain adequate perfusion of the vital organs without excessive pressure variations. The autonomic nervous system adjustments are characterized by a parasympathetic withdrawal and a sympathetic activation. In this review, we briefly summarize neural reflexes operating during dynamic exercise. The main focus of the present review will be on the central command, the arterial baroreflex and chemoreflex, and the exercise pressure reflex. The regulation and integration of these reflexes operating during dynamic exercise and their possible role in the pathophysiology of some cardiovascular diseases are also discussed. PMID:24818143

Bipedal locomotion of bonnet macaques after spinal cord injury.

PubMed

Babu, Rangasamy Suresh; Anand, P; Jeraud, Mathew; Periasamy, P; Namasivayam, A

2007-10-01

Experimental studies concerning the analysis of locomotor behavior in spinal cord injury research are widely performed in rodent models. The purpose of this study was to quantitatively evaluate the degree of functional recovery in reflex components and bipedal locomotor behavior of bonnet macaques (Macaca radiata) after spinal contusive injury. Six monkeys were tested for various reflex components (grasping, righting, hopping, extension withdrawal) and were trained preoperatively to walk in bipedal fashion on the simple and complex locomotor runways (narrow beam, grid, inclined plane, treadmill) of this investigation. The overall performance of the animals'motor behavior and the functional status of limb movements during bipedal locomotion were graded by the Combined Behavioral Score (CBS) system. Using the simple Allen weight-drop technique, a contusive injury was produced by dropping a 13-g weight from a height of 30 cm to the exposed spinal cord at the T12-L1 vertebral level of the trained monkeys. All the monkeys showed significant impairments in every reflex activity and in walking behavior during the early part of the postoperative period. In subsequent periods, the animals displayed mild alterations in certain reflex responses, such as grasping, extension withdrawal, and placing reflexes, which persisted through a 1-year follow-up. The contused animals traversed locomotor runways--narrow beam, incline plane, and grid runways--with more steps and few errors, as evaluated with the CBS system. Eventually, the behavioral performance of all spinal-contused monkeys recovered to near-preoperative level by the fifth postoperative month. The findings of this study reveal the recovery time course of various reflex components and bipedal locomotor behavior of spinal-contused macaques on runways for a postoperative period of up to 1 year. Our spinal cord research in primates is advantageous in understanding the characteristics of hind limb functions only, which possibly mimic the human motor behavior. This study may be also useful in detecting the beneficial effect of various donor tissue-neuroprotective drugs on the repair of impaired functions in a bipedal primate model of spinal injury.

Noninvasive assessment of the facilitation of the nociceptive withdrawal reflex by repeated electrical stimulations in conscious dogs.

PubMed

Bergadano, Alessandra; Andersen, Ole K; Arendt-Nielsen, Lars; Spadavecchia, Claudia

2007-08-01

To investigate the facilitation of the nociceptive withdrawal reflex (NWR) by repeated electrical stimuli and the associated behavioral response scores in conscious, nonmedicated dogs as a measure of temporal summation and analyze the influence of stimulus intensity and frequency on temporal summation responses. 8 adult Beagles. Surface electromyographic responses evoked by transcutaneous constant-current electrical stimulation of ulnaris and digital plantar nerves were recorded from the deltoideus, cleidobrachialis, biceps femoris, and cranial tibial muscles. A repeated stimulus was given at 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, and 1.1 x I(t) (the individual NWR threshold intensity) at 2, 5, and 20 Hz. Threshold intensity and relative amplitude and latency of the reflex were analyzed for each stimulus configuration. Behavioral reactions were subjectively scored. Repeated sub-I(t) stimuli summated and facilitated the NWR. To elicit temporal summation, significantly lower intensities were needed for the hind limb, compared with the forelimb. Stimulus frequency did not influence temporal summation, whereas increasing intensity resulted in significantly stronger electromyographic responses and nociception (determined via behavioral response scoring) among the dogs. In dogs, it is possible to elicit nociceptive temporal summation that correlates with behavioral reactions. These data suggest that this experimental technique can be used to evaluate nociceptive system excitability and efficacy of analgesics in canids.

A Go-type opsin mediates the shadow reflex in the annelid Platynereis dumerilii.

PubMed

Ayers, Thomas; Tsukamoto, Hisao; Gühmann, Martin; Veedin Rajan, Vinoth Babu; Tessmar-Raible, Kristin

2018-04-18

The presence of photoreceptive molecules outside the eye is widespread among animals, yet their functions in the periphery are less well understood. Marine organisms, such as annelid worms, exhibit a 'shadow reflex', a defensive withdrawal behaviour triggered by a decrease in illumination. Herein, we examine the cellular and molecular underpinnings of this response, identifying a role for a photoreceptor molecule of the G o -opsin class in the shadow response of the marine bristle worm Platynereis dumerilii. We found Pdu-Go-opsin1 expression in single specialised cells located in adult Platynereis head and trunk appendages, known as cirri. Using gene knock-out technology and ablation approaches, we show that the presence of Go-opsin1 and the cirri is necessary for the shadow reflex. Consistently, quantification of the shadow reflex reveals a chromatic dependence upon light of approximately 500 nm in wavelength, matching the photoexcitation characteristics of the Platynereis Go-opsin1. However, the loss of Go-opsin1 does not abolish the shadow reflex completely, suggesting the existence of a compensatory mechanism, possibly acting through a ciliary-type opsin, Pdu-c-opsin2, with a Lambda max of approximately 490 nm. We show that a Go-opsin is necessary for the shadow reflex in a marine annelid, describing a functional example for a peripherally expressed photoreceptor, and suggesting that, in different species, distinct opsins contribute to varying degrees to the shadow reflex.

Antinociceptive Effect of Ghrelin in a Rat Model of Irritable Bowel Syndrome Involves TRPV1/Opioid Systems.

PubMed

Mao, Yuqing; Li, Zhengyang; Chen, Kan; Yu, Huafang; Zhang, Shaoren; Jiang, Miao; Ma, Yuanhua; Liang, Chunli; Liu, Hongyan; Li, Huanqing; Hua, Qian; Zhou, Hao; Sun, Yonghong; Fan, Xiaoming

2017-01-01

Irritable bowel syndrome (IBS), defined as recurrent abdominal pain and changes in bowel habits, seriously affects quality of life and ability to work. Ghrelin is a brain-gut hormone, which has been reported to show antinociceptive effects in peripheral pain. We investigated the effect of ghrelin on visceral hypersensitivity and pain in a rat model of IBS. Maternal deprivation (MD) was used to provide a stress-induced model of IBS in Wistar rats. Colorectal distension (CRD) was used to detect visceral sensitivity, which was evaluated by abdominal withdrawal reflex (AWR) scores. Rats that were confirmed to have visceral hypersensitivity after MD were injected with ghrelin (10 µg/kg) subcutaneously twice a week from weeks 7 to 8. [D-Lys3]-GHRP-6 (100 nmol/L) and naloxone (100 nmol/L) were administered subcutaneously to block growth hormone secretagogue receptor 1α (GHS-R1α) and opioid receptors, respectively. Expression of transient receptor potential vanilloid type 1 (TRPV1) and µ and κ opioid receptors (MOR and KOR) in colon, dorsal root ganglion (DRG) and cerebral cortex tissues were detected by western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemical analyses and immunofluorescence. Ghrelin treatment increased expression of opioid receptors and inhibited expression of TRPV1 in colon, dorsal root ganglion (DRG) and cerebral cortex. The antinociceptive effect of ghrelin in the rat model of IBS was partly blocked by both the ghrelin antagonist [D-Lys3]-GHRP-6 and the opioid receptor antagonist naloxone. The results indicate that ghrelin exerted an antinociceptive effect, which was mediated via TRPV1/opioid systems, in IBS-induced visceral hypersensitivity. Ghrelin might potentially be used as a new treatment for IBS. © 2017 The Author(s). Published by S. Karger AG, Basel.

Establishment of model of visceral pain due to colorectal distension and its behavioral assessment in rats

PubMed Central

Yang, Jian-Ping; Yao, Ming; Jiang, Xing-Hong; Wang, Li-Na

2006-01-01

AIM: To establish a visceral pain model via colorectal distension (CRD) and to evaluate the efficiency of behavioral responses of CRD by measuring the score of abdominal withdrawal reflex (AWR) in rats. METHODS: Thirty-eight male SD rats weighing 180-240g were used to establish the visceral pain model. The rat was inserted intra-anally with a 7 cm long flexible latex balloon under ether anesthesia, and colorectal distensions by inflating the balloon with air were made 30 min after recovering from the anesthesia. Five AWR scores (AWR0 to AWR4) were used to assess the intensity of noxious visceral stimuli. It was regarded as the threshold of the minimal pressure (kPa) for abdominal flatting was induced by colorectal distension. RESULTS: A vigorous AWR to distension of the descending colon and rectum was found in 100% of the awake rats tested. The higher the pressure of distension, the higher the score of AWR. The distension pressures of 0, 2.00, 3.33, 5.33 and 8.00 kPa produced different AWR scores (P < 0.05). The pain threshold of AWR was constant for up to 80 min after the initial windup (first 1-3 distensions), the mean threshold was 3.69 ± 0.35 kPa. Systemic administration of morphine sulfate elevated the threshold of visceral pain in a dose-dependent and naloxone reversible manner. CONCLUSION: Scoring the AWR during colorectal distensions can assess the intensity of noxious visceral stimulus. Flatting of abdomen (AWR 3) to CRD as the visceral pain threshold is clear, constant and reliable. This pain model and its behavioral assessment are good for research on visceral pain and analgesics. PMID:16718770

TRPV1-mediated presynaptic transmission in basolateral amygdala contributes to visceral hypersensitivity in adult rats with neonatal maternal deprivation

PubMed Central

Xiao, Ying; Chen, Xiaoqi; Zhang, Ping-An; Xu, Qiya; Zheng, Hang; Xu, Guang-Yin

2016-01-01

The central mechanisms of visceral hypersensitivity remain largely unknown. It’s reported that there are highest densities of TRPV1 labeled neurons within basolateral amygdala (BLA). The aim of this study was to explore the role and mechanisms of TRPV1 in BLA in development of visceral hypersensitivity. Visceral hypersensitivity was induced by neonatal maternal deprivation (NMD) and was quantified by abdominal withdrawal reflex. Expression of TRPV1 was determined by Western blot. The synaptic transmission of neurons in BLA was recorded by patch clamping. It was found that the expression of TRPV1 in BLA was significantly upregulated in NMD rats; glutamatergic synaptic activities in BLA were increased in NMD rats; application of capsazepine (TRPV1 antagonist) decreased glutamatergic synaptic activities of BLA neurons in NMD slices through a presynaptic mechanism; application of capsaicin (TRPV1 agonist) increased glutamatergic synaptic activities of BLA neurons in control slices through presynaptic mechanism without affecting GABAergic synaptic activities; microinjecting capsazepine into BLA significantly increased colonic distension threshold both in control and NMD rats. Our data suggested that upregulation of TRPV1 in BLA contributes to visceral hypersensitivity of NMD rats through enhancing excitation of BLA, thus identifying a potential target for treatment of chronic visceral pain. PMID:27364923

Abdominal pain of spinal origin. Value of intercostal block.

PubMed Central

Ashby, E. C.

1977-01-01

A prospective study was made of 73 patients presenting in one year with abdominal pain provisionally diagnosed as of spinal origin. The criteria for audit of diagnosis and treatment are defined. The diagnosis was confirmed in 53 patients, 49 of whom had been treated with a lignocaine intercostal block in the relevant segment. Thirty-three of these (67.3%) had both complete and prolonged relief. It is suggested that the block causes interruption of a vicious circle of pain and muscle spasm in a 'spinal reflex pain syndrome'. PMID:860866

Variations in the neonatal environment modulate adult behavioral and brain responses to palatable food withdrawal in adult female rats.

PubMed

Colman, Juliana Barcellos; Laureano, Daniela Pereira; Reis, Tatiane Madeira; Krolow, Rachel; Dalmaz, Carla; Benetti, Carla da Silva; Silveira, Patrícia Pelufo

2015-02-01

Early handling alters adult behavioral responses to palatable food and to its withdrawal following a period of chronic exposure. However, the central mechanisms involved in this phenomenon are not known. Since neonatal handling has persistent effects on stress and anxiety responses, we hypothesized that its involvement in the aforementioned association may be associated with differential neuroadaptations in the amygdala during withdrawal periods. Litters were randomized into two groups: handled (H, removed from their dam for 10min per day from the first to the tenth postnatal day and placed in an incubator at 32°C) and non-handled (NH). Experiment 1: on PNDs 80-100, females were assigned to receive palatable food+rat chow for 15 or 30 days, and these two groups were compared in terms of palatable food preference, body weight and abdominal fat deposition. In Experiment 2, H and NH rats were exposed to a chronic diet of palatable food+rat chow for 15 days, followed by (a) no withdrawal, (b) 24h withdrawal from palatable food (receiving only rat chow) or (c) 7-day withdrawal from palatable food (receiving only rat chow). Body weight, 10-min rebound palatable food intake, abdominal fat deposition, serum corticosterone as well as TH and pCREB levels in the amygdala were then compared between groups. Experiment 1-chronic exposure to palatable food induces comparable metabolic effects after 15 and 30 days. Experiment 2-neonatal handling is associated with a peculiar response to palatable food withdrawal following chronic exposure for 15 days. Rats exposed to early handling ingested less of this food after a 24h withdrawal period, and displayed increased amygdala TH and pCREB levels. Variations in the neonatal environment affect both behavioral responses and amygdala neuroadaptation to acute withdrawal from a palatable diet. These findings contribute to the comprehension of the mechanisms that link early life events and altered feeding behavior and related morbidities such as obesity in adulthood. Copyright © 2014 ISDN. Published by Elsevier Ltd. All rights reserved.

Lymphedema of the Transplanted Kidney and Abdominal Wall with Ipsilateral Pleural Effusion Following Kidney Biopsy in a Patient Treated with Sirolimus: A Case Report and Review of the Literature

PubMed Central

Rashid-Farokhi, Farin; Afshar, Hale

2017-01-01

Patient: Female, 32 Final Diagnosis: Sirolimus induced congestion of kidney and overlying abdominal wall Symptoms: Abdominal pain • abdominal swelling • dyspnea Medication: — Clinical Procedure: Improvement of symptoms with drug withdrawal Specialty: Nephrology Objective: Adverse events of drug therapy Background: Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor, which is used in immunosuppressive treatment regimens in organ transplant recipients. Although mTOR inhibitors are well tolerated, their adverse effects have been reported. Sirolimus treatment in transplant recipients has been reported to be associated with lymphedema of the skin and subcutaneous tissues, and with pleural effusion, but edema of internal organs and organomegaly have not been previously reported. A case is presented lymphedema of the transplanted kidney and abdominal wall with ipsilateral pleural effusion following kidney biopsy in a patient treated with sirolimus. Case Report: A 32-year-old woman with a history of end-stage renal disease of unknown etiology had undergone right renal transplantation from an unrelated living donor, eight years previously. She was referred to our hospital with dyspnea, localized abdominal pain, and swelling of the transplanted kidney. The symptoms appeared following a kidney biopsy and the replacement of cyclosporin with sirolimus four months previously. On examination, she had localized swelling of the abdominal wall overlying the transplanted kidney, and a right pleural effusion. Hydronephrosis and nephrotic syndrome were excluded as causes of kidney enlargement. Following the withdrawal of sirolimus therapy her symptoms resolved within three months. Conclusions: A case is described of lymphedema of the transplanted kidney and abdominal wall with ipsilateral pleural effusion following kidney biopsy attributed to her change in anti-rejection therapy to sirolimus. This case report should raise awareness of this unusual complication of sirolimus anti-rejection therapy and its possible effects on the lymphatic system. PMID:29269724

A Novel in Vitro Analog Expressing Learning-Induced Cellular Correlates in Distinct Neural Circuits

ERIC Educational Resources Information Center

Weisz, Harris A.; Wainwright, Marcy L.; Mozzachiodi, Riccardo

2017-01-01

When presented with noxious stimuli, "Aplysia" exhibits concurrent sensitization of defensive responses, such as the tail-induced siphon withdrawal reflex (TSWR) and suppression of feeding. At the cellular level, sensitization of the TSWR is accompanied by an increase in the excitability of the tail sensory neurons (TSNs) that elicit the…

Differential Role of Inhibition in Habituation of Two Independent Afferent Pathways to a Common Motor Output

ERIC Educational Resources Information Center

Bristol, Adam S.; Carew, Thomas J.

2005-01-01

Many studies of the neural mechanisms of learning have focused on habituation, a simple form of learning in which a response decrements with repeated stimulation. In the siphon-elicited siphon withdrawal reflex (S-SWR) of the marine mollusk "Aplysia," the prevailing view is that homosynaptic depression of primary sensory afferents underlies…

Neuromuscular adaptations after a rehabilitation program in patients with chronic low back pain: case series (uncontrolled longitudinal study)

PubMed Central

2013-01-01

Background To investigate the impact of a short-term multimodal rehabilitation program for patients with low back pain (LBP) on trunk muscle reflex responses and feedforward activation induced by postural perturbations. Methods Case series (uncontrolled longitudinal study). Thirty chronic patients with LBP (21 women and 19 men, mean age 42.6 ± 8.6 years, mean weight 73 ± 14 kg, mean height 174 ± 10 cm) were included. The intervention consisted in a 5-day program including therapeutic education sessions (360 min), supervised abdominal and back muscle strength exercises (240 min), general aerobic training (150 min), stretching (150 min), postural education (150 min) and aqua therapy (150 min). Feedforward activation level and reflex amplitude determined by surface electromyographic activity triggered by postural perturbations were recorded from abdominal and paraspinal muscles in unexpected and expected conditions. Subjects were tested before, just after and again one month after the rehabilitation program. Results No main intervention effect was found on feedforward activation levels and reflex amplitudes underlining the absence of changes in the way patients with LBP reacted across perturbation conditions. However, we observed a shift in the behavioral strategy between conditions, in fact feedforward activation (similar in both conditions before the program) decreased in the unexpected condition after the program, whereas reflex amplitudes became similar in both conditions. Conclusions The results suggest that a short-term rehabilitation program modifies trunk behavioral strategies during postural perturbations. These results can be useful to clinicians for explaining to patients how to adapt to daily life activities before and after rehabilitation. PMID:24063646

Control of abdominal and expiratory intercostal muscle activity during vomiting - Role of ventral respiratory group expiratory neurons

NASA Technical Reports Server (NTRS)

Miller, Alan D.; Tan, L. K.; Suzuki, Ichiro

1987-01-01

The role of ventral respiratory group (VRG) expiratory (E) neurons in the control of abdominal and internal intercostal muscle activity during vomiting was investigated in cats. Two series of experiments were performed: in one, the activity of VRG E neurons was recorded during fictive vomiting in cats that were decerebrated, paralyzed, and artificially ventilated; in the second, the abdominal muscle activity during vomiting was compared before and after sectioning the axons of descending VRG E neurons in decerebrate spontaneously breathing cats. The results show that about two-thirds of VRG E neurons that project at least as far caudally as the lower thoracic cord contribute to internal intercostal muscle activity during vomiting. The remaining VRG E neurons contribute to abdominal muscle activation. As shown by severing the axons of the VRG E neurons, other, as yet unidenified, inputs (either descending from the brain stem or arising from spinal reflexes) can also produce abdominal muscle activation.

Effects of a chronic exposure to a highly palatable diet and its withdrawal, in adulthood, on cerebral Na+,K+-ATPase and plasma S100B in neonatally handled rats.

PubMed

da S Benetti, Carla; Silveira, Patrícia P; Matté, Cristiane; Stefanello, Francieli M; Leite, Marina C; Gonçalves, Carlos Alberto S; Wyse, Angela T S; Dalmaz, Carla; Goldani, Marcelo Z

2010-04-01

We have previously demonstrated that early environment influences the metabolic response, affecting abdominal fat deposition in adult female rats exposed to a long-term highly caloric diet. In the present study, our goal was to verify the effects of the chronic exposure, in adulthood, to a highly palatable diet (chocolate) on cerebral Na+,K+-ATPase activity and S100B protein concentrations, and the response to its withdrawal in neonatally handled and non-handled rats. We measured the consumption of foods (standard lab chow and chocolate), body weight gain, S100B protein concentrations, as well as cerebral Na(+),K(+)-ATPase activity during chronic exposure and after chocolate withdrawal in adult female rats that had been exposed or not to neonatal handling (10 min/day, 10 first days of life). Non-handled rats chronically exposed to chocolate exhibited increased plasma S100B levels, but there was no difference in abdominal fat S100B concentration between groups. Chronic chocolate consumption decreased Na+,K+-ATPase activity in both amygdala and hippocampus in non-handled, but not in handled rats, and this effect disappeared after chocolate withdrawal. Non-handled animals also demonstrated increased frequency of head shaking in the open field after 24h of chocolate withdrawal in comparison to handled ones. These findings suggest that neonatal handling modifies the vulnerability to metabolic and brain alterations induced by chronic exposure to a highly palatable diet in adulthood. Copyright 2009 ISDN. Published by Elsevier Ltd. All rights reserved.

Anesthetic and pathological changes following high doses of ketamine and xylazine in Sprague Dawley rats

PubMed Central

GIROUX, Marie-Chantal; HÉLIE, Pierre; BURNS, Patrick; VACHON, Pascal

2015-01-01

The main objective of this study was to compare the effects of ketamine and xylazine in aging rats when coadministered intraperitoneally at high anesthetic doses. Three groups (n=6 rats/group) consisting of rats at 3, 6 and 12 months of age were used. During anesthesia, animals were monitored for heart rate, respiratory frequency, blood oxygen saturation, and rectal temperature. The corneal and paw withdrawal reflex were also examined during anesthesia. During anesthesia, withdrawal and corneal reflexes were absent for progressively longer durations with increasing age. Significant decreases in cardiac and respiratory frequency and, blood oxygen saturation occurred for the 6- and 12-month-old animals. Respiratory frequency and blood oxygen saturation returned to normal at the end of the anesthesia; however, the significant decrease in cardiac frequency persisted in the 6- and 12-month-old animals. Rectal temperature was decreased significantly only in the 3-month-old animals. Pulmonary edema and effusion occurred in 50% of the 12-month-old animals. In conclusion, if ketamine-xylazine are used for anesthesia, the doses should be optimized for the age of the subjects prior to initiation of the research project. PMID:25818316

Effective treatment of dyssynergic defecation using sacral neuromodulation in a patient with cerebral palsy.

PubMed

Chan, Daniel K; Barker, Matthew A

2015-01-01

Dyssynergic defecation is a complex bowel problem that leads to chronic constipation and abdominal pain. Management is often challenging owing to the incoordination of multiple pelvic floor muscles involved in normal defecation. We report a case of dyssynergic defecatory dysfunction in a patient with cerebral palsy treated with sacral neuromodulation. At presentation, Sitz marker study and magnetic resonance defecography showed evidence of chronic functional constipation. Anorectal manometry, rectal anal inhibitory reflex, and rectal sensation study showed intact reflex and decreased first sensation of lower canal at 50 mL. After stage 2 of InterStim implant placement, bowel habits improved to once- to twice-daily soft solid bowel movements from no regular solid bowel movements. Fecal incontinence improved from daily liquid and small solid loss to no stool leakage. In patients with systemic medical problems contributing to defecatory dysfunction and bowel incontinence, such as cerebral palsy, sacral neuromodulation was found to provide significant relief of bowel symptoms in addition to associated abdominal pain. As a result of intervention, the patient reported significant improvement in quality of life and less limitations due to dyssynergic defecation.

Effect of long-term ketamine administration on vocalization to paw pressure and on spinal wind-up activity in monoarthritic rats.

PubMed

Pelissier, Teresa; Alvarez, Pedro; Hernández, Alejandro

2003-09-01

The antinociceptive effect of long-lasting ketamine administration (mini-osmotic pump) was studied in monoarthritic rats by using hindpaw pressure testing and wind-up measurement in a C-fiber reflex paradigm. Chronic ketamine induced antinociception in the monoarthritic paw and significantly suppressed mechanical hyperalgesia during the 14-day treatment period. The treatment also reduced C-reflex wind-up in the monoarthritic hindpaw. After pump removal, vocalization thresholds and spinal wind-up scores from the monoarthritic paw returned to control values, while hyperalgesia developed in the normal paw. Results suggest that ketamine upregulates NMDA receptors upon long-term administration, resulting in hyperalgesic response in the normal paw after drug withdrawal.

Behavioral aging is associated with reduced sensory neuron excitability in Aplysia californica.

PubMed

Kempsell, Andrew T; Fieber, Lynne A

2014-01-01

Invertebrate models have advantages for understanding the basis of behavioral aging due to their simple nervous systems and short lifespans. The potential usefulness of Aplysia californica in aging research is apparent from its long history of neurobiological research, but it has been underexploited in this model use. Aging of simple reflexes at both single sensory neuron and neural circuit levels was studied to connect behavioral aging to neurophysiological aging. The tail withdrawal reflex (TWR), righting reflex, and biting response were measured throughout sexual maturity in 3 cohorts of hatchery-reared animals of known age. Reflex times increased and reflex amplitudes decreased significantly during aging. Aging in sensory neurons of animals with deficits in measures of the TWR and biting response resulted in significantly reduced excitability in old animals compared to their younger siblings. The threshold for firing increased while the number of action potentials in response to depolarizing current injection decreased during aging in sensory neurons, but not in tail motoneurons. Glutamate receptor-activated responses in sensory neurons also decreased with aging. In old tail motoneurons, the amplitude of evoked EPSPs following tail shock decreased, presumably due to reduced sensory neuron excitability during aging. The results were used to develop stages of aging relevant to both hatchery-reared and wild-caught Aplysia. Aplysia is a viable aging model in which the contributions of differential aging of components of neural circuits may be assessed.

Behavioral aging is associated with reduced sensory neuron excitability in Aplysia californica

PubMed Central

Kempsell, Andrew T.; Fieber, Lynne A.

2014-01-01

Invertebrate models have advantages for understanding the basis of behavioral aging due to their simple nervous systems and short lifespans. The potential usefulness of Aplysia californica in aging research is apparent from its long history of neurobiological research, but it has been underexploited in this model use. Aging of simple reflexes at both single sensory neuron and neural circuit levels was studied to connect behavioral aging to neurophysiological aging. The tail withdrawal reflex (TWR), righting reflex, and biting response were measured throughout sexual maturity in 3 cohorts of hatchery-reared animals of known age. Reflex times increased and reflex amplitudes decreased significantly during aging. Aging in sensory neurons of animals with deficits in measures of the TWR and biting response resulted in significantly reduced excitability in old animals compared to their younger siblings. The threshold for firing increased while the number of action potentials in response to depolarizing current injection decreased during aging in sensory neurons, but not in tail motoneurons. Glutamate receptor-activated responses in sensory neurons also decreased with aging. In old tail motoneurons, the amplitude of evoked EPSPs following tail shock decreased, presumably due to reduced sensory neuron excitability during aging. The results were used to develop stages of aging relevant to both hatchery-reared and wild-caught Aplysia. Aplysia is a viable aging model in which the contributions of differential aging of components of neural circuits may be assessed. PMID:24847260

Stress reactivity in childhood functional abdominal pain or irritable bowel syndrome.

PubMed

Gulewitsch, M D; Weimer, K; Enck, P; Schwille-Kiuntke, J; Hautzinger, M; Schlarb, A A

2017-01-01

Frequent abdominal pain (AP) in childhood has been shown to be associated with elevated experience of stress and with deficits in stress coping, but psychophysiological stress reactivity has been studied rarely. We examined whether children with frequent AP show altered reactions of the parasympathetic nervous system and the hypothalamic-pituitary-adrenal (HPA) axis during and following an afternoon laboratory social stress task in comparison to healthy children and children with anxiety disorders. Twenty-four children with frequent AP (18 with functional AP and six with irritable bowel syndrome; M = 9.9 years), and 24 healthy controls underwent stressful free speech and arithmetic tasks. Twelve children with anxiety disorders served as second comparison sample. Groups were compared regarding parasympathetic reaction and saliva cortisol concentration. We found no differences in parasympathetic withdrawal between the groups. Concerning the HPA axis, we detected an attenuated cortisol reactivity in children with AP compared to both other groups. This study provides preliminary evidence that childhood AP is not associated with altered parasympathetic withdrawal during stress. It seems to be related to a down-regulated reactivity of the HPA axis. This pattern was ascertained in comparison to healthy children and also in comparison to children with anxiety disorders. Childhood abdominal pain could be related to down-regulated HPA axis reactivity to stress but not to altered parasympathetic reaction. Children with abdominal pain and children with anxiety disorders exhibit a divergent stress-related HPA axis reaction. © 2016 European Pain Federation - EFIC®.

Flexible strategies for flight control: an active role for the abdomen.

PubMed

Dyhr, Jonathan P; Morgansen, Kristi A; Daniel, Thomas L; Cowan, Noah J

2013-05-01

Moving animals orchestrate myriad motor systems in response to multimodal sensory inputs. Coordinating movement is particularly challenging in flight control, where animals deal with potential instability and multiple degrees of freedom of movement. Prior studies have focused on wings as the primary flight control structures, for which changes in angle of attack or shape are used to modulate lift and drag forces. However, other actuators that may impact flight performance are reflexively activated during flight. We investigated the visual-abdominal reflex displayed by the hawkmoth Manduca sexta to determine its role in flight control. We measured the open-loop stimulus-response characteristics (measured as a transfer function) between the visual stimulus and abdominal response in tethered moths. The transfer function reveals a 41 ms delay and a high-pass filter behavior with a pass band starting at ~0.5 Hz. We also developed a simplified mathematical model of hovering flight wherein articulation of the thoracic-abdominal joint redirects an average lift force provided by the wings. We show that control of the joint, subject to a high-pass filter, is sufficient to maintain stable hovering, but with a slim stability margin. Our experiments and models suggest a novel mechanism by which articulation of the body or 'airframe' of an animal can be used to redirect lift forces for effective flight control. Furthermore, the small stability margin may increase flight agility by easing the transition from stable flight to a more maneuverable, unstable regime.

WITHDRAWN: H-reflex up-conditioning after sciatic nerve transection and regeneration may increase VGLUT-1 terminals and GluR2/3 immunoreactivity in spinal motoneurons.

PubMed

Sun, Chenyou; Wang, Yu; Chen, Xiang Yang

2011-12-17

This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy. Copyright © 2011. Published by Elsevier Ireland Ltd.. All rights reserved.

Action-based sensory encoding in spinal sensorimotor circuits.

PubMed

Schouenborg, Jens

2008-01-01

The concept of a modular organisation of the spinal withdrawal reflex circuits has proven to be fundamental for the understanding of how the spinal cord is organised and how the sensorimotor circuits translate sensory information into adequate movement corrections. Recent studies indicate that a task-related body representation is engraved at the network level through learning-dependent mechanisms involving an active probing procedure termed 'somatosensory imprinting' during development. It was found that somatosensory imprinting depends on the tactile input that is associated with spontaneous movements that occur during sleep and results in elimination of erroneous connections and establishment of correct connections. In parallel studies it was found that the strength of the first order tactile synapses in rostrocaudally elongated zones in the adult dorsal horn in the lower lumbar cord is related to the modular organisation of the withdrawal reflexes. Hence, the topographical organisation of the tactile input to this spinal area seems to be action-based rather than a simple body map as previously thought. Far from being innate and adult like at birth, the adult organisation seems to emerge from an initial 'floating' and diffuse body representation with many inappropriate connections through profound activity-dependent rearrangements of afferent synaptic connections. It is suggested that somatosensory imprinting plays a key role in the self-organisation of the spinal cord during development.

[Effect of preconditioning of thermopaste application at Shenque (CV 8) on stretch reflex induced by procedure for prolapse and hemorrhoids in patients with hemorrhoids].

PubMed

Li, Jun; Wen, Yong; Yue, Chao-Chi; Li, Ya-Ling

2013-08-01

To observe clinical effect, feasibility and security of preconditioning of thermopaste application at Shenque (CV 8) for relieving stretch reflex induced by procedure for prolapse and hemorrhoids (PPH). A total of 100 cases of mixed hemorrhoids (stage III and IV) patients were randomized into 1.0 h, 0.5 h, 0 h and control (no application) groups (n = 25 in each group) according to a random number table. Thermopaste was applied to Shenque (CV 8) 1.0 h and 0.5 h before PPH or conducted simultaneously with PPH. The mean arterial pressure, heart rate, blood oxygen saturation of patients before and after anastomose operation, and the incidence of adverse reactions within 24 hours after the procedure were monitored and recorded. The patient's pain degree was assessed by using visual analogue scale. After the preconditioning, of the 25 patients in the 0.5 h group (0.5 h G), 14 experienced marked improvement (in the stretch reflex during PPH), 10 had an improvement, and 1 was invalid, respectively. The markedly effective rate and the total effective rate were 56% and 96%, respectively. The therapeutic effects for inhibiting stretch reflect being from the better to the poorer were 0.5 h G > 1.0 h G > 0 h G >NG. The heart rate and blood pressure from more stable to lesser stable were 0.5 h G> 1.0 h G > 0 h G > NG. The patients' pain reaction during operation and their adverse effects of nausea, vomiting, abdominal distention and abdominal pain, etc. occurred during operation also presented the same tendency in the 4 groups. Thermopaste application to Shenque (CV 8) can effectively prevent and control visceral reflex in patients undergoing PPH, which effect is significantly better when conducted 0.5 hour before the operation.

Regulation of muscle stiffness during periodic length changes in the isolated abdomen of the hermit crab.

PubMed

Chapple, W D

1997-09-01

Reflex activation of the ventral superficial muscles (VSM) in the abdomen of the hermit crab, Pagurus pollicarus, was studied using sinusoidal and stochastic longitudinal vibration of the muscle while recording the length and force of the muscle and the spike times of three exciter motoneurons. In the absence of vibration, the interspike interval histograms of the two larger motoneurons were bimodal; cutting sensory nerves containing most of the mechanoreceptor input removed the short interval peak in the histogram, indicating that the receptors are important in maintaining tonic firing. Vibration of the muscle evoked a reflex increase in motoneuron frequency that habituated after an initial peak but remained above control levels for the duration of stimulation. Motoneuron frequency increased with root mean square (rms) stimulus amplitude. Average stiffness during stimulation was about two times the stiffness of passive muscle. The reflex did not alter muscle dynamics. Estimated transfer functions were calculated from the fast Fourier transform of length and force signals. Coherence was >0.9 for the frequency range of 3-35 Hz. Stiffness magnitude gradually increased over this range in both reflex activated and passive muscle; phase was between 10 and 20 degrees. Reflex stiffness decreased with increasing stimulus amplitudes, but at larger amplitudes, this decrease was much less pronounced; in this range stiffness was regulated by the reflex. The sinusoidal frequency at which reflex bursts were elicited was approximately 6 Hz, consistent with previous measurements using ramp stretch. During reflex excitation, there was an increase in amplitude of the short interval peak in the interspike interval histogram; this was reduced when the majority of afferent pathways was removed. A phase histogram of motoneuron firing during sinusoidal vibration had a peak at approximately 110 ms, also suggesting that an important component of the reflex is via direct projections from the mechanoreceptors. These results are consistent with the hypothesis that a robust feedforward regulation of abdominal stiffness during continuous disturbances is achieved by mechanoreceptors signalling the absolute value of changing forces; habituation of the reflex, its high-threshold for low frequency disturbances and the activation kinetics of the muscle further modify reflex dynamics.

[Abdominal bloating: an up-to-date].

PubMed

Ducrotté, P

2009-10-01

Bloating is a common symptom, especially in women. In the clinical practice, it remains a therapeutic challenge. Since recently, its pathophysiology is better understood: an impaired transit of gas (particularly in the small bowel) or a visceral hypersensitivity leading to the induction of an abdominal discomfort despite a normal volume of gas are two of the main causes, far more frequent than an excessive production of gas. Moreover, bloating can be related to abnormal viscera-somatic reflexes promoting both an abdomino-phrenic dyssynergia and the relaxation of the muscles of the abdominal wall. From a therapeutic point of view, the efficacy of the gas absorbants remains to be more documented. Besides the treatment of a constipation and the avoidance of nutrients either highly fermentable or rich in fructose, other therapeutic options include prokinetics and drugs acting on visceral sensitivity. Probiotics are another promising option. In some centers, a non pharmacological therapeutic approach, mainly based on hypnosis, is discussed.

Pharmacologic evaluation of pressor and visceromotor reflex responses to bladder distension.

PubMed

Su, Xin; Riedel, Erin S; Leon, Lisa A; Laping, Nicholas J

2008-01-01

Several mechanisms that are involved in acute rat bladder nociception were examined. The nociceptive response was measured by analyzing both cardiovascular and visceromotor reflex responses to urinary bladder distension. The contributions of micro-opioid receptor, kappa-opioid receptor, sodium channels, muscarinic receptors, and cyclooxygenase, were explored with morphine, U50,488, mexiletine, oxybutynin, and naproxen, respectively. Female Sprague-Dawley rats were acutely instrumented with jugular venous, carotid arterial, and bladder cannulas. Needle electrodes were placed directly into the abdominal musculature to measure myoelectrical activity subsequent to repeated phasic urinary bladder distension (60 mmHg for 20 sec in 3 min intervals) under 1% isoflurane. Drugs were administered by i.v. bolus injection 2 min prior to distension. The analgesics morphine (ID50 0.69 mg/kg), U50,488 (1.34 mg/kg), and mexiletine (2.60 mg/kg) significantly inhibited the visceromotor reflex response to noxious urinary bladder distension. Oxybutynin also attenuated reflex responses to noxious urinary bladder distension to 41% of the maximal pressor response and 32% of the control visceromotor reflex response (3.01 and 5.05 mg/kg), respectively, indicating a role of muscarinic receptors in bladder nociception. Naproxen did not attenuate the pressor response, but moderately inhibited visceromotor reflex to 45% of control at 30 mg/kg (P < 0.05). Current results using the rat urinary bladder distension model are consistent with previous research demonstrating a role of the analgesics (morphine, U50,488, and mexiletine) in the inhibition of visceral nociceptive transmission. The utility of the reflex responses to urinary bladder distension may provide a method useful to examine mechanisms which target the bladder sensory pathway. (c) 2007 Wiley-Liss, Inc.

Assessment of abdominal muscle function in individuals with motor-complete spinal cord injury above T6 in response to transcranial magnetic stimulation.

PubMed

Bjerkefors, Anna; Squair, Jordan W; Chua, Romeo; Lam, Tania; Chen, Zhen; Carpenter, Mark G

2015-02-01

To use transcranial magnetic stimulation and electromyography to assess the potential for preserved function in the abdominal muscles in individuals classified with motor-complete spinal cord injury above T6. Five individuals with spinal cord injury (C5-T3) and 5 able-bodied individuals. Transcranial magnetic stimulation was delivered over the abdominal region of primary motor cortex during resting and sub-maximal (or attempted) contractions. Surface electromyography was used to record motor-evoked potentials as well as maximal voluntary (or attempted) contractions in the abdominal muscles and the diaphragm. Responses to transcranial magnetic stimulation in the abdominal muscles occurred in all spinal cord injury subjects. Latencies of muscle response onsets were similar in both groups; however, peak-to-peak amplitudes were smaller in the spinal cord injury group. During maximal voluntary (or attempted) contractions all spinal cord injury subjects were able to elicit electromyography activity above resting levels in more than one abdominal muscle across tasks. Individuals with motor-complete spinal cord injury above T6 were able to activate abdominal muscles in response to transcranial magnetic stimulation and during maximal voluntary (or attempted) contractions. The activation was induced directly through corticospinal pathways, and not indirectly by stretch reflex activations of the diaphragm. Transcranial magnetic stimulation and electromyography measurements provide a useful method to assess motor preservation of abdominal muscles in persons with spinal cord injury.

Identifying Potential Ventilator Auto-Triggering Among Organ Procurement Organization Referrals.

PubMed

Henry, Nicholas R; Russian, Christopher J; Nespral, Joseph

2016-06-01

Ventilator auto-trigger is the delivery of an assisted mechanical ventilated breath over the set ventilator frequency in the absence of a spontaneous inspiratory effort and can be caused by inappropriate ventilator trigger sensitivity. Ventilator auto-trigger can be misinterpreted as a spontaneous breath and has the potential to delay or prevent brain death testing and confuse health-care professionals and/or patient families. To determine the frequency of organ donor referrals from 1 Organ Procurement Organization (OPO) that could benefit from an algorithm designed to assist organ recovery coordinators to identify and correct ventilator auto-triggering. This retrospective analysis evaluated documentation of organ donor referrals from 1 OPO in central Texas during the 2013 calendar year that resulted in the withdrawal of care by the patient's family and the recovery of organs. The frequency of referrals that presented with absent brain stem reflexes except for additional respirations over the set ventilator rate was determined to assess for the need of the proposed algorithm. Documentation of 672 organ procurement organization referrals was evaluated. Documentation from 42 referrals that resulted in the withdrawal of care and 21 referrals that resulted in the recovery of organs were identified with absent brain stem reflexes except for spontaneous respirations on the mechanical ventilator. As a result, an algorithm designed to identify and correct ventilator auto-trigger could have been used 63 times during the 2013 calendar year. © 2016, NATCO.

P2X₇ receptor of rat dorsal root ganglia is involved in the effect of moxibustion on visceral hyperalgesia.

PubMed

Liu, Shuangmei; Shi, Qingming; Zhu, Qicheng; Zou, Ting; Li, Guilin; Huang, An; Wu, Bing; Peng, Lichao; Song, Miaomiao; Wu, Qin; Xie, Qiuyu; Lin, Weijian; Xie, Wei; Wen, Shiyao; Zhang, Zhedong; Lv, Qiulan; Zou, Lifang; Zhang, Xi; Ying, Mofeng; Li, Guodong; Liang, Shangdong

2015-06-01

Irritable bowel syndrome (IBS) and inflammatory bowel disease often display visceral hypersensitivity. Visceral nociceptors after inflammatory stimulation generate afferent nerve impulses through dorsal root ganglia (DRG) transmitting to the central nervous system. ATP and its activated-purinergic 2X7 (P2X7) receptor play an important role in the transmission of nociceptive signal. Purinergic signaling is involved in the sensory transmission of visceral pain. Moxibustion is a therapy applying ignited mugwort directly or indirectly at acupuncture points or other specific parts of the body to treat diseases. Heat-sensitive acupoints are the corresponding points extremely sensitive to moxa heat in disease conditions. In this study, we aimed to investigate the relationship between the analgesic effect of moxibustion on a heat-sensitive acupoint "Dachangshu" and the expression levels of P2X7 receptor in rat DRG after chronic inflammatory stimulation of colorectal distension. Heat-sensitive moxibustion at Dachangshu acupoint inhibited the nociceptive signal transmission by decreasing the upregulated expression levels of P2X7 mRNA and protein in DRG induced by visceral pain, and reversed the abnormal expression of glial fibrillary acidic protein (GFAP, a marker of satellite glial cells) in DRG. Consequently, abdominal withdrawal reflex (AWR) score in a visceral pain model was reduced, and the pain threshold was elevated. Therefore, heat-sensitive moxibustion at Dachangshu acupoint can produce a therapeutic effect on IBS via inhibiting the nociceptive transmission mediated by upregulated P2X7 receptor.

[Effect of changji'an on visceral hypersensitivity in rats with irritable bowel syndrome and its mechanism].

PubMed

Zhu, Qi; Wang, Jing; Lai, Hua-mei

2008-09-01

To explore the mechanism and efficiency of Changji'an (CJA) in treating irritable bowel syndrome through studying the relationship between serotonin transporter (SERT) and visceral hypersensitivity in rats. Male SD rats were randomly divided into 4 groups: the normal control group, the model group, the high-dosage and low-dosage CJA (CJAH and CJAL) groups. Visceral hypersensitivity model was established by colorectal distension. Normal saline and different doses of CJA were administrated to rats respectively, starting from the 10th day of modeling for 10 days. After then, the abdominal withdrawal reflex (AWR) was scored for semi-quantitative estimation of visceral sensitivity, and tissues of brain and colon were harvested for detecting expressions of SERT and serotonin (5-HT) with Western blot, real-time PCR and immunohistochemistry. As compared with the normal controls, in model rats, the AWR score and content of 5-HT in intestinal mucosa were higher (P < 0.05), protein and mRNA expressions of SERT in colon and nucleus raphes dorsalis (NRD) were lower (P < 0.05), but all these indexes were improved significantly after CJA treatment, either in the CJAH or CJAL group (all P < 0.05). Besides, the number of 5-HT energic neuron in the model group and CJA groups was lower than that in the normal control group (P < 0.05). CJA has therapeutic effect for improving visceral hypersensitivity in irritable bowel syndrome by way of regulating colonic expression of SERT and content of 5-HT.

Visceral hypersensitive rats share common dysbiosis features with irritable bowel syndrome patients.

PubMed

Zhou, Xiao-Yan; Li, Ming; Li, Xia; Long, Xin; Zuo, Xiu-Li; Hou, Xiao-Hua; Cong, Ying-Zi; Li, Yan-Qing

2016-06-14

To evaluate gut microbial dysbiosis in two visceral hypersensitive models in comparison with irritable bowel syndrome (IBS) patients and to explore the extent to which these models capture the dysbiosis of IBS patients. Visceral hypersensitivity was developed using the maternal separation (MS) rat model and post-inflammatory rat model. The visceral sensitivity of the model groups and control group was evaluated using the abdominal withdraw reflex score and electromyography in response to graded colorectal distention. The 16S ribosomal RNA gene from fecal samples was pyrosequenced and analyzed. The correlation between dysbiosis in the microbiota and visceral hypersensitivity was calculated. Positive findings were compared to sequencing data from a published human IBS cohort. Dysbiosis triggered by neonatal maternal separation was lasting but not static. Both MS and post-inflammatory rat fecal microbiota deviated from that of the control rats to an extent that was larger than the co-housing effect. Two short chain fatty acid producing genera, Fusobacterium and Clostridium XI, were shared by the human IBS cohort and by the maternal separation rats and post-inflammatory rats, respectively, to different extents. Fusobacterium was significantly increased in the MS group, and its abundance positively correlated with the degree of visceral hypersensitivity. Porphyromonadaceae was a protective biomarker for both the rat control group and healthy human controls. The dysbiosis MS rat model and the post-inflammatory rat model captured some of the dysbiosis features of IBS patients. Fusobacterium, Clostridium XI and Porphyromonadaceae were identified as targets for future mechanistic research.

Cough-Anal Reflex May Be the Expression of a Pre-Programmed Postural Action

PubMed Central

Cavallari, Paolo; Bolzoni, Francesco; Esposti, Roberto; Bruttini, Carlo

2017-01-01

When coughing, an involuntary contraction of the external anal sphincter occurs, in order to prevent unwanted leakages or sagging of the pelvis muscular wall. Literature originally described such cough-anal response as a reflex elicited by cough, therefore identifying a precise cause-effect relationship. However, recent studies report that the anal contraction actually precedes the rise in abdominal pressure during cough expiratory effort, so that the sphincter activity should be pre-programmed. In recent years, an important family of pre-programmed muscle activities has been well documented to precede voluntary movements: these anticipatory actions play a fundamental role in whole body and segmental postural control, hence they are referred to as anticipatory postural adjustments (APAs). On these basis, we searched in literature for similarities between APAs and the cough-anal response, observing that both follow the same predictive homeostatic principle, namely that anticipatory collateral actions are needed to prevent the unwanted mechanical consequences induced by the primary movement. We thus propose that the cough-anal response also belongs to the family of pre-programmed actions, as it may be interpreted as an APA acting on the abdominal-thoracic compartment; in other words, the cough-anal response may actually be an Anticipatory Sphincter Adjustment, the visceral counterpart of APAs. PMID:29021750

Cough-Anal Reflex May Be the Expression of a Pre-Programmed Postural Action.

PubMed

Cavallari, Paolo; Bolzoni, Francesco; Esposti, Roberto; Bruttini, Carlo

2017-01-01

When coughing, an involuntary contraction of the external anal sphincter occurs, in order to prevent unwanted leakages or sagging of the pelvis muscular wall. Literature originally described such cough-anal response as a reflex elicited by cough, therefore identifying a precise cause-effect relationship. However, recent studies report that the anal contraction actually precedes the rise in abdominal pressure during cough expiratory effort, so that the sphincter activity should be pre-programmed . In recent years, an important family of pre-programmed muscle activities has been well documented to precede voluntary movements: these anticipatory actions play a fundamental role in whole body and segmental postural control, hence they are referred to as anticipatory postural adjustments (APAs). On these basis, we searched in literature for similarities between APAs and the cough-anal response, observing that both follow the same predictive homeostatic principle , namely that anticipatory collateral actions are needed to prevent the unwanted mechanical consequences induced by the primary movement. We thus propose that the cough-anal response also belongs to the family of pre-programmed actions, as it may be interpreted as an APA acting on the abdominal-thoracic compartment; in other words, the cough-anal response may actually be an Anticipatory Sphincter Adjustment , the visceral counterpart of APAs .

Interneuronal Mechanism for Tinbergen’s Hierarchical Model of Behavioral Choice

PubMed Central

Pirger, Zsolt; Crossley, Michael; László, Zita; Naskar, Souvik; Kemenes, György; O’Shea, Michael; Benjamin, Paul R.; Kemenes, Ildikó

2014-01-01

Summary Recent studies of behavioral choice support the notion that the decision to carry out one behavior rather than another depends on the reconfiguration of shared interneuronal networks [1]. We investigated another decision-making strategy, derived from the classical ethological literature [2, 3], which proposes that behavioral choice depends on competition between autonomous networks. According to this model, behavioral choice depends on inhibitory interactions between incompatible hierarchically organized behaviors. We provide evidence for this by investigating the interneuronal mechanisms mediating behavioral choice between two autonomous circuits that underlie whole-body withdrawal [4, 5] and feeding [6] in the pond snail Lymnaea. Whole-body withdrawal is a defensive reflex that is initiated by tactile contact with predators. As predicted by the hierarchical model, tactile stimuli that evoke whole-body withdrawal responses also inhibit ongoing feeding in the presence of feeding stimuli. By recording neurons from the feeding and withdrawal networks, we found no direct synaptic connections between the interneuronal and motoneuronal elements that generate the two behaviors. Instead, we discovered that behavioral choice depends on the interaction between two unique types of interneurons with asymmetrical synaptic connectivity that allows withdrawal to override feeding. One type of interneuron, the Pleuro-Buccal (PlB), is an extrinsic modulatory neuron of the feeding network that completely inhibits feeding when excited by touch-induced monosynaptic input from the second type of interneuron, Pedal-Dorsal12 (PeD12). PeD12 plays a critical role in behavioral choice by providing a synaptic pathway joining the two behavioral networks that underlies the competitive dominance of whole-body withdrawal over feeding. PMID:25155505

Evaluation of the Analgesic Activity of the Methanolic Stem Bark Extract of Dialium Guineense (Wild)

PubMed Central

Ezeja, MI; Omeh, YS; Ezeigbo, II; Ekechukwu, A

2011-01-01

Background: Dialium guineense is a medicinal plant used by some communities of Enugu-Ezike in Enugu State, Nigeria for treatment of fever, headache and other diverse ailments. Objectives: The present study evaluated the analgesic activity of the methanolic stem bark extract of the plant. Method: Acetic acid-induced abdominal constriction or writhing, tail immersion and hot plate analgesic models in albino Wistar mice were used for the study. Three test doses (250, 500, 1000 mg/kg body weight) of the extract were administered orally by gastric gavage. The activity was compared with a standard reference drug, acetylsalicylic acid (aspirin) (400 mg/kg) and negative control. The results were analysed by SPSS version 17 using ANOVA and Post Hoc Duncan. Result: In the acetic acid-induced writhing reflex model, D. guineense extract and the reference drug significantly (P =0.014 - 0.002) decreased the mean total number of abdominal constriction in the mice in a dose dependent fashion. The percentage inhibition of the abdominal constriction reflex was increased dose dependently from 0% in the negative control group to 71% at the highest dose of the extract (1000mg/kg). In the tail immersion model the extract at the dose of 1000 mg/kg significantly (P = 0. 048) increased the pain reaction time (PRT) while in hot plate model the extract and drug also significantly (P = 0.048 - 0.05) increased the mean PRT at the doses of 500 and 1000 mg/kg. The dose of 250 mg/kg showed no analgesic activity in tail immersion and hot plate models. Conclusion: Dialium guineense demonstrated significant analgesic activity that may be mediated through peripheral pain mechanism. PMID:23209955

Evaluation of the analgesic activity of the methanolic stem bark extract of dialium guineense (wild).

PubMed

Ezeja, Mi; Omeh, Ys; Ezeigbo, Ii; Ekechukwu, A

2011-01-01

Dialium guineense is a medicinal plant used by some communities of Enugu-Ezike in Enugu State, Nigeria for treatment of fever, headache and other diverse ailments. The present study evaluated the analgesic activity of the methanolic stem bark extract of the plant. Acetic acid-induced abdominal constriction or writhing, tail immersion and hot plate analgesic models in albino Wistar mice were used for the study. Three test doses (250, 500, 1000 mg/kg body weight) of the extract were administered orally by gastric gavage. The activity was compared with a standard reference drug, acetylsalicylic acid (aspirin) (400 mg/kg) and negative control. The results were analysed by SPSS version 17 using ANOVA and Post Hoc Duncan. In the acetic acid-induced writhing reflex model, D. guineense extract and the reference drug significantly (P =0.014 - 0.002) decreased the mean total number of abdominal constriction in the mice in a dose dependent fashion. The percentage inhibition of the abdominal constriction reflex was increased dose dependently from 0% in the negative control group to 71% at the highest dose of the extract (1000mg/kg). In the tail immersion model the extract at the dose of 1000 mg/kg significantly (P = 0. 048) increased the pain reaction time (PRT) while in hot plate model the extract and drug also significantly (P = 0.048 - 0.05) increased the mean PRT at the doses of 500 and 1000 mg/kg. The dose of 250 mg/kg showed no analgesic activity in tail immersion and hot plate models. Dialium guineense demonstrated significant analgesic activity that may be mediated through peripheral pain mechanism.

Effects of ischaemia upon reflex electromyographic responses evoked by stretch and vibration in human wrist flexor muscles.

PubMed Central

Cody, F W; Goodwin, C N; Richardson, H C

1987-01-01

1. The reflex electromyographic responses evoked in a wrist flexor muscle, flexor carpi radialis (f.c.r.), by forcible extension of the wrist ('stretch') and by vibration of the flexor tendon have been studied in normal subjects. Reflexes were elicited during the maintenance of a low level of voluntary flexor contraction (5% maximum). Stretch regularly produced a relatively prolonged (ca. 100 ms duration) increase in e.m.g. activity which was usually divisible into short-latency (ca. 25 ms, M1) and long-latency (ca. 50 ms, M2) peaks. Vibration produced a single, phasic peak, at short latency, with no sign of an accompanying long-latency wave comparable to the M2 stretch response. 2. Ischaemia was induced by inflation of a blood-pressure cuff around the upper arm and its effects upon the reflex patterns were studied. During ischaemia M1 stretch responses showed a more rapid and pronounced decline than did M2 responses and were abolished before voluntary power was appreciably affected. Vibration-evoked short-latency peaks changed in an essentially parallel manner to M1 stretch reflexes. During recovery from ischaemia M2 reflexes were restored before short-latency responses. 3. The patterns of reflex reductions in e.m.g. upon withdrawal of stimulation were also studied. Such troughs in activity, under non-ischaemic conditions, regularly commenced at short latency and were of relatively small amplitude. The records of several of the subjects, and particularly ones obtained during ischaemia, suggested that release of stretch (with concomitant stretch of antagonists) could elicit an additive, long-latency decline in e.m.g. The existence of any such separate, delayed component was never observed upon termination of vibration. 4. Measurements of changes in the latencies and durations of reflex components, accompanying the progression of ischaemia, indicated that depression of early reflex activity resulted in part from increases in the latencies of these initial peaks but predominantly reflected simultaneous and separate reductions in their amplitudes. 5. The generation of short-latency reflexes by stretch and vibration, both of which stimuli powerfully excite muscle spindle primary endings, and the marked susceptibility of these responses to ischaemia supports their being mediated by group Ia afferents. The contrasting behaviour of M2 stretch responses, both regarding their absence with vibration and their resistance to ischaemia, suggests that they depend crucially upon a separate group of reflex afferents.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3443959

Comparison of the effects of the alpha-2 agonists detomidine, romifidine and xylazine on nociceptive withdrawal reflex and temporal summation in horses.

PubMed

Rohrbach, Helene; Korpivaara, Toni; Schatzmann, Urs; Spadavecchia, Claudia

2009-07-01

To evaluate and compare the antinociceptive effects of the three alpha-2 agonists, detomidine, romifidine and xylazine at doses considered equipotent for sedation, using the nociceptive withdrawal reflex (NWR) and temporal summation model in standing horses. Prospective, blinded, randomized cross-over study. Ten healthy adult horses weighing 527-645 kg and aged 11-21 years old. Electrical stimulation was applied to the digital nerves to evoke NWR and temporal summation in the left thoracic limb and pelvic limb of each horse. Electromyographic reflex activity was recorded from the common digital extensor and the cranial tibial muscles. After baseline measurements a single bolus dose of detomidine, 0.02 mg kg(-1), romifidine 0.08 mg kg(-1), or xylazine, 1 mg kg(-1), was administered intravenously (IV). Determinations of NWR and temporal summation thresholds were repeated at 10, 20, 30, 40, 60, 70, 90, 100, 120 and 130 minutes after test-drug administration alternating the thoracic limb and the pelvic limb. Depth of sedation was assessed before measurements at each time point. Behavioural reaction was observed and recorded following each stimulation. The administration of detomidine, romifidine and xylazine significantly increased the current intensities necessary to evoke NWR and temporal summation in thoracic limbs and pelvic limbs of all horses compared with baseline. Xylazine increased NWR thresholds over baseline values for 60 minutes, while detomidine and romifidine increased NWR thresholds over baseline for 100 and 120 minutes, respectively. Temporal summation thresholds were significantly increased for 40, 70 and 130 minutes after xylazine, detomidine and romifidine, respectively. Detomidine, romifidine and xylazine, administered IV at doses considered equipotent for sedation, significantly increased NWR and temporal summation thresholds, used as a measure of antinociceptive activity. The extent of maximal increase of NWR and temporal summation thresholds was comparable, while the duration of action was drug-specific.

PER2 variants are associated with abdominal obesity, psycho-behavioral factors and attrition in the dietary treatment of obesity

USDA-ARS?s Scientific Manuscript database

The purpose was to test for association between polymorphisms in the circadian clock-related gene PER2 and attrition in patients prone to withdrawal from a behavioral weight-reduction-program based on the Mediterranean Diet. 454 overweight/obese subjects (women= 380, men= 74), aged 20-65 years, who ...

The role of excitatory amino acids and substance P in the mediation of the cough reflex within the nucleus tractus solitarii of the rabbit.

PubMed

Mutolo, Donatella; Bongianni, Fulvia; Fontana, Giovanni A; Pantaleo, Tito

2007-09-28

We hypothesized that cough evoked by mechanical stimulation of the tracheobronchial tree in the rabbit is primarily mediated by glutamatergic neurotransmission at the level of the caudal portions of the medial subnucleus of the nucleus tractus solitarii (NTS) and the lateral commissural NTS where cough-related afferents terminate, and that this reflex is potentiated by local release of substance P. To test our hypothesis, we performed bilateral microinjections (30-50 nl) of ionotropic glutamate receptor antagonists or substance P into these locations in pentobarbitone anaesthetized, spontaneously breathing rabbits. Blockade of NMDA and non-NMDA receptors by 50mM kynurenic acid abolished the cough reflex without affecting the Breuer-Hering inflation reflex or the pulmonary chemoreflex. Blockade of non-NMDA receptors using 10mM CNQX or 5mM NBQX caused identical effects. Blockade of NMDA receptors by 10mM D-AP5 strongly reduced, but did not abolish cough responses. Microinjections of 1mM substance P increased peak and rate of rise of abdominal muscle activity as well as cough number. These results are the first to provide evidence that ionotropic glutamate receptors, especially non-NMDA receptors, located within specific regions of NTS are primarily involved in the mediation of cough evoked by mechanical stimulation of the tracheobronchial tree in the rabbit. Present findings on substance P cough-enhancing effects extend previous observations and are relevant to the tachykinin-mediated central sensitization of the cough reflex. They also may provide hints for further studies on centrally acting antitussive drugs.

A Third Type of Defensive Behavior in the Tenebrionid Beetle Zophobas atratus Pupae

PubMed Central

Ichikawa, Toshio; Sakamoto, Hirofumi

2013-01-01

Pupae of the tenebrionid beetle Zophobas atratus Fabricius (Coleoptera: Tenebrionidae) exhibit two types of reflex abdominal motions in response to tactile stimulation: circular rotation and lateral bending to close pinching devices (gin-traps). In the present study, the pupa exhibited novel, sequential abdominal movements at 0.3–2.2 sec after the onset of mechanical stimulation. The most effective stimulation was gentle, double brushing on the ventral surface of an abdominal segment (sternite). The sequential abdominal movements consisted of the following three types of discrete elementary motions (100–350 ms in duration): rapid vibration of 30–40 Hz, circular rotation (or swing), and small wiggling movements. A sequence of abdominal movements generally started with a few bouts of vibration, but the number and order of subsequent motions varied considerably among different sessions and conditions. A restrained pupa often showed a prolonged sequence of many motions, including several rotations, whereas an unrestrained pupa often shortened the sequence by skipping a few rotations after the displacement of its whole body induced by the first abdominal rotation. Stimulation of two types of mechanosensitive sensilla, the hair sensilla (touch sensors) and campaniform sensilla (strain sensors), seemed to be necessary to initiate the defensive response. In natural environments, crawling of a small predator (or parasitoid) on the surface of the abdomen or repeated attacks of a large predator may induce this defensive response in the pupae. PMID:23895506

Nesfatin-1/NUCB2 in the amygdala influences visceral sensitivity via glucocorticoid and mineralocorticoid receptors in male maternal separation rats.

PubMed

Zhou, X-P; Sha, J; Huang, L; Li, T-N; Zhang, R-R; Tang, M-D; Lin, L; Li, X-L

2016-10-01

Nesfatin-1, a recently identified satiety molecule derived from nucleobindin 2 (NUCB2), is associated with visceral hypersensitivity in rats and is expressed in the amygdala. We tested the hypothesis that nesfatin-1 expression in the amygdala is involved in the pathogenesis of irritable bowel syndrome (IBS) visceral hypersensitivity. An animal model of IBS-like visceral hypersensitivity was established using maternal separation (MS) during postnatal days 2-16. The role of nesfatin-1 in the amygdala on visceral sensitivity was evaluated. Rats subjected to MS showed a significantly increased mean abdominal withdrawal reflex (AWR) score and electromyographic (EMG) activity at 40, 60, and 80 mmHg colorectal distension. Plasma concentrations of nesfatin-1 and corticosterone were significantly higher than in non-handled (NH) rats. mRNA and protein expression of nesfatin-1/NUCB2 in the amygdala were increased in MS rats, but not in NH rats. In MS rats, AWR scores and EMG activity were significantly decreased after anti-nesfatin-1/NUCB2 injection. In normal rats, mean AWR score, EMG activity, and corticosterone expression were significantly increased after nesfatin-1 injection into the amygdala. Nesfatin-1-induced visceral hypersensitivity was abolished following application of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) antagonists. Elevated expression of nesfatin-1/NUCB2 in the amygdala in MS rats suggests a potential role in the pathogenesis of visceral hypersensitivity, which could potentially take place via activation of GR and MR signaling pathways. © 2016 John Wiley & Sons Ltd.

Blockage of High-Affinity Choline Transporter Increases Visceral Hypersensitivity in Rats with Chronic Stress

PubMed Central

2018-01-01

Background Visceral hypersensitivity is a common feature of irritable bowel syndrome. Cholinergic system involves in the development of visceral hypersensitivity, and high-affinity choline transporter (CHT1) is of crucial importance in choline uptake system. However, involvement of CHT1 in visceral hypersensitivity remains unknown. The research aimed to study the CHT1 expression in dorsal root ganglions (DRGs) and the role of CHT1 in visceral hypersensitivity. Methods Repetitive water avoidance stress (WAS) was used to induce visceral hypersensitivity in rats. Colorectal distension (CRD) was determined, and the abdominal withdrawal reflex (AWR) and threshold intensity data were recorded to measure the visceral sensitivity. After intraperitoneal injection of hemicholinium-3 (HC-3), the specific inhibitor of CHT1, CRD data were also recorded. The CHT1 expression of DRGs was investigated by Western blotting, immunohistochemistry, and quantitative RT-PCR. Acetylcholine levels in the DRGs were detected by the assay kit. Results Repetitive WAS increased the AWR score of CRD at high distension pressure and decreased the mean threshold of rats. The CHT1 expression and acetylcholine concentration of DRG were significantly increased in WAS rats. After the administration of HC-3, the AWR score in WAS group was significantly increased at higher distension pressure while the threshold intensity was significantly reduced compared to the normal saline group. Acetylcholine concentration was significantly lower than the normal saline rats. Conclusion Our research firstly reports that CHT1 is overexpressed in noninflammatory visceral hypersensitivity, and blockage of CHT1 can enhance the visceral hypersensitivity. CHT1 may play an inhibitory role in visceral hypersensitivity. PMID:29849603

The Protective Effect of Melissa officinalis L. in Visceral Hypersensitivity in Rat Using 2 Models of Acid-induced Colitis and Stress-induced Irritable Bowel Syndrome: A Possible Role of Nitric Oxide Pathway.

PubMed

Dolatabadi, Fatemeh; Abdolghaffari, Amir H; Farzaei, Mohammad H; Baeeri, Maryam; Ziarani, Fatemeh S; Eslami, Majid; Abdollahi, Mohammad; Rahimi, Roja

2018-06-04

The aim of present study is to estimate the effects of Melissa officinalis L. (MO) on visceral hypersensitivity (VH), defecation pattern and biochemical factors in 2 experimental models of irritable bowel syndrome (IBS) and the possible role of nitric oxide. Two individual models of IBS were induced in male Wistar-albino rats. In the acetic acid model, the animals were exposed to rectal distension and abdominal withdrawal reflex, and the defecation patterns were determined. In the restraint stress model, the colons of rats were removed and the levels of TNF-α, myeloperoxidase, lipid peroxidation, and antioxidant powers were determined. Rats had been treated with MO, L-NG-nitroarginine methyl ester (L-NAME), aminoguanidine (AG), MO + AG, or MO + L-NAME in the mentioned experimental models. Hypersensitive response to rectal distension and more stool defecation in control rats have been observed in comparison to shams. MO-300 significantly reduced VH and defecation frequency in comparison to controls. VH and defecation pattern did not show significant change in AG + MO and L-NAME + MO groups compared to controls. Also, significant reduction in TNF-α, myeloperoxidase, TBARS, and an increase in antioxidant power in MO-300 was recorded compared to controls. AG + MO and L-NAME + MO groups showed a reverse pattern compared to MO-300. MO can ameliorate IBS by modulating VH and defecation patterns. Antioxidant and anti-inflammatory properties along with its effect on the nitrergic pathway seems to play important roles in its pharmacological activity.

Visceral hypersensitive rats share common dysbiosis features with irritable bowel syndrome patients

PubMed Central

Zhou, Xiao-Yan; Li, Ming; Li, Xia; Long, Xin; Zuo, Xiu-Li; Hou, Xiao-Hua; Cong, Ying-Zi; Li, Yan-Qing

2016-01-01

AIM: To evaluate gut microbial dysbiosis in two visceral hypersensitive models in comparison with irritable bowel syndrome (IBS) patients and to explore the extent to which these models capture the dysbiosis of IBS patients. METHODS: Visceral hypersensitivity was developed using the maternal separation (MS) rat model and post-inflammatory rat model. The visceral sensitivity of the model groups and control group was evaluated using the abdominal withdraw reflex score and electromyography in response to graded colorectal distention. The 16S ribosomal RNA gene from fecal samples was pyrosequenced and analyzed. The correlation between dysbiosis in the microbiota and visceral hypersensitivity was calculated. Positive findings were compared to sequencing data from a published human IBS cohort. RESULTS: Dysbiosis triggered by neonatal maternal separation was lasting but not static. Both MS and post-inflammatory rat fecal microbiota deviated from that of the control rats to an extent that was larger than the co-housing effect. Two short chain fatty acid producing genera, Fusobacterium and Clostridium XI, were shared by the human IBS cohort and by the maternal separation rats and post-inflammatory rats, respectively, to different extents. Fusobacterium was significantly increased in the MS group, and its abundance positively correlated with the degree of visceral hypersensitivity. Porphyromonadaceae was a protective biomarker for both the rat control group and healthy human controls. CONCLUSION: The dysbiosis MS rat model and the post-inflammatory rat model captured some of the dysbiosis features of IBS patients. Fusobacterium, Clostridium XI and Porphyromonadaceae were identified as targets for future mechanistic research. PMID:27298564

Antinociceptive action against colonic distension by brain orexin in conscious rats.

PubMed

Okumura, Toshikatsu; Nozu, Tsukasa; Kumei, Shima; Takakusaki, Kaoru; Miyagishi, Saori; Ohhira, Masumi

2015-02-19

Increasing evidence has suggested that brain orexins are implicated in a wide variety of physiological functions. With regard to gastrointestinal functions, orexin-A acts centrally to regulate gastrointestinal functions such as gastric and pancreatic secretion, and gastrointestinal motility. Visceral sensation is also known as one of key gastrointestinal functions which are controlled by the central nervous system. Little is, however, known about a role of central orexin in visceral sensation. This study was therefore performed to clarify whether brain orexin may be involved in the process of visceral sensation. Visceral sensation was evaluated by colonic distension-induced abdominal withdrawal reflex (AWR) in conscious rats. Intracisternally administered orexin-A dose-dependently increased the threshold volume of colonic distension-induced AWR. In contrast, neither intraperitoneal injection of orexin-A nor intracisternal orexin-B altered the threshold volume. While intracisternal SB334867, an orexin 1 receptor antagonist, by itself failed to change the threshold volume, SB334867 injected centrally completely blocked the morphine-induced antinociceptive action against colonic distension. These results suggest for the first time that orexin-A specifically acts centrally in the brain to enhance antinociceptive response to colonic distension. We would furthermore suggest that endogenous orexin-A indeed mediates the antinociceptive effect of morphine on visceral sensation through the orexin 1 receptors. All these evidence might indicate that brain orexin plays a role in the pathophysiology of functional gastrointestinal disorders such as irritable bowel syndrome because visceral hypersensitivity of the gut is considered to play a vital role in the diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

Moxibustion relieves visceral hyperalgesia via inhibition of transient receptor potential vanilloid 1 (TRPV1) and heat shock protein (HSP) 70 expression in rat bone marrow cells.

PubMed

Zou, Weiying; Lin, Hua; Liu, Wenwen; Yang, Bei; Wu, Lei; Duan, Limin; Ling, Ping; Zhu, Lingyan; Dai, Qun; Zhao, Lintong; Zou, Ting; Zhang, Dalei

2016-04-01

To investigate the effects of moxibustion on visceral hyperalgesia (VH) and bone marrow cell transient receptor potential vanilloid type 1 (TRPV1) and heat shock protein (HSP) 70 expression in a rat model of VH. Mechanical colorectal distension was performed to induce VH in neonatal Sprague-Dawley rats. Eight-week-old VH rats were treated with moxibustion at acupuncture point BL25 or an ipsilateral non-acupuncture point. Abdominal withdrawal reflex (AWR) scoring and pain threshold pressure assessment were performed before and after moxibustion treatment for 7 consecutive days. The expression of TRPV1 and HSP70 in bone marrow cells was quantified by real-time quantitative PCR. The expression of TRPV1 and HSP70 in bone marrow cells was increased in rats with VH. Moxibustion at BL25 significantly decreased AWR scores and increased pain threshold pressure in rats with VH. Furthermore, moxibustion at BL25 significantly inhibited the VH-induced increase in the expression of TRPV1 and HSP70 in bone marrow cells. The up-regulation of TRPV1 and HSP70 expression in bone marrow cells may be involved in visceral pain development and the analgesic effect of moxibustion on VH may be mediated through down-regulation of TRPV1 and HSP70 expression in bone marrow cells. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

MLCK-mediated intestinal permeability promotes immune activation and visceral hypersensitivity in PI-IBS mice.

PubMed

Long, Y; Du, L; Kim, J J; Chen, B; Zhu, Y; Zhang, Y; Yao, S; He, H; Zheng, X; Huang, Z; Dai, N

2018-04-11

Alterations in intestinal permeability regulated by tight junctions (TJs) are associated with immune activation and visceral hypersensitivity in irritable bowel syndrome (IBS). Myosin light chain kinase (MLCK) is an important mediator of epithelial TJ. The aim of this study is to investigate the role of MLCK in the pathogenesis of IBS using a post infectious IBS (PI-IBS) mouse model. Trichinella spiralis-infected PI-IBS mouse model was used. Urine lactulose/mannitol ratio was measured to assess intestinal epithelial permeability. Western blotting was used to evaluate intestinal TJ protein (zonula occludens-1) and MLCK-associated protein expressions. Immune profile was assessed by measuring Th (T helper) 1/Th2 cytokine expression. Visceral sensitivity was determined by abdominal withdrawal reflex in response to colorectal distension. Eight weeks after inoculation with T. spiralis, PI-IBS mice developed decreased pain and volume thresholds during colorectal distention, increased urine lactulose/mannitol ratio, elevated colonic Th1/Th2 cytokine ratio, and decreased zonula occludens-1 expression compared to the control mice. MLCK expression was dramatically elevated in the colonic mucosa of PI-IBS mice compared to the control mice, alongside increased pMLC/MLC and decreased MLCP expression. Administration of MLCK inhibitor and TJ blocker both reversed the increased intestinal permeability, visceral hypersensitivity, and Th1-dominant immune profile in PI-IBS mice. MLCK is a pivotal step in inducing increased intestinal permeability promoting low-grade intestinal immune activation and visceral hypersensitivity in PI-IBS mice. MLCK inhibitor may provide a potential therapeutic option in the treatment of IBS. © 2018 John Wiley & Sons Ltd.

Delta-Selective Glycopeptides Related to Enkephalin Produce Profound Analgesia with Reduced Side Effects in Mice

DTIC Science & Technology

2004-09-01

depression or the risk of overdose is particularly appealing. Further research needs to be completed in order to quantify the effects of the... fentanyl and other morphine-like analgesics on the warm water-induced tail- withdrawal reflex in rats. Jannsen, P.A.J.; Niemegeers, C.J.E.; Dorg, J.G.H...the delta opioid agonist BW373U86 and the mu opioid agonist fentanyl in mice. O’Neill, S.J.; Collins, M.A.; Pettit, H.O.; McNutt, R.W.; Chang, K.J. J

The influence of gastric pentadecapeptide BPC 157 on acute and chronic ethanol administration in mice. The effect of N(G)-nitro-L-arginine methyl ester and L-arginine.

PubMed

Boban-Blagaic, Alenka; Blagaic, Vladimir; Romic, Zeljko; Jelovac, Nikola; Dodig, Goran; Rucman, Rudolf; Petek, Marijan; Turkovic, Branko; Seiwerth, Sven; Sikiric, Predrag

2006-01-01

Alcohol disturbances, NO stimulation (by the NO-precursor L-arginine), and/or NO-synthesis blockade (by N(G)-nitro-L-arginine methyl ester, i.e. L-NAME) were challenged with stable gastric pentadecapeptide BPC 157, which inhibits both acute alcohol intoxication and alcohol withdrawal symptoms. Mice received intraperitoneally (i.p.) BPC 157 (10 microg/kg), L-NAME (10 mg/kg), and L-arginine (400 mg/kg), alone or in combination, 5 minutes before or after acute ethanol (4 g/kg i.p.) intoxication or after 0, 3, or 7 hours of withdrawal after drinking 20% alcohol for 13 days. BPC 157 rapidly opposes the strongest disturbance presentations in acute intoxication (sustained ethanol anesthesia, complete loss of righting reflex, no reaction to external stimuli, hypothermia, 25% mortality) and withdrawal (prominent seizures). NO-agents: Aggravation of acute alcohol intoxication and opposition to withdrawal are common, but the later intervals affected by L-arginine and the action throughout the experiment by L-NAME are distinctive. Given together, L-arginine and L-NAME counteract each other, while either the "L-NAME presentation" (acute intoxication) or the "L-arginine presentation" (withdrawal) predominates. BPC157+NO-agent: In acute intoxication (L-NAME predominating in NO-system functioning to aggravate intoxication), both BPC157+L-NAME and BPC157+L-arginine follow the presentation of L-NAME, but without worsened mortality. In withdrawal (L-arginine predominating in NO-system functioning to oppose disturbance symptoms), BPC157+L-NAME follows the presentation of L-NAME, while BPC 157+L-arginine imitates that of L-arginine. The relationships among pentadecapeptide BPC 157, the NO-system, acute alcohol intoxication, and opposed withdrawal may be important, presenting pentadecapeptide BPC 157 as a suitable alcohol antagonist.

Thermography Examination of Abdominal Area Skin Temperatures in Individuals With and Without Focal-Onset Epilepsy.

PubMed

King, Hollis H; Cayce, Charles Thomas; Herrin, Jeph

Early osteopathic theory and practice, and the work of the medical intuitive Edgar Cayce suggested that the abdominal areas of individuals with epilepsy would manifest "cold spots." The etiology for this phenomenon was thought to be abdominal adhesions caused by inflammation and viscero-somatic reflexes caused by adhesions or injury to visceral or musculoskeletal system structures. Indeed, until that advent of electroencephalography in the 1930s, medical practice regarding epilepsy focused on abdominal neural and visceral structures. Following two hypotheses were formulated to evaluate any abdominal temperature phenomena: (1) an abdominal quadrant division analysis would find one or more quadrants "colder" in the focal-onset epilepsy group (ICD9-CM 345.4 and 345.5) compared to controls. (2) Total abdominal areas of individuals with focal-onset epilepsy wound be colder than a control group. Overall, 50 patients with the diagnosis of focal-onset epilepsy were recruited from the office of the Epilepsy Foundation of Florida and 50 control subjects with no history of epilepsy were recruited through advertising to the public. Under controlled room conditions all subjects had infrared thermographic images made and recorded by Med-Hot Model MH-731 FLIR equipment. There were no significant demographic difference between experimental patients and control subjects, though the control group tended to be younger and more often male; however, these were controlled for in all analyses. In the quadrant analysis, there were significant differences in that more epileptic patients had colder left upper abdominal quadrant temperatures than the control group (66.8% versus 44.9%; P = .030). In the total abdominal analysis, however, there were no significant differences. The results support the hypothesis that individuals with focal-onset epilepsy have colder abdominal areas. If substantiated in further research, present study results will require further examination of the mechanisms of action for epilepsy, and suggest the need for re-examination of older formulations of abdominal epilepsy, including the place of abdominal injury, inflammation, and adhesions in epileptic pathology. The concept of somato-visceral and viscero-somatic neurological interactions is one of the possible mechanisms underlying the "cold spot" findings and warrants further consideration. Copyright © 2017 Elsevier Inc. All rights reserved.

PubMed Central

Dupras, J; Vachon, P; Cuvelliez, S; Blais, D

2001-01-01

In this study, anesthesia levels obtained with tiletamine-zolazepam (TZ) and ketamine-midazolam (KM) with or without xylazine (X) were compared in rabbits. Reflexes (corneal, palpebral and withdrawal), blood parameters (PaO2, PaCO2, pH and ions HCO3-), cardiovascular function (heart rate and mean arterial blood pressure) and body temperature were evaluated before and after the injections of the anesthetic combination in the same rabbits (n = 10). With KM and TZ, no suppression of reflexes occurred. The body temperature and pH decreased and HCO3- increased similarly to KMX et TZX. Some physiological and blood parameters were less (PAM, PaCO2) and not (PaO2) affected comparatively to KMX et TZX. These protocols were of short duration of action and did not offer any anesthesia or analgesia. Therefore, their utilization should be restricted to short procedures where no painful manipulations are performed. Ketamine-midazolam-xylazine and tiletamine-zolazepam-xylazine on the other hand are indicated for interventions that require anesthesia. With these combinations, all reflexes were absent for 30-45 and 60-90 min following injections of KMX et TZX, respectively. However, these combinations induce cardiac depression, as well as a decrease of all measured blood parameters and body temperature and a reduction of PaO2. Supplementation with oxygen is recommended with the introduction of xylazine in the protocol. PMID:11424577

[Vojta's method as the early neurodevelopmental diagnosis and therapy concept].

PubMed

Banaszek, Grazyna

2010-01-01

Vaclav Vojta (1917-2000) developed an early diagnostic method of the neurodevelopmental disorder of infants and came up with therapeutic concept consisting in releasing of global motor complexes by means of the stimulation of proper areas on patients body. In the diagnostics apart from very careful observation of the spontaneous movement of the infant and examination of the reflexes that are characteristic for the first weeks of human's life, Vojta applied the examination of the 7 postural reactions. Presence of the trouble in patterns and dynamics of the postural reactions Vojta called Central Nervous Coordination Disorder--CNCD and regarded as work diagnosis or alarm signal indicating necessity of application of the therapy, especially when asymmetry of the muscle tone and primitive reflexes beyond their physiological appearance period are observed or the number of the abnormal reactions exceeds 5. Global motor complexes as reflex locomotion--crawling and rotation--consist of all the partial motion patterns, which are gradually used by healthy infant in the process of postural and motor ontogenesis. Providing the central nervous system with proper external stimulation allows to, using neuronal plasticity, recreate an access to the human's postural development program and gradually replace pathological motor patterns by those more regular. Exercises repeated several times a day rebuilt support, erectile and vertical mechanisms, improve automatic postural control and phase lower limb movement. Affecting especially on autochtonic muscles of the spine exercises balance synergic cooperation of muscle groups in the trunk and those surrounding key body joints. This way they correct body's posture and peripheral motion and pathology of the outlasted primitive reflexes gradually withdraws.

Physiological, pharmacokinetic and liver metabolism comparisons between 3-, 6-, 12- and 18-month-old male Sprague Dawley rats under ketamine-xylazine anesthesia

PubMed Central

Giroux, Marie-Chantal; Santamaria, Raphael; Hélie, Pierre; Burns, Patrick; Beaudry, Francis; Vachon, Pascal

2015-01-01

The main objective of this study was to compare the physiological changes (withdrawal and corneal reflexes, respiratory and cardiac frequency, blood oxygen saturation, and rectal temperature) following intraperitoneal administration of ketamine (80 mg/kg) and xylazine (10 mg/kg) to 3-, 6-, 12- and 18-month-old male Sprague Dawley rats (n=6/age group). Plasma pharmacokinetics, liver metabolism, and blood biochemistry were examined for a limited number of animals to better explain anesthetic drug effects. Selected organs were collected for histopathology. The results for the withdrawal and corneal reflexes suggest a shorter duration and decreased depth of anesthesia with aging. Significant cardiac and respiratory depression, as well as decreased blood oxygen saturation, occurred in all age groups however, cardiac frequency was the most affected parameter with aging, since the 6-, 12-, and 18-month-old animals did not recuperate to normal values during recovery from anesthesia. Pharmacokinetic parameters (T1/2 and AUC) increased and drug clearance decreased with aging, which strongly suggests that drug exposure is associated with the physiological results. The findings for liver S9 fractions of 18-month-old rats compared with the other age groups suggest that following a normal ketamine anesthetic dose (80 mg/kg), drug metabolism is impaired, leading to a significant increase of drug exposure. In conclusion, age and related factors have a substantial effect on ketamine and xylazine availability, which is reflected by significant changes in pharmacokinetics and liver metabolism of these drugs, and this translates into shorter and less effective anesthesia with increasing age. PMID:26489361

On the use of information theory for the analysis of synchronous nociceptive withdrawal reflexes and somatosensory evoked potentials elicited by graded electrical stimulation.

PubMed

Arguissain, Federico G; Biurrun Manresa, José A; Mørch, Carsten D; Andersen, Ole K

2015-01-30

To date, few studies have combined the simultaneous acquisition of nociceptive withdrawal reflexes (NWR) and somatosensory evoked potentials (SEPs). In fact, it is unknown whether the combination of these two signals acquired simultaneously could provide additional information on somatosensory processing at spinal and supraspinal level compared to individual NWR and SEP signals. By using the concept of mutual information (MI), it is possible to quantify the relation between electrical stimuli and simultaneous elicited electrophysiological responses in humans based on the estimated stimulus-response signal probability distributions. All selected features from NWR and SEPs were informative in regard to the stimulus when considered individually. Specifically, the information carried by NWR features was significantly higher than the information contained in the SEP features (p<0.05). Moreover, the joint information carried by the combination of features showed an overall redundancy compared to the sum of the individual contributions. Comparison with existing methods MI can be used to quantify the information that single-trial NWR and SEP features convey, as well as the information carried jointly by NWR and SEPs. This is a model-free approach that considers linear and non-linear correlations at any order and is not constrained by parametric assumptions. The current study introduces a novel approach that allows the quantification of the individual and joint information content of single-trial NWR and SEP features. This methodology could be used to decode and interpret spinal and supraspinal interaction in studies modulating the responsiveness of the nociceptive system. Copyright © 2014 Elsevier B.V. All rights reserved.

ERK-GluR1 phosphorylation in trigeminal spinal subnucleus caudalis neurons is involved in pain associated with dry tongue.

PubMed

Nakaya, Yuka; Tsuboi, Yoshiyuki; Okada-Ogawa, Akiko; Shinoda, Masamichi; Kubo, Asako; Chen, Jui Yen; Noma, Noboru; Batbold, Dulguun; Imamura, Yoshiki; Sessle, Barry J; Iwata, Koichi

2016-01-01

Dry mouth is known to cause severe pain in the intraoral structures, and many dry mouth patients have been suffering from intraoral pain. In development of an appropriate treatment, it is crucial to study the mechanisms underlying intraoral pain associated with dry mouth, yet the detailed mechanisms are not fully understood. To evaluate the mechanisms underlying pain related to dry mouth, the dry-tongue rat model was developed. Hence, the mechanical or heat nocifensive reflex, the phosphorylated extracellular signal-regulated kinase and phosphorylated GluR1-IR immunohistochemistries, and the single neuronal activity were examined in the trigeminal spinal subnucleus caudalis of dry-tongue rats. The head-withdrawal reflex threshold to mechanical, but not heat, stimulation of the tongue was significantly decreased on day 7 after tongue drying. The mechanical, but not heat, responses of trigeminal spinal subnucleus caudalis nociceptive neurons were significantly enhanced in dry-tongue rats compared to sham rats on day 7. The number of phosphorylated extracellular signal-regulated kinase-immunoreactive cells was also significantly increased in the trigeminal spinal subnucleus caudalis following noxious stimulation of the tongue in dry-tongue rats compared to sham rats on day 7. The decrement of the mechanical head-withdrawal reflex threshold (HWT) was reversed during intracisternal administration of the mitogen-activated protein kinase kinase 1 inhibitor, PD98059. The trigeminal spinal subnucleus caudalis neuronal activities and the number of phosphorylated extracellular signal-regulated kinase-immunoreactive cells following noxious mechanical stimulation of dried tongue were also significantly decreased following intracisternal administration of PD98059 compared to vehicle-administrated rats. Increased number of the phosphorylated GluR1-IR cells was observed in the trigeminal spinal subnucleus caudalis of dry-tongue rats, and the number of phosphorylated GluR1-IR cells was significantly reduced in PD98059-administrated rats compared to the vehicle-administrated tongue-dry rats. These findings suggest that the pERK-pGluR1 cascade is involved in central sensitization of trigeminal spinal subnucleus caudalis nociceptive neurons, thus resulting in tongue mechanical hyperalgesia associated with tongue drying. © The Author(s) 2016.

Increased excitability of spinal pain reflexes and altered frequency-dependent modulation in the dopamine D3-receptor knockout mouse.

PubMed

Keeler, Benjamin E; Baran, Christine A; Brewer, Kori L; Clemens, Stefan

2012-12-01

Frequency-dependent modulation and dopamine (DA) receptors strongly modulate neural circuits in the spinal cord. Of the five known DA receptor subtypes, the D3 receptor has the highest affinity to DA, and D3-mediated actions are mainly inhibitory. Using an animal model of spinal sensorimotor dysfunction, the D3 receptor knockout mouse (D3KO), we investigated the physiological consequences of D3 receptor dysfunction on pain-associated signaling pathways in the spinal cord, the initial integration site for the processing of pain signaling. In the D3KO spinal cord, inhibitory actions of DA on the proprioceptive monosynaptic stretch reflex are converted from depression to facilitation, but its effects on longer-latency and pain-associated reflex responses and the effects of FM have not been studied. Using behavioral approaches in vivo, we found that D3KO animals exhibit reduced paw withdrawal latencies to thermal pain stimulation (Hargreaves' test) over wild type (WT) controls. Electrophysiological and pharmacological approaches in the isolated spinal cord in vitro showed that constant current stimulation of dorsal roots at a pain-associated frequency was associated with a significant reduction in the frequency-dependent modulation of longer-latency reflex (LLRs) responses but not monosynaptic stretch reflexes (MSRs) in D3KO. Application of the D1 and D2 receptor agonists and the voltage-gated calcium-channel ligand, pregabalin, but not DA, was able to restore the frequency-dependent modulation of the LLR in D3KO to WT levels. Thus we demonstrate that nociception-associated LLRs and proprioceptive MSRs are differentially modulated by frequency, dopaminergics and the Ca(2+) channel ligand, pregabalin. Our data suggest a role for the DA D3 receptor in pain modulation and identify the D3KO as a possible model for increased nociception. Copyright © 2012 Elsevier Inc. All rights reserved.

Optimal positions for the release of primitive neonatal reflexes stimulating breastfeeding.

PubMed

Colson, Suzanne D; Meek, Judith H; Hawdon, Jane M

2008-07-01

Despite widespread skills-teaching, 37% of UK mothers initiating breastfeeding stop by six weeks suggesting a need to reappraise current support strategies. Rooting, sucking and swallowing have been studied extensively but little is known about the role other primitive neonatal reflexes (PNRs) might play to support breastfeeding. To describe and compare PNRs observed during feeding, investigating whether certain feeding behaviours and positions, collectively termed Biological Nurturing, (BN) are associated with the release of those reflexes pivotal in establishing successful feeding. 40 breastfed healthy term mother/baby pairs were recruited using quota sampling to stratify term gestational age. Feeding sessions were videotaped in the first postnatal month, either in hospital or at home. 20 PNRs were validated and classified into 4 types (endogenous, motor, rhythmic and anti-gravity) and 2 functional clusters (finding/latching, milk transfer) either stimulating or hindering feeding. Significantly more PNRs were observed as stimulants in semi-reclined postures (BN) than when mothers were upright or side-lying (p=<0.0005). This study is the first to describe a range of semi-reclined maternal postures interacting with neonatal positions, releasing maternal instinctual behaviours and PNRs stimulating breastfeeding. Traditionally the human neonate has been considered a dorsal feeder with pressure needed along the baby's back. Compelling visual data here illustrate that the newborn is an abdominal feeder and, like some other animals, displays anti-gravity reflexes aiding latch. Findings suggest that breastfeeding initiation is innate for both mother and baby, not learned, thus challenging the routine skills-teaching currently central to breastfeeding support.

Surgical injury in the neonatal rat alters the adult pattern of descending modulation from the rostroventral medulla.

PubMed

Walker, Suellen M; Fitzgerald, Maria; Hathway, Gareth J

2015-06-01

Neonatal pain and injury can alter long-term sensory thresholds. Descending rostroventral medulla (RVM) pathways can inhibit or facilitate spinal nociceptive processing in adulthood. As these pathways undergo significant postnatal maturation, the authors evaluated long-term effects of neonatal surgical injury on RVM descending modulation. Plantar hind paw or forepaw incisions were performed in anesthetized postnatal day (P)3 Sprague-Dawley rats. Controls received anesthesia only. Hind limb mechanical and thermal withdrawal thresholds were measured to 6 weeks of age (adult). Additional groups received pre- and post-incision sciatic nerve levobupivacaine or saline. Hind paw nociceptive reflex sensitivity was quantified in anesthetized adult rats using biceps femoris electromyography, and the effect of RVM electrical stimulation (5-200 μA) measured as percentage change from baseline. In adult rats with previous neonatal incision (n = 9), all intensities of RVM stimulation decreased hind limb reflex sensitivity, in contrast to the typical bimodal pattern of facilitation and inhibition with increasing RVM stimulus intensity in controls (n = 5) (uninjured vs. neonatally incised, P < 0.001). Neonatal incision of the contralateral hind paw or forepaw also resulted in RVM inhibition of hind paw nociceptive reflexes at all stimulation intensities. Behavioral mechanical threshold (mean ± SEM, 28.1 ± 8 vs. 21.3 ± 1.2 g, P < 0.001) and thermal latency (7.1 ± 0.4 vs. 5.3 ± 0.3 s, P < 0.05) were increased in both hind paws after unilateral neonatal incision. Neonatal perioperative sciatic nerve blockade prevented injury-induced alterations in RVM descending control. Neonatal surgical injury alters the postnatal development of RVM descending control, resulting in a predominance of descending inhibition and generalized reduction in baseline reflex sensitivity. Prevention by local anesthetic blockade highlights the importance of neonatal perioperative analgesia.

Intraperitoneal Continuous-Rate Infusion for the Maintenance of Anesthesia in Laboratory Mice (Mus musculus)

PubMed Central

Erickson, Rebecca L; Terzi, Matthew C; Jaber, Samer M; Hankenson, F Claire; McKinstry-Wu, Andrew; Kelz, Max B; Marx, James O

2016-01-01

Intraperitoneal injectable anesthetics are often used to achieve surgical anesthesia in laboratory mice. Because bolus redosing of injectable anesthetics can cause unacceptably high mortality, we evaluated intraperitoneal continuous-rate infusion (CRI) of ketamine with or without xylazine for maintaining surgical anesthesia for an extended period of time. Anesthesia was induced in male C57BL/6J mice by using ketamine (80 mg/kg) and xylazine (8 mg/kg) without or with acepromazine at 0.1 mg/kg or 0.5 mg/kg. At 10 min after induction, CRI for 90 min was initiated and comprised 25%, 50%, or 100% of the initial ketamine dose per hour or 50% of the initial doses of both ketamine and xylazine. Anesthetic regimens were compared on the basis of animal immobility, continuous surgical depth of anesthesia as determined by the absence of a pedal withdrawal reflex, and mortality. Consistent with previous studies, the response to anesthetics was highly variable. Regimens that provided the longest continuous surgical plane of anesthesia with minimal mortality were ketamine–xylazine–acepromazine (0.1 mg/kg) with CRI of 100% of the initial ketamine dose and ketamine–xylazine–acepromazine (0.5 mg/kg) with CRI of 50% of the initial ketamine and xylazine doses. In addition, heart rate and respiratory rate did not increase consistently in response to a noxious stimulus during CRI anesthesia, even when mice exhibited a positive pedal withdrawal reflex, suggesting that these parameters are unreliable indicators of anesthetic depth during ketamine–xylazine anesthesia in mice. We conclude that intraperitoneal CRI anesthesia in mice prolongs injectable anesthesia more consistently and with lower mortality than does bolus redosing. PMID:27657709

GABAA- and glycine-mediated inhibitory modulation of the cough reflex in the caudal nucleus tractus solitarii of the rabbit.

PubMed

Cinelli, Elenia; Iovino, Ludovica; Bongianni, Fulvia; Pantaleo, Tito; Mutolo, Donatella

2016-09-01

Cough-related sensory inputs from rapidly adapting receptors (RARs) and C fibers are processed by second-order neurons mainly located in the caudal nucleus tractus solitarii (NTS). Both GABAA and glycine receptors have been proven to be involved in the inhibitory control of second-order cells receiving RAR projections. We investigated the role of these receptors within the caudal NTS in the modulation of the cough reflex induced by either mechanical or chemical stimulation of the tracheobronchial tree in pentobarbital sodium-anesthetized, spontaneously breathing rabbits. Bilateral microinjections (30-50 nl) of the receptor antagonists bicuculline and strychnine as well as of the receptor agonists muscimol and glycine were performed. Bicuculline (0.1 mM) and strychnine (1 mM) caused decreases in peak abdominal activity and marked increases in respiratory frequency due to decreases in both inspiratory time (Ti) and expiratory time (Te), without concomitant changes in arterial blood pressure. Noticeably, these microinjections induced potentiation of the cough reflex consisting of increases in the cough number associated with decreases either in cough-related Ti after bicuculline or in both cough-related Ti and Te after strychnine. The effects caused by muscimol (0.1 mM) and glycine (10 mM) were in the opposite direction to those produced by the corresponding antagonists. The results show that both GABAA and glycine receptors within the caudal NTS mediate a potent inhibitory modulation of the pattern of breathing and cough reflex responses. They strongly suggest that disinhibition is one important mechanism underlying cough regulation and possibly provide new hints for novel effective antitussive strategies. Copyright © 2016 the American Physiological Society.

Spatial encoding in spinal sensorimotor circuits differs in different wild type mice strains

PubMed Central

Thelin, Jonas; Schouenborg, Jens

2008-01-01

Background Previous studies in the rat have shown that the spatial organisation of the receptive fields of nociceptive withdrawal reflex (NWR) system are functionally adapted through experience dependent mechanisms, termed somatosensory imprinting, during postnatal development. Here we wanted to clarify 1) if mice exhibit a similar spatial encoding of sensory input to NWR as previously found in the rat and 2) if mice strains with a poor learning capacity in various behavioural tests, associated with deficient long term potention, also exhibit poor adaptation of NWR. The organisation of the NWR system in two adult wild type mouse strains with normal long term potentiation (LTP) in hippocampus and two adult wild type mouse strains exhibiting deficiencies in corresponding LTP were used and compared to previous results in the rat. Receptive fields of reflexes in single hindlimb muscles were mapped with CO2 laser heat pulses. Results While the spatial organisation of the nociceptive receptive fields in mice with normal LTP were very similar to those in rats, the LTP impaired strains exhibited receptive fields of NWRs with aberrant sensitivity distributions. However, no difference was found in NWR thresholds or onset C-fibre latencies suggesting that the mechanisms determining general reflex sensitivity and somatosensory imprinting are different. Conclusion Our results thus confirm that sensory encoding in mice and rat NWR is similar, provided that mice strains with a good learning capability are studied and raise the possibility that LTP like mechanisms are involved in somatosensory imprinting. PMID:18495020

A Report of Nausea and Vomiting with Discontinuation of Chronic Use of Salvia divinorum

PubMed Central

Travis, C. R.; Ray, G. A.; Marlowe, K. F.

2012-01-01

Introduction. This is the first reported case of gastrointestinal symptoms associated with withdrawal after chronic use of this substance. Case Presentation. A 51-year-old Caucasian woman was referred to a hospital with a 3-day history of nausea, vomiting, diarrhea, and abdominal discomfort. She reported no sick family members or contact with anyone who was ill. She did report smoking 3–5 cigarettes of the herb “Salvia” consistently for 3-4 months and quit approximately 48 hours before symptoms appeared. Her use of the herb had been consistent; she smoked several cigarettes each day. Laboratory results were essentially normal including the white blood cell count. She received symptomatic treatment and was released after one day. Discussion. Salvinorin A, a kappa-opioid receptor agonist, is the major active ingredient of S. divinorum. The unique opioid properties of this herb may explain its ability to cause changes in intestinal transit time. Conclusion. A 51-year-old woman possibly developed gastrointestinal manifestations suggestive of withdrawal from Salvia divinorum after smoking the substance consistently for 3 to 4 months. The widespread use of this herb will make the potential for withdrawal syndromes more commonplace. PMID:22611407

A Report of Nausea and Vomiting with Discontinuation of Chronic Use of Salvia divinorum.

PubMed

Travis, C R; Ray, G A; Marlowe, K F

2012-01-01

Introduction. This is the first reported case of gastrointestinal symptoms associated with withdrawal after chronic use of this substance. Case Presentation. A 51-year-old Caucasian woman was referred to a hospital with a 3-day history of nausea, vomiting, diarrhea, and abdominal discomfort. She reported no sick family members or contact with anyone who was ill. She did report smoking 3-5 cigarettes of the herb "Salvia" consistently for 3-4 months and quit approximately 48 hours before symptoms appeared. Her use of the herb had been consistent; she smoked several cigarettes each day. Laboratory results were essentially normal including the white blood cell count. She received symptomatic treatment and was released after one day. Discussion. Salvinorin A, a kappa-opioid receptor agonist, is the major active ingredient of S. divinorum. The unique opioid properties of this herb may explain its ability to cause changes in intestinal transit time. Conclusion. A 51-year-old woman possibly developed gastrointestinal manifestations suggestive of withdrawal from Salvia divinorum after smoking the substance consistently for 3 to 4 months. The widespread use of this herb will make the potential for withdrawal syndromes more commonplace.

Effect of head and limb orientation on trunk muscle activation during abdominal hollowing in chronic low back pain.

PubMed

Parfrey, Kevin; Gibbons, Sean G T; Drinkwater, Eric J; Behm, David G

2014-02-22

Individuals with chronic low back pain (CLBP) have altered activations patterns of the anterior trunk musculature when performing the abdominal hollowing manœuvre (attempt to pull umbilicus inward and upward towards the spine). There is a subgroup of individuals with CLBP who have high neurocognitive and sensory motor deficits with associated primitive reflexes (PR). The objective of the study was to determine if orienting the head and extremities to positions, which mimic PR patterns would alter anterior trunk musculature activation during the hollowing manoeuvre. This study compared surface electromyography (EMG) of bilateral rectus abdominis (RA), external oblique (EO), and internal obliques (IO) of 11 individuals with CLBP and evident PR to 9 healthy controls during the hollowing manoeuvre in seven positions of the upper quarter. Using magnitude based inferences it was likely (>75%) that controls had a higher ratio of left IO:RA activation with supine (cervical neutral), asymmetrical tonic neck reflex (ATNR) left and right, right cervical rotation and cervical extension positions. A higher ratio of right IO:RA was detected in the cervical neutral and ATNR left position for the control group. The CLBP group were more likely to show higher activation of the left RA in the cervical neutral, ATNR left and right, right cervical rotation and cervical flexion positions as well as in the cervical neutral and cervical flexion position for the right RA. Individuals with CLBP and PR manifested altered activation patterns during the hollowing maneuver compared to healthy controls and that altering cervical and upper extremity position can diminish the group differences. Altered cervical and limb positions can change the activation levels of the IO and EO in both groups.

Evaluation of pressor and visceromotor reflex responses to bladder distension in urethane anesthetized rats.

PubMed

Blatt, Lauren K; Lashinger, Erin S R; Laping, Nicholas J; Su, Xin

2009-01-01

We tested cardiovascular and visceromotor reflex (VMR) responses to urinary bladder distension (UBD) in urethane anesthetized rats to see if it can replicate the response pattern and the inhibition of bladder nociceptive transmission by analgesics seen in isoflurane anesthetized animals. Female Sprague-Dawley rats under 3% isoflurane anesthesia were acutely instrumented with jugular venous, carotid arterial, and bladder cannulas for drug administration, blood pressure (BP) measurement, and bladder distension, respectively. Needle electrodes were placed directly into the abdominal musculature to measure myoelectrical activity subsequent to phasic UBD (30 sec in 3 min intervals). A cardiovascular response (pressor) and a VMR response (a contraction of abdominal and hind limb musculature) to UBD were evaluated in urethane (1.2 g/kg, i.v.) or isoflurane (1%) anesthetized rats. Pressor and VMR responses to noxious UBD (60 mmHg) were generated under both anesthesics. The thresholds of stimulus response functions for both pressor and VMR responses were not affected by either anesthesics. However, the magnitude of the maximal pressor response was significantly reduced in urethane anesthesia. The analgesics, morphine, and mexiletine, significantly inhibited the VMR response to noxious UBD under both anesthetics, but the intensities of the inhibition from both analgesics under urethane anesthesia were much lower than under isoflurane anesthesia (ID50: 2.07 mg/kg vs. 0.88 mg/kg for morphine, >10 mg/kg vs. 0.47 mg/kg for mexiletine). The rat urinary bladder distension model in urethane anesthetized rats demonstrates a blunted maximal pressor response and a reduced inhibition of visceral nociceptive transmission by analgesics. Neurourol. Urodynam. 28:442-446, 2009. (c) 2008 Wiley-Liss, Inc.

Carbon dioxide insufflation during colonoscopy in deeply sedated patients

PubMed Central

Singh, Rajvinder; Neo, Eu Nice; Nordeen, Nazree; Shanmuganathan, Ganesananthan; Ashby, Angelie; Drummond, Sharon; Nind, Garry; Murphy, Elizabeth; Luck, Andrew; Tucker, Graeme; Tam, William

2012-01-01

AIM: To compare the impact of carbon dioxide (CO2) and air insufflation on patient tolerance/safety in deeply sedated patients undergoing colonoscopy. METHODS: Patients referred for colonoscopy were randomized to receive either CO2 or air insufflation during the procedure. Both the colonoscopist and patient were blinded to the type of gas used. During the procedure, insertion and withdrawal times, caecal intubation rates, total sedation given and capnography readings were recorded. The level of sedation and magnitude of patient discomfort during the procedure was assessed by a nurse using a visual analogue scale (VAS) (0-3). Patients then graded their level of discomfort and abdominal bloating using a similar VAS. Complications during and after the procedure were recorded. RESULTS: A total of 142 patients were randomized with 72 in the air arm and 70 in the CO2 arm. Mean age between the two study groups were similar. Insertion time to the caecum was quicker in the CO2 group at 7.3 min vs 9.9 min with air (P = 0.0083). The average withdrawal times were not significantly different between the two groups. Caecal intubation rates were 94.4% and 100% in the air and CO2 groups respectively (P = 0.012). The level of discomfort assessed by the nurse was 0.69 (air) and 0.39 (CO2) (P = 0.0155) and by the patient 0.82 (air) and 0.46 (CO2) (P = 0.0228). The level of abdominal bloating was 0.97 (air) and 0.36 (CO2) (P = 0.001). Capnography readings trended to be higher in the CO2 group at the commencement, caecal intubation, and conclusion of the procedure, even though this was not significantly different when compared to readings obtained during air insufflation. There were no complications in both arms. CONCLUSION: CO2 insufflation during colonoscopy is more efficacious than air, allowing quicker and better cecal intubation rates. Abdominal discomfort and bloating were significantly less with CO2 insufflation. PMID:22783048

Carbon dioxide insufflation during colonoscopy in deeply sedated patients.

PubMed

Singh, Rajvinder; Neo, Eu Nice; Nordeen, Nazree; Shanmuganathan, Ganesananthan; Ashby, Angelie; Drummond, Sharon; Nind, Garry; Murphy, Elizabeth; Luck, Andrew; Tucker, Graeme; Tam, William

2012-07-07

To compare the impact of carbon dioxide (CO₂) and air insufflation on patient tolerance/safety in deeply sedated patients undergoing colonoscopy. Patients referred for colonoscopy were randomized to receive either CO₂ or air insufflation during the procedure. Both the colonoscopist and patient were blinded to the type of gas used. During the procedure, insertion and withdrawal times, caecal intubation rates, total sedation given and capnography readings were recorded. The level of sedation and magnitude of patient discomfort during the procedure was assessed by a nurse using a visual analogue scale (VAS) (0-3). Patients then graded their level of discomfort and abdominal bloating using a similar VAS. Complications during and after the procedure were recorded. A total of 142 patients were randomized with 72 in the air arm and 70 in the CO₂ arm. Mean age between the two study groups were similar. Insertion time to the caecum was quicker in the CO₂ group at 7.3 min vs 9.9 min with air (P = 0.0083). The average withdrawal times were not significantly different between the two groups. Caecal intubation rates were 94.4% and 100% in the air and CO₂ groups respectively (P = 0.012). The level of discomfort assessed by the nurse was 0.69 (air) and 0.39 (CO₂) (P = 0.0155) and by the patient 0.82 (air) and 0.46 (CO₂) (P = 0.0228). The level of abdominal bloating was 0.97 (air) and 0.36 (CO₂) (P = 0.001). Capnography readings trended to be higher in the CO₂ group at the commencement, caecal intubation, and conclusion of the procedure, even though this was not significantly different when compared to readings obtained during air insufflation. There were no complications in both arms. CO₂ insufflation during colonoscopy is more efficacious than air, allowing quicker and better cecal intubation rates. Abdominal discomfort and bloating were significantly less with CO₂ insufflation.

Social stimuli increase physiological reactivity but not defensive responses.

PubMed

Kosonogov, Vladimir; Sanchez-Navarro, Juan Pedro; Martinez-Selva, Jose Maria; Torrente, Ginesa; Carrillo-Verdejo, Eduvigis

2016-10-01

Emotional reactions are crucial in survival because they provide approach and withdrawal behaviors. However, an unsolved question is whether the social content of the affective stimuli has a specific effect on emotional responses. We studied whether the social content of affective pictures influenced the defensive response and response mobilization. For this purpose, we recorded startle blink reflex (a defensive response) and skin conductance responses (a measure of unspecific physiological reactivity or arousal) in 73 participants while they viewed a series of 81 pictures of varying affective valence and social content. Our results revealed that defense response, as indicated by increases in the magnitude of the startle blink reflex, was mainly dependent on threatening or unpleasant cues, but was unrelated to the social content of the pictures. The social content, however, had an influence on pleasant stimuli, provoking an increase in resource mobilization, as reflected by changes in electrodermal activity. Hence, the social content of the affective stimuli may increase the physiological arousal elicited by pleasant stimuli, and it appears to be unrelated to the defense reactivity provoked by unpleasant stimuli. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Segmentally distributed metamorphic changes in neural circuits controlling abdominal bending in the hawk moth Manduca sexta.

PubMed

Lemon, W C; Levine, R B

1997-06-01

During the metamorphosis of Manduca sexta the larval nervous system is reorganized to allow the generation of behaviors that are specific to the pupal and adult stages. In some instances, metamorphic changes in neurons that persist from the larval stage are segment-specific and lead to expression of segment-specific behavior in later stages. At the larval-pupal transition, the larval abdominal bending behavior, which is distributed throughout the abdomen, changes to the pupal gin trap behavior which is restricted to three abdominal segments. This study suggests that the neural circuit that underlies larval bending undergoes segment specific modifications to produce the segmentally restricted gin trap behavior. We show, however, that non-gin trap segments go through a developmental change similar to that seen in gin trap segments. Pupal-specific motor patterns are produced by stimulation of sensory neurons in abdominal segments that do not have gin traps and cannot produce the gin trap behavior. In particular, sensory stimulation in non-gin trap pupal segments evokes a motor response that is faster than the larval response and that displays the triphasic contralateral-ipsilateral-contralateral activity pattern that is typical of the pupal gin trap behavior. Despite the alteration of reflex activity in all segments, developmental changes in sensory neuron morphology are restricted to those segments that form gin traps. In non-gin trap segments, persistent sensory neurons do not expand their terminal arbors, as do sensory neurons in gin trap segments, yet are capable of eliciting gin trap-like motor responses.

Chronic voluntary alcohol consumption results in tolerance to sedative/hypnotic and hypothermic effects of alcohol in hybrid mice

PubMed Central

Ozburn, Angela Renee; Harris, R. Adron; Blednov, Yuri A.

2013-01-01

The continuous two bottle choice test is the most common measure of alcohol consumption but there is remarkably little information about the development of tolerance or dependence with this procedure. We showed that C57BL/6JxFVB/NJ and FVB/NJxC57BL/6J F1 hybrid mice demonstrate greater preference for and consumption of alcohol than either parental strain. In order to test the ability of this genetic model of high alcohol consumption to produce neuroadaptation, we examined development of alcohol tolerance and dependence after chronic self-administration using a continuous access two-bottle choice paradigm. Ethanol-experienced mice stably consumed about 16–18 g/kg/day of ethanol. Ethanol-induced withdrawal severity was assessed (after 59 days of drinking) by scoring handling-induced convulsions; withdrawal severity was minimal and did not differ between ethanol-experienced and -naïve mice. After 71 days of drinking, the rate of ethanol clearance was similar for ethanol-experienced and -naïve mice. After 77 days of drinking, ethanol-induced loss of righting reflex (LORR) was tested daily for 5 days. Ethanol-experienced mice had a shorter duration of LORR. For both ethanol-experienced and -naïve mice, blood ethanol concentrations taken at gain of righting reflex were greater on day 5 than on day 1, indicative of tolerance. After 98 days of drinking, ethanol-induced hypothermia was assessed daily for 3 days. Both ethanol-experienced and –naïve mice developed rapid and chronic tolerance to ethanol-induced hypothermia, with significant group differences on the first day of testing. In summary, chronic, high levels of alcohol consumption in F1 hybrid mice produced rapid and chronic tolerance to both the sedative/hypnotic and hypothermic effects of ethanol; additionally, a small degree of metabolic tolerance developed. The development of tolerance supports the validity of using this model of high alcohol consumption in genetic studies of alcoholism. PMID:23313769

A Novel EphA2 Inhibitor Exerts Beneficial Effects in PI-IBS in Vivo and in Vitro Models via Nrf2 and NF-κB Signaling Pathways.

PubMed

Zeng, Li; Li, Kaixue; Wei, Hong; Hu, Jingjing; Jiao, Lu; Yu, Shaoyong; Xiong, Ying

2018-01-01

Though the detailed pathological mechanism of post-infectious irritable bowel syndrome (PI-IBS) remains unclear, accumulating evidence indicates that oxidative stress and inflammation are implicated in the process of PI-IBS. Oxidative stress and inflammation are regulated by Nrf2 and NF-κB signaling pathways, respectively. EphA2, a member of Eph receptor family, promotes oxidative stress and inflammatory responses via regulation of Nrf2 and NF-κB signaling pathways in various types of human diseases. Understanding the mechanisms by which EphA2 regulate oxidative stress and inflammation in PI-IBS is important for the development of new strategies to treat PI-IBS. However, the effects of ALW-II-41-27, a novel EphA2 inhibitor on PI-IBS and the underlying molecular mechanisms have never been studied. In the present study, we showed that ALW-II-41-27 decreased gastrointestinal motility and abdominal withdrawal reflex (AWR) scores, markedly reduced the levels of oxidative stress markers [4-hydroxy-2-nonenal (4-HNE), protein carbonyl, and 8-hydroxy-2-de-axyguanine (8-OHdG)] and proinflammatory cytokines (TNF-α, IL-6, IL-17, and ICAM-1), and remarkably increased the level of anti-inflammatory cytokine (IL-10) in serum and colon of Trichinella spiralis -infected mice. Moreover, ALW-II-41-27 was effective in suppressing oxidative stress and inflammation in LPS-treated NCM460 colonic cells. Treatment of ALW-II-41-27 reversed the activation of NF-κB and inactivation of Nrf2 in LPS-treated NCM460 cells. Importantly, these protective effects of ALW-II-41-27 were partially inhibited by EphA2 KO and abolished by EphA2 overexpression. In conclusion, EphA2 may represent a promising therapeutic target for patients with PI-IBS and ALW-II-41-27 might function as a novel therapeutic agent for PI-IBS.

A comparison of medetomidine and its active enantiomer dexmedetomidine when administered with ketamine in mice

PubMed Central

2013-01-01

Background Medetomidine-ketamine (MK) and dexmedetomidine-ketamine (DK) are widely used to provide general anaesthesia in laboratory animals, but have not been compared directly in many of these species, including rodents. This study aimed to compare the onset and depth of anaesthesia, and changes in vital signs, after intraperitoneal (IP) or subcutaneous (SC) administration of ketamine (75 mg kg-1) combined with medetomidine (1 mg kg-1) or dexmedetomidine (0.5 mg kg-1) using a randomised semi-crossover design with ≥ 48 hours between treatments in 10 male and 10 female mice. Each mouse was anaesthetised twice using the same administration route (IP or SC): once with each drug-ketamine combination. Anaesthetised mice were monitored on a heating pad without supplemental oxygen for 89 minutes; atipamezole was administered for reversal. The times that the righting reflex was lost post-injection and returned post-reversal were analysed using general linear models. Tail-pinch and pedal reflexes were examined using binomial generalized linear models. Pulse rate (PR), respiratory rate (fr), and arterial haemoglobin saturation (SpO2) were compared using generalized additive mixed models. Results There were no significant differences among treatments for the times taken for loss and return of the righting reflex, or response of the tail-pinch reflex. The pedal withdrawal reflex was abolished more frequently with MK than DK over time (P = 0.021). The response of PR and SpO2 were similar among treatments, but fr was significantly higher with MK than DK (P ≤ 0.0005). Markedly low SpO2 concentrations occurred within 5 minutes post-injection (83.8 ± 6.7%) in all treatment groups and were most severe after 89 minutes lapsed (66.7 ± 7.5%). No statistical differences were detected in regards to administration route (P ≤ 0.94). Conclusions This study failed to demonstrate clinical advantages of the enantiomer dexmedetomidine over medetomidine when combined with ketamine to produce general anaesthesia in mice. At the doses administered, deep surgical anaesthesia was not consistently produced with either combination; therefore, anaesthetic depth must be assessed before performing surgical procedures. Supplemental oxygen should always be provided during anaesthesia to prevent hypoxaemia. PMID:23497612

Thoracic spinal anesthesia is safe for patients undergoing abdominal cancer surgery

PubMed Central

Ellakany, Mohamed Hamdy

2014-01-01

Aim: A double-blinded randomized controlled study to compare discharge time and patient satisfaction between two groups of patients submitted to open surgeries for abdominal malignancies using segmental thoracic spinal or general anesthesia. Background: Open surgeries for abdominal malignancy are usually done under general anesthesia, but many patients with major medical problems sometimes can’t tolerate such anesthesia. Regional anesthesia namely segmental thoracic spinal anesthesia may be beneficial in such patients. Materials and Methods: A total of 60 patients classified according to American Society of Anesthesiology (ASA) as class II or III undergoing surgeries for abdominal malignancy, like colonic or gastric carcinoma, divided into two groups, 30 patients each. Group G, received general anesthesia, Group S received a segmental (T9-T10 injection) thoracic spinal anesthesia with intrathecal injection of 2 ml of hyperbaric bupivacaine 0.5% (10 mg) and 20 ug fentanyl citrate. Intraoperative monitoring, postoperative pain, complications, recovery time, and patient satisfaction at follow-up were compared between the two groups. Results: Spinal anesthesia was performed easily in all 30 patients, although two patients complained of paraesthesiae, which responded to slight needle withdrawal. No patient required conversion to general anesthesia, six patients required midazolam for anxiety and six patients required phenylephrine and atropine for hypotension and bradycardia, recovery was uneventful and without sequelae. The two groups were comparable with respect to gender, age, weight, height, body mass index, ASA classification, preoperative oxygen saturation and preoperative respiratory rate and operative time. Conclusion: This preliminary study has shown that segmental thoracic spinal anesthesia can be used successfully and effectively for open surgeries for abdominal malignancies by experienced anesthetists. It showed shorter postanesthesia care unit stay, better postoperative pain relief and patient satisfaction than general anesthesia. PMID:25886230

Thoracic spinal anesthesia is safe for patients undergoing abdominal cancer surgery.

PubMed

Ellakany, Mohamed Hamdy

2014-01-01

A double-blinded randomized controlled study to compare discharge time and patient satisfaction between two groups of patients submitted to open surgeries for abdominal malignancies using segmental thoracic spinal or general anesthesia. Open surgeries for abdominal malignancy are usually done under general anesthesia, but many patients with major medical problems sometimes can't tolerate such anesthesia. Regional anesthesia namely segmental thoracic spinal anesthesia may be beneficial in such patients. A total of 60 patients classified according to American Society of Anesthesiology (ASA) as class II or III undergoing surgeries for abdominal malignancy, like colonic or gastric carcinoma, divided into two groups, 30 patients each. Group G, received general anesthesia, Group S received a segmental (T9-T10 injection) thoracic spinal anesthesia with intrathecal injection of 2 ml of hyperbaric bupivacaine 0.5% (10 mg) and 20 ug fentanyl citrate. Intraoperative monitoring, postoperative pain, complications, recovery time, and patient satisfaction at follow-up were compared between the two groups. Spinal anesthesia was performed easily in all 30 patients, although two patients complained of paraesthesiae, which responded to slight needle withdrawal. No patient required conversion to general anesthesia, six patients required midazolam for anxiety and six patients required phenylephrine and atropine for hypotension and bradycardia, recovery was uneventful and without sequelae. The two groups were comparable with respect to gender, age, weight, height, body mass index, ASA classification, preoperative oxygen saturation and preoperative respiratory rate and operative time. This preliminary study has shown that segmental thoracic spinal anesthesia can be used successfully and effectively for open surgeries for abdominal malignancies by experienced anesthetists. It showed shorter postanesthesia care unit stay, better postoperative pain relief and patient satisfaction than general anesthesia.

Lymphedema of the Transplanted Kidney and Abdominal Wall with Ipsilateral Pleural Effusion Following Kidney Biopsy in a Patient Treated with Sirolimus: A Case Report and Review of the Literature.

PubMed

Rashid-Farokhi, Farin; Afshar, Haleh

2017-12-22

BACKGROUND Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor, which is used in immunosuppressive treatment regimens in organ transplant recipients. Although mTOR inhibitors are well tolerated, their adverse effects have been reported. Sirolimus treatment in transplant recipients has been reported to be associated with lymphedema of the skin and subcutaneous tissues, and with pleural effusion, but edema of internal organs and organomegaly have not been previously reported. A case is presented lymphedema of the transplanted kidney and abdominal wall with ipsilateral pleural effusion following kidney biopsy in a patient treated with sirolimus. CASE REPORT A 32-year-old woman with a history of end-stage renal disease of unknown etiology had undergone right renal transplantation from an unrelated living donor, eight years previously. She was referred to our hospital with dyspnea, localized abdominal pain, and swelling of the transplanted kidney. The symptoms appeared following a kidney biopsy and the replacement of cyclosporin with sirolimus four months previously. On examination, she had localized swelling of the abdominal wall overlying the transplanted kidney, and a right pleural effusion. Hydronephrosis and nephrotic syndrome were excluded as causes of kidney enlargement. Following the withdrawal of sirolimus therapy her symptoms resolved within three months. CONCLUSIONS A case is described of lymphedema of the transplanted kidney and abdominal wall with ipsilateral pleural effusion following kidney biopsy attributed to her change in anti-rejection therapy to sirolimus. This case report should raise awareness of this unusual complication of sirolimus anti-rejection therapy and its possible effects on the lymphatic system.

The effect of esophageal and gastric distension on the crural diaphragm.

PubMed

Shafik, Ahmed; Shafik, Ismail; El Sibai, Olfat; Mostafa, Randa M

2006-02-01

The mechanism of prevention of gastric reflux into the esophagus is not exactly known. The lower esophagus has a barrier function provided by the lower esophageal sphincter. We investigated the hypothesis that the crural diaphragm shares in the barrier function not only mechanically but also actively through a crural-esophageal-gastric reflex action. The study was performed during repair of abdominal ventral and incisional hernias in 20 subjects (11 men, 9 women; age 38.6+/-4.8 years). The electromyographic response of the crural diaphragm to individual balloon distension of esophagus and stomach was recorded by means of a needle electrode inserted into the crural diaphragm and connected to an electromyographic apparatus. The recordings were repeated after separate crural, esophageal, and gastric anesthetization. The crural diaphragm exhibited basal motor unit action potentials, which decreased on esophageal distension (P<0.001) after a mean latency of 17.3+/-2.8 SD ms. The crural diaphragm response to esophageal distension did not occur after the crural diaphragm or esophagus was anesthetized. Gastric distension effected an increase of crural diaphragm electromyographic activity with a mean latency of 18.4+/-4.6 ms; this effect could not be achieved after the crural diaphragm or stomach was anesthetized. The crural diaphragm has a resting tone that relaxes after esophageal distension and contracts after gastric distension. This sphincter-like action of the crural diaphragm appears to be a reflex and is mediated through the esophagocrural inhibitory and gastrocrural excitatory reflexes. The crural diaphragm seems to share actively in the gastroesophageal competence mechanism.

The effect of carbon dioxide flow rate on the euthanasia of laboratory mice.

PubMed

Moody, C M; Chua, B; Weary, D M

2014-10-01

Laboratory rodents are commonly euthanized by exposure to gradually increasing concentrations of carbon dioxide (CO2). Current recommended flow rates range between 10 and 30% chamber vol/min and result in insensibility before exposure to painful concentrations (<40%). However, this method causes dyspnea, indicated by deep, rapid breathing. In humans dyspnea is associated with a negative affective experience. Sensations of dyspnea may explain why rodents find CO2 concentrations >3% aversive. This study aimed to assess the effect of CO2 flow rates on time between the onset of dyspnea and various measures of insensibility (recumbency, loss of the righting reflex and loss of the pedal withdrawal reflex) to identify flow rates that minimize the potential experience of dyspnea. The results of this study indicate that a flow rate of 50% chamber vol/min, while holding the CO2 cage concentration just below 40%, minimizes the interval between the onset of labored breathing and recumbency. Using a 50% flow rate this interval averaged (± SE) 30.3 ± 2.9 s versus 49.7 ± 2.9 s at 20% chamber vol/min (F3,22 = 7.83, P = 0.0013). Similarly, the interval between the onset of labored breathing and loss of the righting reflex averaged 38.2 ± 2.4 s at a flow rate of 50% versus 59.2 ± 2.4 s at 20% chamber vol/min of CO2 (F3,22 = 13.62, P < 0.0001). We conclude that higher flow rates reduce the duration of dyspnea, but even at the highest flow rate mice experience more than 30 s between the onset of dyspnea and the most conservative estimate of insensibility. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Colitis with wall thickening and edematous changes during oral administration of the powdered form of Qing-dai in patients with ulcerative colitis: a report of two cases.

PubMed

Kondo, Satoru; Araki, Toshimitsu; Okita, Yoshiki; Yamamoto, Akira; Hamada, Yasuhiko; Katsurahara, Masaki; Horiki, Noriyuki; Nakamura, Misaki; Shimoyama, Takahiro; Yamamoto, Takayuki; Takei, Yoshiyuki; Kusunoki, Masato

2018-03-16

Orally administered Qing-dai, called indigo naturalis in Latin, is reportedly useful for the treatment of ulcerative colitis. We herein describe two patients with ulcerative colitis who developed colitis with wall thickening and edematous changes during oral administration of the powdered form of Qing-dai. In Case 1, a 35-year-old man developed colitis similar to ischemic colitis with bloody stool that recurred each time he ingested Qing-dai. He had no signs of recurrence upon withdrawal of Qing-dai. In Case 2, a 43-year-old woman underwent ileocecal resection for treatment of an intussusception 2 months after beginning oral administration of Qing-dai. Edema and congestion but no ulceration were present in the mucosa of the resected specimen. Both patients exhibited abdominal pain with bloody diarrhea, and abdominal computed tomography showed marked wall edema affecting an extensive portion of the large bowel.

Pharmacokinetics of Understudied Drugs Administered to Children Per Standard of Care

ClinicalTrials.gov

2018-04-02

Adenovirus; Anesthesia; Anxiety; Anxiolysis; Autism; Autistic Disorder; Bacterial Meningitis; Bacterial Septicemia; Benzodiazepine; Bipolar Disorder; Bone and Joint Infections; Central Nervous System Infections; Convulsions; Cytomegalovirus Retinitis; Early-onset Schizophrenia Spectrum Disorders; Epilepsy; General Anesthesia; Gynecologic Infections; Herpes Simplex Virus; Infantile Hemangioma; Infection; Inflammation; Inflammatory Conditions; Intra-abdominal Infections; Lower Respiratory Tract Infections; Migraines; Pain; Pneumonia; Schizophrenia; Sedation; Seizures; Skeletal Muscle Spasms; Skin and Skin-structure Infections; Thromboprophylaxis; Thrombosis; Treatment-resistant Schizophrenia; Urinary Tract Infections; Withdrawal; Sepsis; Gram-negative Infection; Bradycardia; Cardiac Arrest; Cardiac Arrhythmia; Staphylococcal Infections; Nosocomial Pneumonia; Neuromuscular Blockade; Methicillin Resistant Staphylococcus Aureus; Endocarditis; Neutropenia; Headache

Withdrawal from Buprenorphine/Naloxone and Maintenance with a Natural Dopaminergic Agonist: A Cautionary Note.

PubMed

Blum, Kenneth; Oscar-Berman, Marlene; Femino, John; Waite, Roger L; Benya, Lisa; Giordano, John; Borsten, Joan; Downs, William B; Braverman, Eric R; Loehmann, Raquel; Dushaj, Kristina; Han, David; Simpatico, Thomas; Hauser, Mary; Barh, Debmalya; McLaughlin, Thomas

2013-04-23

While numerous studies support the efficacy of methadone and buprenorphine for the stabilization and maintenance of opioid dependence, clinically significant opioid withdrawal symptoms occur upon tapering and cessation of dosage. We present a case study of a 35 year old Caucasian female (Krissie) who was prescribed increasing dosages of prescription opioids after carpel tunnel surgery secondary to chronic pain from reflex sympathetic dystrophy and fibromyalgia. Over the next 5 years, daily dosage requirements increased to over 80 mg of Methadone and 300 ug/hr Fentanyl transdermal patches, along with combinations of 12-14 1600 mcg Actig lollipop and oral 100 mg Morphine and 30 mg oxycodone 1-2 tabs q4-6hr PRN for breakthrough pain. Total monthly prescription costs including supplemental benzodiazepines, hypnotics and stimulants exceeded $50,000. The patient was subsequently transferred to Suboxone® in 2008, and the dosage was gradually tapered until her admission for inpatient detoxification with KB220Z a natural dopaminergic agonist. We carefully documented her withdrawal symptoms when she precipitously stopped taking buprenorphine/naloxone and during follow-up while taking KB220Z daily. We also genotyped the patient using a reward gene panel including (9 genes 18 alleles): DRD 2,3,4; MOA-A; COMT; DAT1; 5HTTLLR; OPRM1; and GABRA3. At 432 days post Suboxone® withdrawal the patient is being maintained on KB220Z, has been urine tested and is opioid free. Genotyping data revealed a moderate genetic risk for addiction showing a hypodopaminergic trait. This preliminary case data suggest that the daily use of KB220Z could provide a cost effective alternative substitution adjunctive modality for Suboxone®. We encourage double-blind randomized -placebo controlled studies to test the proposition that KB220Z may act as a putative natural opioid substitution maintenance adjunct.

Theory of gastric CO2 ventilation and its control during respiratory acidosis: implications for central chemosensitivity, pH regulation, and diseases causing chronic CO2 retention.

PubMed

Dean, Jay B

2011-02-15

The theory of gastric CO(2) ventilation describes a previously unrecognized reflex mechanism controlled by neurons in the caudal solitary complex (cSC) for non-alveolar elimination of systemic CO(2) during respiratory acidosis. Neurons in the cSC, which is a site of CO(2) chemosensitivity for cardiorespiratory control, also control various gastroesophageal reflexes that remove CO(2) from blood. CO(2) is consumed in the production of gastric acid and bicarbonate in the gastric epithelium and then reconstituted as CO(2) in the stomach lumen from the reaction between H(+) and HCO(3)(-). Respiratory acidosis and gastric CO(2) distension induce cSC/vagovagal mediated transient relaxations of the lower esophageal sphincter to vent gastric CO(2) upwards by bulk flow along an abdominal-to-esophageal (=intrapleural) pressure gradient the magnitude of which increases during abdominal (gastric) compression caused by increased contractions of respiratory muscles. Esophageal distension induces cSC/nucleus ambiguus/vagovagal reflex relaxation of the upper esophageal sphincter and CO(2) is vented into the pharynx and mixed with pulmonary gas during expiration or, alternatively, during eructation. It is proposed that gastric CO(2) ventilation provides explanations for (1) the postprandial increase in expired CO(2) and (2) the negative P(blood - expired)CO₂difference that occurs with increased inspired CO(2). Furthermore, it is postulated that gastric CO(2) ventilation and alveolar CO(2) ventilation are coordinated under dual control by CO(2) chemosensitive neurons in the cSC. This new theory, therefore, presupposes a level of neural control and coordination between two previously presumed dissimilar organ systems and supports the notion that different sites of CO(2) chemosensitivity address different aspects of whole body pH regulation. Consequently, not all sites of central chemosensitivity are equal regarding the mechanism(s) activated for CO(2) elimination. A distributed CO(2) chemosensitive network-at least nine different areas in the CNS, including the cSC, have been reported to date-may reflect the complexity and dynamic nature of the fundamental neural circuitry required to achieve CO(2)/pH regulation across multiple organ systems under various states of arousal, oxygenation, pH status, and redox state. Moreover, coordination of respiratory and digestive control networks through the cSC could also account for the frequent co-expression of pulmonary diseases that cause chronic respiratory acidosis (and overstimulation of cSC neurons) with peptic ulcer disease or gastroesophageal reflux disease. Copyright © 2010 Elsevier B.V. All rights reserved.

PERIOD2 variants are associated with abdominal obesity, psycho-behavioral factors, and attrition in the dietary treatment of obesity.

PubMed

Garaulet, Marta; Corbalán-Tutau, M Dolores; Madrid, Juan A; Baraza, Juan C; Parnell, Laurence D; Lee, Yu-Chi; Ordovas, Jose M

2010-06-01

The purpose of this research was to test for association between polymorphisms in the circadian clock-related gene PERIOD2 (PER2) and attrition in patients prone to withdrawal from a behavioral weight-reduction program based on the Mediterranean diet. A total of 454 overweight/obese participants (women=380, men=74), aged 20 to 65 years, who attended outpatient clinics specializing in obesity between January and December 2008, were studied. Anthropometric, biochemical, and dietary-intake variables were analyzed. Effectiveness of the program was assessed, and a questionnaire of barriers to weight loss was considered. Multivariate analysis and logistic regression models were performed. Results indicate that PER2 polymorphisms rs2304672C>G and rs4663302C>T were associated with abdominal obesity (P<0.05). Participants who withdrew from treatment were significantly more obese and had more barriers to lose weight (P<0.05). They also displayed a lower likelihood of planning eating in advance and experiencing stress with dieting than those who completed treatment. Frequency of rs4663307 minor allele was significantly greater in withdrawers than in those who successfully completed treatment (P<0.05). Logistic regression analysis showed that rs2304672 C>G minor allele carriers had a greater probability of dropping out, displaying extreme snacking, experiencing stress with dieting, eating when bored, and skipping breakfast than noncarriers. PER2 is implicated in attrition in weight-loss treatment and may modulate eating-behavior-related phenotypes. These findings could represent a step toward personalized health care and nutrition based on a combination of genotyping and psycho-behavioral characterization. 2010 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

The effects of intrathecal midazolam on sympathetic nervous system reflexes in man--a pilot study.

PubMed Central

Goodchild, C S; Noble, J

1987-01-01

Nine patients were given intrathecal injections of midazolam (dose 0.3-2 mg dissolved in 3 ml 5% dextrose). No changes in motor power or general sensation were produced. Resting heart rate and blood pressure were unchanged and normal valsalva manoeuvres were elicited 30 min post-injection. Cardiovascular responses were provoked at a light plane of anaesthesia by intubation of the trachea and manipulation of peritoneum and bowel but not by surgical incision of the skin. Intrathecal administration of midazolam relieved post-operative pain of somatic origin but not of visceral origin. It is concluded that intrathecal midazolam in the dosage used interrupts somatic nociceptive afferent pathways but not abdominal visceral nociceptive afferent pathways. PMID:3567043

Effects of Vojta method on trunk stability in healthy individuals

PubMed Central

Ha, Sun-Young; Sung, Yun-Hee

2016-01-01

Vojta reflex locomotion is important to main upright posture through stimulation of breast zone to patient with cerebral palsy. However, application in other diseases is no investigated. So, we determined the effects of stimulation of the breast zone on trunk stability in healthy individuals. Fourteen young healthy adults (7 males and 7 females) voluntarily participated in this study. The subjects were randomly divided into an experimental group (breast zone) and control group (arbitrary point). All groups were stimulated for 5 min on the left and right sides, respectively, for a total 10 times. We used the thickness of the external oblique abdominal muscle (EO), the internal oblique abdominal muscle, the transversus abdominis muscle (TrA), and the rectus abdominis muscles, as well as the area of the diaphragm by using ultrasonography. In the experimental group, the thickness of the TrA significantly increased during stimulation (P<0.05) while the thickness of the EO significantly decreased (P<0.05). Also, the area of diaphragm in inspiration was significantly different (P<0.05). Therefore, stimulation of the breast zone may be effective to improve trunk stability through activation of the TrA muscle and the diaphragm. PMID:28119875

Effects of Vojta method on trunk stability in healthy individuals.

PubMed

Ha, Sun-Young; Sung, Yun-Hee

2016-12-01

Vojta reflex locomotion is important to main upright posture through stimulation of breast zone to patient with cerebral palsy. However, application in other diseases is no investigated. So, we determined the effects of stimulation of the breast zone on trunk stability in healthy individuals. Fourteen young healthy adults (7 males and 7 females) voluntarily participated in this study. The subjects were randomly divided into an experimental group (breast zone) and control group (arbitrary point). All groups were stimulated for 5 min on the left and right sides, respectively, for a total 10 times. We used the thickness of the external oblique abdominal muscle (EO), the internal oblique abdominal muscle, the transversus abdominis muscle (TrA), and the rectus abdominis muscles, as well as the area of the diaphragm by using ultrasonography. In the experimental group, the thickness of the TrA significantly increased during stimulation ( P <0.05) while the thickness of the EO significantly decreased ( P <0.05). Also, the area of diaphragm in inspiration was significantly different ( P <0.05). Therefore, stimulation of the breast zone may be effective to improve trunk stability through activation of the TrA muscle and the diaphragm.

X-ray examination of the stomach bubble after frequent experimental swallowing of saliva: the mechanism of aerophagia.

PubMed

Ogami, Junya; Ono, Shigeru; Naka, Naoko; Watanuki, Kei; Ishida, Satoshi

2005-12-01

While the mechanism of aerophagia remains unclear, the frequency of clenching has been reported to be increased when under stress. We hypothesized that, via the swallowing reflex, chronic air swallowing was induced through a "learned habit" of the oral cavity, which was acquired through psychological factors. This study examined whether the habitual repeated swallowing in the oral cavity was a process of aerophagia. After continuous experimental saliva swallowing, changes in the stomach bubble were examined by abdominal X-rays in a standing position. The subjects included 9 males and 10 females aged 20 to 36 years that were without organic disease in the pharynx and nasal cavity. X-ray images were digitized, and the area of the stomach bubble was measured by tracing. A close correlation was revealed in the stomach bubble area between posteroanterior and lateral views in six males (p<0.001, r = 0.910). In 3 males and 10 females, the area of the stomach bubble by posteroanterior view after 30 swallows was significantly increased compared with that before swallowing (p = 0.004). In the present study, abdominal X-rays confirmed that frequent saliva swallowing expanded the stomach bubble.

Control of moth flight posture is mediated by wing mechanosensory feedback.

PubMed

Dickerson, Bradley H; Aldworth, Zane N; Daniel, Thomas L

2014-07-01

Flying insects rapidly stabilize after perturbations using both visual and mechanosensory inputs for active control. Insect halteres are mechanosensory organs that encode inertial forces to aid rapid course correction during flight but serve no aerodynamic role and are specific to two orders of insects (Diptera and Strepsiptera). Aside from the literature on halteres and recent work on the antennae of the hawkmoth Manduca sexta, it is unclear how other flying insects use mechanosensory information to control body dynamics. The mechanosensory structures found on the halteres, campaniform sensilla, are also present on wings, suggesting that the wings can encode information about flight dynamics. We show that the neurons innervating these sensilla on the forewings of M. sexta exhibit spike-timing precision comparable to that seen in previous reports of campaniform sensilla, including haltere neurons. In addition, by attaching magnets to the wings of moths and subjecting these animals to a simulated pitch stimulus via a rotating magnetic field during tethered flight, we elicited the same vertical abdominal flexion reflex these animals exhibit in response to visual or inertial pitch stimuli. Our results indicate that, in addition to their role as actuators during locomotion, insect wings serve as sensors that initiate reflexes that control body dynamics. © 2014. Published by The Company of Biologists Ltd.

Hepatic laceration because of malpositioning of the umbilical vein catheter: case report and literature review.

PubMed

Yiğiter, Murat; Arda, Irfan Serdar; Hiçsönmez, Akgün

2008-05-01

Umbilical vein catheterization that is a common bedside procedure in the neonatal intensive care units is not without complication. The most common complications are thrombus formation, embolism, vessel perforation, hemorrhage, and infection. Complications related to the liver carry a high risk for mortality. Laceration is an ominous complication of umbilical vein catheter that is generally a result of direct injury through the liver parenchyma. Abdominal distension that develops gradually should alert the physician for a likely development of intrahepatic bleeding. Surgery is mandatory in patients with ongoing bleeding after the withdrawal of the catheter. Early diagnosis and treatment are lifesaving in these patients.

Sleep duration, depression, and oxytocinergic genotype influence prepulse inhibition of the startle reflex in postpartum women.

PubMed

Comasco, Erika; Gulinello, Maria; Hellgren, Charlotte; Skalkidou, Alkistis; Sylven, Sara; Sundström-Poromaa, Inger

2016-04-01

The postpartum period is characterized by a post-withdrawal hormonal status, sleep deprivation, and susceptibility to affective disorders. Postpartum mothering involves automatic and attentional processes to screen out new external as well as internal stimuli. The present study investigated sensorimotor gating in relation to sleep duration, depression, as well as catecholaminergic and oxytocinergic genotypes in postpartum women. Prepulse inhibition (PPI) of the startle reflex and startle reactivity were assessed two months postpartum in 141 healthy and 29 depressed women. The catechol-O-methyltransferase (COMT) Val158Met, and oxytocin receptor (OXTR) rs237885 and rs53576 polymorphisms were genotyped, and data on sleep duration were collected. Short sleep duration (less than four hours in the preceding night) and postpartum depression were independently associated with lower PPI. Also, women with postpartum depression had higher startle reactivity in comparison with controls. The OXTR rs237885 genotype was related to PPI in an allele dose-dependent mode, with T/T healthy postpartum women carriers displaying the lowest PPI. Reduced sensorimotor gating was associated with sleep deprivation and depressive symptoms during the postpartum period. Individual neurophysiological vulnerability might be mediated by oxytocinergic genotype which relates to bonding and stress response. These findings implicate the putative relevance of lower PPI of the startle response as an objective physiological correlate of liability to postpartum depression. Copyright © 2016 Elsevier B.V. and ECNP. All rights reserved.

Injection anaesthesia with fentanyl-midazolam-medetomidine in adult female mice: importance of antagonization and perioperative care.

PubMed

Fleischmann, Thea; Jirkof, Paulin; Henke, Julia; Arras, Margarete; Cesarovic, Nikola

2016-08-01

Injection anaesthesia is commonly used in laboratory mice; however, a disadvantage is that post-anaesthesia recovery phases are long. Here, we investigated the potential for shortening the recovery phase after injection anaesthesia with fentanyl-midazolam-medetomidine by antagonization with naloxone-flumazenil-atipamezole. In order to monitor side-effects, the depth of anaesthesia, heart rate (HR), core body temperature (BT) and concentration of blood gases, as well as reflex responses, were assessed during a 50 min anaesthesia. Mice were allowed to recover from the anaesthesia in their home cages either with or without antagonization, while HR, core BT and spontaneous home cage behaviours were recorded for 24 h. Mice lost righting reflex at 330 ± 47 s after intraperitoneal injection of fentanyl-midazolam-medetomidine. During anaesthesia, HR averaged 225 ± 23 beats/min, respiratory rate and core BT reached steady state at 131 ± 15 breaths/min and 34.3 ± 0.25℃, respectively. Positive pedal withdrawal reflex, movement triggered by tail pinch and by toe pinch, still occurred in 25%, 31.2% and 100% of animals, respectively. Arterial blood gas analysis revealed acidosis, hypoxia, hypercapnia and a marked increase in glucose concentration. After anaesthesia reversal by injection with naloxone-flumazenil-atipamezole, animals regained consciousness after 110 ± 18 s and swiftly returned to physiological baseline values, yet they displayed diminished levels of locomotion and disrupted circadian rhythm. Without antagonization, mice showed marked hypothermia (22 ± 1.9℃) and bradycardia (119 ± 69 beats/min) for several hours. Fentanyl-midazolam-medetomidine provided reliable anaesthesia in mice with reasonable intra-anaesthetic side-effects. Post-anaesthetic period and related adverse effects were both reduced substantially by antagonization with naloxone-flumazenil-atipamezole. © The Author(s) 2016.

Neonatal withdrawal syndrome after chronic maternal consumption of 4-methylethcathinone.

PubMed

Pichini, Simona; Rotolo, Maria Concetta; García, Jordi; Girona, Noelia; Leal, Lorna; García-Algar, Oscar; Pacifici, Roberta

2014-12-01

Synthetic cathinones have been markedly present in the Spanish drug market in recent years. These substances can be easily obtained in "smart shops", smoke shops, gas stations and web sites where they can be bought and received anonymously avoiding normal law controls. For the first time we present a case of a neonatal withdrawal syndrome in a baby born to a woman who was a chronic consumer of 4-methylethcathinone. The newborn presented with increased jitteriness and irritability, highpitched cry, hypertonia in the limbs and brisk tendon reflexes. 4-Methylethcathinone was identified and quantified by liquid chromatography tandem mass spectrometry in the four subsequent 3cm segments of maternal hair (4.3, 4.0, 4.0 and 3.9ng/mg hair starting from most proximal segment) accounting for maternal consumption during the whole pregnancy and before and in neonatal meconium (0.7ng/g) confirming fetal exposure during intrauterine life. Methadone and its metabolite were also measured in maternal and neonatal matrices. Counseling pregnant women and women who may become pregnant on the consequences of fetal drug exposure to new designer drugs like 4-methylethcathinone is critical to preventing poor neonatal outcomes. This case report is informative to those studying designer drugs and those clinically involved with pregnant women abusing psychoactive substances. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Autonomic control of cardiorespiratory interactions in fish, amphibians and reptiles.

PubMed

Taylor, E W; Leite, C A C; Skovgaard, N

2010-07-01

Control of the heart rate and cardiorespiratory interactions (CRI) is predominantly parasympathetic in all jawed vertebrates, with the sympathetic nervous system having some influence in tetrapods. Respiratory sinus arrhythmia (RSA) has been described as a solely mammalian phenomenon but respiration-related beat-to-beat control of the heart has been described in fish and reptiles. Though they are both important, the relative roles of feed-forward central control and peripheral reflexes in generating CRI vary between groups of fishes and probably between other vertebrates. CRI may relate to two locations for the vagal preganglionic neurons (VPN) and in particular cardiac VPN in the brainstem. This has been described in representatives from all vertebrate groups, though the proportion in each location is variable. Air-breathing fishes, amphibians and reptiles breathe discontinuously and the onset of a bout of breathing is characteristically accompanied by an immediate increase in heart rate plus, in the latter two groups, a left-right shunting of blood through the pulmonary circuit. Both the increase in heart rate and opening of a sphincter on the pulmonary artery are due to withdrawal of vagal tone. An increase in heart rate following a meal in snakes is related to withdrawal of vagal tone plus a non-adrenergic-non-cholinergic effect that may be due to humoral factors released by the gut. Histamine is one candidate for this role.

An Unusual Cause of Headache in a Medical Tourist

PubMed Central

Desai, Soaham Dilip; Mehta, Manan M.

2015-01-01

With booming medical tourism, Indian doctors are seeing a lot of patients from other countries for varied medical conditions. A citizen of Nairobi presented for treatment of his complaints consisting of severe episodic headache, with abdominal pain, spermatorrhea, decreased libido, constipation, and impotence. On detailed evaluation, he was found to have developed dependence to khat chewing; a social habit in his native country and his symptoms were attributed to effects of khat withdrawal. He improved after treatment with topiramate and escitalopram and lifestyle modification. Physicians need to be aware about various cultural habits of addiction in different parts of the world and their common presentations in view of globalization of health care. PMID:25811009

Herbal prescription Chang'an II repairs intestinal mucosal barrier in rats with post-inflammation irritable bowel syndrome

PubMed Central

Wang, Feng-yun; Su, Min; Zheng, Yong-qiu; Wang, Xiao-ge; Kang, Nan; Chen, Ting; Zhu, En-lin; Bian, Zhao-xiang; Tang, Xu-dong

2015-01-01

Aim: The herbal prescription Chang'an II is derived from a classical TCM formula Tong-Xie-Yao-Fang for the treatment of liver-qi stagnation and spleen deficiency syndrome of irritable bowel syndrome (IBS). In this study we investigated the effects of Chang'an II on the intestinal mucosal immune barrier in a rat post-inflammation IBS (PI-IBS) model. Methods: A rat model of PI-IBS was established using a multi-stimulation paradigm including early postnatal sibling deprivation, bondage and intrarectal administration of TNBS. Four weeks after TNBS administration, the rats were treated with Chang'an II (2.85, 5.71 and 11.42 g·kg−1·d−1, ig) for 14 d. Intestinal sensitivity was assessed based on the abdominal withdrawal reflex (AWR) scores and fecal water content. Open field test and two-bottle sucrose intake test were used to evaluate the behavioral changes. CD4+ and CD8+ cells were counted and IL-1β and IL-4 levels were measured in intestinal mucosa. Transmission electron microscopy was used to evaluate ultrastructural changes of the intestinal mucosal barrier. Results: PI-IBS model rats showed significantly increased AWR reactivity and fecal water content, and decreased locomotor activity and sucrose intake. Chang'an II treatment not only reduced AWR reactivity and fecal water content, but also suppressed the anxiety and depressive behaviors. Ultrastructural study revealed that the gut mucosal barrier function was severely damaged in PI-IBS model rats, whereas Chang'an II treatment relieved intestinal mucosal inflammation and repaired the gut mucosal barrier. Furthermore, PI-IBS model rats showed a significantly reduced CD4+/CD8+ cell ratio in lamina propria and submucosa, and increased IL-1β and reduced IL-4 expression in intestinal mucosa, whereas Chang'an II treatment reversed PI-IBS-induced changes in CD4+/CD8+ cell ratio and expression of IL-1β and IL-4. Conclusion: Chang'an II treatment protects the intestinal mucosa against PI-IBS through anti-inflammatory, immunomodulatory and anti-anxiety effects. PMID:25960135

Downregulation of the spinal NMDA receptor NR2B subunit during electro-acupuncture relief of chronic visceral hyperalgesia.

PubMed

Liu, Hongping; Zhang, Yuhua; Qi, Debo; Li, Weimin

2017-01-01

The involvement of spinal NR2B, a N-methyl-D-aspartate (NMDA) receptor subunit, in the therapeutic effect of electro-acupuncture (EA) on chronic visceral hyperalgesia was investigated. Chronic visceral hyperalgesia was induced using an irritable bowel syndrome (IBS) model in rats. Graded colorectal distention (CRD) stimuli at strengths of 20, 40, 60 and 80 mmHg were applied, and behavioral tests were performed to measure the abdominal withdrawal reflex (AWR) in response to the CRD stimuli and assess the severity of the visceral hyperalgesia. Rats were randomly divided into four groups: normal intact (control) group, IBS model (model) group, EA-treated IBS rats (EA) group and sham EA-treated IBS rats (sham EA) group. For the EA treatment, electric stimuli were applied through needles inserted into two acupoints [Zu-san-li (ST-36) and Shang-ju-xu (ST-37)] in both hind limbs, while the sham EA treatment consisted of only the insertion of needles into these same acupoints without an application of electric stimuli. Our results showed that AWR scores of the model group responding to CRD stimuli of 20, 40, 60 and 80 mmHg were significantly increased. These increased scores subsequently decreased following EA treatment (P < 0.05) compared with those for the other groups. The expression of NR2B in the superficial laminae (SDH, laminae I and II), nucleus proprius (NP, laminae III and IV), neck of the dorsal horn (NECK, laminae V and VI) and central canal region (lamina X) at thoracolumbar (T13-L2) and lumbosacral (L6-S2) segmental level significantly increased in the model group versus the control group (P < 0.05) and significantly decreased after EA treatment (P < 0.05). There were no significant changes in neither AWR scores nor expression of the NR2B subunit in these spinal regions after the sham EA treatment. These results confirm that EA can relieve chronic visceral hyperalgesia in IBS model rats and suggest that such an effect is possibly mediated through the downregulation of the NR2B subunits of NMDA at the spinal level.

Herbal prescription Chang'an II repairs intestinal mucosal barrier in rats with post-inflammation irritable bowel syndrome.

PubMed

Wang, Feng-yun; Su, Min; Zheng, Yong-qiu; Wang, Xiao-ge; Kang, Nan; Chen, Ting; Zhu, En-lin; Bian, Zhao-xiang; Tang, Xu-dong

2015-06-01

The herbal prescription Chang'an II is derived from a classical TCM formula Tong-Xie-Yao-Fang for the treatment of liver-qi stagnation and spleen deficiency syndrome of irritable bowel syndrome (IBS). In this study we investigated the effects of Chang'an II on the intestinal mucosal immune barrier in a rat post-inflammation IBS (PI-IBS) model. A rat model of PI-IBS was established using a multi-stimulation paradigm including early postnatal sibling deprivation, bondage and intrarectal administration of TNBS. Four weeks after TNBS administration, the rats were treated with Chang'an II (2.85, 5.71 and 11.42 g · kg(-1) · d(-1), ig) for 14 d. Intestinal sensitivity was assessed based on the abdominal withdrawal reflex (AWR) scores and fecal water content. Open field test and two-bottle sucrose intake test were used to evaluate the behavioral changes. CD4(+) and CD8(+) cells were counted and IL-1β and IL-4 levels were measured in intestinal mucosa. Transmission electron microscopy was used to evaluate ultrastructural changes of the intestinal mucosal barrier. PI-IBS model rats showed significantly increased AWR reactivity and fecal water content, and decreased locomotor activity and sucrose intake. Chang'an II treatment not only reduced AWR reactivity and fecal water content, but also suppressed the anxiety and depressive behaviors. Ultrastructural study revealed that the gut mucosal barrier function was severely damaged in PI-IBS model rats, whereas Chang'an II treatment relieved intestinal mucosal inflammation and repaired the gut mucosal barrier. Furthermore, PI-IBS model rats showed a significantly reduced CD4(+)/CD8(+) cell ratio in lamina propria and submucosa, and increased IL-1β and reduced IL-4 expression in intestinal mucosa, whereas Chang'an II treatment reversed PI-IBS-induced changes in CD4(+)/CD8(+) cell ratio and expression of IL-1β and IL-4. Chang'an II treatment protects the intestinal mucosa against PI-IBS through anti-inflammatory, immunomodulatory and anti-anxiety effects.

Fetal Heart Rate Monitoring during Intrauterine Open Surgery for Myelomeningocele Repair.

PubMed

Santana, Eduardo Félix Martins; Moron, Antônio Fernandes; Barbosa, Maurício Mendes; Milani, Herbene Jose Figuinha; Sarmento, Stephanno Gomes Pereira; Araujo Júnior, Edward; Rolo, Liliam Cristine; Cavalheiro, Sérgio

2016-01-01

The aim of this study was to assess fetal hemodynamics during intrauterine open surgery for myelomeningocele (MMC) repair by describing fetal heart rate (FHR) monitoring in detail related to each part of the procedure. A study was performed with 57 fetuses submitted to intrauterine MMC repair between the 24th and 27th week of gestation. Evaluations of FHR were made in specific periods: before anesthesia, after anesthesia, at the beginning of laparotomy, during uterus abdominal withdrawal, hysterotomy, neurosurgery (before incision, during early skin manipulation, spinal cord releasing, and at the end of neurosurgery), abdominal cavity reintroduction, and abdominal closure, and at the end of surgery. Means ± standard deviations of FHR were established for each period, and analysis of variance with repeated measures was used to assess differences between these periods. The mean differences were assessed with 95% confidence intervals and were analyzed by Tukey's multiple comparison test. The mean FHR during the specific periods mentioned above was 140.2, 140, 139.2, 138.8, 135.1, 133.9, 123.1, 134.0, 134.5, 137.9, and 139.9 bpm, respectively (p < 0.0001). Comparing the different periods, the highest frequencies were observed in the initial and final moments. The neurosurgery stage presents lower frequencies, especially during the release of the spinal cord. FHR monitoring revealed interesting findings in terms of physiological fetal changes during MMC repair, especially during neurosurgery, which was the most critical period. © 2015 S. Karger AG, Basel.

Immobilization of free-ranging maned wolf (Chrysocyon brachyurus) with tiletamine and zolazepam in central Brazil.

PubMed

Furtado, Mariana Malzoni; Kashivakura, Cynthia Kayo; Ferro, Claudia; de Almeida, Jácomo Anah Tereza; Silveira, Leandro; Astete, Samuel

2006-03-01

A tiletamine hydrochloride-zolazepam hydrochloride combination was used successfully to immobilize 27 free-ranging maned wolves (Chrysocyon brachyurus) at a mean dose of 2.77+/-0.56 (mean+/-SD) mg/kg. The induction time ranged from 3-15 min. Animals remained immobilized for periods of 48.56 +/-12.65 min. Compulsive licking, excessive salivation, muscle twitching, muscle tremors, tachypnea, and bradycardia were observed associated with the induction of the anesthesia in 13 of 27 maned wolves. Muscle twitching, pedal withdrawal reflex, muscle tremors, and ataxia were observed during recovery in three (11%) maned wolves. There were no significant differences in heart rates (P = 0.44), respiratory rates (P = 0.82), and rectal temperatures (P = 0.54) recorded at 5, 15, and 25 min after induction at these dosages. The tiletamine hydrochloride-zolazepam hydrochloride combination was shown to be an effective and safe immobilizing agent for free-ranging maned wolves.

Persistent pain after spinal cord injury is maintained by primary afferent activity.

PubMed

Yang, Qing; Wu, Zizhen; Hadden, Julia K; Odem, Max A; Zuo, Yan; Crook, Robyn J; Frost, Jeffrey A; Walters, Edgar T

2014-08-06

Chronic pain caused by insults to the CNS (central neuropathic pain) is widely assumed to be maintained exclusively by central mechanisms. However, chronic hyperexcitablility occurs in primary nociceptors after spinal cord injury (SCI), suggesting that SCI pain also depends upon continuing activity of peripheral sensory neurons. The present study in rats (Rattus norvegicus) found persistent upregulation after SCI of protein, but not mRNA, for a voltage-gated Na(+) channel, Nav1.8, that is expressed almost exclusively in primary afferent neurons. Selectively knocking down Nav1.8 after SCI suppressed spontaneous activity in dissociated dorsal root ganglion neurons, reversed hypersensitivity of hindlimb withdrawal reflexes, and reduced ongoing pain assessed by a conditioned place preference test. These results show that activity in primary afferent neurons contributes to ongoing SCI pain. Copyright © 2014 the authors 0270-6474/14/3410765-05$15.00/0.

MULTIPLE ELECTRON BEAM ION PUMP AND SOURCE

DOEpatents

Ellis, R.E.

1962-02-27

A vacuum pump is designed which operates by ionizing incoming air and by withdrawing the ions from the system by means of electrical fields. The apparatus comprises a cylindrical housing communicable with the vessel to be evacuated and having a thin wall section in one end. Suitable coils provide a longitudinal magnetic field within the cylinder. A broad cathode and an anode structure is provided to establish a plurality of adjacent electron beams which are parallel to the cylinder axis. Electron reflector means are provided so that each of the beams constitutes a PIG or reflex discharge. Such structure provides a large region in which incoming gas molecules may be ionized by electron bombardment. A charged electrode assembly accelerates the ions through the thin window, thereby removing the gas from the system. The invention may also be utilized as a highly efficient ion source. (AEC)

Confounding factors in diagnosing brain death: a case report.

PubMed

Burns, Jeffrey M; Login, Ivan S

2002-06-26

Brain death is strictly defined medically and legally. This diagnosis depends on three cardinal neurological features: coma, absent brainstem reflexes, and apnea. The diagnosis can only be made, however, in the absence of intoxication, hypothermia, or certain medical illnesses. A patient with severe hypoxic-ischemic brain injury met the three cardinal neurological features of brain death but concurrent profound hypothyroidism precluded the diagnosis. Our clinical and ethical decisions were further challenged by another facet of this complex case. Although her brain damage indicated a hopeless prognosis, we could not discontinue care based on futility because the only known surrogate was mentally retarded and unable to participate in medical planning. The presence of certain medical conditions prohibits a diagnosis of brain death, which is a medicolegal diagnosis of death, not a prediction or forecast of future outcome. While prognostication is important in deciding to withdraw care, it is not a component in diagnosing brain death.

Antinociceptive effect of cyclic phosphatidic acid and its derivative on animal models of acute and chronic pain.

PubMed

Kakiuchi, Yasutaka; Nagai, Jun; Gotoh, Mari; Hotta, Harumi; Murofushi, Hiromu; Ogawa, Tomoyo; Ueda, Hiroshi; Murakami-Murofushi, Kimiko

2011-05-14

Cyclic phosphatidic acid (cPA) is a structural analog of lysophosphatidic acid (LPA), but possesses different biological functions, such as the inhibition of autotaxin (ATX), an LPA-synthesizing enzyme. As LPA is a signaling molecule involved in nociception in the peripheral and central systems, cPA is expected to possess analgesic activity. We characterized the effects of cPA and 2-carba-cPA (2ccPA), a chemically stable cPA analog, on acute and chronic pain. (1) The systemic injection of 2ccPA significantly inhibited somato-cardiac and somato-somatic C-reflexes but not the corresponding A-reflexes in anesthetized rats. (2) 2ccPA reduced sensitivity measured as the paw withdrawal response to electrical stimulation applied to the hind paws of mice through the C-fiber, but not Aδ or Aβ. (3) In mice, pretreatment with 2ccPA dose-dependently inhibited the second phase of formalin-induced licking and biting responses. (4) In mice, pretreatment and repeated post-treatments with 2ccPA significantly attenuated thermal hyperalgesia and mechanical allodynia following partial ligation of the sciatic nerve. (5) In rats, repeated post-treatments with 2ccPA also significantly attenuated thermal hyperalgesia and mechanical allodynia following chronic sciatic nerve constriction. Our results suggest that cPA and its stable analog 2ccPA inhibit chronic and acute inflammation-induced C-fiber stimulation, and that the central effects of 2ccPA following repeated treatments attenuate neuropathic pain.

Interaction of the adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA) and opioid receptors in spinal cord nociceptive reflexes.

PubMed

Ramos-Zepeda, Guillermo; Herrero, Juan F

2013-08-14

We previously observed that the adenosine A1 receptor agonist N6-cyclopentyladenosine (CPA) is a very effective antinociceptive agent on intact but not on spinalized adult rats with inflammation. Since a close connection between opioid and adenosine A1 receptors has been described, we studied a possible relationship between these systems in the spinal cord. CPA-mediated antinociception was challenged by the selective adenosine A1 receptor antagonist 8-cyclopentyl-1, 3-dimethylxanthine (CPT) and by the opioid receptor antagonist naloxone on male adult Wistar rats with carrageenan-induced inflammation. Withdrawal reflexes activated by noxious mechanical and electrical stimulation were recorded using the single motor technique in intact and sham-spinalized animals. CPA was very effective in intact and sham spinalized rats but not in spinalized animals. Full reversal of CPA antinociception was observed with i.v. 1mg/kg of naloxone but not with 20mg/kg of CPT i.v. in responses to noxious mechanical and electrical stimulation. CPT fully prevented CPA from any antinociceptive action whereas naloxone did not modify CPA activity. These results suggest a centrally-mediated action, since CPA depressed the wind-up phenomenon which is derived of the activity of spinal cord neurons. The present study provides strong in vivo evidence of an antinociceptive activity mediated by the adenosine A1 receptor system in the spinal cord, linked to an activation of opioid receptors in adult animals with inflammation. © 2013.

Effects of gum chewing on abdominal discomfort, nausea, vomiting and intake adherence to polyethylene glycol solution of patients in colonoscopy preparation.

PubMed

Lee, Jisun; Lee, Eunjin; Kim, Yumi; Kim, Eun; Lee, Yaera

2016-02-01

This study aimed to reduce the common discomfort of colonoscopy patients when taking a bowel cleansing solution. Gum chewing, a form of sham feeding, was examined as a possible efficient intervention to reduce the discomfort from consuming polyethylene glycol. Sham feeding is a method that is similar to food intake, which stimulates the cephalic-vagal reflex, promotes secretion of gastrointestinal hormones, and stimulates movement of the gastrointestinal tract. Sham feeding with chewing gum has been shown to promote bowel motility. This was an experimental study utilising a randomised control group post-test design. This study was conducted in Seoul, Korea from August-October 2012. Patients were randomly allocated into two groups; a gum-chewing group (n = 66) or a control group (n = 65). In the control group, patients drank a polyethylene glycol solution according to the general protocol. For the gum-chewing group, patients had to chew one stick of sugarless gum during the pause interval of drinking the polyethylene glycol solution. Results were analysed using the Mann-Whitney U-test, t-test, Chi-square test or Fisher's exact test. The gum-chewing group reported significantly lower abdominal discomfort, nausea and vomiting and took a shorter time to ingest the polyethylene glycol solution than the control group. Gum chewing is efficient in improving abdominal discomfort, nausea, vomiting and the intake adherence of patients in colonoscopy preparation. Gum chewing was demonstrated by this study to be a potentially effective nursing intervention that is easy for patients to perform with simple instructions and is low cost with no side effects. © 2016 John Wiley & Sons Ltd.

Infant reflexes

MedlinePlus

... infants; Tonic neck reflex; Galant reflex; Truncal incurvation; Rooting reflex; Parachute reflex; Grasp reflex ... up if both hands are grasping your fingers. ROOTING REFLEX This reflex occurs when the baby's cheek ...

The Antinociceptive and Antihyperalgesic Effects of Topical Propofol on Dorsal Horn Neurons in the Rat

PubMed Central

Takechi, Kenichi; Carstens, Mirela Iodi; Klein, Amanda H.; Carstens, E.

2013-01-01

Background Propofol (2,6-diisopropylphenol) is an IV anesthetic used for general anesthesia. Recent evidence suggests that propofol-anesthetized patients experience less postoperative pain, and that propofol has analgesic properties when applied topically. We presently investigated the antinociceptive effects of topical propofol using behavioral and single-unit electrophysiological methods in rats. Methods In behavioral experiments with rats, we assessed the effect of topical hindpaw application of propofol (1–25%) on heat and mechanically evoked paw withdrawals. In electrophysiology experiments we recorded from lumbar dorsal horn wide dynamic range (WDR)-type neurons in pentobarbital-anesthetized rats. We assessed the effect of topical application of propofol to the ipsilateral hindpaw on neuronal responses elicited by noxious heat, cold and mechanical stimuli. We additionally tested if propofol blocks heat sensitization of paw withdrawals and WDR neuronal responses induced by topical application of allyl isothiocyanate (AITC; mustard oil). Results Topical application of propofol (1–25%) significantly increased the mean latency of the thermally evoked hindpaw withdrawal reflex on the treated (but not opposite) side in a concentration-dependent manner, with no effect on mechanically evoked hindpaw withdrawal thresholds. Propofol also prevented shortening of paw withdrawal latency induced by AITC. In electrophysiological experiments, topical application of 10 and 25% propofol, but not 1% propofol or vehicle (10% intralipid), to the ipsilateral hindpaw significantly attenuated the magnitude of responses of WDR neurons to noxious heating of glabrous hindpaw skin with no significant change in thermal thresholds. Maximal suppression of noxious heat-evoked responses was achieved 15-min after application followed by recovery to the pre-propofol baseline by 30 min. Responses to skin cooling or graded mechanical stimuli were not significantly affected by any concentration of propofol. Topical application of AITC enhanced the noxious heat-evoked response of dorsal horn neurons. This enhancement of heat-evoked responses was attenuated when 10% propofol was applied topically after application of AITC. Conclusions The results indicate that topical propofol inhibits responses of WDR neurons to noxious heat consistent with analgesia, and reduced AITC sensitization of WDR neurons consistent with an antihyperalgesic effect. These results are consistent with clinical studies demonstrating reduced postoperative pain in surgical patients anesthetized with propofol. The mechanism of analgesic action of topical propofol is not clear, but may involve desensitization of TRPV1 or TRPA1 receptors expressed in peripheral nociceptive nerve endings, engagement of endocannabinoids, or activation of peripheral gamma-aminobutyric acid A receptors. PMID:23337417

Differential effect of central command on aortic and carotid sinus baroreceptor-heart rate reflexes at the onset of spontaneous, fictive motor activity.

PubMed

Matsukawa, Kanji; Ishii, Kei; Kadowaki, Akito; Liang, Nan; Ishida, Tomoko

2012-08-15

Our laboratory has reported that central command blunts the sensitivity of the aortic baroreceptor-heart rate (HR) reflex at the onset of voluntary static exercise in conscious cats and spontaneous contraction in decerebrate cats. The purpose of this study was to examine whether central command attenuates the sensitivity of the carotid sinus baroreceptor-HR reflex at the onset of spontaneous, fictive motor activity in paralyzed, decerebrate cats. We confirmed that aortic nerve (AN)-stimulation-induced bradycardia was markedly blunted to 26 ± 4.4% of the control (21 ± 1.3 beats/min) at the onset of spontaneous motor activity. Although the baroreflex bradycardia by electrical stimulation of the carotid sinus nerve (CSN) was suppressed (P < 0.05) to 86 ± 5.6% of the control (38 ± 1.2 beats/min), the inhibitory effect of spontaneous motor activity was much weaker (P < 0.05) with CSN stimulation than with AN stimulation. The baroreflex bradycardia elicited by brief occlusion of the abdominal aorta was blunted to 36% of the control (36 ± 1.6 beats/min) during spontaneous motor activity, suggesting that central command is able to inhibit the cardiomotor sensitivity of arterial baroreflexes as the net effect. Mechanical stretch of the triceps surae muscle never affected the baroreflex bradycardia elicited by AN or CSN stimulation and by aortic occlusion, suggesting that muscle mechanoreflex did not modify the cardiomotor sensitivity of aortic and carotid sinus baroreflex. Since the inhibitory effect of central command on the carotid baroreflex pathway, associated with spontaneous motor activity, was much weaker compared with the aortic baroreflex pathway, it is concluded that central command does not force a generalized modulation on the whole pathways of arterial baroreflexes but provides selective inhibition for the cardiomotor component of the aortic baroreflex.

[Toxicity study of cefmatilen hydrochloride hydrate (S-1090) (5)--Six-month repeated oral dose toxicity study and supplement study in rats].

PubMed

Sameshima, H; Omori, M; Nishimura, Y; Chihaya, Y; Itoh, F; Mizushima, Y; Yabuuchi, K; Ohno, K; Furukawa, H; Yoshida, I; Ueno, M; Yahara, I; Kato, I

2001-05-01

Cefmatilen hydrochloride hydrate (S-1090) was orally administered to rats at dose levels of 100, 300 and 1000 mg potency/kg once daily for 6 months. All the S-1090 treated groups showed soft feces, reddish-brown feces (due to chelated products of S-1090 or its decomposition products with Fe3+ in the diet), abdominal distention, increased food and water consumption, lower urine pH, and a decrease of white blood cells counts (except for males of the 100 mg potency/kg group). One male in the 300 mg potency/kg group showed mucous feces and marked decrease in body weight, and diet in the middle stage of the administration period. In necropsy of the survivors of all treated groups, marked cecal enlargement was noted. No remarkable changes were observed in the other examination items. From the early stage of the withdrawal period, animals in the 1000 mg potency/kg group showed again soft or mucous feces and a marked decrease in body weight. Of these animals, one male died and another male was sacrificed in a moribund state at about 2 weeks of the withdrawal period. Enterocolitis was observed in these cases. Almost all animals recovered within 3 weeks of withdrawal. A supplemental study of the 6-month toxicity study was conducted to examine the mechanisms of enterocolitis and the changes observable in the 100 or 300 mg potency/kg groups after drug withdrawal. As a reference, cefdinir (CFDN), an oral cephem antibiotic the same as S-1090, was added in the 1000 mg potency/kg group. No deaths occurred in any groups. Decreased intestinal flora were noted in all the groups treated with S-1090 or CFDN at the end of the dosing period. At 2 weeks of the withdrawal period, C. difficile and its D-1 toxin in the cecal contents were highly detected in the S-1090 300 and 1000 mg potency/kg groups and CFDN group. Inflammatory changes in the cecum and colon were observed in these groups. At 4 weeks of the withdrawal period, intestinal flora in the S-1090 groups almost returned to the condition before dosing, but those in the CFDN group were retained highly. Cecal D-1 toxin in the CFDN group was positive and higher than in the S-1090 groups. It was thus considered that the critical condition with enterocolitis resulted from C. difficile, which proliferated more rapidly than the other bacteria and D-1 toxin produced by this bacteria in the withdrawal period. Above changes were commonly observed in the CFDN group. The NOAEL of S-1090 was assessed to be 100 mg potency/kg/day which induced no enteritis.

Stress, abdominal obesity and intrarenal resistive index in essential hypertension.

PubMed

Trovato, G M; Pace, P; Martines, G F; Trovato, F M; Pirri, C; Catalano, D

2012-07-01

Although it is commonly believed that a strong causal link exists between psychological stress and hypertension, as well with other factors, such as obesity, just what kind of empirical evidence supports this assumption is still controversial. The aim of the study is to investigate if perceived stress have any interference with intrarenal resistance and hence with mechanisms related to Essential Hypertension (EH) and if Anxiety, Depression, Self efficacy and Illness Perception can account for perceived stress. Obesity, insulin resistance (HOMA), Doppler Renal Resistive Index (RRI) and glomerular filtration rate (GFR) are studied along with Psychological Stress Measure (PSM), Illness Perception Questionnaire (IPQ-R), Generalized Self-Efficacy scale (GSE) and Hospital Anxiety and Depression Scale (HADS) in 119 hypertensive patients referred for stable lasting EH, and 150 normal controls. Lower salt/lower calories Mediterranean diet, physical activity increase and smoking withdrawal counseling were provided. By Odds Ratios, higher risk of EH is associated with greater perceived stress, older age, lower GFR, obesity, greater RRI and insulin resistance. By Multiple Linear Regression the most significant variable that accounts for higher RRI are abdominal obesity and arterial pulse pressure; the only significant independent psychological variable that accounts for abdominal obesity are PSM and identity IPQ subscale. Self-Efficacy anxiety and Illness perception subscales (IPQr), accounts significantly for 62.0% of the variance to PSM, with possible effects on RRI and on the pathophysiological hypertension cascade. Worst identity and treatment control perceptions of EH, and a lower self-efficacy are the main psychological factors accounting for a greater stress. Interventions aimed to reduce perceived stress can be warranted in EH.

Randomized controlled trial of probiotics after colonoscopy.

PubMed

D'Souza, Basil; Slack, Timothy; Wong, Shing W; Lam, Francis; Muhlmann, Mark; Koestenbauer, Jakob; Dark, Jonathan; Newstead, Graham

2017-09-01

Up to 20% of patients have ongoing abdominal symptoms at day 2 and beyond following colonoscopy. It was hypothesized that some of these symptoms are related to alterations in gut microbiota secondary to bowel preparation and would improve with probiotics compared with placebo. Patients were given either a probiotic or placebo capsule in the days following colonoscopy. Colonoscopy was performed with air insufflation. The probiotic capsule contained the strains Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07. Patients recorded their symptoms at 1 h, 1, 2, 4, 7 and 14 days post colonoscopy and returned results once their symptoms had resolved. The primary outcomes used were the length of days to resolution of bloating, abdominal pain and altered bowel function post colonoscopy. A total of 320 patients were randomized. After loss to follow-up and withdrawal, 133 patients were analysed in the probiotic group and 126 in the placebo group. Patients having probiotic had a lower number of pain days following colonoscopy, 1.99 versus 2.78 days (P < 0.033). There was no significant difference in bloating or return to normal bowel habit days (P = 0.139 and 0.265 respectively). Subgroup analysis revealed that patients with pre-existing abdominal pain benefited from probiotics in number of pain days, 2.16 versus 4.08 (P = 0.0498). Our study has shown a significant reduction in the duration of pain days post colonoscopy in patients taking probiotic compared with placebo. No significant effect was seen in terms of return to normal bowel function or bloating post colonoscopy. © 2015 Royal Australasian College of Surgeons.

Surgical Site Infiltration for Abdominal Surgery: A Novel Neuroanatomical-based Approach

PubMed Central

Janis, Jeffrey E.; Haas, Eric M.; Ramshaw, Bruce J.; Nihira, Mikio A.; Dunkin, Brian J.

2016-01-01

Background: Provision of optimal postoperative analgesia should facilitate postoperative ambulation and rehabilitation. An optimal multimodal analgesia technique would include the use of nonopioid analgesics, including local/regional analgesic techniques such as surgical site local anesthetic infiltration. This article presents a novel approach to surgical site infiltration techniques for abdominal surgery based upon neuroanatomy. Methods: Literature searches were conducted for studies reporting the neuroanatomical sources of pain after abdominal surgery. Also, studies identified by preceding search were reviewed for relevant publications and manually retrieved. Results: Based on neuroanatomy, an optimal surgical site infiltration technique would consist of systematic, extensive, meticulous administration of local anesthetic into the peritoneum (or preperitoneum), subfascial, and subdermal tissue planes. The volume of local anesthetic would depend on the size of the incision such that 1 to 1.5 mL is injected every 1 to 2 cm of surgical incision per layer. It is best to infiltrate with a 22-gauge, 1.5-inch needle. The needle is inserted approximately 0.5 to 1 cm into the tissue plane, and local anesthetic solution is injected while slowly withdrawing the needle, which should reduce the risk of intravascular injection. Conclusions: Meticulous, systematic, and extensive surgical site local anesthetic infiltration in the various tissue planes including the peritoneal, musculofascial, and subdermal tissues, where pain foci originate, provides excellent postoperative pain relief. This approach should be combined with use of other nonopioid analgesics with opioids reserved for rescue. Further well-designed studies are necessary to assess the analgesic efficacy of the proposed infiltration technique. PMID:28293525

Catechol-O-methlytransferase inhibition alters pain and anxiety-related volitional behaviors through activation of β-adrenergic receptors in the rat

PubMed Central

Kline, R. H.; Exposto, F. G.; O’Buckley, S. C.; Westlund, K. N.; Nackley, A. G.

2015-01-01

Reduced catechol-O-methyltransferase (COMT) activity resulting from genetic variation or pharmacological depletion results in enhanced pain perception in humans and nociceptive behaviors in animals. Using phasic mechanical and thermal reflex tests (e.g. von Frey, Hargreaves), recent studies show that acute COMT-dependent pain in rats is mediated by β-adrenergic receptors (βARs). In order to more closely mimic the characteristics of human chronic pain conditions associated with prolonged reductions in COMT, the present study sought to determine volitional pain-related and anxiety-like behavioral responses following sustained as well as acute COMT inhibition using an operant 10–45°C thermal place preference task and a light/dark preference test. In addition, we sought to evaluate the effects of sustained COMT inhibition on generalized body pain by measuring tactile sensory thresholds of the abdominal region. Results demonstrated that acute and sustained administration of the COMT inhibitor OR486 increased pain behavior in response to thermal heat. Further, sustained administration of OR486 increased anxiety behavior in response to bright light, as well as abdominal mechanosensation. Finally, all pain-related behaviors were blocked by the non-selective βAR antagonist propranolol. Collectively, these findings provide the first evidence that stimulation of ARs following acute or chronic COMT inhibition drives cognitive-affective behaviors associated with heightened pain that affects multiple body sites. PMID:25659347

The proprioceptive reflex control of the intercostal muscles during their voluntary activation

PubMed Central

Davis, J. Newsom; Sears, T. A.

1970-01-01

1. A quantitative study has been made of the reflex effects of sudden changes in mechanical load on contracting human intercostal muscles during willed breathing movements involving the chest wall. Averaging techniques were applied to recordings of electromyogram (EMG) and lung volume, and to other parameters of breathing. 2. Load changes were effected for brief periods (10-150 msec) at any predetermined lung volume by sudden connexion of the airway to a pressure source variable between ± 80 cm H2O so that respiratory movement could be either assisted or opposed. In some experiments airway resistance was suddenly reduced by porting from a high to a low resistance external airway. 3. Contracting inspiratory and expiratory intercostal muscles showed a `silent period' with unloading which is attributed to the sudden withdrawal from intercostal motoneurones of monosynaptic excitation of muscle spindle origin. 4. For both inspiratory and expiratory intercostal muscles the typical immediate effect of an increase in load was an inhibitory response (IR) with a latency of about 22 msec followed by an excitatory response (ER) with a latency of 50-60 msec. 5. It was established using brief duration stimuli (< 40 msec) that the IR depended on mechanical events associated with the onset of stimulation, whereas stimuli greater than 40 msec in duration were required to evoke the ER. 6. For constant expiratory flow rate and a constant load, the ER of expiratory intercostal muscles increased as lung volume decreased within the limits set by maximal activation of the motoneurone pool as residual volume was approached. 7. The ER to a constant load increased directly with the expiratory flow rate at which the load applied, also within limits set by maximal activation of the motoneurone pool. 8. For a given load, the ER during phonation was greater than that occurring at a similar expiratory flow rate without phonation when the resistance of the phonating larynx was mimicked by an external airway resistance. 9. It is argued that the IR is due to autogenetic inhibition arising from tendon organs and that the ER is due to autogenetic excitation arising from intercostal muscle spindles. 10. The initial dominance of inhibition in this dual proprioceptive reflex control was not predicted by the servo theory. It is proposed that the reflex pathways subserving autogenetic inhibition are under a centrifugal control which determines in relation to previous experience (learning) the conditions under which autogenetic facilitation is allowed. PMID:5499805

Baclofen pump catheter leakage after migration of the abdominal catheter in a pediatric patient with spasticity.

PubMed

Dastgir, Amer; Ranalli, Nathan J; MacGregor, Theresa L; Aldana, Philipp R

2015-09-01

The authors report an unusual case of intrathecal baclofen withdrawal due to the perforation and subsequent leakage of a baclofen pump catheter in a patient with spastic cerebral palsy. A 15-year-old boy underwent an uncomplicated placement of an intrathecal baclofen pump for the treatment of spasticity due to cerebral palsy. After excellent control of symptoms for 3 years, the patient presented to the emergency department with increasing tremors following a refill of his baclofen pump. Initial evaluation consisted of radiographs of the pump and catheter, which appeared normal, and a successful aspiration of CSF from the pump's side port. A CT dye study revealed a portion of the catheter directly overlying the refill port and extravasation of radiopaque dye into the subfascial pocket anterior to the pump. During subsequent revision surgery, a small puncture hole in the catheter was seen to be leaking the drug. The likely cause of the puncture was an inadvertent perforation of the catheter by a needle during the refilling of the pump. This case report highlights a unique complication in a patient with an intrathecal baclofen pump. Physicians caring for these patients should be aware of this rare yet potential complication in patients presenting with baclofen withdrawal symptoms.

Concentrations of dimethylaniline and other metabolites in milk and tissues of dairy cows treated with lidocaine.

PubMed

Hoogenboom, Ron L A P; Zuidema, Tina; Essers, Martien; van Vuuren, Ad M; van Wikselaar, Piet G; van Eijkeren, Jan C H; Mengelers, Marcel J B; Zeilmaker, Marco J; Bulder, Astrid S

2015-01-01

Lidocaine is a topical anaesthetic drug used in dairy cows for laparotomy (caesarean section, abomasal displacement). Because there are no registered drugs for this indication, it can be applied under the so-called Cascade rules (off-label use), with the restriction that the off-label withdrawal periods of 7 days for milk and 28 days for meat are taken into account. In animals, lidocaine is rapidly metabolised into various metabolites, one being 2,6-dimethylaniline (DMA) which is reported to possess carcinogenic and mutagenic properties and detected also in milk. To investigate whether the off-label withdrawal periods are long enough to exclude the presence of lidocaine and DMA, and potential other metabolites, in edible products, a study was performed with eight dairy cows treated with lidocaine by injection in the abdominal muscles. At various time points blood samples, milk and urine were collected. Four animals were slaughtered 3.5 h after treatment, the other four after 48.5 h. The injection site, meat, liver and kidney were analysed for levels of lidocaine, DMA, monoethylglycinexylidide (MEGX) and 3-OH-lidocaine. It was shown that DMA is an important metabolite in dairy cows and can be detected in both meat and milk. In addition, also MEGX, 3-OH-lidocaine and three other metabolites were identified and to some extent quantified. These metabolites were 4-OH-lidocaine, lidocaine-N-oxide and 4-hydroxy-DMA. The latter compound was the most important metabolite in urine. However, levels in milk and meat decreased rapidly after the application. Overall, it can be concluded that the off-label withdrawal times of 7 and 28 days for milk and meat, respectively, guarantee the absence of detectable levels of lidocaine and metabolites.

Functional relationship between brainstem putative pain-facilitating neurons and spinal nociceptfive neurons during development of inflammation in rats.

PubMed

Salas, Rafael; Ramirez, Karla; Tortorici, Victor; Vanegas, Horacio; Vazquez, Enrique

2018-05-01

The so-called on- and off-cells of the rostral ventromedial medulla (RVM) send their axons to the spinal dorsal horn. Activation of on-cells precedes and coincides with a facilitation, and activation of off-cells coincides with an inhibition, of withdrawal reflexes elicited by noxious agents. Considerable evidence supports the notion that on- and off-cells modulate nocifensive reflexes during opioid and non-opioid action and also during normal circumstances and during peripheral neuropathy and inflammation. Yet it is unclear whether on- and off-cells act upon sensory spinal circuits that might lead to ascending projections and the experience of pain. Here, in deeply anesthetized rats we recorded single unit discharges from pairs of one on-like or off-like cell in RVM and a nociceptive neuron in the spinal dorsal horn with input from a hind paw. Both ongoing activity and responses to a calibrated noxious stimulus applied to the paw were documented during basal conditions and during development of paw inflammation. Probably due to the strong barbiturate anesthesia, off-like cells were depressed and did not yield interpretable results. However, we showed for the first time that during the increase in neuronal activity that results from paw inflammation the activity of spinal nociceptive neurons reflects the activity of their partner on-like cells in a highly correlated manner. This implies a tight relationship between spinal sensory and RVM modulatory functions that may underlie inflammation-induced hyperreflexia and clinically relevant hyperalgesia. Copyright © 2018 Elsevier B.V. All rights reserved.

Bedding material affects mechanical thresholds, heat thresholds and texture preference

PubMed Central

Moehring, Francie; O’Hara, Crystal L.; Stucky, Cheryl L.

2015-01-01

It has long been known that the bedding type animals are housed on can affect breeding behavior and cage environment. Yet little is known about its effects on evoked behavior responses or non-reflexive behaviors. C57BL/6 mice were housed for two weeks on one of five bedding types: Aspen Sani Chips® (standard bedding for our institute), ALPHA-Dri®, Cellu-Dri™, Pure-o’Cel™ or TEK-Fresh. Mice housed on Aspen exhibited the lowest (most sensitive) mechanical thresholds while those on TEK-Fresh exhibited 3-fold higher thresholds. While bedding type had no effect on responses to punctate or dynamic light touch stimuli, TEK-Fresh housed animals exhibited greater responsiveness in a noxious needle assay, than those housed on the other bedding types. Heat sensitivity was also affected by bedding as animals housed on Aspen exhibited the shortest (most sensitive) latencies to withdrawal whereas those housed on TEK-Fresh had the longest (least sensitive) latencies to response. Slight differences between bedding types were also seen in a moderate cold temperature preference assay. A modified tactile conditioned place preference chamber assay revealed that animals preferred TEK-Fresh to Aspen bedding. Bedding type had no effect in a non-reflexive wheel running assay. In both acute (two day) and chronic (5 week) inflammation induced by injection of Complete Freund’s Adjuvant in the hindpaw, mechanical thresholds were reduced in all groups regardless of bedding type, but TEK-Fresh and Pure-o’Cel™ groups exhibited a greater dynamic range between controls and inflamed cohorts than Aspen housed mice. PMID:26456764

Long-lasting involuntary motor activity after spinal cord injury.

PubMed

McKay, W B; Ovechkin, A V; Vitaz, T W; Terson de Paleville, D G L; Harkema, S J

2011-01-01

The study design used is prospective cohort study. This study was designed to neurophysiologically characterize spinal motor activity during recovery from spinal cord injury (SCI). University of Louisville, Louisville, Kentucky, USA. Twenty-five consecutive acute SCI admissions were recruited for this study. The American Spinal Injury Association Impairment Scale (AIS) was used to categorize injury level and severity at onset. Surface EMG recording was carried out initially between the day of admission and 17 days post-onset (6.0 ± 4.3, mean ± s.d. days). Follow-up recordings were performed for up to 9 months after injury. Initial AIS distribution was 7 AIS-A; 3 AIS-B; 2 AIS-C; 13 AIS-D. Twelve subjects (48%) showed long-duration involuntary motor-unit activation during relaxation. This activity was seen on initial examination in nine and on follow-up by 3 months post-injury in three others. It was seen in muscles innervated from the injury zone in 11 and caudal to the lesion in 9 subjects. This activity was independent of the presence or absence of tendon reflexes and the ability to volitionally suppress plantar stimulation elicited reflex withdrawal. The form of involuntary activity described here is the likely result of the altered balance of excitation and inhibition reaching spinal motor neurons because of the loss of inhibitory interneurons or their reduced activation by damaged supraspinal drive and the synaptic reorganization that follows SCI. As such, this activity may be useful for monitoring the effects of neuroprotective and restorative intervention strategies in persons with SCI.

Long-lasting Involuntary Motor Activity After Spinal Cord Injury

PubMed Central

McKay, WB; Ovechkin, AV; Vitaz, TW; de Paleville, DGLTerson; Harkema, SJ

2010-01-01

Study Design Prospective cohort study Objective This study was designed to neurophysiologically characterize spinal motor activity during recovery from spinal cord injury (SCI). Setting University of Louisville, Louisville, Kentucky, USA. Material Twenty five consecutive acute SCI admissions were recruited for this study. Methods The American Spinal Injury Association Impairment Scale (AIS) was used to categorize injury level and severity at onset. Surface EMG recording, was carried out initially between the day of admission and 17 days post onset (6.0 ± 4.3, mean ± SD days). Follow-up recordings were performed for up to 9 months after injury. Initial AIS distribution was: 7 AIS-A; 3 AIS-B; 2 AIS-C; 13 AIS-D. Results Twelve subjects (48%) showed long-duration involuntary motor unit activation during relaxation. This activity was seen on initial examination in nine and on follow-up by three months post-injury in three others. It was seen in muscles innervated from the injury zone in 11 and caudal to the lesion in 9 subjects. This activity was independent of the presence or absence of tendon reflexes and the ability to volitionally suppress plantar stimulation elicited reflex withdrawal. Conclusions The form of involuntary activity described here is the likely result of the altered balance of excitation and inhibition reaching spinal motor neurons due to the loss of inhibitory interneurons or their reduced activation by damaged supraspinal drive and the synaptic reorganization that follows SCI. As such, this activity may be useful for monitoring the effects of neuroprotective and restorative intervention strategies in persons with SCI. PMID:20585326

Long-term sensitization training in Aplysia leads to an increase in the expression of BiP, the major protein chaperon of the ER.

PubMed

Kuhl, D; Kennedy, T E; Barzilai, A; Kandel, E R

1992-12-01

Long-term memory for sensitization of the gill- and siphon-withdrawal reflexes in Aplysia californica requires RNA and protein synthesis. These long-term behavioral changes are accompanied by long-term facilitation of the synaptic connections between the gill and siphon sensory and motor neurons, which are similarly dependent on transcription and translation. In addition to showing an increase in over-all protein synthesis, long-term facilitation is associated with changes in the expression of specific early, intermediate, and late proteins, and with the growth of new synaptic connections between the sensory and motor neurons of the reflex. We previously focused on early proteins and have identified four proteins as members of the immunoglobulin family of cell adhesion molecules related to NCAM and fasciclin II. We have now cloned the cDNA corresponding to one of the late proteins, and identified it as the Aplysia homolog of BiP, an ER resident protein involved in the folding and assembly of secretory and membrane proteins. Behavioral training increases the steady-state level of BiP mRNA in the sensory neurons. The increase in the synthesis of BiP protein is first detected 3 h after the onset of facilitation, when the increase in overall protein synthesis reaches its peak and the formation of new synaptic terminals becomes apparent. These findings suggest that the chaperon function of BiP might serve to fold proteins and assemble protein complexes necessary for the structural changes characteristic of long-term memory.

Intramuscular administration of alfaxalone for sedation in rabbits.

PubMed

Huynh, Minh; Poumeyrol, Séverine; Pignon, Charly; Le Teuff, Gwenaël; Zilberstein, Luca

2015-03-07

Alfaxalone is a neuroactive steroid derivative of pregnanedione that was recently reintroduced to the market for use as an induction agent in small animal anaesthesia. The aim of this study was to determine an intramuscular alfaxalone dose for safe immobilisation. Ten healthy New Zealand white rabbits were used to evaluate a single intramuscular injection of alfaxalone. The design of the study was a three-way, complete block, cross-over trial to compare the effect of alfaxalone at three doses (4, 6 and 8 mg). The mean duration of the effect for the 4, 6 and 8 mg/kg doses was, respectively, 36.9 (95% CI (31.6 to 42.3)), 51.8 (46.4 to 57.2) and 58.4 (52.8 to 63.9) minutes. The loss of the righting reflex was achieved after 3.1 (2.5 to 3.8), 2.4 (1.7 to 3.1) and 2.3 (1.6 to 2.9) minutes, respectively. The mean duration of the effect for the 6 and 8 mg doses was significantly higher than for the 4 mg dose (with estimated differences of 14.8 95% CI (8.8 to 20.8) minutes and 21.4 (15.3 to 27.6) minutes, respectively). No significant dose effect was observed before the loss of the righting reflex (P=0.14). Ear pinching and limb withdrawal were elicited in all groups at every dose. Doses of 4 or 6 mg/kg could be recommended; higher doses do not provide clinical benefits and can be associated with anaesthetic complication. British Veterinary Association.

Being reflexive in qualitative grounded theory: discussion and application of a model of reflexivity.

PubMed

Engward, Hilary; Davis, Geraldine

2015-07-01

A discussion of the meaning of reflexivity in research with the presentation of examples of how a model of reflexivity was used in a grounded theory research project. Reflexivity requires the researcher to make transparent the decisions they make in the research process and is therefore important in developing quality in nursing research. The importance of being reflexive is highlighted in the literature in relation to nursing research, however, practical guidance as to how to go about doing research reflexively is not always clearly articulated. This is a discussion paper. The concept of reflexivity in research is explored using the Alvesson and Skoldberg model of reflexivity and practical examples of how a researcher developed reflexivity in a grounded theory project are presented. Nurse researchers are encouraged to explore and apply the concept of reflexivity in their research practices to develop transparency in the research process and to increase robustness in their research. The Alvesson and Skoldberg model is of value in applying reflexivity in qualitative nursing research, particularly in grounded theory research. Being reflexive requires the researcher to be completely open about decisions that are made in the research process. The Alvesson and Skolberg model of reflexivity is a useful model that can enhance reflexivity in the research process. It can be a useful practical tool to develop reflexivity in grounded theory research. © 2015 John Wiley & Sons Ltd.

Variability in Hoffmann and tendon reflexes in healthy male subjects

NASA Technical Reports Server (NTRS)

Good, E.; Do, S.; Jaweed, M.

1992-01-01

There is a time dependent decrease in amplitude of H- and T-reflexes during Zero-G exposure and subsequently an increase in the amplitude of the H-reflex 2-4 hours after return to a 1-G environment. These alterations have been attributed to the adaptation of the human neurosensory system to gravity. The Hoffman reflex (H-reflex) is an acknowledged method to determine the integrity of the monosynaptic reflex arc. However deep tendon reflexes (DTR's or T-reflexes), elicited by striking the tendon also utilize the entire reflex arc. The objective of this study was to compare the variability in latency and amplitude of the two reflexes in healthy subjects. Methods: Nine healthy male subjects, 27-43 years in age, 161-175 cm in height plus 60-86 Kg in weight, underwent weekly testing for four weeks with a Dan-Tec EMG counterpoint EMG system. Subjects were studied prone and surface EMG electrodes were placed on the right and left soleus muscles. The H-reflex was obtained by stimulating the tibial nerve in the politeal fossa with a 0.2 msec square wave pulse delivered at 2 Hz until the maximum H-reflex was obtained. The T-reflex was invoked by tapping the achilles tendon with a self triggering reflex hammer connected to the EMG system. The latencies and amplitudes for the H- and T-reflexes were measured. Results: These data indicate that the amplitudes of these reflexes varied considerably. However, latencies to invoked responses were consistent. The latency of the T-reflex was approximately 3-5 msec longer than the H-reflex. Conclusion: The T-reflex is easily obtained, requires less time, and is more comfortable to perform. Qualitative data can be obtained by deploying self triggering, force plated reflex hammers both in the 1-G and Zero-G environment.

Hypergravity modulates behavioral nociceptive responses in rats

NASA Astrophysics Data System (ADS)

Kumei, Y.; Shimokawa, R.; Toda, K.; Kawauchi, Y.; Makita, K.; Terasawa, M.; Ohya, K.; Shimokawa, H.

Hypergravity (2G) exposure elevated the nociceptive threshold (pain suppression) concomitantly with evoked neuronal activity in the hypothalamus. Young Wistar male rats were exposed to 2G by centrifugal rotation for 10 min. Before and after 2G exposure, the nociceptive threshold was measured as the withdrawal reflex by using the von Frey type needle at a total of 8 sites of each rat (nose, four quarters, upper and lower back, tail), and then rats were sacrificed. Fos expression was examined immunohistochemically in the hypothalamic slices of the 2G-treated rats. When rats were exposed to 2G hypergravity, the nociceptive threshold was significantly elevated to approximately 150 to 250% of the 1G baseline control levels in all the examination sites. The 2G hypergravity remarkably induced Fos expression in the paraventricular and arcuate nuclei of the hypothalamus. The analgesic effects of 2G hypergravity were attenuated by naloxone pretreatment. Data indicate that hypergravity induces analgesic effects in rats, mediated through hypothalamic neuronal activity in the endogenous opioid system and hypothalamo-pituitary-adrenal axis.

Aging in Sensory and Motor Neurons Results in Learning Failure in Aplysia californica.

PubMed

Kempsell, Andrew T; Fieber, Lynne A

2015-01-01

The physiological and molecular mechanisms of age-related memory loss are complicated by the complexity of vertebrate nervous systems. This study takes advantage of a simple neural model to investigate nervous system aging, focusing on changes in learning and memory in the form of behavioral sensitization in vivo and synaptic facilitation in vitro. The effect of aging on the tail withdrawal reflex (TWR) was studied in Aplysia californica at maturity and late in the annual lifecycle. We found that short-term sensitization in TWR was absent in aged Aplysia. This implied that the neuronal machinery governing nonassociative learning was compromised during aging. Synaptic plasticity in the form of short-term facilitation between tail sensory and motor neurons decreased during aging whether the sensitizing stimulus was tail shock or the heterosynaptic modulator serotonin (5-HT). Together, these results suggest that the cellular mechanisms governing behavioral sensitization are compromised during aging, thereby nearly eliminating sensitization in aged Aplysia.

A Single Aplysia Neurotrophin Mediates Synaptic Facilitation via Differentially Processed Isoforms Secreted as Mature or Precursor Forms

PubMed Central

Kassabov, Stefan R.; Choi, Yun-Beom; Karl, Kevin A.; Vishwasrao, Harshad D.; Bailey, Craig H.; Kandel, Eric R.

2014-01-01

Summary Neurotrophins control the development and adult plasticity of the vertebrate nervous system. Failure to identify invertebrate neurotrophin orthologs, however, has precluded studies in invertebrate models, limiting understanding of fundamental aspects of neurotrophin biology and function. We identified a neurotrophin (ApNT) and Trk receptor (ApTrk) in the mollusk Aplysia and find they play a central role in learning related synaptic plasticity. ApNT increases the magnitude and lowers the threshold for induction of long-term facilitation and initiates the growth of new synaptic varicosities at the monosynaptic connection between sensory and motor neurons of the gill-withdrawal reflex. Unlike vertebrate neurotrophins, ApNT has multiple coding exons and exerts distinct synaptic effects through differentially processed and secreted splice isoforms. Our findings demonstrate the existence of bona-fide neurotrophin signaling in invertebrates and reveal a novel, post-transcriptional mechanism, regulating neurotrophin processing and the release of pro- and mature neurotrophins which differentially modulate synaptic plasticity. PMID:23562154

Confounding factors in diagnosing brain death: a case report

PubMed Central

Burns, Jeffrey M; Login, Ivan S

2002-01-01

Background Brain death is strictly defined medically and legally. This diagnosis depends on three cardinal neurological features: coma, absent brainstem reflexes, and apnea. The diagnosis can only be made, however, in the absence of intoxication, hypothermia, or certain medical illnesses. Case presentation A patient with severe hypoxic-ischemic brain injury met the three cardinal neurological features of brain death but concurrent profound hypothyroidism precluded the diagnosis. Our clinical and ethical decisions were further challenged by another facet of this complex case. Although her brain damage indicated a hopeless prognosis, we could not discontinue care based on futility because the only known surrogate was mentally retarded and unable to participate in medical planning. Conclusion The presence of certain medical conditions prohibits a diagnosis of brain death, which is a medicolegal diagnosis of death, not a prediction or forecast of future outcome. While prognostication is important in deciding to withdraw care, it is not a component in diagnosing brain death. PMID:12097152

Associative Learning in Invertebrates

PubMed Central

Hawkins, Robert D.; Byrne, John H.

2015-01-01

This work reviews research on neural mechanisms of two types of associative learning in the marine mollusk Aplysia, classical conditioning of the gill- and siphon-withdrawal reflex and operant conditioning of feeding behavior. Basic classical conditioning is caused in part by activity-dependent facilitation at sensory neuron–motor neuron (SN–MN) synapses and involves a hybrid combination of activity-dependent presynaptic facilitation and Hebbian potentiation, which are coordinated by trans-synaptic signaling. Classical conditioning also shows several higher-order features, which might be explained by the known circuit connections in Aplysia. Operant conditioning is caused in part by a different type of mechanism, an intrinsic increase in excitability of an identified neuron in the central pattern generator (CPG) for feeding. However, for both classical and operant conditioning, adenylyl cyclase is a molecular site of convergence of the two signals that are associated. Learning in other invertebrate preparations also involves many of the same mechanisms, which may contribute to learning in vertebrates as well. PMID:25877219

Evaluation of efficacy of valsalva maneuver for attenuating propofol injection pain: a prospective, randomised, single blind, placebo controlled study.

PubMed

Kumar, Sanjay; Khuba, Sandeep; Agarwal, Anil; Gautam, Sujeet; Yadav, Madhulika; Dixit, Aanchal

2018-05-30

Pain on propofol injection is a limitation of propofol. So far, there has been no study about valsalva to reduce pain on propofol injection. Valsalva reduces pain via sinoaortic baroreceptor reflex arc and distraction both. We planned this study for assessing efficacy of Valsalva maneuver to reduce pain on propofol injection. Eighty American Society of Anesthesiologists grade I enrolled adult patients undergoing general anesthesia were divided into 2 groups of 40 each. Group I (Valsalva): blew into sphygmomanometer tube and raised mercury column up to 30 mmHg for 20 seconds; Group II (Control): didn't blow. Immediately after intervention, patients were induced with 1% propofol. Pain was assessed using visual analog scale (VAS) scoring [0-10; where 0 as no pain and 10 as worst imaginable pain] and Withdrawal response scoring [0-3; where 0 as no pain and 3 as worst pain] and presented as Median [interquartile range]. Seventy patient's data were analyzed. Incidence of pain was significantly reduced in Valsalva group (53% i.e. 18 out of 34) in comparison to control (78% i.e. 28 out of 36) (P < 0.05). Withdrawal response score was significantly reduced in the Valsalva group (1 [0.00]) as compared to control (2 [1.00]) (P < 0.05). VAS was significantly reduced in the Valsalva group (3.50 [1.25]) as compared to control (7 [1.00]) (P < 0.05). Valsalva performed before propofol induction is effective in attenuating propofol pain with an advantage of being non- pharmacological, safe, easy and time effective.

Effect of intrathecal non-NMDA EAA receptor antagonist LY293558 in rats: a new class of drugs for spinal anesthesia.

PubMed

Von Bergen, Nicholas H; Subieta, Alberto; Brennan, Timothy J

2002-07-01

Excitatory amino acid receptors are important for both sensory and motor function in the spinal cord. We studied the effects of intrathecal LY293558, a competitive non-N-methyl-D-aspartate excitatory amino acid receptor antagonist, on motor and sensory function in rats to determine whether drugs blocking these receptors could potentially be used as alternative agents to local anesthetics for spinal anesthesia. Rats were tested before and 15-240 min after intrathecal injection of 5 nmol (in 10 microl) LY293558. Sensory function was tested at the hind paw using withdrawal response to pin prick and withdrawal to pinch with sharp forceps. Motor performance (ambulation, placing reflex, and Rotorod time), blood pressure, and heart rate were also evaluated. Some tests were repeated the next day. Responses after LY293558 were compared to injection of 40 microl bupivacaine, 0.75%. Pin-prick responses at the forepaw, chest, abdomen, hind leg, and hind paw were also examined after intrathecal LY293558. Intrathecal LY293558 blocked both sensory and motor responses through 180 min; complete recovery was present the following day. No change in blood pressure or heart rate occurred. The effects of LY293558 were more pronounced and sustained than those of bupivacaine. Segmental blockade of the response to pin prick was present after LY293558. Drugs like LY293558 that block alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)/kainate receptors may be an alternative to local anesthetics for spinal anesthesia in humans.

National Rugby League athletes and tendon tap reflex assessment: a matched cohort clinical study.

PubMed

Maurini, James; Ohmsen, Paul; Condon, Greg; Pope, Rodney; Hing, Wayne

2016-11-04

Limited research suggests elite athletes may differ from non-athletes in clinical tendon tap reflex responses. In this matched cohort study, 25 elite rugby league athletes were compared with 29 non-athletes to examine differences in tendon reflex responses. Relationships between reflex responses and lengths of players' careers were also examined. Biceps, triceps, patellar and Achilles tendon reflexes were clinically assessed. Right and left reflexes were well correlated for each tendon (r S  = 0.7-0.9). The elite rugby league athletes exhibited significantly weaker reflex responses than non-athletes in all four tendons (p < 0.005). Biceps reflexes demonstrated the largest difference and Achilles reflexes the smallest difference. Moderate negative correlations (r S  = -0.3-0.6) were observed between reflex responses and lengths of players' careers. Future research is required to further elucidate mechanisms resulting in the observed differences in tendon reflexes and to ensure clinical tendon tap examinations and findings can be interpreted appropriately in this athletic population.

PHYLOGENETIC ANALYSIS OF LEARNING-RELATED NEUROMODULATION IN MOLLUSCAN MECHANOSENSORY NEURONS.

PubMed

Wright, William G; Kirschman, David; Rozen, Danny; Maynard, Barbara

1996-12-01

In spite of significant advances in our understanding of mechanisms of learning and memory in a variety of organisms, little is known about how such mechanisms evolve. Even mechanisms of simple forms of learning, such as habituation and sensitization, have not been studied phylogenetically. Here we begin an evolutionary analysis of learning-related neuromodulation in species related to the well-studied opisthobranch gastropod, Aplysia californica. In Aplysia, increased spike duration and excitability in mechanosensory neurons contribute to several forms of learning-related changes to defensive withdrawal reflexes. The modulatory transmitter serotonin (5-hydroxytryptamine, or 5-HT), is thought to play a critical role in producing these firing property changes. In the present study, we tested mechanosensory homologs of the tail-withdrawal reflex in species related to Aplysia for 5-HT-mediated increases in spike duration and excitability. Criteria used to identify homologous tail-sensory neurons included position, relative size, resting electrical properties, expression of a sensory neuron-specific protein, neuroanatomy, and receptive field. The four ingroup species studied (Aplysia californica, Dolabella auricularia, Bursatella leachii, and Dolabrifera dolabrifera) belong to two clades (two species each) within the family Aplysiidae. In the first clade (Aplysia/Dolabella), we found that the tail-sensory neurons of A. californica and tail-sensory homologs of a closely related species, D. auricularia, responded to bath-applied serotonin in essentially similar fashion: significant increases in spike duration as well as excitability. In the other clade (Dolabrifera/Bursatella), more distantly related to Aplysia, one species (B. leachii) showed spike broadening and increased excitability. However, the other species (D. dolabrifera) showed neither spike broadening nor increased excitability. The firing properties of tail-sensory homologs of D. dolabrifera were insensitive to 5-HT over a wide range of concentrations. We also performed experiments on two outgroup species (Akera bullata and Bulla gouldiana) and found that spike duration was unaffected by 5-HT, whereas excitability was increased. This study suggests that 5-HT-induced spike broadening arose more recently in opisthobranch evolution, whereas 5-HT-induced excitability increase is a more ancestral trait that may have been expressed in the earliest opisthobranchs. Both traits are absent in the aplysiid species D. dolabrifera, demonstrating that a lineage can lose learning-related mechanisms. The phylogenetic variation observed in the present study presents the opportunity to test general models about learning mechanisms and their evolution in unique ways. © 1996 The Society for the Study of Evolution.

[H reflex in patients with spastic quadriplegia].

PubMed

Miyama, Sahoko; Arimoto, Kiyoshi; Kimiya, Satoshi

2009-01-01

Hoffmann reflex (H reflex) is an electrically elicited spinal monosynaptic reflex. H reflex was examined in 18 patients with spastic quadriplegia who had perinatal or postnatal problems. H reflex was elicitable in 11 patients for the abductor pollicis brevis (61.1%), 10 for the abductor digiti minimi (55.6%) and 16 for the abductor hallucis (88.9%). Because the abductor pollicis brevis and the abductor digiti minimi do not exhibit H reflex in normal subjects, it was suggested that the excitability of alpha motor neurons innervating these muscles was increased. H reflex was not detected for the extensor digitorum brevis in any patients, indicating the difference in the excitability among alpha motor neurons. In some patients, H reflex did not disappear under supramaximal stimuli. We conclude that the mechanism of evolution of H reflex in patients with spastic quadriplegia is different from that in normal subjects.

Effects of electroacupuncture on corticotropin-releasing hormone in rats with chronic visceral hypersensitivity.

PubMed

Liu, Hui-Rong; Fang, Xiao-Yi; Wu, Huan-Gan; Wu, Lu-Yi; Li, Jing; Weng, Zhi-Jun; Guo, Xin-Xin; Li, Yu-Guang

2015-06-21

To investigate the effect of electroacupuncture on corticotropin-releasing hormone (CRH) in the colon, spinal cord, and hypothalamus of rats with chronic visceral hypersensitivity. A rat model of chronic visceral hypersensitivity was generated according to the internationally accepted method of colorectal balloon dilatation. In the 7(th) week after the procedure, rats were randomly divided into a model group (MG), electroacupuncture group (EA), and sham electroacupuncture group (S-EA). After treatment, the abdominal withdrawal reflex (AWR) score was used to assess the behavioral response of visceral hyperalgesia. Immunohistochemistry (EnVision method), ELISA, and fluorescence quantitative PCR methods were applied to detect the expression of CRH protein and mRNA in the colon, spinal cord, and hypothalamus. The sensitivity of the rats to the colorectal distension stimulus applied at different strengths (20-80 mmHg) increased with increasing stimulus strength, resulting in increasing AWR scores in each group. Compared with NG, the AWR score of MG was significantly increased (P < 0.01). After conducting EA, the AWR scores of the rats were decreased compared with MG rats. The relative expression of CRH mRNA in the colon, spinal cord, and hypothalamus of MG rats was significantly increased compared with NG rats (P < 0.01). CRH mRNA in the colon and spinal cord of EA and S-EA rats was decreased to varying degrees (P > 0.05) compared with normal rats (NG). However, the decrease in EA compared with MG rats was statistically significant (P < 0.01). The average optical density of CRH expression in the colon of the MG rats was significantly enhanced compared with NG (P < 0.05), while the average optical density of CRH expression in the EA and S-EA rats was significantly decreased compared with MG rats (P < 0.01, P < 0.05, respectively). Compared with MG rats, the CRH concentration in the spinal cord of EA rats was significantly reduced (P < 0.01), but there was no significant change in S-EA rats (P > 0.05). Electroacupuncture at the Shangjuxu acupoint was able to significantly reduce the visceral hypersensitivity in rats, and regulated the expression of CRH protein and mRNA in the colon, spinal cord and hypothalamus at different levels, playing a therapeutic role in this model of irritable bowel syndrome.

Effects of electroacupuncture on corticotropin-releasing hormone in rats with chronic visceral hypersensitivity

PubMed Central

Liu, Hui-Rong; Fang, Xiao-Yi; Wu, Huan-Gan; Wu, Lu-Yi; Li, Jing; Weng, Zhi-Jun; Guo, Xin-Xin; Li, Yu-Guang

2015-01-01

AIM: To investigate the effect of electroacupuncture on corticotropin-releasing hormone (CRH) in the colon, spinal cord, and hypothalamus of rats with chronic visceral hypersensitivity. METHODS: A rat model of chronic visceral hypersensitivity was generated according to the internationally accepted method of colorectal balloon dilatation. In the 7th week after the procedure, rats were randomly divided into a model group (MG), electroacupuncture group (EA), and sham electroacupuncture group (S-EA). After treatment, the abdominal withdrawal reflex (AWR) score was used to assess the behavioral response of visceral hyperalgesia. Immunohistochemistry (EnVision method), ELISA, and fluorescence quantitative PCR methods were applied to detect the expression of CRH protein and mRNA in the colon, spinal cord, and hypothalamus. RESULTS: The sensitivity of the rats to the colorectal distension stimulus applied at different strengths (20-80 mmHg) increased with increasing stimulus strength, resulting in increasing AWR scores in each group. Compared with NG, the AWR score of MG was significantly increased (P < 0.01). After conducting EA, the AWR scores of the rats were decreased compared with MG rats. The relative expression of CRH mRNA in the colon, spinal cord, and hypothalamus of MG rats was significantly increased compared with NG rats (P < 0.01). CRH mRNA in the colon and spinal cord of EA and S-EA rats was decreased to varying degrees (P > 0.05) compared with normal rats (NG). However, the decrease in EA compared with MG rats was statistically significant (P < 0.01). The average optical density of CRH expression in the colon of the MG rats was significantly enhanced compared with NG (P < 0.05), while the average optical density of CRH expression in the EA and S-EA rats was significantly decreased compared with MG rats (P < 0.01, P < 0.05, respectively). Compared with MG rats, the CRH concentration in the spinal cord of EA rats was significantly reduced (P < 0.01), but there was no significant change in S-EA rats (P > 0.05). CONCLUSION: Electroacupuncture at the Shangjuxu acupoint was able to significantly reduce the visceral hypersensitivity in rats, and regulated the expression of CRH protein and mRNA in the colon, spinal cord and hypothalamus at different levels, playing a therapeutic role in this model of irritable bowel syndrome. PMID:26109804

Friedreich Ataxia and nephrotic syndrome: a series of two patients.

PubMed

Shinnick, Julianna E; Isaacs, Charles J; Vivaldi, Sharon; Schadt, Kimberly; Lynch, David R

2016-01-12

Friedreich Ataxia (FRDA) is a neurodegenerative disorder characterized by gait and balance abnormalities, sensory loss, weakness, loss of reflexes, and ataxia. Previously, two cases of FRDA and Nephrotic Syndrome (NS) have been reported. Here we report two additional individuals with NS and FRDA, providing further evidence for a possible connection between the two diseases and focusing on the neuromuscular responsiveness of one individual to corticosteroid treatment, an effect not previously described in FRDA. We describe two patients with FRDA also presenting with NS. The first patient was diagnosed with FRDA at age 5 and NS at age 7 following the development of periorbital edema, abdominal swelling, problems with urination, and weight gain. The second patient was diagnosed with NS at age 2 after presenting with periorbital edema, lethargy, and abdominal swelling. He was diagnosed with FRDA at age 10. Nephrotic syndrome was confirmed by laboratory testing in both cases and both individuals were treated with corticosteroids. Nephrotic syndrome may occur in individuals with FRDA, but was not associated with myoclonic epilepsy in our patients as previously described. It is unlikely that this association is coincidental given the rarity of both conditions and the association of NS with mitochondrial disease in model systems, though coincidental coexistence is possible. One patient showed neurological improvement following steroid treatment. Although neurological improvement could be attributed to the treatment of NS, we also identified some degree of steroid responsiveness in a series of patients with FRDA but without NS.

Catechol-O-methyltransferase inhibition alters pain and anxiety-related volitional behaviors through activation of β-adrenergic receptors in the rat.

PubMed

Kline, R H; Exposto, F G; O'Buckley, S C; Westlund, K N; Nackley, A G

2015-04-02

Reduced catechol-O-methyltransferase (COMT) activity resulting from genetic variation or pharmacological depletion results in enhanced pain perception in humans and nociceptive behaviors in animals. Using phasic mechanical and thermal reflex tests (e.g. von Frey, Hargreaves), recent studies show that acute COMT-dependent pain in rats is mediated by β-adrenergic receptors (βARs). In order to more closely mimic the characteristics of human chronic pain conditions associated with prolonged reductions in COMT, the present study sought to determine volitional pain-related and anxiety-like behavioral responses following sustained as well as acute COMT inhibition using an operant 10-45°C thermal place preference task and a light/dark preference test. In addition, we sought to evaluate the effects of sustained COMT inhibition on generalized body pain by measuring tactile sensory thresholds of the abdominal region. Results demonstrated that acute and sustained administration of the COMT inhibitor OR486 increased pain behavior in response to thermal heat. Further, sustained administration of OR486 increased anxiety behavior in response to bright light, as well as abdominal mechanosensation. Finally, all pain-related behaviors were blocked by the non-selective βAR antagonist propranolol. Collectively, these findings provide the first evidence that stimulation of βARs following acute or chronic COMT inhibition drives cognitive-affective behaviors associated with heightened pain that affects multiple body sites. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

Operant conditioning of the soleus H-reflex does not induce long-term changes in the gastrocnemius H-reflexes and does not disturb normal locomotion in humans.

PubMed

Makihara, Yukiko; Segal, Richard L; Wolpaw, Jonathan R; Thompson, Aiko K

2014-09-15

In normal animals, operant conditioning of the spinal stretch reflex or the H-reflex has lesser effects on synergist muscle reflexes. In rats and people with incomplete spinal cord injury (SCI), soleus H-reflex operant conditioning can improve locomotion. We studied in normal humans the impact of soleus H-reflex down-conditioning on medial (MG) and lateral gastrocnemius (LG) H-reflexes and on locomotion. Subjects completed 6 baseline and 30 conditioning sessions. During conditioning trials, the subject was encouraged to decrease soleus H-reflex size with the aid of visual feedback. Every sixth session, MG and LG H-reflexes were measured. Locomotion was assessed before and after conditioning. In successfully conditioned subjects, the soleus H-reflex decreased 27.2%. This was the sum of within-session (task dependent) adaptation (13.2%) and across-session (long term) change (14%). The MG H-reflex decreased 14.5%, due mainly to task-dependent adaptation (13.4%). The LG H-reflex showed no task-dependent adaptation or long-term change. No consistent changes were detected across subjects in locomotor H-reflexes, EMG activity, joint angles, or step symmetry. Thus, in normal humans, soleus H-reflex down-conditioning does not induce long-term changes in MG/LG H-reflexes and does not change locomotion. In these subjects, task-dependent adaptation of the soleus H-reflex is greater than it is in people with SCI, whereas long-term change is less. This difference from results in people with SCI is consistent with the fact that long-term change is beneficial in people with SCI, since it improves locomotion. In contrast, in normal subjects, long-term change is not beneficial and may necessitate compensatory plasticity to preserve satisfactory locomotion. Copyright © 2014 the American Physiological Society.

Vestibular activation of sympathetic nerve activity

NASA Technical Reports Server (NTRS)

Ray, C. A.; Carter, J. R.

2003-01-01

AIM: The vestibulosympathetic reflex refers to sympathetic nerve activation by the vestibular system. Animal studies indicate that the vestibular system assists in blood pressure regulation during orthostasis. Although human studies clearly demonstrate activation of muscle sympathetic nerve activity (MSNA) during engagement of the otolith organs, the role of the vestibulosympathetic reflex in maintaining blood pressure during orthostasis is not well-established. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes indicates that it is a powerful and independent reflex. Ageing, which is associated with an increased risk for orthostatic hypotension, attenuates the vestibulosympathetic reflex. The attenuated reflex is associated with a reduction in arterial pressure. CONCLUSION: These findings suggest that the vestibulosympathetic reflex assists in blood pressure regulation in humans, but future studies examining this reflex in other orthostatically intolerant populations are necessary to address this hypothesis.

On the Second Language Acquisition of Spanish Reflexive Passives and Reflexive Impersonals by French- and English-Speaking Adults

ERIC Educational Resources Information Center

Tremblay, Annie

2006-01-01

This study, a partial replication of Bruhn de Garavito (1999a; 1999b), investigates the second language (L2) acquisition of Spanish reflexive passives and reflexive impersonals by French- and English-speaking adults at an advanced level of proficiency. The L2 acquisition of Spanish reflexive passives and reflexive impersonals by native French and…

Endogenous inhibition of pain and spinal nociception in women with premenstrual dysphoric disorder

PubMed Central

Palit, Shreela; Bartley, Emily J; Kuhn, Bethany L; Kerr, Kara L; DelVentura, Jennifer L; Terry, Ellen L; Rhudy, Jamie L

2016-01-01

Purpose Premenstrual dysphoric disorder (PMDD) is characterized by severe affective and physical symptoms, such as increased pain, during the late-luteal phase of the menstrual cycle. The mechanisms underlying hyperalgesia in women with PMDD have yet to be identified, and supraspinal pain modulation has yet to be examined in this population. The present study assessed endogenous pain inhibitory processing by examining conditioned pain modulation (CPM, a painful conditioning stimulus inhibiting pain evoked by a test stimulus at a distal body site) of pain and the nociceptive flexion reflex (NFR, a spinally-mediated withdrawal reflex) during the mid-follicular, ovulatory, and late-luteal phases of the menstrual cycle. Methods Participants were regularly-cycling women (14 without PMDD; 14 with PMDD). CPM was assessed by delivering electrocutaneous test stimuli to the sural nerve before, during, and after a painful conditioning ischemia task. Participants rated their pain to electrocutaneous stimuli, and NFR magnitudes were measured. A linear mixed model analysis was used to assess the influence of group and menstrual phase on CPM. Results Compared with controls, women with PMDD experienced greater pain during the late-luteal phase and enhanced spinal nociception during the ovulation phase, both of which were independent of CPM. Both groups showed CPM inhibition of pain that did not differ by menstrual phase. Only women with PMDD evidenced CPM inhibition of NFR. Conclusion Endogenous modulation of pain and spinal nociception is not disrupted in women with PMDD. Additionally, greater NFR magnitudes during ovulation in PMDD may be due to tonically-engaged descending mechanisms that facilitate spinal nociception, leading to enhanced pain during the premenstrual phase. PMID:26929663

Implementation of a smartphone as a wireless gyroscope application for the quantification of reflex response.

PubMed

LeMoyne, Robert; Mastroianni, Timothy

2014-01-01

The patellar tendon reflex constitutes a fundamental aspect of the conventional neurological evaluation. Dysfunctional characteristics of the reflex response can augment the diagnostic acuity of a clinician for subsequent referral to more advanced medical resources. The capacity to quantify the reflex response while alleviating the growing strain on specialized medical resources is a topic of interest. The quantification of the tendon reflex response has been successfully demonstrated with considerable accuracy and consistency through using a potential energy impact pendulum attached to a reflex hammer for evoking the tendon reflex with a smartphone, such as an iPhone, application representing a wireless accelerometer platform to quantify reflex response. Another sensor integrated into the smartphone, such as an iPhone, is the gyroscope, which measures rate of angular rotation. A smartphone application enables wireless transmission through Internet connectivity of the gyroscope signal recording of the reflex response as an email attachment. The smartphone wireless gyroscope application demonstrates considerable accuracy and consistency for the quantification of the tendon reflex response.

H-reflex modulation in the human medial and lateral gastrocnemii during standing and walking

PubMed Central

Makihara, Yukiko; Segal, Richard L.; Wolpaw, Jonathan R.; Thompson, Aiko K.

2011-01-01

Introduction The soleus H-reflex is dynamically modulated during walking. However, modulation of the gastrocnemii H-reflexes has not been studied systematically. Methods The medial and lateral gastrocnemii (MG and LG) and soleus H-reflexes were measured during standing and walking in humans. Results Maximum H-reflex amplitude was significantly smaller in MG (mean 1.1 mV) or LG (1.1 mV) than in soleus (3.3 mV). Despite these size differences, the reflex amplitudes of the three muscles were positively correlated. The MG and LG H-reflexes were phase- and task-dependently modulated in ways similar to the soleus H-reflex. Discussion Although there are anatomical and physiological differences between the soleus and gastrocnemii muscles, the reflexes of the three muscles are similarly modulated during walking and between standing and walking. The findings support the hypothesis that these reflexes are synergistically modulated during walking to facilitate ongoing movement. PMID:22190317

Implementation of an iPhone wireless accelerometer application for the quantification of reflex response.

PubMed

LeMoyne, Robert; Mastroianni, Timothy; Grundfest, Warren; Nishikawa, Kiisa

2013-01-01

The patellar tendon reflex represents an inherent aspect of the standard neurological evaluation. The features of the reflex response provide initial perspective regarding the status of the nervous system. An iPhone wireless accelerometer application integrated with a potential energy impact pendulum attached to a reflex hammer has been successfully developed, tested, and evaluated for quantifying the patellar tendon reflex. The iPhone functions as a wireless accelerometer platform. The wide coverage range of the iPhone enables the quantification of reflex response samples in rural and remote settings. The iPhone has the capacity to transmit the reflex response acceleration waveform by wireless transmission through email. Automated post-processing of the acceleration waveform provides feature extraction of the maximum acceleration of the reflex response ascertained after evoking the patellar tendon reflex. The iPhone wireless accelerometer application demonstrated the utility of the smartphone as a biomedical device, while providing accurate and consistent quantification of the reflex response.

Soleus H-reflex gain in humans walking and running under simulated reduced gravity

NASA Technical Reports Server (NTRS)

Ferris, D. P.; Aagaard, P.; Simonsen, E. B.; Farley, C. T.; Dyhre-Poulsen, P.

2001-01-01

The Hoffmann (H-) reflex is an electrical analogue of the monosynaptic stretch reflex, elicited by bypassing the muscle spindle and directly stimulating the afferent nerve. Studying H-reflex modulation provides insight into how the nervous system centrally modulates stretch reflex responses.A common measure of H-reflex gain is the slope of the relationship between H-reflex amplitude and EMG amplitude. To examine soleus H-reflex gain across a range of EMG levels during human locomotion, we used simulated reduced gravity to reduce muscle activity. We hypothesised that H-reflex gain would be independent of gravity level.We recorded EMG from eight subjects walking (1.25 m s-1) and running (3.0 m s-1) at four gravity levels (1.0, 0.75, 0.5 and 0.25 G (Earth gravity)). We normalised the stimulus M-wave and resulting H-reflex to the maximal M-wave amplitude (Mmax) elicited throughout the stride to correct for movement of stimulus and recording electrodes relative to nerve and muscle fibres. Peak soleus EMG amplitude decreased by 30% for walking and for running over the fourfold change in gravity. As hypothesised, slopes of linear regressions fitted to H-reflex versus EMG data were independent of gravity for walking and running (ANOVA, P > 0.8). The slopes were also independent of gait (P > 0.6), contrary to previous studies. Walking had a greater y-intercept (19.9% Mmax) than running (-2.5% Mmax; P < 0.001). At all levels of EMG, walking H-reflex amplitudes were higher than running H-reflex amplitudes by a constant amount. We conclude that the nervous system adjusts H-reflex threshold but not H-reflex gain between walking and running. These findings provide insight into potential neural mechanisms responsible for spinal modulation of the stretch reflex during human locomotion.

Soleus H-reflex gain in humans walking and running under simulated reduced gravity

PubMed Central

Ferris, Daniel P; Aagaard, Per; Simonsen, Erik B; Farley, Claire T; Dyhre-Poulsen, Poul

2001-01-01

The Hoffmann (H-) reflex is an electrical analogue of the monosynaptic stretch reflex, elicited by bypassing the muscle spindle and directly stimulating the afferent nerve. Studying H-reflex modulation provides insight into how the nervous system centrally modulates stretch reflex responses. A common measure of H-reflex gain is the slope of the relationship between H-reflex amplitude and EMG amplitude. To examine soleus H-reflex gain across a range of EMG levels during human locomotion, we used simulated reduced gravity to reduce muscle activity. We hypothesised that H-reflex gain would be independent of gravity level. We recorded EMG from eight subjects walking (1.25 m s−1) and running (3.0 m s−1) at four gravity levels (1.0, 0.75, 0.5 and 0.25 G (Earth gravity)). We normalised the stimulus M-wave and resulting H-reflex to the maximal M-wave amplitude (Mmax) elicited throughout the stride to correct for movement of stimulus and recording electrodes relative to nerve and muscle fibres. Peak soleus EMG amplitude decreased by ≈30% for walking and for running over the fourfold change in gravity. As hypothesised, slopes of linear regressions fitted to H-reflex versus EMG data were independent of gravity for walking and running (ANOVA, P > 0.8). The slopes were also independent of gait (P > 0.6), contrary to previous studies. Walking had a greater y-intercept (19.9%Mmax) than running (-2.5%Mmax; P < 0.001). At all levels of EMG, walking H-reflex amplitudes were higher than running H-reflex amplitudes by a constant amount. We conclude that the nervous system adjusts H-reflex threshold but not H-reflex gain between walking and running. These findings provide insight into potential neural mechanisms responsible for spinal modulation of the stretch reflex during human locomotion. PMID:11136869

The utility of bispectral index monitoring for prevention of rocuronium-induced withdrawal movement in children

PubMed Central

Lim, Byung Gun; Lee, Il Ok; Kim, Young Sung; Won, Young Ju; Kim, Heezoo; Kong, Myoung Hoon

2017-01-01

Abstract Background: This study was designed to determine whether a deep hypnotic state with a bispectral index (BIS) value less than 40 could alleviate withdrawal movement (WM) upon rocuronium injection during anesthesia induction in children. Methods: Finally, 135 healthy children (3–12 years) scheduled for minor elective surgery were studied. Without premedication, anesthesia was induced with thiopental sodium 5 mg/kg. Patients were randomized into 2 groups (control vs experimental) and then by virtue of rocuronium injection time, patients in the experimental group were allocated into 2 groups, as follows: in the control group (group C; n = 45), rocuronium 0.6 mg/kg was administered at the loss of eyelash reflex; in the 1st experimental group, rocuronium 0.6 mg/kg was administered when BIS fell to less than 40 (group T; n = 45); however, if BIS did not fall below 40 after thiopental sodium administration, manual ventilation was provided with oxygen 6 L/minute using sevoflurane 8% and then rocuronium was administered when BIS fell below 40 (the 2nd experimental group, group S; n = 45). Rocuronium-induced WM was evaluated using a 4-point scale (no movement; movement/withdrawal involving the arm only; generalized response, with movement/withdrawal of more than 1 extremity, but no requirement for restraint of the body; and generalized response which required restraint of the body and caused coughing or breath-holding). Results: No significant differences were found among the groups for patient characteristics including age, sex, height, and location of venous cannula. However, body weight, height, and body mass index in group S were all smaller than those in group T. The incidence of WM caused by rocuronium was 100% in group C, 95.6% in group T, and 80% in group S, and was significantly lower in group S than in group C. The grade of WM was 3.7 ± 0.6 in group C, 3.2 ± 0.9 in group T, and 2.6 ± 1.0 in group S. It was significantly lower in group T than in group C and significantly lower in group S than in groups C and T. Conclusion: The confirmation of a deep hypnotic state with BIS values lower than 40 using BIS monitoring can reduce the grade of rocuronium-induced WMs during anesthesia induction using thiopental sodium or sevoflurane in children. PMID:28079825

The utility of bispectral index monitoring for prevention of rocuronium-induced withdrawal movement in children: A randomized controlled trial.

PubMed

Lim, Byung Gun; Lee, Il Ok; Kim, Young Sung; Won, Young Ju; Kim, Heezoo; Kong, Myoung Hoon

2017-01-01

This study was designed to determine whether a deep hypnotic state with a bispectral index (BIS) value less than 40 could alleviate withdrawal movement (WM) upon rocuronium injection during anesthesia induction in children. Finally, 135 healthy children (3-12 years) scheduled for minor elective surgery were studied. Without premedication, anesthesia was induced with thiopental sodium 5 mg/kg. Patients were randomized into 2 groups (control vs experimental) and then by virtue of rocuronium injection time, patients in the experimental group were allocated into 2 groups, as follows: in the control group (group C; n = 45), rocuronium 0.6 mg/kg was administered at the loss of eyelash reflex; in the 1st experimental group, rocuronium 0.6 mg/kg was administered when BIS fell to less than 40 (group T; n = 45); however, if BIS did not fall below 40 after thiopental sodium administration, manual ventilation was provided with oxygen 6 L/minute using sevoflurane 8% and then rocuronium was administered when BIS fell below 40 (the 2nd experimental group, group S; n = 45). Rocuronium-induced WM was evaluated using a 4-point scale (no movement; movement/withdrawal involving the arm only; generalized response, with movement/withdrawal of more than 1 extremity, but no requirement for restraint of the body; and generalized response which required restraint of the body and caused coughing or breath-holding). No significant differences were found among the groups for patient characteristics including age, sex, height, and location of venous cannula. However, body weight, height, and body mass index in group S were all smaller than those in group T. The incidence of WM caused by rocuronium was 100% in group C, 95.6% in group T, and 80% in group S, and was significantly lower in group S than in group C. The grade of WM was 3.7 ± 0.6 in group C, 3.2 ± 0.9 in group T, and 2.6 ± 1.0 in group S. It was significantly lower in group T than in group C and significantly lower in group S than in groups C and T. The confirmation of a deep hypnotic state with BIS values lower than 40 using BIS monitoring can reduce the grade of rocuronium-induced WMs during anesthesia induction using thiopental sodium or sevoflurane in children.

Neurodevelopmental Reflex Testing in Neonatal Rat Pups.

PubMed

Nguyen, Antoinette T; Armstrong, Edward A; Yager, Jerome Y

2017-04-24

Neurodevelopmental reflex testing is commonly used in clinical practice to assess the maturation of the nervous system. Neurodevelopmental reflexes are also referred to as primitive reflexes. They are sensitive and consistent with later outcomes. Abnormal reflexes are described as an absence, persistence, reappearance, or latency of reflexes, which are predictive indices of infants that are at high risk for neurodevelopmental disorders. Animal models of neurodevelopmental disabilities, such as cerebral palsy, often display aberrant developmental reflexes, as would be observed in human infants. The techniques described assess a variety of neurodevelopmental reflexes in neonatal rats. Neurodevelopmental reflex testing offers the investigator a testing method that is not otherwise available in such young animals. The methodology presented here aims to assist investigators in examining developmental milestones in neonatal rats as a method of detecting early-onset brain injury and/or determining the effectiveness of therapeutic interventions. The methodology presented here aims to provide a general guideline for investigators.

Reliability of the Achilles tendon tap reflex evoked during stance using a pendulum hammer.

PubMed

Mildren, Robyn L; Zaback, Martin; Adkin, Allan L; Frank, James S; Bent, Leah R

2016-01-01

The tendon tap reflex (T-reflex) is often evoked in relaxed muscles to assess spinal reflex circuitry. Factors contributing to reflex excitability are modulated to accommodate specific postural demands. Thus, there is a need to be able to assess this reflex in a state where spinal reflex circuitry is engaged in maintaining posture. The aim of this study was to determine whether a pendulum hammer could provide controlled stimuli to the Achilles tendon and evoke reliable muscle responses during normal stance. A second aim was to establish appropriate stimulus parameters for experimental use. Fifteen healthy young adults stood on a forceplate while taps were applied to the Achilles tendon under conditions in which postural sway was constrained (by providing centre of pressure feedback) or unconstrained (no feedback) from an invariant release angle (50°). Twelve participants repeated this testing approximately six months later. Within one experimental session, tap force and T-reflex amplitude were found to be reliable regardless of whether postural sway was constrained (tap force ICC=0.982; T-reflex ICC=0.979) or unconstrained (tap force ICC=0.968; T-reflex ICC=0.964). T-reflex amplitude was also reliable between experimental sessions (constrained ICC=0.894; unconstrained ICC=0.890). When a T-reflex recruitment curve was constructed, optimal mid-range responses were observed using a 50° release angle. These results demonstrate that reliable Achilles T-reflexes can be evoked in standing participants without the need to constrain posture. The pendulum hammer provides a simple method to allow researchers and clinicians to gather information about reflex circuitry in a state where it is involved in postural control. Copyright © 2015 Elsevier B.V. All rights reserved.

Factors Affecting the Occurrence of Spinal Reflexes in Brain Dead Cases.

PubMed

Hosseini, Mahsa Sadat; Ghorbani, Fariba; Ghobadi, Omid; Najafizadeh, Katayoun

2015-08-01

Brain death is defined as the permanent absence of all cortical and brain stem reflexes. A wide range of spontaneous or reflex movements that are considered medullary reflexes are observed in heart beating cases that appear brain dead, which may create uncertainty about the diagnosis of brain death and cause delays in deceased-donor organ donation process. We determined the frequency and type of medullary reflexes and factors affecting their occurrence in brain dead cases. During 1 year, 122 cases who fulfilled the criteria for brain death were admitted to the special intensive care unit for organ procurement of Masih Daneshvari Hospital. Presence of spinal reflexes was evaluated by trained coordinators and was recorded in a form in addition to other information including demographic characteristics, cause of brain death, time from detection of brain death, history of craniotomy, vital signs, serum electrolyte levels, and parameters of arterial blood gas determination. Most cases (63%) included in this study were male, and mean age was 33 ± 15 y. There was > 1 spinal reflex observed in 40 cases (33%). The most frequent reflex was plantar response (17%) following by myoclonus (10%), triple flexion reflex (9%), pronator extension reflex (8%), and undulating toe reflex (7%). Mean systolic blood pressure was significantly higher in cases who exhibited medullary reflexes than other cases (126 ± 19 mm Hg vs 116 ± 17 mm Hg; P = .007). Spinal reflexes occur frequently in brain dead cases, especially when they become hemodynamically stable after treatment in the organ procurement unit. Observing these movements by caregivers and family members has a negative effect on obtaining family consent and organ donation. Increasing awareness about spinal reflexes is necessary to avoid suspicion about the brain death diagnosis and delays in organ donation.

Objective methods for the assessment of the spinal and supraspinal effects of opioids.

PubMed

Fischer, Iben W; Hansen, Tine M; Lelic, Dina; Brokjaer, Anne; Frøkjær, Jens; Christrup, Lona L; Olesen, Anne E

2017-01-01

Opioids are potent analgesics. Opioids exert effects after interaction with opioid receptors. Opioid receptors are present in the peripheral- and central nervous system (CNS), but the analgesic effects are primarily mediated via receptors in the CNS. Objective methods for assessment of opioid effects may increase knowledge on the CNS processes responsible for analgesia. The aim of this review was to provide an overview of the most common objective methods for assessment of the spinal and supraspinal effects of opioids and discuss their advantages and limitations. The literature search was conducted in Pub Med (http://www.ncbi.nlm.nih.gov/pubmed) from November 2014 to June 2016, using free-text terms: "opioid", "morphine" and "oxycodone" combined with the terms "pupillometry," "magnetic resonance spectroscopy," "fMRI," "BOLD," "PET," "pharmaco-EEG", "electroencephalogram", "EEG," "evoked potentials," and "nociceptive reflex". Only original articles published in English were included. For assessment of opioid effects at the supraspinal level, the following methods are evaluated: pupillometry, proton magnetic resonance spectroscopy, functional resonance magnetic imaging (fMRI), positron emission tomography (PET), spontaneous electroencephalogram (EEG) and evoked potentials (EPs). Pupillometry is a non-invasive tool used in research as well as in the clinical setting. Proton magnetic resonance spectroscopy has been used for the last decades and it is a non-invasive technique for measurement of in vivo brain metabolite concentrations. fMRI has been a widely used non-invasive method to estimate brain activity, where typically from the blood oxygen level-dependent (BOLD) signal. PET is a nuclear imaging technique based on tracing radio labeled molecules injected into the blood, where receptor distribution, density and activity in the brain can be visualized. Spontaneous EEG is typically quantified in frequency bands, power spectrum and spectral edge frequency. EPs are brain responses (assessed by EEG) to a predefined number of short phasic stimuli. EPs are quantified by their peak latencies and amplitudes, power spectrum, scalp topographies and brain source localization. For assessment of opioid effects at the spinal level, the following methods are evaluated: the nociceptive withdrawal reflex (NWR) and spinal EPs. The nociceptive withdrawal reflex can be recorded from all limbs, but it is standard to record the electromyography signal at the biceps femoris muscle after stimulation of the ipsilateral sural nerve; EPs can be recorded from the spinal cord and are typically recorded after stimulation of the median nerve at the wrist. The presented methods can all be used as objective methods for assessing the centrally mediated effects of opioids. Advantages and limitations should be considered before implementation in drug development, future experimental studies as well as in clinical settings. In conclusion, pupillometry is a sensitive measurement of opioid receptor activation in the CNS and from a practical and economical perspective it may be used as a biomarker for opioid effects in the CNS. However, if more detailed information is needed on opioid effects at different levels of the CNS, then EEG, fMRI, PET and NWR have the potential to be used. Finally, it is conceivable that information from different methods should be considered together for complementary information. Copyright © 2016 Scandinavian Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

The differential role of motor cortex in the stretch reflex modulation induced by changes in environmental mechanics and verbal instruction

PubMed Central

Shemmell, Jonathan; An, Je Hi; Perreault, Eric J.

2009-01-01

The motor cortex assumes an increasingly important role in higher mammals relative to that in lower mammals. This is true to such an extent that the human motor cortex is deeply involved in reflex regulation and it is common to speak of “transcortical reflex loops”. Such loops appear to add flexibility to the human stretch reflex, once considered to be immutable, allowing it to adapt across a range of functional tasks. However, the purpose of this adaptation remains unclear. A common proposal is that stretch reflexes contribute to the regulation of limb stability; increased reflex sensitivity during tasks performed in unstable environments supports this hypothesis. Alternatively, prior to movement onset, stretch reflexes can assist an imposed stretch, opposite to what would be expected from a stabilizing response. Here we show that stretch reflex modulation in tasks that require changes in limb stability is mediated by motor cortical pathways, and that these differ from pathways contributing to reflex modulation that depends on how the subject is instructed to react to an imposed perturbation. By timing muscle stretches such that the modulated portion of the reflex occurred within a cortical silent period induced by transcranial magnetic stimulation, we abolished the increase in reflex sensitivity observed when individuals stabilized arm posture within a compliant environment. Conversely, reflex modulation caused by altered task instruction was unaffected by cortical silence. These results demonstrate that task-dependent changes in reflex function can be mediated through multiple neural pathways and that these pathways have task specific roles. PMID:19846713

The differential role of motor cortex in stretch reflex modulation induced by changes in environmental mechanics and verbal instruction.

PubMed

Shemmell, Jonathan; An, Je Hi; Perreault, Eric J

2009-10-21

The motor cortex assumes an increasingly important role in higher mammals relative to that in lower mammals. This is true to such an extent that the human motor cortex is deeply involved in reflex regulation and it is common to speak of "transcortical reflex loops." Such loops appear to add flexibility to the human stretch reflex, once considered to be immutable, allowing it to adapt across a range of functional tasks. However, the purpose of this adaptation remains unclear. A common proposal is that stretch reflexes contribute to the regulation of limb stability; increased reflex sensitivity during tasks performed in unstable environments supports this hypothesis. Alternatively, before movement onset, stretch reflexes can assist an imposed stretch, opposite to what would be expected from a stabilizing response. Here we show that stretch reflex modulation in tasks that require changes in limb stability is mediated by motor cortical pathways, and that these differ from pathways contributing to reflex modulation that depend on how the subject is instructed to react to an imposed perturbation. By timing muscle stretches such that the modulated portion of the reflex occurred within a cortical silent period induced by transcranial magnetic stimulation, we abolished the increase in reflex sensitivity observed when individuals stabilized arm posture within a compliant environment. Conversely, reflex modulation caused by altered task instruction was unaffected by cortical silence. These results demonstrate that task-dependent changes in reflex function can be mediated through multiple neural pathways and that these pathways have task-specific roles.

Hypoglossal-facial nerve reconstruction using a Y-tube-conduit reduces aberrant synkinetic movements of the orbicularis oculi and vibrissal muscles in rats.

PubMed

Kaya, Yasemin; Ozsoy, Umut; Turhan, Murat; Angelov, Doychin N; Sarikcioglu, Levent

2014-01-01

The facial nerve is the most frequently damaged nerve in head and neck trauma. Patients undergoing facial nerve reconstruction often complain about disturbing abnormal synkinetic movements of the facial muscles (mass movements, synkinesis) which are thought to result from misguided collateral branching of regenerating motor axons and reinnervation of inappropriate muscles. Here, we examined whether use of an aorta Y-tube conduit during reconstructive surgery after facial nerve injury reduces synkinesis of orbicularis oris (blink reflex) and vibrissal (whisking) musculature. The abdominal aorta plus its bifurcation was harvested (N = 12) for Y-tube conduits. Animal groups comprised intact animals (Group 1), those receiving hypoglossal-facial nerve end-to-end coaptation alone (HFA; Group 2), and those receiving hypoglossal-facial nerve reconstruction using a Y-tube (HFA-Y-tube, Group 3). Videotape motion analysis at 4 months showed that HFA-Y-tube group showed a reduced synkinesis of eyelid and whisker movements compared to HFA alone.

Hypoglossal-Facial Nerve Reconstruction Using a Y-Tube-Conduit Reduces Aberrant Synkinetic Movements of the Orbicularis Oculi and Vibrissal Muscles in Rats

PubMed Central

Kaya, Yasemin; Ozsoy, Umut; Turhan, Murat; Angelov, Doychin N.; Sarikcioglu, Levent

2014-01-01

The facial nerve is the most frequently damaged nerve in head and neck trauma. Patients undergoing facial nerve reconstruction often complain about disturbing abnormal synkinetic movements of the facial muscles (mass movements, synkinesis) which are thought to result from misguided collateral branching of regenerating motor axons and reinnervation of inappropriate muscles. Here, we examined whether use of an aorta Y-tube conduit during reconstructive surgery after facial nerve injury reduces synkinesis of orbicularis oris (blink reflex) and vibrissal (whisking) musculature. The abdominal aorta plus its bifurcation was harvested (N = 12) for Y-tube conduits. Animal groups comprised intact animals (Group 1), those receiving hypoglossal-facial nerve end-to-end coaptation alone (HFA; Group 2), and those receiving hypoglossal-facial nerve reconstruction using a Y-tube (HFA-Y-tube, Group 3). Videotape motion analysis at 4 months showed that HFA-Y-tube group showed a reduced synkinesis of eyelid and whisker movements compared to HFA alone. PMID:25574468

Primitive Reflexes and Attention-Deficit/Hyperactivity Disorder: Developmental Origins of Classroom Dysfunction

ERIC Educational Resources Information Center

Taylor, Myra; Houghton, Stephen; Chapman, Elaine

2004-01-01

The present research studied the symptomatologic overlap of AD/HD behaviours and retention of four primitive reflexes (Moro, Tonic Labyrinthine Reflex [TLR], Asymmetrical Tonic Neck Reflex [ATNR], Symmetrical Tonic Neck Reflex [STNR]) in 109 boys aged 7-10 years. Of these, 54 were diagnosed with AD/HD, 34 manifested sub-syndromal coordination,…

Development of the Stretch Reflex in the Newborn: Reciprocal Excitation and Reflex Irradiation.

ERIC Educational Resources Information Center

Myklebust, Barbara M.; Gottlieb, Gerald L.

1993-01-01

When tendon jerk reflexes were tested in seven newborns from one- to three-days old, stretch reflex responses in all major muscle groups of the lower limb were elicited. This "irradiation of reflexes" is a normal phenomenon in newborns, with the pathway becoming suppressed during normal maturation. In individuals with cerebral palsy,…

Supraspinal control of spinal reflex responses to body bending during different behaviours in lampreys

PubMed Central

Hsu, Li‐Ju; Zelenin, Pavel V.; Orlovsky, Grigori N.

2016-01-01

Key points Spinal reflexes are substantial components of the motor control system in all vertebrates and centrally driven reflex modifications are essential to many behaviours, but little is known about the neuronal mechanisms underlying these modifications.To study this issue, we took advantage of an in vitro brainstem–spinal cord preparation of the lamprey (a lower vertebrate), in which spinal reflex responses to spinal cord bending (caused by signals from spinal stretch receptor neurons) can be evoked during different types of fictive behaviour.Our results demonstrate that reflexes observed during fast forward swimming are reversed during escape behaviours, with the reflex reversal presumably caused by supraspinal commands transmitted by a population of reticulospinal neurons.NMDA receptors are involved in the formation of these commands, which are addressed primarily to the ipsilateral spinal networks.In the present study the neuronal mechanisms underlying reflex reversal have been characterized for the first time. Abstract Spinal reflexes can be modified during different motor behaviours. However, our knowledge about the neuronal mechanisms underlying these modifications in vertebrates is scarce. In the lamprey, a lower vertebrate, body bending causes activation of intraspinal stretch receptor neurons (SRNs) resulting in spinal reflexes: activation of motoneurons (MNs) with bending towards either the contralateral or ipsilateral side (a convex or concave response, respectively). The present study had two main aims: (i) to investigate how these spinal reflexes are modified during different motor behaviours, and (ii) to reveal reticulospinal neurons (RSNs) transmitting commands for the reflex modification. For this purpose in in vitro brainstem–spinal cord preparation, RSNs and reflex responses to bending were recorded during different fictive behaviours evoked by supraspinal commands. We found that during fast forward swimming MNs exhibited convex responses. By contrast, during escape behaviours, MNs exhibited concave responses. We found RSNs that were activated during both stimulation causing reflex reversal without initiation of any specific behaviour, and stimulation causing reflex reversal during escape behaviour. We suggest that these RSNs transmit commands for the reflex modification. Application of the NMDA antagonist (AP‐5) to the brainstem significantly decreased the reversed reflex, suggesting involvement of NMDA receptors in the formation of these commands. Longitudinal split of the spinal cord did not abolish the reflex reversal caused by supraspinal commands, suggesting an important role for ipsilateral networks in determining this type of motor response. This is the first study to reveal the neuronal mechanisms underlying supraspinal control of reflex reversal. PMID:27589479

Protective role of aerodigestive reflexes against aspiration: study on subjects with impaired and preserved reflexes.

PubMed

Dua, Kulwinder; Surapaneni, Sri Naveen; Kuribayashi, Shiko; Hafeezullah, Mohammed; Shaker, Reza

2011-06-01

Direct evidence to support the airway protective function of aerodigestive reflexes triggered by pharyngeal stimulation was previously demonstrated by abolishing these reflexes by topical pharyngeal anesthesia in normal subjects. Studies have also shown that these reflexes deteriorate in cigarette smokers. Aim of this study was to determine the influence of defective pharyngeal aerodigestive reflexes on airway protection in cigarette smokers. Pharyngoglottal Closure reflex; PGCR, Pharyngo-UES Contractile reflex; PUCR, and Reflexive Pharyngeal Swallow; RPS were studied in 15 healthy non-smokers (24.2±3.3 SD y, 7 males) and 15 healthy chronic smokers (27.3±8.1, 7 males). To elicit these reflexes and to evaluate aspiration, colored water was perfused into the hypopharynx at the rate of 1 mL/min. Maximum volume of water that can safely dwell in the hypopharynx before spilling into the larynx (Hypopharyngeal Safe Volume; HPSV) and the threshold volume to elicit PGCR, PUCR, and RPS were determined in smokers and results compared with non-smokers. At baseline, RPS was elicited in all non-smokers (100%) and in only 3 of 15 smokers (20%; P<.001). None of the non-smokers showed evidence of laryngeal spillage of water, whereas 12 of 15 smokers with absent RPS had laryngeal spillage. Pharyngeal anesthesia abolished RPS reflex in all non-smokers resulting in laryngeal spillage. The HPSV was 0.61±0.06 mL and 0.76±0.06 mL in non-smokers and smokers respectively (P=.1). Deteriorated reflexive pharyngeal swallow in chronic cigarette smokers predispose them to risks of aspiration and similarly, abolishing this reflex in non-smokers also results in laryngeal spillage. These observations directly demonstrate the airway protective function of RPS. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

Clinical application of diadenosine tetraphosphate (Ap4A:F-1500) for controlled hypotension.

PubMed

Kikuta, Y; Ohiwa, E; Okada, K; Watanabe, A; Haruki, S

1999-01-01

In our animal study, it was revealed that diadenosine tetraphosphate (Ap4A:F-1500) has a dose-dependent hypotension effect of up to 60% decrease in mean arterial pressure compared to control value. Furthermore, in healthy male volunteers, the safety of Ap4A up to 4 mg.min-1 was confirmed. In patients who require surgical procedures under general anesthesia together with controlled hypotension, hypotension was induced by Ap4A in order to examine its hypotensive effect and modulating action on the blood pressure. Ten patients who required controlled hypotension and who were scheduled for elective surgery under general anesthesia were studied. Anesthesia was maintained with isoflurane (n = 7) or sevoflurane (n = 3) in oxygen-nitrous oxide. Controlled hypotension was induced by Ap4A administered at a rate of 10-20 micrograms.kg-1.min-1. The dose was adjusted at a maximum rate of 80 micrograms.kg-1.min-1 until the target blood pressure was achieved. Arterial blood pressure and heart rate were monitored. Arterial samples were drawn at 4 separate time points to measure the concentration of Ap4A in the plasma. The time required for attaining the target blood pressure after initiation of Ap4A infusion was about 16 min, and the time lapse between withdrawal of infusion to recovery of blood pressure was about 18 min. No reflex tachycardia was observed during infusion of Ap4A and no rebound hypertension was evident after withdrawal. The plasma Ap4A concentration increased in response to the acceleration rate of Ap4A administration with a tendency of augmented hypotensive effect. As it produces an excellent hypotensive effect together with a modulating action on blood pressure, Ap4A was assessed as useful in producing controlled hypotension.

Noxious heat threshold temperature and pronociceptive effects of allyl isothiocyanate (mustard oil) in TRPV1 or TRPA1 gene-deleted mice.

PubMed

Tékus, Valéria; Horváth, Ádám; Hajna, Zsófia; Borbély, Éva; Bölcskei, Kata; Boros, Melinda; Pintér, Erika; Helyes, Zsuzsanna; Pethő, Gábor; Szolcsányi, János

2016-06-01

To investigate the roles of TRPV1 and TRPA1 channels in baseline and allyl isothiocyanate (AITC)-evoked nociceptive responses by comparing wild-type and gene-deficient mice. In contrast to conventional methods of thermonociception measuring reflex latencies, we used our novel methods to determine the noxious heat threshold. It was revealed that the heat threshold of the tail measured by an increasing-temperature water bath is significantly higher in TRPV1(-/-), but not TRPA1(-/-), mice compared to respective wild-types. There was no difference between the noxious heat thresholds of the hind paw as measured by an increasing-temperature hot plate in TRPV1(-/-), TRPA1(-/-) and the corresponding wild-type mice. The withdrawal latency of the tail from 0°C water was prolonged in TRPA1(-/-), but not TRPV1(-/-), mice compared to respective wild-types. In wild-type animals, dipping the tail or paw into 1% AITC induced an 8-14°C drop of the noxious heat threshold (heat allodynia) of both the tail and paw, and 40-50% drop of the mechanonociceptive threshold (mechanical allodynia) of the paw measured by dynamic plantar esthesiometry. These AITC-evoked responses were diminished in TRPV1(-/-), but not TRPA1(-/-), mice. Tail withdrawal latency to 1% AITC was significantly prolonged in both gene-deleted strains. Different heat sensors determine the noxious heat threshold in distinct areas: a pivotal role for TRPV1 on the tail is contrasted with no involvement of either TRPV1 or TRPA1 on the hind paw. Noxious heat threshold measurement appears appropriate for preclinical screening of TRP channel ligands as novel analgesics. Copyright © 2016 Elsevier Inc. All rights reserved.

Reversible grasp reflexes in normal pressure hydrocephalus.

PubMed

Thomas, Rhys H; Bennetto, Luke; Silva, Mark T

2009-05-01

We present two cases of normal pressure hydrocephalus in combination with grasp reflexes. In both cases the grasp reflexes disappeared following high volume cerebrospinal fluid removal. In one of the cases the grasp reflexes returned over a period of weeks but again resolved following definitive cerebrospinal fluid shunting surgery, and remained absent until final follow up at 9 months. We hypothesise that resolving grasp reflexes following high volume CSF removal has both diagnostic and prognostic value in normal pressure hydrocephalus, encouraging larger studies on the relevance of primitive reflexes in NPH.

Simultaneous measurement of noise-activated middle-ear muscle reflex and stimulus frequency otoacoustic emissions.

PubMed

Goodman, Shawn S; Keefe, Douglas H

2006-06-01

Otoacoustic emissions serve as a noninvasive probe of the medial olivocochlear (MOC) reflex. Stimulus frequency otoacoustic emissions (SFOAEs) elicited by a low-level probe tone may be the optimal type of emission for studying MOC effects because at low levels, the probe itself does not elicit the MOC reflex [Guinan et al. (2003) J. Assoc. Res. Otolaryngol. 4:521]. Based on anatomical considerations, the MOC reflex activated by ipsilateral acoustic stimulation (mediated by the crossed olivocochlear bundle) is predicted to be stronger than the reflex to contralateral stimulation. Broadband noise is an effective activator of the MOC reflex; however, it is also an effective activator of the middle-ear muscle (MEM) reflex, which can make results difficult to interpret. The MEM reflex may be activated at lower levels than measured clinically, and most previous human studies have not explicitly included measurements to rule out MEM reflex contamination. The current study addressed these issues using a higher-frequency SFOAE probe tone to test for cochlear changes mediated by the MOC reflex, while simultaneously monitoring the MEM reflex using a low-frequency probe tone. Broadband notched noise was presented ipsilaterally at various levels to elicit probe-tone shifts. Measurements are reported for 15 normal-hearing subjects. With the higher-frequency probe near 1.5 kHz, only 20% of subjects showed shifts consistent with an MOC reflex in the absence of an MEM-induced shift. With the higher-frequency probe near 3.5 kHz, up to 40% of subjects showed shifts in the absence of an MEM-induced shift. However, these responses had longer time courses than expected for MOC-induced shifts, and may have been dominated by other cochlear processes, rather than MOC reflex. These results suggest caution in the interpretation of effects observed using ipsilaterally presented acoustic activators intended to excite the MOC reflex.

Retention of primitive reflexes and delayed motor development in very low birth weight infants.

PubMed

Marquis, P J; Ruiz, N A; Lundy, M S; Dillard, R G

1984-06-01

Primitive reflexes and motor development were evaluated in 127 very low birth weight (VLBW) infants (birth weight less than 1501 grams) at four months corrected age. The asymmetrical tonic neck reflex, tonic labyrinth reflex, and Moro reflex were assessed for each child. The ability of each child to reach (obtain a red ring) and roll were observed. The child's performance on the gross motor scale of the Denver Development Screening Test was recorded. Thirty-seven term infants were administered identical evaluations at four months of age. The VLBW infants retained stronger primitive reflexes and exhibited a significantly higher incidence of motor delays than term infants. Significant correlations existed between the strength of the primitive reflexes and early motor development for VLBW infants. This study confirms a high incidence of motor delays among VLBW infants and demonstrates a clear association between retained primitive reflexes and delayed motor development in VLBW infants.

Interlimb Reflexes Induced by Electrical Stimulation of Cutaneous Nerves after Spinal Cord Injury

PubMed Central

Butler, Jane E.; Godfrey, Sharlene; Thomas, Christine K.

2016-01-01

Whether interlimb reflexes emerge only after a severe insult to the human spinal cord is controversial. Here the aim was to examine interlimb reflexes at rest in participants with chronic (>1 year) spinal cord injury (SCI, n = 17) and able-bodied control participants (n = 5). Cutaneous reflexes were evoked by delivering up to 30 trains of stimuli to either the superficial peroneal nerve on the dorsum of the foot or the radial nerve at the wrist (5 pulses, 300 Hz, approximately every 30 s). Participants were instructed to relax the test muscles prior to the delivery of the stimuli. Electromyographic activity was recorded bilaterally in proximal and distal arm and leg muscles. Superficial peroneal nerve stimulation evoked interlimb reflexes in ipsilateral and contralateral arm and contralateral leg muscles of SCI and control participants. Radial nerve stimulation evoked interlimb reflexes in the ipsilateral leg and contralateral arm muscles of control and SCI participants but only contralateral leg muscles of control participants. Interlimb reflexes evoked by superficial peroneal nerve stimulation were longer in latency and duration, and larger in magnitude in SCI participants. Interlimb reflex properties were similar for both SCI and control groups for radial nerve stimulation. Ascending interlimb reflexes tended to occur with a higher incidence in participants with SCI, while descending interlimb reflexes occurred with a higher incidence in able-bodied participants. However, the overall incidence of interlimb reflexes in SCI and neurologically intact participants was similar which suggests that the neural circuitry underlying these reflexes does not necessarily develop after central nervous system injury. PMID:27049521

The Dynamics of the Stapedial Acoustic Reflex.

NASA Astrophysics Data System (ADS)

Moss, Sherrin Mary

Available from UMI in association with The British Library. This thesis aims to separate the neural and muscular components of the stapedial acoustic reflex, both anatomically and physiologically. It aims to present an hypothesis to account for the differences between ipsilateral and contralateral reflex characteristics which have so far been unexplained, and achieve a greater understanding of the mechanisms underlying the reflex dynamics. A technique enabling faithful reproduction of the time course of the reflex is used throughout the experimental work. The technique measures tympanic membrane displacement as a result of reflex stapedius muscle contraction. The recorded response can be directly related to the mechanics of the middle ear and stapedius muscle contraction. Some development of the technique is undertaken by the author. A model of the reflex neural arc and stapedius muscle dynamics is evolved that is based upon a second order system. The model is unique in that it includes a latency in the ipsilateral negative feedback loop. Oscillations commonly observed on reflex responses are seen to be produced because of the inclusion of a latency in the feedback loop. The model demonstrates and explains the complex relationships between neural and muscle dynamic parameters observed in the experimental work. This more comprehensive understanding of the interaction between the stapedius dynamics and the neural arc of the reflex would not usually have been possible using human subjects, coupled with a non-invasive measurement technique. Evidence from the experimental work revealed the ipsilateral reflex to have, on average, a 5 dB lower threshold than the contralateral reflex. The oscillatory charcteristics, and the steady state response, of the contralateral reflex are also seen to be significantly different from those of the ipsilateral reflex. An hypothesis to account for the experimental observations is proposed. It is propounded that chemical neurotransmitters, and their effect upon the contralateral reflex arc from the site of the superior olivary complex to the motoneurones innervating the stapedius, account for the difference between the contralateral and ipsilateral reflex thresholds and dynamic characteristics. In the past two years the measurement technique used for the experimental work has developed from an audiological to a neurological diagnostic tool. This has enabled the results from the study to be applied in the field for valuable biomechanical and neurological explanations of the reflex response. (Abstract shortened by UMI.).

Sensory feedback from the urethra evokes state-dependent lower urinary tract reflexes in rat.

PubMed

Danziger, Zachary C; Grill, Warren M

2017-08-15

The lower urinary tract is regulated by reflexes responsible for maintaining continence and producing efficient voiding. It is unclear how sensory information from the bladder and urethra engages differential, state-dependent reflexes to either maintain continence or promote voiding. Using a new in vivo experimental approach, we quantified how sensory information from the bladder and urethra are integrated to switch reflex responses to urethral sensory feedback from maintaining continence to producing voiding. The results demonstrate how sensory information regulates state-dependent reflexes in the lower urinary tract and contribute to our understanding of the pathophysiology of urinary retention and incontinence where sensory feedback may engage these reflexes inappropriately. Lower urinary tract reflexes are mediated by peripheral afferents from the bladder (primarily in the pelvic nerve) and the urethra (in the pudendal and pelvic nerves) to maintain continence or initiate micturition. If fluid enters the urethra at low bladder volumes, reflexes relax the bladder and evoke external urethral sphincter (EUS) contraction (guarding reflex) to maintain continence. Conversely, urethral flow at high bladder volumes, excites the bladder (micturition reflex) and relaxes the EUS (augmenting reflex). We conducted measurements in a urethane-anaesthetized in vivo rat preparation to characterize systematically the reflexes evoked by fluid flow through the urethra. We used a novel preparation to manipulate sensory feedback from the bladder and urethra independently by controlling bladder volume and urethral flow. We found a distinct bladder volume threshold (74% of bladder capacity) above which flow-evoked bladder contractions were 252% larger and evoked phasic EUS activation 2.6 times as often as responses below threshold, clearly demonstrating a discrete transition between continence (guarding) and micturition (augmenting) reflexes. Below this threshold urethral flow evoked tonic EUS activity, indicative of the guarding reflex, that was proportional to the urethral flow rate. These results demonstrate the complementary roles of sensory feedback from the bladder and urethra in regulating reflexes in the lower urinary tract that depend on the state of the bladder. Understanding the neural control of functional reflexes and how they are mediated by sensory information in the bladder and urethra will open new opportunities, especially in neuromodulation, to treat pathologies of the lower urinary tract. © 2017 The Authors. The Journal of Physiology © 2017 The Physiological Society.

Subacute cholestatic hepatitis likely related to the use of senna for chronic constipation.

PubMed

Sonmez, Alper; Yilmaz, M Ilker; Mas, Refik; Ozcan, Ayhan; Celasun, Bülent; Dogru, Teoman; Taslipinar, Abdullah; Kocar, I Hakki

2005-01-01

We report a case of senna-induced cholestatic hepatitis which was not diagnosed at presentation. A 77 year old male was referred with abdominal pain, jaundice and elevated transaminase levels. A diagnosis of extrahepatic cholestasis was first suspected, due to the observation of a duodenal diverticulum and dilated proximal choledocus. However, the sphincterotomy did not improve cholestasis. At further evaluation, HBsAg was positive but serological work up was compatible with a healthy-carrier status. Further interrogation of the patient revealed a history of chronic senna intake to treat a chronic constipation. Liver biopsy showed bridging hepatocellular necrosis as well as canalicular cholestasis. Drug withdrawal resulted in a slow and progressive reduction in bilirubin levels and liver enzymes. In this case senna was likely the cause of a subacute cholestatic hepatitis exemplifying again the potential role of herbal related liver injury.

[Alcoholic ketoacidosis and reversible neurological complications due to hypophosphataemia].

PubMed

Fernández López, Ma T; García Bargo, Ma D; Rivero Luis, Ma T; Álvarez Vázquez, P; Saenz Fernández, C A; Mato Mato, J A

2012-01-01

A 57-year-old man with chronic alcoholism was admitted to our hospital due to disturbance of consciousness and polyradiculitis. Laboratory examination revealed metabolic acidosis, hypokalemia and hypophosphataemia. Alcoholic ketoacidosis is a common disorder in alcoholic patients. All patients present with a history of heavy alcohol misuse, preceding a bout of particularly excesive intake, which had been terminated by nausea, vomiting and abdominal pain. The most important laboratory results are: normal or low glucose level, metabolic acidosis with a raised anion GAP, low or absent blood alcohol level and urinary ketones. The greatest threats to patients are: hypovolemia, hypokaliemia, hypoglucemia and acidosis. Alcohol abuse may result in a wide range of electrolyte and acid-base disorders including hypophosphataemia, hypomagnesemia, hypocalcemia, hypokalemia, metabolic acidosis and respiratory alkalosis. Disturbance of consciousness in alcoholic patients is observed in several disorders, such drunkenness, Wernicke encephalopathy, alcohol withdrawal syndrome, central pontine myelinolysis, hepatic encephalopathy, hypoglucemia and electrolyte disorders.

Evaluation of Isoflurane Overdose for Euthanasia of Neonatal Mice.

PubMed

Seymour, Travis L; Nagamine, Claude M

2016-01-01

Neonatal mice (that is, pups younger than 6 d) must be exposed to CO2 for as long as 50 min to achieve euthanasia. Alternatively, other inhalant anesthetic agents have been used to euthanize laboratory rodent species. We investigated the efficacy of isoflurane at saturated vapor pressure to euthanize neonatal mice. Neonatal mice (n = 76; age, 1 or 2 d) were exposed to isoflurane in a sealed, quart-size (0.95-L) plastic bag at room temperature. Righting and withdrawal reflexes were absent in less than 2 min. After 30 min of exposure to isoflurane, pups were removed and monitored for recovery. All pups were cyanotic and showed no detectable signs of life when they were removed from the bag. However, after 30 to 120 min after removal from the bag, 24% of isoflurane-overexposed pups began gasping and then resumed normal respiration and regained a normal pink coloration. These results demonstrate that isoflurane overexposure at saturated vapor pressure for 30 min is insufficient to euthanize neonatal mice and that isoflurane overexposure must be followed by a secondary means of euthanasia.

Evaluation of Isoflurane Overdose for Euthanasia of Neonatal Mice

PubMed Central

Seymour, Travis L; Nagamine, Claude M

2016-01-01

Neonatal mice (that is, pups younger than 6 d) must be exposed to CO2 for as long as 50 min to achieve euthanasia. Alternatively, other inhalant anesthetic agents have been used to euthanize laboratory rodent species. We investigated the efficacy of isoflurane at saturated vapor pressure to euthanize neonatal mice. Neonatal mice (n = 76; age, 1 or 2 d) were exposed to isoflurane in a sealed, quart-size (0.95-L) plastic bag at room temperature. Righting and withdrawal reflexes were absent in less than 2 min. After 30 min of exposure to isoflurane, pups were removed and monitored for recovery. All pups were cyanotic and showed no detectable signs of life when they were removed from the bag. However, after 30 to 120 min after removal from the bag, 24% of isoflurane-overexposed pups began gasping and then resumed normal respiration and regained a normal pink coloration. These results demonstrate that isoflurane overexposure at saturated vapor pressure for 30 min is insufficient to euthanize neonatal mice and that isoflurane overexposure must be followed by a secondary means of euthanasia. PMID:27177567

Asymmetric localization of natural antisense RNA of neuropeptide sensorin in Aplysia sensory neurons during aging and activity.

PubMed

Kadakkuzha, Beena M; Liu, Xin-An; Narvaez, Maria; Kaye, Alexandra; Akhmedov, Komolitdin; Puthanveettil, Sathyanarayanan V

2014-01-01

Despite the advances in our understanding of transcriptome, regulation and function of its non-coding components continue to be poorly understood. Here we searched for natural antisense transcript for sensorin (NAT-SRN), a neuropeptide expressed in the presynaptic sensory neurons of gill-withdrawal reflex of the marine snail Aplysia californica. Sensorin (SRN) has a key role in learning and long-term memory storage in Aplysia. We have now identified NAT-SRN in the central nervous system (CNS) and have confirmed its expression by northern blotting and fluorescent RNA in situ hybridization. Quantitative analysis of NAT-SRN in micro-dissected cell bodies and processes of sensory neurons suggest that NAT-SRN is present in the distal neuronal processes along with sense transcripts. Importantly, aging is associated with reduction in levels of NAT-SRN in sensory neuron processes. Furthermore, we find that forskolin, an activator of CREB signaling, differentially alters the distribution of SRN and NAT-SRN. These studies reveal novel insights into physiological regulation of natural antisense RNAs.

A retrospective evaluation of coral snake envenomation in dogs and cats: 20 cases (1996-2011).

PubMed

Pérez, Mayrim L; Fox, Karlie; Schaer, Michael

2012-12-01

To describe the clinical signs, treatment, and outcomes of dogs and cats following envenomation by the eastern coral snake and to report our clinical experience with the use of Coralmyn. Retrospective study (1996-2011). University teaching hospital. Sixteen dogs and 4 cats with eastern coral snake envenomation. Medical records meeting the study inclusion criteria were reviewed and evaluated for signalment, date and time of the snake encounter, elapsed time between encounter and hospital examination, initial physical examination findings, antivenom type, length of hospitalization, and outcome. Initial physical examination findings included: quiet mentation, tetraparesis, ptyalism, tachypnea, abdominal breathing, shallow breathing, decreased to absent gag reflex, ataxia, muscle fasciculations, and decreased spinal reflexes. Laboratory findings in dogs included proteinuria, bilirubinuria, hemeproteinuria, increased aspartate aminotransferase activity, increased alanine aminotransferase activity, and hemolysis. Four dogs and 2 cats received Coralmyn and 4 dogs received North American Coral Snake Antivenom. Adverse reaction to antivenom was suspected in 1 dog that received North American Coral Snake Antivenom. Eight of 11 envenomated dogs survived with a median length of hospitalization of 4.5 days. Two of 3 envenomated cats survived with a median length of hospitalization of 4 days. Two dogs were euthanized, 1 dog suffered acute respiratory arrest, and 1 cat developed tachycardia that progressed to pulseless electrical activity. Five dogs and 1 cat in the encounter group survived to discharge. Diagnosis of eastern coral snake envenomation is likely in the dog that has concomitant lower motor neuron neuropathy, bulbar palsy, and hemolysis. Early diagnosis is crucial as antivenom administration can reduce morbidity. Prognosis is considered good with 71% of the envenomated patients in this study surviving to discharge. Supportive care that may include ventilator assistance and antivenom administration are the mainstays of therapy. © Veterinary Emergency and Critical Care Society 2012.

Why Can’t Rodents Vomit? A Comparative Behavioral, Anatomical, and Physiological Study

PubMed Central

Horn, Charles C.; Kimball, Bruce A.; Wang, Hong; Kaus, James; Dienel, Samuel; Nagy, Allysa; Gathright, Gordon R.; Yates, Bill J.; Andrews, Paul L. R.

2013-01-01

The vomiting (emetic) reflex is documented in numerous mammalian species, including primates and carnivores, yet laboratory rats and mice appear to lack this response. It is unclear whether these rodents do not vomit because of anatomical constraints (e.g., a relatively long abdominal esophagus) or lack of key neural circuits. Moreover, it is unknown whether laboratory rodents are representative of Rodentia with regards to this reflex. Here we conducted behavioral testing of members of all three major groups of Rodentia; mouse-related (rat, mouse, vole, beaver), Ctenohystrica (guinea pig, nutria), and squirrel-related (mountain beaver) species. Prototypical emetic agents, apomorphine (sc), veratrine (sc), and copper sulfate (ig), failed to produce either retching or vomiting in these species (although other behavioral effects, e.g., locomotion, were noted). These rodents also had anatomical constraints, which could limit the efficiency of vomiting should it be attempted, including reduced muscularity of the diaphragm and stomach geometry that is not well structured for moving contents towards the esophagus compared to species that can vomit (cat, ferret, and musk shrew). Lastly, an in situ brainstem preparation was used to make sensitive measures of mouth, esophagus, and shoulder muscular movements, and phrenic nerve activity–key features of emetic episodes. Laboratory mice and rats failed to display any of the common coordinated actions of these indices after typical emetic stimulation (resiniferatoxin and vagal afferent stimulation) compared to musk shrews. Overall the results suggest that the inability to vomit is a general property of Rodentia and that an absent brainstem neurological component is the most likely cause. The implications of these findings for the utility of rodents as models in the area of emesis research are discussed. PMID:23593236

Colorectal distension-induced pseudoaffective changes as indices of nociception in the anesthetized female rat: morphine and strain effects on visceral sensitivity.

PubMed

Sivarao, Digavalli V; Langdon, Shaun; Bernard, Christopher; Lodge, Nicholas

2007-01-01

Colorectal distension of a sufficient intensity evokes several characteristic postural, visceromotor and cardiovascular reflexes in conscious rats that have been extensively utilized for testing putative visceral analgesics. The neural circuitry for these reflexes is encompassed within the spinobulbar region and continues to be robust even after decerebration. Yet, these are not consistently replicated in anesthetized animals, presumably due to medullary depression. In the following studies, we tested the hypothesis that a carefully chosen anesthetic regimen can replicate the pattern of pseudoaffective responses seen in awake animals. Female rats were anesthetized with methohexital sodium and equipped with arterial and venous catheters, a colorectal balloon and abdominal wire electrodes. Subsequent anesthesia was maintained with urethane. Colorectal distension produced clear changes in visceromotor and cardiovascular indices that not only mimicked responses to distension seen in conscious rats, but also importantly, showed a comparable stimulus sensitivity and stability. Morphine (ED(50), 0.17 mg/kg, iv) was highly efficacious in attenuating response in a dose-dependent and naloxone-selective manner. Using this model, we compared three commonly used rat strains (Wistar, Wistar-Kyoto and Sprague-Dawley) for distension-mediated responses. Whereas Wistar-Kyoto rats were significantly hyper-responsive to distension, the sensory threshold for distension was nearly identical across strains. Thus, we report an anesthetized female rat model that replicates characteristic responses associated with visceral pain in conscious rats and its modulation by known factors like analgesia and strain. These findings provide a simple insensate model for testing novel visceral analgesics while eliminating postoperative recovery and motion-related artifact typically associated with colorectal distension studies in conscious rats. Thus, a viable and humane alternative to visceral nociception studies in conscious animals is offered.

Abnormal flexor carpi radialis H-reflex as a specific indicator of C7 as compared with C6 radiculopathy.

PubMed

Zheng, Chaojun; Zhu, Yu; Lv, Feizhou; Ma, Xiaosheng; Xia, Xinlei; Wang, Lixun; Jin, Xiang; Weber, Robert; Jiang, Jianyuan; Anuvat, Kevin

2014-12-01

The H-reflex of the flexor carpi radialis (FCR H-reflex) has not been commonly used for the diagnosis of cervical radiculopathy when compared with the routinely tested soleus H-reflex. Although both S1 and S2 roots innervate the soleus, the H-reflex is selectively related to S1 nerve root function clinically. Flexor carpi radialis is also innervated by two nerve roots which are C6 and C7. Although they are among the most common roots involved in cervical radiculopathy, few studies reported if the attenuation of the FCR H-reflex is caused by lesions affecting C7 or C6 nerve roots, or both. We aimed to identify whether an abnormal FCR H-reflex was attributed to the C7 or C6 nerve root lesion, or both. The sensitivities of needle electromyography, FCR H-reflex, and provocative tests in unilateral C7 or C6 radiculopathy were also compared in this study. A concentric needle electrode recorded bilateral FCR H-reflexes in 41 normal subjects (control group), 51 patients with C7 radiculopathy, and 54 patients with C6 radiculopathy. Clinical, radiological, and surgical approaches identified the precise single cervical nerve root involved in all patient groups. The H-reflex and M-wave latencies were measured and compared bilaterally. Abnormal FCR H-reflex was defined as the absence of the H-reflex or a side-to-side difference over 1.5 milliseconds which was based on the normal side-to-side difference of the H-reflex latency of 16.9 milliseconds (SD = 1.7 milliseconds) from the control group. We also determined standard median and ulnar conduction and needle electromyography. The provocative tests included bilateral determination of the Shoulder Abduction and Spurling's tests in all radiculopathy group patients. Abnormal FCR H-reflexes were recorded in 45 (88.2%) of C7 radiculopathy group patients, and 2 (3.7%) of C6 radiculopathy group patients (P < 0.05). Needle electromyography was abnormal in 41 (80.4%) of C7 radiculopathy patients and 43 (79.6%) of C6 radiculopathy patients. Provocative tests were positive in 15 (29.4%) of C7 radiculopathy patients and 25 (46.3%) of C6 radiculopathy patients. Flexor carpi radialis H-Reflex provides a sensitive assessment of evaluating the C7 spinal reflex pathway. Clinically, a combination of the FCR H-reflex with needle electromyography may yield the highest level of diagnostic information for evaluating clinical cases of C7 radiculopathy.

A new hypothesis of cause of syncope: trigeminocardiac reflex during extraction of teeth.

PubMed

Arakeri, Gururaj; Arali, Veena

2010-02-01

Transient Loss Of Consciousness (TLOC) or vasovagal syncope is well known phenomenon in dental/maxillofacial surgery. Despite considerable study of vasovagal syncope, its pathophysiology remains to be fully elucidated. After having encountered a case of trigeminocardiac reflex after extraction of maxillary first molar we observed and studied 400 extractions under local anesthesia to know the relation between trigeminocardiac reflex and syncope. We make hypothesis that trigeminocardiac reflex which is usually seen under general anesthesia when all sympathetic reflexes are blunted can also occur under local anesthesia during extractions of maxillary molars (dento-cardiac reflex) and mediate syncope.

The Reflexes of the Fundus Oculi

PubMed Central

Ballantyne, A. J.

1940-01-01

The fundus reflexes reveal, in a manner not yet completely understood, the texture and contour of the reflecting surfaces and the condition of the underlying tissues. In this way they may play an important part in the biomicroscopy of the eye. The physiological reflexes are seen at their best in the eyes of young subjects, in well-pigmented eyes, with undilated pupils and with emmetropic refraction. Their absence during the first two decades, or their presence after the forties, their occurrence in one eye only, their appearance, disappearance or change of character should suggest the possibility of some pathological state. The investigation and interpretation of the reflexes are notably assisted by comparing the appearances seen with long and short wave lights such as those of the sodium and mercury vapour lamps, in addition to the usual ophthalmoscopic lights. Most of the surface reflexes disappear in the light of the sodium lamp, sometimes revealing important changes in the deeper layers of the retina and choroid. The physiological reflexes, chiefly formed on the surface of the internal limiting membrane, take the forms of the familiar watered silk or patchy reflexes, the peri-macular halo, the fan reflex in the macular depression and the reflex from the foveal pit. The watered silk or patchy reflexes often show a delicate striation which follows the pattern of the nerve-fibre layer, or there may be a granular or criss-cross texture. Reflexes which entirely lack these indications of “texture” should be considered as possibly pathological. This applies to the “beaten metal” reflexes and to those formed on the so-called hyaloid membrane. The occurrence of physiological reflexes in linear form is doubtful, and the only admittedly physiological punctate reflexes are the so-called Gunn's dots. Surface reflexes which are broken up into small points or flakes are pathological, and are most frequently seen in the central area of the fundus in cases of pigmentary degeneration of the retina or after the subsidence of severe retinitis or retino-choroiditis. A mirror reflex from the layer of pigmented epithelium or from the external limiting membrane is sometimes recognizable in normal eyes, especially in the brunette fundus. In such, it forms the background to a striking picture of the fine circumfoveal vessels. Pathological reflexes from the level of the pigmented epithelium or of the external limiting membrane are also observed, and these often present a granular, frosted or crystalline appearance. They may indicate a senile change, or result from trauma or from retino-choroidal degeneraion. Somewhat similar reflexes may sometimes be present as small frosted patches anterior to the retinal vessels. Linear sinuous, whether appearing in annular form, as straight needles, as broader single sinuous lines, as the tapering, branched double reflexes of Vogt, or in association with traction or pressure folds, in the retina, are probably always pathological. By the use of selected light of long and short wave lengths, it can be shown that intraretinal or true retinal folds may exist with or without the surface reflexes which indicate a corresponding folding of the internal limiting membrane. On the other hand, superficial linear reflexes of various types may occur without evidence of retinal folding. Annular reflexes usually accompany a rounded elevation of the retina due to tumour, hæmorrhage or exudate, but may indicate the presence of rounded depressions; traction folds occur where there is choroido-retinal scarring, or in association with macular hole or cystic degeneraion at the macula; pressure folds in cases of orbital cyst, abscess or neoplasm; and the other linear reflexes in association with papillo-retinal œdema, for example, in retrobulbar neuritis, in hypertensive neuro-retinitis, in contusio bulbi and in anterior uveitis. Punctate reflexes, other than Gunn's dots, are also pathological. They may occur as one variety of “fragmented” surface reflexes, or as evidence of the presence of some highly refractile substance, such as cholesterin or calcium carbonate, in a retinal exudate or other lesion. It is characteristic of the pathological reflexes that they come and go and change their character according to the progress of the pathological condition. The linear reflexes in particular may change from one from to another, and may be finally transformed into surface reflexes of physiological character. ImagesFig. 1Fig. 2Fig. 3Fig. 4Fig. 5Fig. 6Fig. 7Fig. 8Fig. 9Fig. 10Fig. 11Fig. 12Fig. 13Fig. 14Fig. 15Fig. 16Fig. 17Fig. 18Fig. 19Fig. 20Fig. 21Fig. 22Fig. 23Fig. 24Fig. 25Fig. 26 PMID:19992307

[Clinical techniques for use in neurological physical examinations. II. Motor and reflex functions].

PubMed

Rodríguez-García, P L; Rodríguez-Pupo, L; Rodríguez-García, D

The aim of this study is to highlight the chief practical aspects of the techniques used in the neurological physical examination of the motor and reflex functions. We recommend clinicians to carry out a brief but consistent and effective exploration in a systematic, flexible and orderly manner to check for abnormalities in the motor and reflex functions of the nervous system. Should any anomalies be detected, then a more detailed and thorough neurological exploration must be performed selectively. We present a detailed review of the practical aspects of the main techniques used in the physical examination of these neurological categories. The motor function is explored using techniques that examine muscle tone, muscle strength, muscle fatigability, hypokinesia, tremor, coordination and gait. Lastly, in this category several manoeuvres that are useful in hysterical or mimicking paralyses are also dealt with. Reflexes to examination are usually divided into: 1. Myotatic reflexes; 2. Cutaneomucous reflexes; 3. Spinal cord or defence automatism reflexes; 4. Posture and attitude reflexes. We also add the study of primitive pathological reflexes, remote reflexes, synkinesias and signs of meningeal irritation. We present a detailed description of the main clinical techniques used in the neurological physical examination of motility and reflexes, as well as an approach that allows them to be performed on adult patients. In addition, we underline the importance of physically examining the nervous system in contemporary medicine and the need to continually perfect the way these techniques are performed in order to achieve an efficient clinical practice.

Decision Space Operations: Campaign Design Aimed at an Adversary’s Decision Making

DTIC Science & Technology

2003-01-01

14 Figure 3: Reflexive control, Initial situation (physical reality ...20 Figure 4: Reflexive control, reality as X imagines it to be...20 Figure 5: Reflexive control, reality as Y imagines it to be .......................................................21 Figure 6: Reflexive

The trigeminocardiac reflex – a comparison with the diving reflex in humans

PubMed Central

Lemaitre, Frederic; Schaller, Bernhard

2015-01-01

The trigeminocardiac reflex (TCR) has previously been described in the literature as a reflexive response of bradycardia, hypotension, and gastric hypermotility seen upon mechanical stimulation in the distribution of the trigeminal nerve. The diving reflex (DR) in humans is characterized by breath-holding, slowing of the heart rate, reduction of limb blood flow and a gradual rise in the mean arterial blood pressure. Although the two reflexes share many similarities, their relationship and especially their functional purpose in humans have yet to be fully elucidated. In the present review, we have tried to integrate and elaborate these two phenomena into a unified physiological concept. Assuming that the TCR and the DR are closely linked functionally and phylogenetically, we have also highlighted the significance of these reflexes in humans. PMID:25995761

Wh-filler-gap dependency formation guides reflexive antecedent search

PubMed Central

Frazier, Michael; Ackerman, Lauren; Baumann, Peter; Potter, David; Yoshida, Masaya

2015-01-01

Prior studies on online sentence processing have shown that the parser can resolve non-local dependencies rapidly and accurately. This study investigates the interaction between the processing of two such non-local dependencies: wh-filler-gap dependencies (WhFGD) and reflexive-antecedent dependencies. We show that reflexive-antecedent dependency resolution is sensitive to the presence of a WhFGD, and argue that the filler-gap dependency established by WhFGD resolution is selected online as the antecedent of a reflexive dependency. We investigate the processing of constructions like (1), where two NPs might be possible antecedents for the reflexive, namely which cowgirl and Mary. Even though Mary is linearly closer to the reflexive, the only grammatically licit antecedent for the reflexive is the more distant wh-NP, which cowgirl. (1). Which cowgirl did Mary expect to have injured herself due to negligence? Four eye-tracking text-reading experiments were conducted on examples like (1), differing in whether the embedded clause was non-finite (1 and 3) or finite (2 and 4), and in whether the tail of the wh-dependency intervened between the reflexive and its closest overt antecedent (1 and 2) or the wh-dependency was associated with a position earlier in the sentence (3 and 4). The results of Experiments 1 and 2 indicate the parser accesses the result of WhFGD formation during reflexive antecedent search. The resolution of a wh-dependency alters the representation that reflexive antecedent search operates over, allowing the grammatical but linearly distant antecedent to be accessed rapidly. In the absence of a long-distance WhFGD (Experiments 3 and 4), wh-NPs were not found to impact reading times of the reflexive, indicating that the parser's ability to select distant wh-NPs as reflexive antecedents crucially involves syntactic structure. PMID:26500579

Simultaneous characterizations of reflex and nonreflex dynamic and static changes in spastic hemiparesis

PubMed Central

Chung, Sun G.; Ren, Yupeng; Liu, Lin; Roth, Elliot J.; Rymer, W. Zev

2013-01-01

This study characterizes tonic and phasic stretch reflex and stiffness and viscosity changes associated with spastic hemiparesis. Perturbations were applied to the ankle of 27 hemiparetic and 36 healthy subjects under relaxed or active contracting conditions. A nonlinear delay differential equation model characterized phasic and tonic stretch reflex gains, elastic stiffness, and viscous damping. Tendon reflex was characterized with reflex gain and threshold. Reflexively, tonic reflex gain was increased in spastic ankles at rest (P < 0.038) and was not regulated with muscle contraction, indicating impaired tonic stretch reflex. Phasic-reflex gain in spastic plantar flexors was higher and increased faster with plantar flexor contraction (P < 0.012) than controls (P < 0.023) and higher in dorsi-flexors at lower torques (P < 0.038), primarily because of its increase at rest (P = 0.045), indicating exaggerated phasic stretch reflex especially in more spastic plantar flexors, which showed higher phasic stretch reflex gain than dorsi-flexors (P < 0.032). Spasticity was associated with increased tendon reflex gain (P = 0.002) and decreased threshold (P < 0.001). Mechanically, stiffness in spastic ankles was higher than that in controls across plantar flexion/dorsi-flexion torque levels (P < 0.032), and the more spastic plantar flexors were stiffer than dorsi-flexors at comparable torques (P < 0.031). Increased stiffness in spastic ankles was mainly due to passive stiffness increase (P < 0.001), indicating increased connective tissues/shortened fascicles. Viscous damping in spastic ankles was increased across the plantar flexion torque levels and at lower dorsi-flexion torques, reflecting increased passive viscous damping (P = 0.033). The more spastic plantar flexors showed higher viscous damping than dorsi-flexors at comparable torque levels (P < 0.047). Simultaneous characterizations of reflex and nonreflex changes in spastic hemiparesis may help to evaluate and treat them more effectively. PMID:23636726

Soleus and lateral gastrocnemius H-reflexes during standing with unstable footwear.

PubMed

Friesenbichler, Bernd; Lepers, Romuald; Maffiuletti, Nicola A

2015-05-01

Unstable footwear has been shown to increase lower extremity muscle activity, but the reflex response to perturbations induced by this intervention is unknown. Twenty healthy subjects stood in stable and unstable footwear conditions (presented randomly) while H-reflex amplitude and background muscle activity were measured in the soleus and lateral gastrocnemius (LG) muscles. Wearing unstable footwear resulted in larger H-reflexes (normalized to the maximal M-wave) for the LG (+12%; P = 0.025), but not for the soleus (+4%; P > 0.05). Background activity of both muscles was significantly higher in the unstable condition. The H-reflex facilitation observed with unstable footwear was unexpected, as challenging postural conditions usually result in reflex depression. Increased muscle activity, decreased presynaptic inhibition, and/or more forward postural position may have (over-)compensated the expected reflex depression. Differences between LG and soleus H-reflex modulation may be due to diverging motor unit recruitment thresholds. © 2015 Wiley Periodicals, Inc.

Enhancement of the intrinsic defecation reflex by mosapride, a 5-HT4 agonist, in chronically lumbosacral denervated guinea pigs.

PubMed

Kojima, Yu; Fujii, Hisao; Katsui, Renta; Nakajima, Yoshiyuki; Takaki, Miyako

2006-10-01

The defecation reflex is composed of rectal distension-evoked rectal (R-R) reflex contractions and synchronous internal anal sphincter (R-IAS) reflex relaxations in guinea pigs. These R-R and R-IAS reflexes are controlled via extrinsic sacral excitatory nerve pathway (pelvic nerves), lumbar inhibitory nerve pathways (colonic nerves) and by intrinsic cholinergic excitatory and nitrergic inhibitory nerve pathways. The effect of mosapride (a prokinetic benzamide) on the intrinsic reflexes, mediated via enteric 5-HT(4) receptors, was evaluated by measuring the mechanical activity of the rectum and IAS in anesthetized guinea pigs using an intrinsic R-R and R-IAS reflex model resulting from chronic (two to nine days) lumbosacral denervation (PITH). In this model, the myenteric plexus remains undamaged and the distribution of myenteric and intramuscular interstitial cells of Cajal is unchanged. Although R-R and R-IAS reflex patterns markedly changed, the reflex indices (reflex pressure or force curve-time integral) of both the R-R contractions and the synchronous R-IAS relaxations were unchanged. The frequency of the spontaneous R and IAS motility was also unchanged. Mosapride (0.1-1.0 mg/kg) dose-dependently increased both intrinsic R-R (maximum: 1.82) and R-IAS reflex indices (maximum: 2.76) from that of the control (1.0) 6-9 days following chronic PITH. The dose-response curve was similar to that in the intact guinea pig, and had shifted to the left from that in the guinea pig after acute PITH. A specific 5-HT(4) receptor antagonist, GR 113808 (1.0 mg/kg), decreased both reflex indices by approximately 50% and antagonized the effect of mosapride 1.0 mg/kg. This was quite different from the result in the intact guinea pig where GR 113808 (1.0 mg/kg) did not affect either of the reflex indices. The present results indicate that mosapride enhanced the intrinsic R-R and R-IAS reflexes and functionally compensated for the deprivation of extrinsic innervation. The actions of mosapride were mediated through endogenously active, intrinsic 5-HT(4) receptors which may be post-synaptically located in the myenteric plexus of the anorectum.

Golden tapetal reflex in male patients with X-linked retinitis pigmentosa. Case report and practical implications.

PubMed

van Osch, L; van Schooneveld, M; Bleekerwagemakers, E M

1990-12-01

The golden tapetal reflex in the ocular fundus is considered pathognomonic of the carrier state in some families with X-linked retinitis pigmentosa (XRP). Reports concerning affected males with this characteristic reflex are scarce. A six-year-old boy with XRP having a tapetal reflex is described. Recently the tapetal reflex has drawn attention in linkage studies. XRP is probably genetically heterogeneous and has at least two genetic forms. The finding of a tapetal reflex in one or more female carriers in a family with XRP may be helpful in differentiating between these two genetic forms.

Chronic intermittent ethanol exposure in early adolescent and adult male rats: effects on tolerance, social behavior, and ethanol intake.

PubMed

Broadwater, Margaret; Varlinskaya, Elena I; Spear, Linda P

2011-08-01

Given the prevalence of alcohol use in adolescence, it is important to understand the consequences of chronic ethanol exposure during this critical period in development. The purpose of this study was to assess possible age-related differences in susceptibility to tolerance development to ethanol-induced sedation and withdrawal-related anxiety, as well as voluntary ethanol intake after chronic exposure to relatively high doses of ethanol during adolescence or adulthood. Juvenile/adolescent and adult male Sprague-Dawley rats were assigned to one of five 10-day exposure conditions: chronic ethanol (4 g/kg every 48 hours), chronic saline (equivalent volume every 24 hours), chronic saline/acutely challenged with ethanol (4 g/kg on day 10), nonmanipulated/acutely challenged with ethanol (4 g/kg on day 10), or nonmanipulated. For assessment of tolerance development, duration of the loss of righting reflex (LORR) and blood ethanol concentrations (BECs) upon regaining of righting reflex (RORR) were tested on the first and last ethanol exposure days in the chronic ethanol group, with both saline and nonmanipulated animals likewise challenged on the last exposure day. Withdrawal-induced anxiety was indexed in a social interaction test 24 hours after the last ethanol exposure, with ethanol-naïve chronic saline and nonmanipulated animals serving as controls. Voluntary intake was assessed 48 hours after the chronic exposure period in chronic ethanol, chronic saline and nonmanipulated animals using an 8-day 2 bottle choice, limited-access ethanol intake procedure. In general, adolescent animals showed shorter durations of LORR and higher BECs upon RORR than adults on the first and last ethanol exposure days, regardless of chronic exposure condition. Adults, but not adolescents, developed chronic tolerance to the sedative effects of ethanol, tolerance that appeared to be metabolic in nature. Social deficits were observed after chronic ethanol in both adolescents and adults. Adolescents drank significantly more ethanol than adults on a gram per kilogram basis, with intake uninfluenced by prior ethanol exposure at both ages. Adolescents and adults may differ in their ability and/or propensity to adapt to chronic ethanol exposure, with adults, but not adolescents, developing chronic metabolic tolerance. However, this chronic exposure regimen was sufficient to disrupt baseline levels of social behavior at both ages. Taken together, these results suggest that, despite the age-related differences in tolerance development, adolescents are as susceptible as adults to consequences of chronic ethanol exposure, particularly in terms of disruptions in social behavior. Whether these effects would last into adulthood remains to be determined. Copyright © 2011 by the Research Society on Alcoholism.

Suppression of the oculocephalic reflex (doll's eyes phenomenon) in normal full-term babies.

PubMed

Snir, Moshe; Hasanreisoglu, Murat; Hasanreisoglue, Murat; Goldenberg-Cohen, Nitza; Friling, Ronit; Katz, Kalman; Nachum, Yoav; Benjamini, Yoav; Herscovici, Zvi; Axer-Siegel, Ruth

2010-05-01

To determine the precise age of suppression of the oculocephalic reflex in infants and its relationship to specific clinical characteristics. The oculocephalic reflex was prospectively tested in 325 healthy full-term babies aged 1 to 32 weeks attending an orthopedic outpatient clinic. Two ophthalmologists raised the baby's head 30 degrees above horizontal and rapidly rotated it in the horizontal and vertical planes while watching the conjugate eye movement. Suppression of the reflex, by observer agreement, was analyzed in relation to gestational age, postpartum age, postconceptional age, birth weight, and current weight. The data were fitted to a logistic regression model to determine the probability of suppression of the reflex according to the clinical variables. The oculocephalic reflex was suppressed in 75% of babies by the age of 11.5 weeks and in more than 95% of babies aged 20 weeks. Although postpartum age had a greater influence than gestational age, both were significantly correlated with suppression of the reflex (p = 0.01 and p = 0.04, respectively; two-sided t-test). Postpartum age was the best single variable explaining absence of the reflex. On logistic regression with cross-validation, the model including postpartum age and current weight yielded the best results; both these factors were highly correlated with suppression of the reflex (r = 0.74). The oculocephalic reflex is suppressed in the vast majority of normal infants by age 11.5 weeks. The disappearance of the reflex occurs gradually and longitudinally and is part of the normal maturation of the visual system.

Aural Acoustic Stapedius-Muscle Reflex Threshold Procedures to Test Human Infants and Adults.

PubMed

Keefe, Douglas H; Feeney, M Patrick; Hunter, Lisa L; Fitzpatrick, Denis F

2017-02-01

Power-based procedures are described to measure acoustic stapedius-muscle reflex threshold and supra-threshold responses in human adult and infant ears at frequencies from 0.2 to 8 kHz. The stimulus set included five clicks in which four pulsed activators were placed between each pair of clicks, with each stimulus set separated from the next by 0.79 s to allow for reflex decay. Each click response was used to detect the presence of reflex effects across frequency that were elicited by a pulsed broadband-noise or tonal activator in the ipsilateral or contralateral test ear. Acoustic reflex shifts were quantified in terms of the difference in absorbed sound power between the initial baseline click and the later four clicks in each set. Acoustic reflex shifts were measured over a 40-dB range of pulsed activators, and the acoustic reflex threshold was objectively calculated using a maximum 10 likelihood procedure. To illustrate the principles underlying these new reflex tests, reflex shifts in absorbed sound power and absorbance are presented for data acquired in an adult ear with normal hearing and in two infant ears in the initial and follow-up newborn hearing screening exams, one with normal hearing and the other with a conductive hearing loss. The use of absorbed sound power was helpful in classifying an acoustic reflex shift as present or absent. The resulting reflex tests are in use in a large study of wideband clinical diagnosis and monitoring of middle-ear and cochlear function in infant and adult ears.

Passiflora incarnata attenuation of neuropathic allodynia and vulvodynia apropos GABA-ergic and opioidergic antinociceptive and behavioural mechanisms.

PubMed

Aman, Urooj; Subhan, Fazal; Shahid, Muhammad; Akbar, Shehla; Ahmad, Nisar; Ali, Gowhar; Fawad, Khwaja; Sewell, Robert D E

2016-02-24

Passiflora incarnata is widely used as an anxiolytic and sedative due to its putative GABAergic properties. Passiflora incarnata L. methanolic extract (PI-ME) was evaluated in an animal model of streptozotocin-induced diabetic neuropathic allodynia and vulvodynia in rats along with antinociceptive, anxiolytic and sedative activities in mice in order to examine possible underlying mechanisms. PI-ME was tested preliminary for qualitative phytochemical analysis and then quantitatively by proximate and GC-MS analysis. The antinociceptive property was evaluated using the abdominal constriction assay and hot plate test. The anxiolytic activity was performed in a stair case model and sedative activity in an open field test. The antagonistic activities were evaluated using naloxone and/or pentylenetetrazole (PTZ). PI-ME was evaluated for prospective anti-allodynic and anti-vulvodynic properties in a rat model of streptozotocin induced neuropathic pain using the static and dynamic testing paradigms of mechanical allodynia and vulvodynia. GC-MS analysis revealed that PI-ME contained predominant quantities of oleamide (9-octadecenamide), palmitic acid (hexadecanoic acid) and 3-hydroxy-dodecanoic acid, among other active constituents. In the abdominal constriction assay and hot plate test, PI-ME produced dose dependant, naloxone and pentylenetetrazole reversible antinociception suggesting an involvement of opioidergic and GABAergic mechanisms. In the stair case test, PI-ME at 200 mg/kg increased the number of steps climbed while at 600 mg/kg a significant decrease was observed. The rearing incidence was diminished by PI-ME at all tested doses and in the open field test, PI-ME decreased locomotor activity to an extent that was analagous to diazepam. The effects of PI-ME were antagonized by PTZ in both the staircase and open field tests implicating GABAergic mechanisms in its anxiolytic and sedative activities. In the streptozotocin-induced neuropathic nociceptive model, PI-ME (200 and 300 mg/kg) exhibited static and dynamic anti-allodynic effects exemplified by an increase in paw withdrawal threshold and paw withdrawal latency. PI-ME relieved only the dynamic component of vulvodynia by increasing flinching response latency. These findings suggest that Passiflora incarnata might be useful for treating neuropathic pain. The antinociceptive and behavioural findings inferring that its activity may stem from underlying opioidergic and GABAergic mechanisms though a potential oleamide-sourced cannabimimetic involvement is also discussed.

Affective Modulation of the Startle Eyeblink and Postauricular Reflexes in Autism Spectrum Disorder

ERIC Educational Resources Information Center

Dichter, Gabriel S.; Benning, Stephen D.; Holtzclaw, Tia N.; Bodfish, James W.

2010-01-01

Eyeblink and postauricular reflexes to standardized affective images were examined in individuals without (n = 37) and with (n = 20) autism spectrum disorders (ASDs). Affective reflex modulation in control participants replicated previous findings. The ASD group, however, showed anomalous reflex modulation patterns, despite similar self-report…

The Use of an Alternative Extraoral Periapical Technique for Patients with Severe Gag Reflex

PubMed Central

e Silva, Mauro Henrique Chagas; Santos, Mariane Floriano Lopes; de Lima, Carolina Oliveira; Campos, Celso Neiva

2016-01-01

Gag reflex is a physiologic mechanism that promotes contraction of the muscles of the tongue and pharyngeal walls. Different factors, including intraoral radiographic films and sensors, may trigger this reflex. Patients with severe gag reflex may not be able to tolerate the presence of intraoral radiographic films or sensors during root canal therapy (RCT). This factor may prevent an appropriate intraoral radiograph, which is important in RCT. Different approaches have been used to facilitate dental procedures in patients suffering from severe gag reflex. The use of an extraoral radiographic technique is an alternative method to obtain working length confirmation in patients with severe gag reflex. In this report of 2 cases, the use of an extraoral radiographic technique as an alternative approach during RCT in patients with severe gag reflex associated with phobic behavior and trismus was successfully demonstrated. PMID:27547474

The parallel programming of voluntary and reflexive saccades.

PubMed

Walker, Robin; McSorley, Eugene

2006-06-01

A novel two-step paradigm was used to investigate the parallel programming of consecutive, stimulus-elicited ('reflexive') and endogenous ('voluntary') saccades. The mean latency of voluntary saccades, made following the first reflexive saccades in two-step conditions, was significantly reduced compared to that of voluntary saccades made in the single-step control trials. The latency of the first reflexive saccades was modulated by the requirement to make a second saccade: first saccade latency increased when a second voluntary saccade was required in the opposite direction to the first saccade, and decreased when a second saccade was required in the same direction as the first reflexive saccade. A second experiment confirmed the basic effect and also showed that a second reflexive saccade may be programmed in parallel with a first voluntary saccade. The results support the view that voluntary and reflexive saccades can be programmed in parallel on a common motor map.

[Effects of morphine on pupillary light reflex in monkeys].

PubMed

Meng, Zhi-Qiang; Zhang, Yu-Hua; Chen, Nan-Hui; Miao, Ying-Da; Hu, Xin-Tian; Ma, Yuan-Ye

2010-06-01

The pupil size of both human and other animals can be affected by light. Many kinds of psychiatrical and psychological disorders, such as drug abuse, associate with abnormal properties of pupillary light reflex. Thus, the properties of pupillary light reflex could serve as an indicator for drug abuse detection. However, the effect of drug abuse on pupillary light reflex is till unclear. To assess the effects of addictive drugs on pupillary light reflex quantificationally, in the present study, we examined the effects of morphine on pupil diameter and pupillary light reflex in rhesus monkeys. By measuring the pupil diameter at different timing points before and after the administration of morphine, we found that morphine administration reduced the diameter of pupil and decreased the constriction rate. Our present results provide an experimental support for applying the properties of pupillary light reflex as a reference in addicts' detection.

Snout and Visual Rooting Reflexes in Infantile Autism. Brief Report.

ERIC Educational Resources Information Center

Minderaa, Ruud B.; And Others

1985-01-01

The authors conducted extensive neurological evaluations of 42 autistic individuals and were surprised to discover a consistently positive snout reflex in most of them. Difficulties with assessing the reflex are noted. The authors then reassessed the Ss for a series of primitive reflexes which are interpreted as signs of diffuse cortical brain…

On Reflection: Is Reflexivity Necessarily Beneficial in Intercultural Education?

ERIC Educational Resources Information Center

Blasco, Maribel

2012-01-01

This article explores how the concept of reflexivity is used in intercultural education. Reflexivity is often presented as a key learning goal in acquiring intercultural competence (ICC). Yet, reflexivity can be defined in different ways, and take different forms across time and space, depending on the concepts of selfhood that prevail and how…

The Limits of Institutional Reflexivity in Bulgarian Universities

ERIC Educational Resources Information Center

Slantcheva, Snejana

2004-01-01

This article focuses on the notion of institutional reflexivity. Its theoretical framework is based on the views of a group of sociologists--Anthony Giddens, Ulrich Beck, Scott Lash--who developed the concept of reflexive modernization. The article applies the notion of institutional reflexivity to the field of higher education and reviews the…

The Pivotal Role of the Parieto-Occipital Lobe in Card Game-Induced Reflex Epilepsy: A Voxel-Based Morphometry Study.

PubMed

Park, Kang Min; Kim, Sung Eun; Lee, Byung In

2016-01-01

The pathogenesis of card game-induced reflex epilepsy has not been determined so far. The aim of this study was to evaluate structural abnormalities using voxel-based morphometry (VBM) analysis, which may give some clue about the pathogenesis in card game-induced reflex epilepsy. The 3 subjects were diagnosed with card game-induced reflex epilepsy. Evaluation involved a structured interview to obtain clinical information and brain MRI. In VBM analysis, Statistical Parametric Mapping 8 running on the MATLAB platform was employed to analyze the structural differences between patients with card game-induced reflex epilepsy and age- and sex-matched control subjects. The results of VBM analysis revealed that patients with card game-induced reflex epilepsy had significantly increased gray matter volume in the right occipital and parietal lobe. However, there were no structures with decreased gray matter volume in patients with card game-induced reflex epilepsy compared with control subjects. In addition, we found that the patients with card game-induced reflex epilepsy had onset of seizures in adulthood rather than in adolescence, and all of the patients were men. The parieto-occipital lobes might be partially involved in the neuronal network responsible for card game-induced reflex epilepsy. © 2016 S. Karger AG, Basel.

Intrapartum synthetic oxytocin reduce the expression of primitive reflexes associated with breastfeeding.

PubMed

Marín Gabriel, Miguel A; Olza Fernández, Ibone; Malalana Martínez, Ana M; González Armengod, Carmen; Costarelli, Valeria; Millán Santos, Isabel; Fernández-Cañadas Morillo, Aurora; Pérez Riveiro, Pilar; López Sánchez, Francisco; García Murillo, Lourdes

2015-05-01

Several synthetic peptide manipulations during the time surrounding birth can alter the specific neurohormonal status in the newborn brain. This study is aimed at assessing whether intrapartum oxytocin administration has any effect on primitive neonatal reflexes and determining whether such an effect is dose-dependent. A cohort prospective study was conducted at a tertiary hospital. Mother-infant dyads who received intrapartum oxytocin (n=53) were compared with mother-infant dyads who did not receive intrapartum oxytocin (n=45). Primitive neonatal reflexes (endogenous, antigravity, motor, and rhythmic reflexes) were quantified by analyzing videotaped breastfeeding sessions in a biological nurturing position. Two observers blind to the group assignment and the oxytocin dose analyzed the videotapes and assesed the newborn's state of consciousness according to the Brazelton scale. The release of all rhythmic reflexes (p=0.01), the antigravity reflex (p=0.04), and total primitive neonatal reflexes (p=0.02) in the group exposed to oxytocin was lower than in the group not exposed to oxytocin. No correlations were observed between the dose of oxytocin administered and the percentage of primitive neonatal reflexes released (r=0.03; p=0.82). Intrapartum oxytocin administration might inhibit the expression of several primitive neonatal reflexes associated with breastfeeding. This correlation does not seem to be dose-dependent.

Dendritic spine dysgenesis contributes to hyperreflexia after spinal cord injury

PubMed Central

Bandaru, Samira P.; Liu, Shujun; Waxman, Stephen G.

2014-01-01

Hyperreflexia and spasticity are chronic complications in spinal cord injury (SCI), with limited options for safe and effective treatment. A central mechanism in spasticity is hyperexcitability of the spinal stretch reflex, which presents symptomatically as a velocity-dependent increase in tonic stretch reflexes and exaggerated tendon jerks. In this study we tested the hypothesis that dendritic spine remodeling within motor reflex pathways in the spinal cord contributes to H-reflex dysfunction indicative of spasticity after contusion SCI. Six weeks after SCI in adult Sprague-Dawley rats, we observed changes in dendritic spine morphology on α-motor neurons below the level of injury, including increased density, altered spine shape, and redistribution along dendritic branches. These abnormal spine morphologies accompanied the loss of H-reflex rate-dependent depression (RDD) and increased ratio of H-reflex to M-wave responses (H/M ratio). Above the level of injury, spine density decreased compared with below-injury spine profiles and spine distributions were similar to those for uninjured controls. As expected, there was no H-reflex hyperexcitability above the level of injury in forelimb H-reflex testing. Treatment with NSC23766, a Rac1-specific inhibitor, decreased the presence of abnormal dendritic spine profiles below the level of injury, restored RDD of the H-reflex, and decreased H/M ratios in SCI animals. These findings provide evidence for a novel mechanistic relationship between abnormal dendritic spine remodeling in the spinal cord motor system and reflex dysfunction in SCI. PMID:25505110

Comparison of single bout effects of bicycle training versus locomotor training on paired reflex depression of the soleus H-reflex after motor incomplete spinal cord injury.

PubMed

Phadke, Chetan P; Flynn, Sheryl M; Thompson, Floyd J; Behrman, Andrea L; Trimble, Mark H; Kukulka, Carl G

2009-07-01

To examine paired reflex depression changes post 20-minute bout each of 2 training environments: stationary bicycle ergometer training (bicycle training) and treadmill with body weight support and manual assistance (locomotor training). Pretest-posttest repeated-measures. Locomotor laboratory. Motor incomplete SCI (n=12; mean, 44+/-16y); noninjured subjects (n=11; mean, 30.8+/-8.3y). All subjects received each type of training on 2 separate days. Paired reflex depression at different interstimulus intervals (10 s, 1 s, 500 ms, 200 ms, and 100 ms) was measured before and after both types of training. (1) Depression was significantly less post-SCI compared with noninjured subjects at all interstimulus intervals and (2) post-SCI at 100-millisecond interstimulus interval: reflex depression significantly increased postbicycle training in all SCI subjects and in the chronic and spastic subgroups (P<.05). Phase-dependent regulation of reflex excitability, essential to normal locomotion, coordinated by pre- and postsynaptic inhibitory processes (convergent action of descending and segmental inputs onto spinal circuits) is impaired post-SCI. Paired reflex depression provides a quantitative assay of inhibitory processes contributing to phase-dependent changes in reflex excitability. Because bicycle training normalized reflex depression, we propose that bicycling may have a potential role in walking rehabilitation, and future studies should examine the long-term effects on subclinical measures of reflex activity and its relationship to functional outcomes.

Short-term locomotor adaptation to a robotic ankle exoskeleton does not alter soleus Hoffmann reflex amplitude.

PubMed

Kao, Pei-Chun; Lewis, Cara L; Ferris, Daniel P

2010-07-26

To improve design of robotic lower limb exoskeletons for gait rehabilitation, it is critical to identify neural mechanisms that govern locomotor adaptation to robotic assistance. Previously, we demonstrated soleus muscle recruitment decreased by approximately 35% when walking with a pneumatically-powered ankle exoskeleton providing plantar flexor torque under soleus proportional myoelectric control. Since a substantial portion of soleus activation during walking results from the stretch reflex, increased reflex inhibition is one potential mechanism for reducing soleus recruitment when walking with exoskeleton assistance. This is clinically relevant because many neurologically impaired populations have hyperactive stretch reflexes and training to reduce the reflexes could lead to substantial improvements in their motor ability. The purpose of this study was to quantify soleus Hoffmann (H-) reflex responses during powered versus unpowered walking. We tested soleus H-reflex responses in neurologically intact subjects (n=8) that had trained walking with the soleus controlled robotic ankle exoskeleton. Soleus H-reflex was tested at the mid and late stance while subjects walked with the exoskeleton on the treadmill at 1.25 m/s, first without power (first unpowered), then with power (powered), and finally without power again (second unpowered). We also collected joint kinematics and electromyography. When the robotic plantar flexor torque was provided, subjects walked with lower soleus electromyographic (EMG) activation (27-48%) and had concomitant reductions in H-reflex amplitude (12-24%) compared to the first unpowered condition. The H-reflex amplitude in proportion to the background soleus EMG during powered walking was not significantly different from the two unpowered conditions. These findings suggest that the nervous system does not inhibit the soleus H-reflex in response to short-term adaption to exoskeleton assistance. Future studies should determine if the findings also apply to long-term adaption to the exoskeleton.

Respiratory kinematic and airflow differences between reflex and voluntary cough in healthy young adults

PubMed Central

Brandimore, Alexandra E.; Troche, Michelle S.; Huber, Jessica E.; Hegland, Karen W.

2015-01-01

Background: Cough is a defensive behavior that can be initiated in response to a stimulus in the airway (reflexively), or on command (voluntarily). There is evidence to suggest that physiological differences exist between reflex and voluntary cough; however, the output (mechanistic and airflow) differences between the cough types are not fully understood. Therefore, the aims of this study were to determine the lung volume, respiratory kinematic, and airflow differences between reflex and voluntary cough in healthy young adults. Methods: Twenty-five participants (14 female; 18–29 years) were recruited for this study. Participants were evaluated using respiratory inductance plethysmography calibrated with spirometry. Experimental procedures included: (1) respiratory calibration, (2) three voluntary sequential cough trials, and (3) three reflex cough trials induced with 200 μM capsaicin. Results: Lung volume initiation (LVI; p = 0.003) and lung volume excursion (LVE; p < 0.001) were significantly greater for voluntary cough compared to reflex cough. The rib cage and abdomen significantly influenced LVI for voluntary cough (p < 0.001); however, only the rib cage significantly impacted LVI for reflex cough (p < 0.001). LVI significantly influenced peak expiratory flow rate (PEFR) for voluntary cough (p = 0.029), but not reflex cough (p = 0.610). Discussion: Production of a reflex cough results in significant mechanistic and airflow differences compared to voluntary cough. These findings suggest that detection of a tussigenic stimulus modifies motor aspects of the reflex cough behavior. Further understanding of the differences between reflex and voluntary cough in older adults and in persons with dystussia (cough dysfunction) will be essential to facilitate the development of successful cough treatment paradigms. PMID:26500560

Trigeminal Proprioception Evoked by Strong Stretching of the Mechanoreceptors in Müller's Muscle Induces Reflex Contraction of the Orbital Orbicularis Oculi Slow-Twitch Muscle Fibers.

PubMed

Matsuo, Kiyoshi; Ban, Ryokuya; Ban, Midori; Yuzuriha, Shunsuke

2014-01-01

The mixed orbicularis oculi muscle lacks an intramuscular proprioceptive system such as muscle spindles, to induce reflex contraction of its slow-twitch fibers. We evaluated whether the mechanoreceptors in Müller's muscle function as extrinsic mechanoreceptors to induce reflex contraction of the slow-twitch fibers of the orbicularis oculi in addition to those of the levator and frontalis muscles. We evaluated in patients with aponeurosis-disinserted blepharoptosis whether strong stretching of the mechanoreceptors in Müller's muscle from upgaze with unilateral lid load induced reflex contraction of the orbicularis oculi slow-twitch fibers and whether anesthesia of Müller's muscle precluded the contraction. We compared the electromyographic responses of the bilateral orbicularis oculi muscles to unilateral intraoperative direct stimulation of the trigeminal proprioceptive nerve with those to unilateral transcutaneous electrical stimulation of the supraorbital nerve. Upgaze with a unilateral 3-g lid load induced reflex contraction of the bilateral orbicularis oculi muscles with ipsilateral dominance. Anesthesia of Müller's muscle precluded the reflex contraction. The orbicularis oculi reflex evoked by stimulation of the trigeminal proprioceptive nerve differed from that by electrical stimulation of the supraorbital nerve in terms of the intensity of current required to induce the reflex, the absence of R1, and duration. The mechanoreceptors in Müller's muscle functions as an extramuscular proprioceptive system to induce reflex contraction of the orbital orbicularis oculi slow-twitch fibers. Whereas reflex contraction of the pretarsal orbicularis fast-twitch fibers functions in spontaneous or reflex blinking, that of the orbital orbicularis oculi slow-twitch fibers may factor in grimacing and blepharospasm.

Trigeminal Proprioception Evoked by Strong Stretching of the Mechanoreceptors in Müller's Muscle Induces Reflex Contraction of the Orbital Orbicularis Oculi Slow-Twitch Muscle Fibers

PubMed Central

Ban, Ryokuya; Ban, Midori; Yuzuriha, Shunsuke

2014-01-01

Objective: The mixed orbicularis oculi muscle lacks an intramuscular proprioceptive system such as muscle spindles, to induce reflex contraction of its slow-twitch fibers. We evaluated whether the mechanoreceptors in Müller's muscle function as extrinsic mechanoreceptors to induce reflex contraction of the slow-twitch fibers of the orbicularis oculi in addition to those of the levator and frontalis muscles. Methods: We evaluated in patients with aponeurosis-disinserted blepharoptosis whether strong stretching of the mechanoreceptors in Müller's muscle from upgaze with unilateral lid load induced reflex contraction of the orbicularis oculi slow-twitch fibers and whether anesthesia of Müller's muscle precluded the contraction. We compared the electromyographic responses of the bilateral orbicularis oculi muscles to unilateral intraoperative direct stimulation of the trigeminal proprioceptive nerve with those to unilateral transcutaneous electrical stimulation of the supraorbital nerve. Results: Upgaze with a unilateral 3-g lid load induced reflex contraction of the bilateral orbicularis oculi muscles with ipsilateral dominance. Anesthesia of Müller's muscle precluded the reflex contraction. The orbicularis oculi reflex evoked by stimulation of the trigeminal proprioceptive nerve differed from that by electrical stimulation of the supraorbital nerve in terms of the intensity of current required to induce the reflex, the absence of R1, and duration. Conclusions: The mechanoreceptors in Müller's muscle functions as an extramuscular proprioceptive system to induce reflex contraction of the orbital orbicularis oculi slow-twitch fibers. Whereas reflex contraction of the pretarsal orbicularis fast-twitch fibers functions in spontaneous or reflex blinking, that of the orbital orbicularis oculi slow-twitch fibers may factor in grimacing and blepharospasm. PMID:25210572

Reflexive contraction of the levator palpebrae superioris muscle to involuntarily sustain the effective eyelid retraction through the transverse trigeminal proprioceptive nerve on the proximal Mueller's muscle: verification with evoked electromyography.

PubMed

Ban, Ryokuya; Matsuo, Kiyoshi; Osada, Yoshiro; Ban, Midori; Yuzuriha, Shunsuke

2010-01-01

We have proposed a hypothetical mechanism to involuntarily sustain the effective eyelid retraction, which consists of not only voluntary but also reflexive contractions of the levator palpebrae superior muscle (LPSM). Voluntary contraction of fast-twitch fibres of the LPSM stretches the mechanoreceptors in Mueller's muscle to evoke trigeminal proprioception, which induces continuous reflexive contraction of slow-twitch fibres of the LPSM through the trigeminal proprioceptive nerve fibres innervating the mechanoreceptors in Mueller's muscle via the oculomotor neurons, as a tonic trigemino-oculomotor reflex. In the common skeletal mixed muscles, electrical stimulation of the proprioceptive nerve, which apparently connects the mechanoreceptors in muscle spindles to the motoneurons, induces the electromyographic response as the Hoffmann reflex. To verify the presence of the trigemino-oculomotor reflex, we confirmed whether intra-operative electrical simulation of the transverse trigeminal proprioceptive nerve on the proximal Mueller's muscle evokes an electromyographic response in the LPSM under general anaesthesia in 12 patients. An ipsilateral, phasic, short-latency response (latency: 2.8+/-0.3 ms) was induced in the ipsilateral LPSM in 10 of 12 subjects. As successful induction of the short-latency response in the ipsilateral LPSM corresponds to the Hoffmann reflex in the common skeletal mixed muscles, the present study is the first electromyographic verification of the presence of the monosynaptic trigemino-oculomotor reflex to induce reflexive contraction of the LPSM. The presence of the trigemino-oculomotor reflex may elucidate the unexplainable blepharoptosis due to surgery, trauma and tumour, all of which may damage the trigeminal proprioceptive nerve fibres to impair the trigemino-oculomotor reflex. Copyright (c) 2008. Published by Elsevier Ltd.

Contributions of Altered Stretch Reflex Coordination to Arm Impairments Following Stroke

PubMed Central

Ravichandran, Vengateswaran J.; Krutky, Matthew A.; Perreault, Eric J.

2010-01-01

Patterns of stereotyped muscle coactivation, clinically referred to as synergies, emerge following stroke and impair arm function. Although researchers have focused on cortical contributions, there is growing evidence that altered stretch reflex pathways may also contribute to impairment. However, most previous reflex studies have focused on passive, single-joint movements without regard to their coordination during volitional actions. The purpose of this study was to examine the effects of stroke on coordinated activity of stretch reflexes elicited in multiple arm muscles following multijoint perturbations. We hypothesized that cortical injury results in increased stretch reflexes of muscles characteristic of the abnormal flexor synergy during active arm conditions. To test this hypothesis, we used a robot to apply position perturbations to impaired arms of 10 stroke survivors and dominant arms of 8 healthy age-matched controls. Corresponding reflexes were assessed during volitional contractions simulating different levels of gravitational support, as well as during voluntary flexion and extension of the elbow and shoulder. Reflexes were quantified by average rectified surface electromyogram, recorded from eight muscles spanning the elbow and shoulder. Reflex coordination was quantified using an independent components analysis. We found stretch reflexes elicited in the stroke group were significantly less sensitive to changes in background muscle activation compared with those in the control group (P < 0.05). We also observed significantly increased reflex coupling between elbow flexor and shoulder abductor–extensor muscles in stroke subjects relative to that in control subjects. This increased coupling was present only during volitional tasks that required elbow flexion (P < 0.001), shoulder extension (P < 0.01), and gravity opposition (P < 0.01), but not during the “no load” condition. During volitional contractions, reflex amplitudes scaled with the level of impairment, as assessed by Fugl-Meyer scores (r2 = 0.63; P < 0.05). We conclude that altered reflex coordination is indicative of motor impairment level and may contribute to impaired arm function following stroke. PMID:20962072

Neuroanatomical basis of Sandifer's syndrome: a new vagal reflex?

PubMed

Cerimagic, Denis; Ivkic, Goran; Bilic, Ervina

2008-01-01

Sandifer's syndrome is a gastrointestinal disorder with neurological features. It is characterized by reflex torticollis following deglutition in patients with gastroesophageal reflux and/or hiatal hernia. The authors believe that neurological manifestations of the syndrome are the consequence of vagal reflex with the reflex center in nucleus tractus solitarii (NTS). Three models for the neuroanatomical basis of the hypothetic reflex arc are presented. In the first one the hypothetic reflex arc is based on the classic hypothesis of two components nervus accessorius (n.XI) - radix cranialis (RC) and radix spinalis (RS) The nervous impulses are transmitted by nervus vagus (n.X) general visceral afferent (GVA) fibers to NTS situated in medulla oblongata, then by interneuronal connections on nucleus ambiguus (NA) and nucleus dorsalis nervi vagi (NDX). Special visceral efferent fibers (SVE) impulses from NA are in part transferred to n.XI ramus externus (RE) (carrying the majority of general somatic efferent (GSE) fibers) via hypothetic anastomoses in the region of foramen jugulare. This leads to contraction of trapezius and sternocleidomastoideus muscles, and the occurrence of intermittent torticollis. In the second suggested neuroanatomical model the hypothetic reflex arc is organized in the absence of n.XI RC, the efferent part of the reflex arc continues as NA, which is motor nucleus of nervus glossopharyngeus (n.IX) and n.X in this case while distal roots of n.XI that appear at the level of the olivary nucleus lower edge represent n.X roots. In the third presented model the hypothetic reflex arc includes no jugular transfer and could be realized via interneuronal connections directly from NTS to the spinal motoneurons within nucleus radicis spinalis nervi accessorii (NRS n.XI) or from NA to NRS n.XI. The afferent segment of the postulated reflex arc in all three models is mediated via n.X. We conclude that Sandifer's syndrome is a clinical manifestation of another vagal reflex that could be termed a "vagocervical" or "esophagocervical" reflex, based on the neuroanatomical hypotheses elaborated in this paper.

"On Becoming a Critically Reflexive Practitioner" Redux: What Does It Mean to "Be" Reflexive?

ERIC Educational Resources Information Center

Cunliffe, Ann L.

2016-01-01

In this commentary, Cunliffe states that is convinced that reflexivity offers a way of foregrounding our moral and ethical responsibility for people and for the world around us. To "BE" reflexive was defined as embracing "subjective understandings of reality as a basis for thinking more critically about the impact of our…

Introducing Reflexivity to Evaluation Practice: An In-Depth Case Study

ERIC Educational Resources Information Center

van Draanen, Jenna

2017-01-01

There is currently a paucity of literature in the field of evaluation regarding the practice of reflection and reflexivity and a lack of available tools to guide this practice--yet using a reflexive model can enhance evaluation practice. This paper focuses on the methods and results of a reflexive inquiry that was conducted during a participatory…

The stiff-man syndrome: new pathophysiological aspects from abnormal exteroceptive reflexes and the response to clomipramine, clonidine, and tizanidine.

PubMed Central

Meinck, H M; Ricker, K; Conrad, B

1984-01-01

Neurophysiological investigations of a patient suffering from the stiff-man syndrome revealed that exteroceptive reflexes, in particular those elicited from the skin, were excessively enhanced. In contrast, no abnormalities were found within the monosynaptic reflex arc. Clomipramine injection severely aggravated the clinical symptoms whereas diazepam, clonidine, and tizanidine decreased both muscular stiffness and abnormal exteroceptive reflexes. The hypothesis is put forward that the stiff-man syndrome is a disorder of descending brain-stem systems which exert a net inhibitory control on axial and limb girdle muscle tone as well as on exteroceptive reflex transmission. Detection of abnormal exteroceptive reflex activity in conjunction with neuropharmacological testing might help in the diagnosis of this rare disease. PMID:6707674

[Reflex seizures, cinema and television].

PubMed

Olivares-Romero, Jesús

2015-12-16

In movies and television series are few references to seizures or reflex epilepsy even though in real life are an important subgroup of total epileptic syndromes. It has performed a search on the topic, identified 25 films in which they appear reflex seizures. Most seizures observed are tonic-clonic and visual stimuli are the most numerous, corresponding all with flashing lights. The emotions are the main stimuli in higher level processes. In most cases it is not possible to know if a character suffers a reflex epilepsy or suffer reflex seizures in the context of another epileptic syndrome. The main conclusion is that, in the movies, the reflex seizures are merely a visual reinforcing and anecdotal element without significant influence on the plot.

Tofacitinib Versus Biologic Treatments in Patients With Active Rheumatoid Arthritis Who Have Had an Inadequate Response to Tumor Necrosis Factor Inhibitors: Results From a Network Meta-analysis.

PubMed

Vieira, Maria-Cecilia; Zwillich, Samuel H; Jansen, Jeroen P; Smiechowski, Brielan; Spurden, Dean; Wallenstein, Gene V

2016-12-01

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). This analysis compared the efficacy and safety of tofacitinib with biologic disease-modifying antirheumatic drugs in patients with RA and a prior inadequate response (IR) to tumor necrosis factor inhibitors (TNFi). A systematic literature review identified 5 randomized placebo-controlled trials that evaluated tofacitinib or biologic disease-modifying antirheumatic drugs (bDMARDs) against placebo in patient populations with RA with a prior IR to TNFi. The definition of TNFi-IR varied across studies, and included patients with an IR or who had failed treatment with TNFi for any reason. A network meta-analysis was conducted comparing study data with regard to American College of Rheumatology response rates and Health Assessment Questionnaire-Disability Index improvement at weeks 12 and 24, rates of treatment withdrawal due to all causes; adverse events (AEs) and lack of efficacy; and rates of AEs, serious AEs, and serious infections. The 5 trials included a total of 2136 patients. Tofacitinib 5 mg twice daily combined with methotrexate was found to have relative risk estimates of American College of Rheumatology responses and change from baseline in Health Assessment Questionnaire-Disability Index score comparable with abatacept, golimumab, rituximab, and tocilizumab combined with conventional synthetic disease-modifying antirheumatic drugs. Withdrawal rates from trials due to all causes and AEs were comparable between treatments, and tofacitinib had a lower rate of withdrawals due to lack of efficacy. Rates of AEs and HAQ-DI were comparable between tofacitinib, other active treatments, and placebo. No serious infections were reported with tofacitinib during the placebo-controlled period (up to week 12) in this study population; rates of serious infection with other active treatments were generally low and similar to placebo. During a 24-week period, tofacitinib had efficacy and rates of AEs comparable with currently available bDMARDs in the treatment of patients with RA who had a prior IR to TNFi. ClinicalTrials.gov identifiers: ORAL Step, NCT00960440; ATTAIN, NCT00124982; GO-AFTER, NCT00299546; RADIATE, NCT00106522; REFLEX, NCT00462345. Copyright © 2016 Elsevier HS Journals, Inc. All rights reserved.

Tendon reflex is suppressed during whole-body vibration.

PubMed

Karacan, Ilhan; Cidem, Muharrem; Yilmaz, Gizem; Sebik, Oguz; Cakar, Halil Ibrahim; Türker, Kemal Sıtkı

2016-10-01

In this study we have investigated the effect of whole body vibration (WBV) on the tendon reflex (T-reflex) amplitude. Fifteen young adult healthy volunteer males were included in this study. Records of surface EMG of the right soleus muscle and accelerometer taped onto the right Achilles tendon were obtained while participant stood upright with the knees in extension, on the vibration platform. Tendon reflex was elicited before and during WBV. Subjects completed a set of WBV. Each WBV set consisted of six vibration sessions using different frequencies (25, 30, 35, 40, 45, 50Hz) applied randomly. In each WBV session the Achilles tendon was tapped five times with a custom-made reflex hammer. The mean peak-to-peak (PP) amplitude of T-reflex was 1139.11±498.99µV before vibration. It decreased significantly during WBV (p<0.0001). The maximum PP amplitude of T-reflex was 1333±515μV before vibration. It decreased significantly during WBV (p<0.0001). No significant differences were obtained in the mean acceleration values of Achilles tendon with tapping between before and during vibration sessions. This study showed that T-reflex is suppressed during WBV. T-reflex suppression indicates that the spindle primary afferents must have been pre-synaptically inhibited during WBV similar to the findings in high frequency tendon vibration studies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Intrapartum Synthetic Oxytocin Reduce the Expression of Primitive Reflexes Associated with Breastfeeding

PubMed Central

Olza Fernández, Ibone; Malalana Martínez, Ana M.; González Armengod, Carmen; Costarelli, Valeria; Millán Santos, Isabel; Fernández-Cañadas Morillo, Aurora; Pérez Riveiro, Pilar; López Sánchez, Francisco; García Murillo, Lourdes

2015-01-01

Abstract Aim: Several synthetic peptide manipulations during the time surrounding birth can alter the specific neurohormonal status in the newborn brain. This study is aimed at assessing whether intrapartum oxytocin administration has any effect on primitive neonatal reflexes and determining whether such an effect is dose-dependent. Materials and Methods: A cohort prospective study was conducted at a tertiary hospital. Mother–infant dyads who received intrapartum oxytocin (n=53) were compared with mother–infant dyads who did not receive intrapartum oxytocin (n=45). Primitive neonatal reflexes (endogenous, antigravity, motor, and rhythmic reflexes) were quantified by analyzing videotaped breastfeeding sessions in a biological nurturing position. Two observers blind to the group assignment and the oxytocin dose analyzed the videotapes and assesed the newborn's state of consciousness according to the Brazelton scale. Results: The release of all rhythmic reflexes (p=0.01), the antigravity reflex (p=0.04), and total primitive neonatal reflexes (p=0.02) in the group exposed to oxytocin was lower than in the group not exposed to oxytocin. No correlations were observed between the dose of oxytocin administered and the percentage of primitive neonatal reflexes released (r=0.03; p=0.82). Conclusions: Intrapartum oxytocin administration might inhibit the expression of several primitive neonatal reflexes associated with breastfeeding. This correlation does not seem to be dose-dependent. PMID:25785487

Manual therapy directed at the knee or lumbopelvic region does not influence quadriceps spinal reflex excitability.

PubMed

Grindstaff, Terry L; Pietrosimone, Brian G; Sauer, Lindsay D; Kerrigan, D Casey; Patrie, James T; Hertel, Jay; Ingersoll, Christopher D

2014-08-01

Manual therapies, directed to the knee and lumbopelvic region, have demonstrated the ability to improve neuromuscular quadriceps function in individuals with knee pathology. It remains unknown if manual therapies may alter impaired spinal reflex excitability, thus identifying a potential mechanism in which manual therapy may improve neuromuscular function following knee injury. To determine the effect of local and distant mobilisation/manipulation interventions on quadriceps spinal reflex excitability. Seventy-five individuals with a history of knee joint injury and current quadriceps inhibition volunteered for this study. Participants were randomised to one of five intervention groups: lumbopelvic manipulation (grade V), lumbopelvic manipulation positioning (no thrust), grade IV patellar mobilisation, grade I patellar mobilisation, and control (no treatment). Changes in spinal reflex excitability were quantified by assessing the Hoffmann reflex (H-reflex), presynaptic, and postsynaptic excitability. A hierarchical linear-mixed model for repeated measures was performed to compare changes in outcome variables between groups over time (pre, post 0, 30, 60, 90 min). There were no significant differences in H-reflex, presynaptic, or postsynaptic excitability between groups across time. Manual therapies directed to the knee or lumbopelvic region did not acutely change quadriceps spinal reflex excitability. Although manual therapies may improve impairments and functional outcomes the underlying mechanism does not appear to be related to changes in spinal reflex excitability. Copyright © 2014 Elsevier Ltd. All rights reserved.

No evidence hip joint angle modulates intrinsically produced stretch reflex in human hopping.

PubMed

Gibson, W; Campbell, A; Allison, G

2013-09-01

Motor output in activities such as walking and hopping is suggested to be mediated neurally by purported stretch reflex augmentation of muscle output. Reflex EMG activity during these tasks has been frequently investigated in the soleus muscle; with alterations in reflex amplitude being associated with changes in hip joint angle/phase of the gait cycle. Previous work has focussed on reflex activity induced by an artificial perturbation or by induction of H-reflexes. As such, it is currently unknown if stretch reflex activity induced intrinsically (as part of the task) is modulated by changes in hip joint angle. This study investigated whether hip joint angle modulated reflex EMG 'burst' activity during a hopping task performed on a custom-built partially reclined sleigh. Ten subjects participated; EMG and kinematic data (VICON motor capture system) was collected for each hop cycle. Participants completed 5 sets of 30s of self-paced hopping in (1) hip neutral and (2) hip 60° flexion conditions. There was no difference in EMG 'burst' activity or in sagittal plane kinematics (knee/ankle) in the hopping task between the two conditions. The results indicate that during a functional task such as hopping, changes in hip angle do not alter the stretch reflex-like activity associated with landing. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of noxious electrical stimulation of the peroneal nerve on stretch reflex activity of the hamstring muscle in rats: possible implications of neuronal mechanisms in the development of tight hamstrings in lumbar disc herniation.

PubMed

Hirayama, Jiro; Yamagata, Masatsune; Takahashi, Kazuhisa; Moriya, Hideshige

2005-05-01

The effect of noxious electrical stimulation of the peroneal nerve on the stretch reflex electromyogram activity of the hamstring muscle (semitendinous) was studied. To verify the following hypothetical mechanisms underlying tight hamstrings in lumbar disc herniation: stretch reflex muscle activity of hamstrings is increased by painful inputs from an injured spinal nerve root and the increased stretch reflex muscle activity is maintained by central sensitization. It is reported that stretch reflex activity of the trunk muscles is induced by noxious stimulation of the sciatic nerve and maintained by central sensitization. In spinalized rats (transected spinal cord), the peroneal nerve was stimulated electrically as a conditioning stimulus. Stretch reflex electromyogram activity of the semitendinous muscle was recorded before and after the conditioning stimulus. Even after electrical stimulation was terminated, an increased stretch reflex activity of the hamstring muscle was observed. It is likely that a central sensitization mechanism at the spinal cord level was involved in the increased reflex activity. Central sensitization may play a part in the neuronal mechanisms of tight hamstrings in lumbar disc herniation.

Anatomically remote muscle contraction facilitates patellar tendon reflex reinforcement while mental activity does not: a within-participants experimental trial.

PubMed

Passmore, Steven R; Bruno, Paul A

2012-09-07

The Jendrassik maneuver (JM) is a remote facilitation muscular contraction shown to affect amplitude and temporal components of the human stretch reflex. Conflicting theoretical models exist regarding the neurological mechanism related to its ability to reinforce reflex parameters. One mechanism involves the gamma motoneurons of the fusimotor system, which are subject to both physical and mental activity. A second mechanism describes reduced alpha motoneuron presynaptic inhibition, which is not subject to mental activity. In the current study, we determined if mental activity could be used to create a reflex facilitation comparable to a remote muscle contraction. Using a within-participants design, we investigated the relative effect of the JM and a successfully employed mental task (Stroop task) on the amplitude and temporal components of the patellar tendon reflex. We found that the addition of mental activity had no influence on the patellar tendon reflex parameters measured, while the JM provided facilitation (increased reflex amplitude, decreased total reflex time). The findings from this study support the view that the mechanism for the JM is a reduction in presynaptic inhibition of alpha motoneurons as it is influenced by physical and not mental activity.

Emotional Dissonance and Burnout: The Moderating Role of Team Reflexivity and Re-Evaluation.

PubMed

Andela, Marie; Truchot, Didier

2017-08-01

The aim of the present study was to better understand the relationship between emotional dissonance and burnout by exploring the buffering effects of re-evaluation and team reflexivity. The study was conducted with a sample of 445 nurses and healthcare assistants from a general hospital. Team reflexivity was evaluated with the validation of the French version of the team reflexivity scale (Facchin, Tschan, Gurtner, Cohen, & Dupuis, 2006). Burnout was measured with the MBI General Survey (Schaufeli, Leiter, Maslach, & Jackson, 1996). Emotional dissonance and re-evaluation were measured with the scale developed by Andela, Truchot, & Borteyrou (2015). With reference to Rimé's theoretical model (2009), we suggested that both dimensions of team reflexivity (task and social reflexivity) respond to both psychological necessities induced by dissonance (cognitive clarification and socio-affective necessities). Firstly, results indicated that emotional dissonance was related to burnout. Secondly, regression analysis confirmed the buffering role of re-evaluation and social reflexivity on the emotional exhaustion of emotional dissonance. Overall, results contribute to the literature by highlighting the moderating effect of re-evaluation and team reflexivity in analysing the relationship between emotional dissonance and burnout. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Reflex responses of lip muscles in young and older women.

PubMed

Wohlert, A B

1996-06-01

The perioral reflex in response to innocuous mechanical stimulation of the lip vermilion was studied in 20 young and 20 older women. Responses to stimuli at the right and left sides of both the upper and lower lips were recorded. Results show significant specificity of response, especially for upper lip sites. Reflex response at the site of stimulation was greatest in amplitude and shortest in latency, followed by response at sites ipsilateral to the site of stimulation. Younger subjects showed greater localizing tendency than older subjects. Stimulation was significantly less likely to produce a reflex response in the older group. When reflex responses did occur, they were significantly lower in amplitude and longer in latency than the responses of the younger group. Nonetheless, reflex responses were common in both groups, with responses at the site of stimulation occurring 78% of the time in older women and 90% of the time in younger women. Every participant showed at least one reflex response to lip stimulation. Results suggest decreasing complexity of synaptic drive to the perioral system in old age but also show that reflexive response does not deteriorate completely, remaining an available element for motor control in normal older women.

Reflex limb dilatation following norepinephrine and angiotensin II in conscious dogs

NASA Technical Reports Server (NTRS)

Vatner, S. F.; Mcritchie, R. J.

1976-01-01

The extent to which norepinephrine (NE) and angiotensin II (AN) constrict the mesenteric, renal, and iliac beds in conscious dogs is evaluated with a view to elicit opposing reflex actions tempering the vasoconstriction in the limb of the animals tested. The afferent and efferent mechanisms mediating this reflex are analyzed. It is shown that intravenous NE and AN cause striking reflex iliac dilatation in the limb of the conscious dog. The afferent arc of this reflex involves both arterial baroreceptor and vagal path-ways, whereas the efferent mechanism involves an interaction of alpha-adrenergic and histaminergic receptors.

The Moro reaction: More than a reflex, a ritualized behavior of nonverbal communication.

PubMed

Rousseau, Pierre V; Matton, Florence; Lecuyer, Renaud; Lahaye, Willy

2017-02-01

To propose a phylogenetic significance to the Moro reflex which remains unexplained since its publication in 1918 because both hands are free at the end of the gesture. Among the 75 videos of healthy term newborns we have filmed in a research project on antenatal education to parenthood, we describe a sequence that clearly showed the successive movements of the Moro reflex and we report the occurrence of this reflex in the videos that were recorded from Time 0 of birth defined as the moment that lies between the birth of the thorax and the pelvis of the infant. The selected sequence showed the following succession of the newborn's actions: quick extension-adduction of both arms, the orientation of the body, head and eyes towards a human person, and full extension-abduction of both arms with spreading of the fingers, crying and a distressed face. There were 13 Moro reflexes between 2 and 14s from Time 0 of birth. We found a significant association between the occurrence of the Moro reflex and the placement of the newborn at birth in supine position on the mother's abdomen (p=0.002). The quick extension-adduction of both arms which started the sequence may be considered as a startle reflex controlled by the neural fear system and the arm extension-adduction which followed as a Moro reflex. The characteristics of all Moro reflexes were those of ritualization: amplitude, duration, stereotype of the gestures. This evolutionary process turns a physiological behavior, grasping in this case, to a non-verbal communicative behavior whose meaning is a request to be picked up in the arms. The gestures associated with the Moro reflex: crying and orientation of the body, head, and eyes towards a human person, are gestures of intention to communicate which support our hypothesis. The neural mechanism of the Moro reaction probably involves both the fear and the separation-distress systems. This paper proposes for the first time a phylogenetic significance to the Moro reflex: a ritualized behavior of nonverbal communication. Professionals should avoid stimulating the newborns' fear system by unnecessarily triggering Moro reflexes. Antenatal education should teach parents to respond to the Moro reflexes of their newborn infant by picking her up in their arms with mother talk. Copyright © 2017 Elsevier Inc. All rights reserved.

The Cerebellum in Maintenance of a Motor Skill: A Hierarchy of Brain and Spinal Cord Plasticity Underlies H-Reflex Conditioning

ERIC Educational Resources Information Center

Wolpaw, Jonathan R.; Chen, Xiang Yang

2006-01-01

Operant conditioning of the H-reflex, the electrical analog of the spinal stretch reflex, is a simple model of skill acquisition and involves plasticity in the spinal cord. Previous work showed that the cerebellum is essential for down-conditioning the H-reflex. This study asks whether the cerebellum is also essential for maintaining…

Indicators used in livestock to assess unconsciousness after stunning: a review.

PubMed

Verhoeven, M T W; Gerritzen, M A; Hellebrekers, L J; Kemp, B

2015-02-01

Assessing unconsciousness is important to safeguard animal welfare shortly after stunning at the slaughter plant. Indicators that can be visually evaluated are most often used when assessing unconsciousness, as they can be easily applied in slaughter plants. These indicators include reflexes originating from the brain stem (e.g. eye reflexes) or from the spinal cord (e.g. pedal reflex) and behavioural indicators such as loss of posture, vocalisations and rhythmic breathing. When physically stunning an animal, for example, captive bolt, most important indicators looked at are posture, righting reflex, rhythmic breathing and the corneal or palpebral reflex that should all be absent if the animal is unconscious. Spinal reflexes are difficult as a measure of unconsciousness with this type of stunning, as they may occur more vigorous. For stunning methods that do not physically destroy the brain, for example, electrical and gas stunning, most important indicators looked at are posture, righting reflex, natural blinking response, rhythmic breathing, vocalisations and focused eye movement that should all be absent if the animal is unconscious. Brain stem reflexes such as the cornea reflex are difficult as measures of unconsciousness in electrically stunned animals, as they may reflect residual brain stem activity and not necessarily consciousness. Under commercial conditions, none of the indicators mentioned above should be used as a single indicator to determine unconsciousness after stunning. Multiple indicators should be used to determine unconsciousness and sufficient time should be left for the animal to die following exsanguination before starting invasive dressing procedures such as scalding or skinning. The recording and subsequent assessment of brain activity, as presented in an electroencephalogram (EEG), is considered the most objective way to assess unconsciousness compared with reflexes and behavioural indicators, but is only applied in experimental set-ups. Studies performed in an experimental set-up have often looked at either the EEG or reflexes and behavioural indicators and there is a scarcity of studies that correlate these different readout parameters. It is recommended to study these correlations in more detail to investigate the validity of reflexes and behavioural indicators and to accurately determine the point in time at which the animal loses consciousness.

Signals for nausea and emesis: Implications for models of upper gastrointestinal diseases

PubMed Central

Andrews, Paul L.R.; Horn, Charles C.

2009-01-01

Nausea and vomiting are amongst the most common symptoms encountered in medicine as either symptoms of diseases or side effects of treatments. In a more biological setting they are also important components of an organism’s defences against ingested toxins. Identification of treatments for nausea and vomiting and reduction of emetic liability of new therapies has largely relied on the use of animal models, and although such models have proven invaluable in identification of the anti-emetic effects of both 5-hydroxytryptamine3 and neurokinin1 receptor antagonists selection of appropriate models is still a matter of debate. The present paper focuses on a number of controversial issues and gaps in our knowledge in the study of the physiology of nausea and vomiting including: The choice of species for the study of emesis and the underlying behavioural (e.g. neophobia), anatomical (e.g. elongated, narrow abdominal oesophagus with reduced ability to shorten) and physiological (e.g. brainstem circuitry) mechanisms that explain the lack of a vomiting reflex in certain species (e.g. rats); The choice of response to measure (emesis[retching and vomiting], conditioned flavour avoidance or aversion, ingestion of clay[pica], plasma hormone levels[e.g. vasopressin], gastric dysrhythmias) and the relationship of these responses to those observed in humans and especially to the sensation of nausea; The stimulus coding of nausea and emesis by abdominal visceral afferents and especially the vagus—how do the afferents encode information for normal postprandial sensations, nausea and finally vomiting?; Understanding the central processing of signals for nausea and vomiting is particularly problematic in the light of observations that vomiting is more readily amenable to pharmacological treatment than is nausea, despite the assumption that nausea represents “low” intensity activation of pathways that can evoke vomiting when stimulated more intensely. PMID:16556512

Successful implantation of an abdominal aortic blood pressure transducer and radio-telemetry transmitter in guinea pigs - Anaesthesia, analgesic management and surgical methods, and their influence on hemodynamic parameters and body temperature.

PubMed

Schmitz, Sabrina; Henke, Julia; Tacke, Sabine; Guth, Brian

2016-01-01

Guinea pigs (GPs) are a valuable cardiovascular pharmacology model. Implantation of a radio-telemetry system into GPs is, however, challenging and has been associated with a high failure rate in the past. We provide information on a novel procedure for implanting telemetry devices into GPs and we have measured the hemodynamics (arterial blood pressure, BP and heart rate, HR) and core body temperature (BT) in the 24h after surgery. Male Hartley GPs (Crl:HA, 350-400g, 6.5weeks, n=16) were implanted with a radio transmitter abdominally and were then monitored continuously (HR, BP and BT) for 24h after surgery. 13 of 16 GPs (81%) survived the surgery. Surgery duration was 94min (min) (range: 76-112min) and anaesthesia duration was 131min (range: 107-158min). GPs lost body weight until 2days after surgery and then regained weight. Mean arterial BP increased from 33.7mmHg directly after surgery to 59.1mmHg after 24h. HR increased from 206bpm directly after surgery to 286bpm at 8h and fell to 251bpm at 24h after implantation. BT was 36°C directly after surgery, fell to 35.4°C until regaining of the righting reflex and then stabilized at 38.5°C after 24h. A high survival rate in telemetered GPs is possible. We achieved this through a procedure with minimal stress through habituation and planning, continuous warming during anaesthesia, an optimal anaesthetic and analgesic management, efficient surgical techniques and vitamin C supplementation. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Tramadol reduces anxiety-related and depression-associated behaviors presumably induced by pain in the chronic constriction injury model of neuropathic pain in rats.

PubMed

Caspani, Ombretta; Reitz, Marie-Céline; Ceci, Angelo; Kremer, Andreas; Treede, Rolf-Detlef

2014-09-01

Depression and anxiety are common comorbidities of neuropathic pain (NP). Pharmacological preclinical studies on NP have given abundant information on the effects of drugs on reflex measures of stimulus-evoked pain. However, few preclinical studies focus on relief of comorbidities evoked by NP. In this study, we investigated the effects of tramadol on nociceptive reflex, depression-associated and anxiety-related behaviors in a NP model in rats. We used chronic constriction injury (CCI) of the sciatic nerve as an animal model of neuropathic pain. We performed electronic von Frey tests (evF) to measure mechanical sensitivity, elevated plus maze tests (EPM) to record anxiety-related behaviors and forced swimming tests (FST) to evaluate depression-associated behaviors. In the evF, CCI rats showed a decrease of 82% of the paw withdrawal threshold (PWT) compared to sham (P<0.001). Tramadol increased the PWT by 336% in CCI rats (P<0.001) and by 16% in sham (P<0.05). On the EPM, CCI rats spent 45% less time than sham on the open arms of the maze (P<0.05). Tramadol increased the time spent on the open arms of CCI rats by 67% (P<0.05) and had no significant effect on sham. During the FST, CCI rats showed 28% longer immobility than sham (P<0.01). Tramadol reduced the immobility time in CCI rats by 22% (P<0.001), while having no effect on sham. Tramadol reversed the changes in mechanical sensitivity as well as anxiety-related and depression-associated behaviors that are caused by injury of the sciatic nerve with only minor effects in the absence of injury. These data suggest that tramadol relieves chronic pain and its indirect consequences and comorbidities, and that this study also is a model for pharmacological studies seeking to investigate the effect of drugs on the major disabling symptoms of NP. Copyright © 2014 Elsevier Inc. All rights reserved.

Alfaxalone versus alfaxalone-dexmedetomidine anaesthesia by immersion in oriental fire-bellied toads (Bombina orientalis).

PubMed

Adami, Chiara; d'Ovidio, Dario; Casoni, Daniela

2016-05-01

To determine a dexmedetomidine concentration, to be added to an alfaxalone-based bath solution, that will enhance the anaesthetic and analgesic effects of alfaxalone; and to compare the quality of anaesthesia and analgesia provided by immersion with either alfaxalone alone or alfaxalone with dexmedetomidine in oriental fire-bellied toads (Bombina orientalis). Pilot study followed by a prospective, randomized, experimental trial. Fourteen oriental fire-bellied toads. The pilot study aimed to identify a useful dexmedetomidine concentration to be added to an anaesthetic bath containing 20 mg 100 mL(-1) alfaxalone. Thereafter, the toads were assigned to one of two groups, each comprising eight animals, to be administered either alfaxalone (group A) or alfaxalone-dexmedetomidine (group AD). After immersion for 20 minutes, the toads were removed from the anaesthetic bath and the righting, myotactic and nociceptive reflexes, cardiopulmonary variables and von Frey filaments threshold were measured at 5 minute intervals and compared statistically between groups. Side effects and complications were noted and recorded. In the pilot study, a dexmedetomidine concentration of 0.3 mg 100 mL(-1) added to the alfaxalone-based solution resulted in surgical anaesthesia. The toads in group AD showed higher von Frey thresholds and lower nociceptive withdrawal reflex scores than those in group A. However, in group AD, surgical anaesthesia was observed in two out of eight toads only, and induction of anaesthesia was achieved in only 50% of the animals, as compared with 100% of the toads in group A. The addition of dexmedetomidine to an alfaxalone-based solution for immersion anaesthesia provided some analgesia in oriental fire-bellied toads, but failed to potentiate the level of unconsciousness and appeared to lighten the depth of anaesthesia. This limitation renders the combination unsuitable for anaesthetizing oriental fire-bellied toads for invasive procedures. © 2015 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesia and Analgesia.

Parallel facilitatory reflex pathways from the foot and hip to flexors and extensors in the injured human spinal cord

PubMed Central

Knikou, Maria; Kay, Elizabeth; Schmit, Brian D.

2007-01-01

Spinal integration of sensory signals associated with hip position, muscle loading, and cutaneous sensation of the foot contributes to movement regulation. The exact interactive effects of these sensory signals under controlled dynamic conditions are unknown. The purpose of the present study was to establish the effects of combined plantar cutaneous afferent excitation and hip movement on the Hoffmann (H) and flexion reflexes in people with a spinal cord injury (SCI). The flexion and H-reflexes were elicited through stimulation of the right sural (at non-nociceptive levels) and posterior tibial nerves respectively. Reflex responses were recorded from the ipsilateral tibialis anterior (TA) (flexion reflex) and soleus (H-reflex) muscles. The plantar cutaneous afferents were stimulated at three times the perceptual threshold (200 Hz, 24-ms pulse train) at conditioning–test intervals that ranged from 3 to 90 ms. Sinusoidal movements were imposed to the right hip joint at 0.2 Hz with subjects supine. Control and conditioned reflexes were recorded as the hip moved in flexion and extension. Leg muscle activity and sagittal-plane joint torques were recorded. We found that excitation of plantar cutaneous afferents facilitated the soleus H-reflex and the long latency flexion reflex during hip extension. In contrast, the short latency flexion reflex was depressed by plantar cutaneous stimulation during hip flexion. Oscillatory joint forces were present during the transition phase of the hip movement from flexion to extension when stimuli were delivered during hip flexion. Hip-mediated input interacts with feedback from the foot sole to facilitate extensor and flexor reflex activity during the extension phase of movement. The interactive effects of these sensory signals may be a feature of impaired gait, but when they are appropriately excited, they may contribute to locomotion recovery in these patients. PMID:17543951

Short-term locomotor adaptation to a robotic ankle exoskeleton does not alter soleus Hoffmann reflex amplitude

PubMed Central

2010-01-01

Background To improve design of robotic lower limb exoskeletons for gait rehabilitation, it is critical to identify neural mechanisms that govern locomotor adaptation to robotic assistance. Previously, we demonstrated soleus muscle recruitment decreased by ~35% when walking with a pneumatically-powered ankle exoskeleton providing plantar flexor torque under soleus proportional myoelectric control. Since a substantial portion of soleus activation during walking results from the stretch reflex, increased reflex inhibition is one potential mechanism for reducing soleus recruitment when walking with exoskeleton assistance. This is clinically relevant because many neurologically impaired populations have hyperactive stretch reflexes and training to reduce the reflexes could lead to substantial improvements in their motor ability. The purpose of this study was to quantify soleus Hoffmann (H-) reflex responses during powered versus unpowered walking. Methods We tested soleus H-reflex responses in neurologically intact subjects (n=8) that had trained walking with the soleus controlled robotic ankle exoskeleton. Soleus H-reflex was tested at the mid and late stance while subjects walked with the exoskeleton on the treadmill at 1.25 m/s, first without power (first unpowered), then with power (powered), and finally without power again (second unpowered). We also collected joint kinematics and electromyography. Results When the robotic plantar flexor torque was provided, subjects walked with lower soleus electromyographic (EMG) activation (27-48%) and had concomitant reductions in H-reflex amplitude (12-24%) compared to the first unpowered condition. The H-reflex amplitude in proportion to the background soleus EMG during powered walking was not significantly different from the two unpowered conditions. Conclusion These findings suggest that the nervous system does not inhibit the soleus H-reflex in response to short-term adaption to exoskeleton assistance. Future studies should determine if the findings also apply to long-term adaption to the exoskeleton. PMID:20659331

Convergence of flexor reflex and corticospinal inputs on tibialis anterior network in humans.

PubMed

Mackey, Ann S; Uttaro, Denise; McDonough, Maureen P; Krivis, Lisa I; Knikou, Maria

2016-01-01

Integration between descending and ascending inputs at supraspinal and spinal levels is a key characteristic of neural control of movement. In this study, we characterized convergence of the flexor reflex and corticospinal inputs on the tibialis anterior (TA) network in healthy human subjects. Specifically, we characterized the modulation profiles of the spinal TA flexor reflex following subthreshold and suprathreshold transcranial magnetic stimulation (TMS). We also characterized the modulation profiles of the TA motor evoked potentials (MEPs) following medial arch foot stimulation at sensory and above reflex threshold. TA flexor reflexes were evoked following stimulation of the medial arch of the foot with a 30 ms pulse train at innocuous intensities. TA MEPs were evoked following TMS of the leg motor cortex area. TMS at 0.7 and at 1.2 MEP resting threshold increased the TA flexor reflex when TMS was delivered 40-100 ms after foot stimulation, and decreased the TA flexor reflex when TMS was delivered 25-110 ms before foot stimulation. Foot stimulation at sensory and above flexor reflex threshold induced a similar time-dependent modulation in resting TA MEPs, that were facilitated when foot stimulation was delivered 40-100 ms before TMS. The flexor reflex and MEPs recorded from the medial hamstring muscle were modulated in a similar manner to that observed for the TA flexor reflex and MEP. Cutaneomuscular afferents from the distal foot can increase the output of the leg motor cortex area. Descending motor volleys that directly or indirectly depolarize flexor motoneurons increase the output of the spinal FRA interneuronal network. The parallel facilitation of flexor MEPs and flexor reflexes is likely cortical in origin. Afferent mediated facilitation of corticospinal excitability can be utilized to strengthen motor cortex output in neurological disorders. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Rate of EGFR mutation testing for patients with nonsquamous non-small-cell lung cancer with implementation of reflex testing by pathologists

PubMed Central

Cheema, P.K.; Raphael, S.; El-Maraghi, R.; Li, J.; McClure, R.; Zibdawi, L.; Chan, A.; Victor, J.C.; Dolley, A.; Dziarmaga, A.

2017-01-01

Background Testing for mutation of the EGFR (epidermal growth factor receptor) gene is a standard of care for patients with advanced nonsquamous non-small-cell lung cancer (nsclc). To improve timely access to EGFR results, a few centres implemented reflex testing, defined as a request for EGFR testing by the pathologist at the time of a nonsquamous nsclc diagnosis. We evaluated the impact of reflex testing on EGFR testing rates. Methods A retrospective observational review of the Web-based AstraZeneca Canada EGFR Database from 1 April 2010 to 31 March 2014 found centres within Ontario that had requested EGFR testing through the database and that had implemented reflex testing (with at least 2 years’ worth of data, including the pre- and post-implementation period). Results The 7 included centres had requested EGFR tests for 2214 patients. The proportion of pathologists requesting EGFR tests increased after implementation of reflex testing (53% vs. 4%); conversely, the proportion of medical oncologists requesting tests decreased (46% vs. 95%, p < 0.001). After implementation of reflex testing, the mean number of patients having EGFR testing per centre per month increased significantly [12.6 vs. 4.9 (range: 4.5–14.9), p < 0.001]. Before reflex testing, EGFR testing rates showed a significant monthly increase over time (1.37 more tests per month; 95% confidence interval: 1.19 to 1.55 tests; p < 0.001). That trend could not account for the observed increase with reflex testing, because an immediate increase in EGFR test requests was observed with the introduction of reflex testing (p = 0.003), and the overall trend was sustained throughout the post–reflex testing period (p < 0.001). Conclusions Reflex EGFR testing for patients with nonsquamous nsclc was successfully implemented at multiple centres and was associated with an increase in EGFR testing. PMID:28270720

29 CFR 4219.11 - Withdrawal liability upon mass withdrawal.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Withdrawal liability upon mass withdrawal. 4219.11 Section... Redetermination of Withdrawal Liability Upon Mass Withdrawal § 4219.11 Withdrawal liability upon mass withdrawal. (a) Initial withdrawal liability. The plan sponsor of a multiemployer plan that experiences a mass...

29 CFR 4219.11 - Withdrawal liability upon mass withdrawal.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 9 2011-07-01 2011-07-01 false Withdrawal liability upon mass withdrawal. 4219.11 Section... Redetermination of Withdrawal Liability Upon Mass Withdrawal § 4219.11 Withdrawal liability upon mass withdrawal. (a) Initial withdrawal liability. The plan sponsor of a multiemployer plan that experiences a mass...

Modulation of spinal inhibitory reflexes depends on the frequency of transcutaneous electrical nerve stimulation in spastic stroke survivors.

PubMed

Koyama, Soichiro; Tanabe, Shigeo; Takeda, Kazuya; Sakurai, Hiroaki; Kanada, Yoshikiyo

2016-03-01

Neurophysiological studies in healthy subjects suggest that increased spinal inhibitory reflexes from the tibialis anterior (TA) muscle to the soleus (SOL) muscle might contribute to decreased spasticity. While 50 Hz is an effective frequency for transcutaneous electrical nerve stimulation (TENS) in healthy subjects, in stroke survivors, the effects of TENS on spinal reflex circuits and its appropriate frequency are not well known. We examined the effects of different frequencies of TENS on spinal inhibitory reflexes from the TA to SOL muscle in stroke survivors. Twenty chronic stroke survivors with ankle plantar flexor spasticity received 50-, 100-, or 200-Hz TENS over the deep peroneal nerve (DPN) of the affected lower limb for 30 min. Before and immediately after TENS, reciprocal Ia inhibition (RI) and presynaptic inhibition of the SOL alpha motor neuron (D1 inhibition) were assessed by adjusting the unconditioned H-reflex amplitude. Furthermore, during TENS, the time courses of spinal excitability and spinal inhibitory reflexes were assessed via the H-reflex, RI, and D1 inhibition. None of the TENS protocols affected mean RI, whereas D1 inhibition improved significantly following 200-Hz TENS. In a time-series comparison during TENS, repeated stimulation did not produce significant changes in the H-reflex, RI, or D1 inhibition regardless of frequency. These results suggest that the frequency-dependent effect of TENS on spinal reflexes only becomes apparent when RI and D1 inhibition are measured by adjusting the amplitude of the unconditioned H-reflex. However, 200-Hz TENS led to plasticity of synaptic transmission from the antagonist to spastic muscles in stroke survivors.

Neuromuscular function during drop jumps in young and elderly males.

PubMed

Piirainen, Jarmo M; Linnamo, Vesa; Sippola, Niina; Avela, Janne

2012-12-01

The Hoffman reflex (H-reflex), indicating alpha-motoneuron pool activity, has been shown to be task - and in resting conditions - age dependent. How aging affects H-reflex activity during explosive movements is not clear at present. The purpose of this study was to examine the effects of aging on H-reflexes during drop jumps, and its possible role in drop jump performance. Ten young (26.8 ± 2.7 years) and twenty elderly (64.2 ± 2.7 years) subjects participated in the study. Maximal drop jump performance and soleus H-reflex response (H/M jump) 20 ms after ground contact were measured in a sledge ergometer. Maximal H-reflex, maximal M-wave, Hmax/Mmax-ratio and H-reflex excitability curves were measured during standing rest. Although in young the H-reflex response (Hmax/Mmax) was 6.5% higher during relaxed standing and 19.7% higher during drop jumps (H jump/M jump) than in the elderly group, these differences were not statistically significant. In drop jumps, the elderly subjects had lower jumping height (30.4%, p < 0.001), longer braking time (32.4%, p < 0.01), lower push-off force (18.0%, p < 0.05) and longer push-off time (31.0% p < 0.01). H jump/M jump correlated with the average push-off force (r = 0.833, p < 0.05) and with push-off time (r = -0.857, p < 0.01) in young but not in the elderly. Correlations between H-reflex response and jumping parameters in young may indicate different jumping and activation strategies in drop jumps. However, it does not fully explain age related differences in jumping performance, since age related differences in H-reflex activity were non-significant. Copyright © 2012 Elsevier Ltd. All rights reserved.

Detection and identification of oral anaerobes in intraoperative bronchial fluids of patients with pulmonary carcinoma.

PubMed

Hasegawa, Ayako; Sato, Takuichi; Hoshikawa, Yasushi; Ishida, Naoko; Tanda, Naoko; Kawamura, Yoshiaki; Kondo, Takashi; Takahashi, Nobuhiro

2014-07-01

Postoperative pneumonia may occur when upper respiratory tract protective reflexes such as cough and/or swallowing reflexes are impaired; thus, silent aspiration of oral bacteria may be a causative factor in postoperative pneumonia. This study aimed to quantify and identify bacteria in intraoperative bronchial fluids and to evaluate the relationship between impairment of cough/swallowing reflexes and silent aspiration of oral bacteria in elderly patients. After obtaining informed consent, cough and swallowing reflexes were assessed using an ultrasonic nebulizer and a nasal catheter, respectively. Using a micro-sampling probe, intraoperative bronchial fluids were collected from nine subjects with pulmonary carcinoma and cultured anaerobically on blood agar plates. After 7 days, CFUs were counted and isolated bacteria were identified by 16S rRNA gene sequencing. Four subjects (aged 71.0 ± 8.4 years) had impaired swallowing reflexes with normal cough reflexes, whereas five subjects (73.6 ± 6.5 years) had normal cough and swallowing reflexes. The bacterial counts (mean CFU ± SD) tended to be higher in intraoperative bronchial fluids of subjects with impaired swallowing reflexes ([5.1 ± 7.7] × 10(5)) than in those of subjects with normal reflexes ([1.2 ± 1.9] × 10(5)); however, this difference was not statistically significant. Predominant isolates from intraoperative bronchial fluids were Streptococcus (41.8%), Veillonella (11.4%), Gemella (8.9%), Porphyromonas (7.6%), Olsenella (6.3%) and Eikenella (6.3%). These findings indicate that intraoperative bronchial fluids contain bacteria, probably derived from the oral microbiota, and suggest that silent aspiration of oral bacteria occurs in elderly patients irrespective of impairment of swallowing reflex. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.

Hip proprioceptors preferentially modulate reflexes of the leg in human spinal cord injury

PubMed Central

Onushko, Tanya; Hyngstrom, Allison

2013-01-01

Stretch-sensitive afferent feedback from hip muscles has been shown to trigger long-lasting, multijoint reflex responses in people with chronic spinal cord injury (SCI). These reflexes could have important implications for control of leg movements during functional activities, such as walking. Because the control of leg movement relies on reflex regulation at all joints of the limb, we sought to determine whether stretch of hip muscles modulates reflex activity at the knee and ankle and, conversely, whether knee and ankle stretch afferents affect hip-triggered reflexes. A custom-built servomotor apparatus was used to stretch the hip muscles in nine chronic SCI subjects by oscillating the legs about the hip joint bilaterally from 10° of extension to 40° flexion. To test whether stretch-related feedback from the knee or ankle would be affected by hip movement, patellar tendon percussions and Achilles tendon vibration were delivered when the hip was either extending or flexing. Surface electromyograms (EMGs) and joint torques were recorded from both legs. Patellar tendon percussions and Achilles tendon vibration both elicited reflex responses local to the knee or ankle, respectively, and did not influence reflex responses observed at the hip. Rather, the movement direction of the hip modulated the reflex responses local to the joint. The patellar tendon reflex amplitude was larger when the perturbation was delivered during hip extension compared with hip flexion. The response to Achilles vibration was modulated by hip movement, with an increased tonic component during hip flexion compared with extension. These results demonstrate that hip-mediated sensory signals modulate activity in distal muscles of the leg and appear to play a unique role in modulation of spastic muscle activity throughout the leg in SCI. PMID:23615544

Are H-reflex and M-wave recruitment curve parameters related to aerobic capacity?

PubMed

Piscione, Julien; Grosset, Jean-François; Gamet, Didier; Pérot, Chantal

2012-10-01

Soleus Hoffmann reflex (H-reflex) amplitude is affected by a training period and type and level of training are also well known to modify aerobic capacities. Previously, paired changes in H-reflex and aerobic capacity have been evidenced after endurance training. The aim of this study was to investigate possible links between H- and M-recruitment curve parameters and aerobic capacity collected on a cohort of subjects (56 young men) that were not involved in regular physical training. Maximal H-reflex normalized with respect to maximal M-wave (H(max)/M(max)) was measured as well as other parameters of the H- or M-recruitment curves that provide information about the reflex or direct excitability of the motoneuron pool, such as thresholds of stimulus intensity to obtain H or M response (H(th) and M(th)), the ascending slope of H-reflex, or M-wave recruitment curves (H(slp) and M(slp)) and their ratio (H(slp)/M(slp)). Aerobic capacity, i.e., maximal oxygen consumption and maximal aerobic power (MAP) were, respectively, estimated from a running field test and from an incremental test on a cycle ergometer. Maximal oxygen consumption was only correlated with M(slp), an indicator of muscle fiber heterogeneity (p < 0.05), whereas MAP was not correlated with any of the tested parameters (p > 0.05). Although higher H-reflex are often described for subjects with a high aerobic capacity because of endurance training, at a basic level (i.e., without training period context) no correlation was observed between maximal H-reflex and aerobic capacity. Thus, none of the H-reflex or M-wave recruitment curve parameters, except M(slp), was related to the aerobic capacity of young, untrained male subjects.

Locomotor impact of beneficial or nonbeneficial H-reflex conditioning after spinal cord injury

PubMed Central

Chen, Yi; Chen, Lu; Liu, Rongliang; Wang, Yu; Wolpaw, Jonathan R.

2013-01-01

When new motor learning changes neurons and synapses in the spinal cord, it may affect previously learned behaviors that depend on the same spinal neurons and synapses. To explore these effects, we used operant conditioning to strengthen or weaken the right soleus H-reflex pathway in rats in which a right spinal cord contusion had impaired locomotion. When up-conditioning increased the H-reflex, locomotion improved. Steps became longer, and step-cycle asymmetry (i.e., limping) disappeared. In contrast, when down-conditioning decreased the H-reflex, locomotion did not worsen. Steps did not become shorter, and asymmetry did not increase. Electromyographic and kinematic analyses explained how H-reflex increase improved locomotion and why H-reflex decrease did not further impair it. Although the impact of up-conditioning or down-conditioning on the H-reflex pathway was still present during locomotion, only up-conditioning affected the soleus locomotor burst. Additionally, compensatory plasticity apparently prevented the weaker H-reflex pathway caused by down-conditioning from weakening the locomotor burst and further impairing locomotion. The results support the hypothesis that the state of the spinal cord is a “negotiated equilibrium” that serves all the behaviors that depend on it. When new learning changes the spinal cord, old behaviors undergo concurrent relearning that preserves or improves their key features. Thus, if an old behavior has been impaired by trauma or disease, spinal reflex conditioning, by changing a specific pathway and triggering a new negotiation, may enable recovery beyond that achieved simply by practicing the old behavior. Spinal reflex conditioning protocols might complement other neurorehabilitation methods and enhance recovery. PMID:24371288

Vastus Medialis Hoffmann Reflex Excitability Is Associated With Pain Level, Self-Reported Function, and Chronicity in Women With Patellofemoral Pain.

PubMed

de Oliveira Silva, Danilo; Magalhães, Fernando Henrique; Faria, Nathálie Clara; Ferrari, Deisi; Pazzinatto, Marcella Ferraz; Pappas, Evangelos; de Azevedo, Fábio Mícolis

2017-01-01

To determine the association between the amplitude of vastus medialis (VM) Hoffmann reflex (H-reflex) and pain level, self-reported physical function, and chronicity of pain in women with patellofemoral pain (PFP). Cross-sectional study. Laboratory of biomechanics and motor control. Women diagnosed with PFP (N=15) aged 18 to 35 years. Not applicable. Data on worst pain level during the previous month, self-reported physical function, and symptom duration (chronicity) were collected from the participants. Maximum evoked responses were obtained by electrical stimulation applied to the femoral nerve and peak-to-peak amplitudes of normalized maximal H-reflexes (maximal Hoffmann reflex/maximal motor wave ratios) of the VM were calculated. A Pearson product-moment correlation matrix (r) was used to explore the relations between the amplitude of VM H-reflex and worst pain during the previous month, self-reported function, and chronicity of pain. Strong negative correlations were found between the amplitude of VM H-reflex and worst pain in the previous month (r=-.71; P=.003) and chronicity (r=-.74; P=.001). A strong positive correlation was found between the amplitude of VM H-reflex and self-reported physical function (r=.62; P=.012). The strong and significant relations reported in this study suggest that women with PFP showing greater VM H-reflex excitability tend to have lower pain, better physical function, and more recent symptoms. Therefore, rehabilitation strategies designed to increase the excitability of the monosynaptic stretch reflex should be considered in the treatment of women with PFP if their effectiveness is demonstrated in future studies. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Learning reflexively from a health promotion professional development program in Canada.

PubMed

Tremblay, Marie-Claude; Richard, Lucie; Brousselle, Astrid; Beaudet, Nicole

2014-09-01

In recent decades, reflexivity has received much attention in the professional education and training literature, especially in the public health and health promotion fields. Despite general agreement on the importance of reflexivity, there appears to be no consensus on how to assess reflexivity or to conceptualize the different forms developed among professionals and participants of training programs. This paper presents an analysis of the reflexivity outcomes of the Health Promotion Laboratory, an innovative professional development program aimed at supporting practice changes among health professionals by fostering competency development and reflexivity. More specifically, this paper explores the difference between two levels of reflexivity (formative and critical) and highlights some implications of each for practice. Data were collected through qualitative interviews with participants from two intervention sites. Results showed that involvement in the Health Promotion Laboratory prompted many participants to modify their vision of their practice and professional role, indicating an impact on reflexivity. In many cases, new understandings seem to have played a formative function in enabling participants to improve their practice and their role as health promoters. The reflective process also served a critical function culminating in a social and moral understanding of the impacts on society of the professionals' practices and roles. This type of outcome is greatly desired in health promotion, given the social justice and equity concerns of this field of practice. By redefining the theoretical concept of reflexivity on two levels and discussing their impacts on practice, this study supports the usefulness of both levels of reflexivity. © The Author (2013). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The forces generated at the human elbow joint in response to imposed sinusoidal movements of the forearm

PubMed Central

Joyce, G. C.; Rack, Peter M. H.; Ross, H. F.

1974-01-01

1. The mechanical resistance of the human forearm has been measured during imposed sinusoidal flexion-extension movements of the elbow joint. 2. The force required to move the limb can be divided into components required to move the mass, and components required to overcome the resistance offered by elastic and frictional properties of the muscles and other soft tissues. 3. When during a vigorous flexing effort the limb was subjected to a small amplitude sinusoidal movement each extension was followed by a considerable reflex contraction of the flexor muscles. At low frequencies of movement this reflex provided an added resistance to extension, but at 8-12 Hz the delay in the reflex pathway was such that the reflex response to extension occurred after the extension phase of the movement was over and during the subsequent flexion movement. The reflex activity then assisted the movement whereas at other frequencies it impeded it. 4. The reflex response to movement increased as the subject exerted a greater flexing force. 5. Small movements generated a relatively larger reflex response than big ones. 6. Even with large amplitudes of movement when the reflex activity was relatively small, the limb resisted extension with a high level of stiffness; this was comparable with the short range stiffness of muscles in experimental animals. 7. The fact that at some frequencies the reflex response assisted the movement implies that with appropriate loading the limb could undergo a self-sustaining oscillation at those frequencies. PMID:4420490

Ultimate concerns in late modernity: Archer, Bourdieu and reflexivity.

PubMed

Farrugia, David; Woodman, Dan

2015-12-01

Through a critique of Margaret Archer's theory of reflexivity, this paper explores the theoretical contribution of a Bourdieusian sociology of the subject for understanding social change. Archer's theory of reflexivity holds that conscious 'internal conversations' are the motor of society, central both to human subjectivity and to the 'reflexive imperative' of late modernity. This is established through critiques of Bourdieu, who is held to erase creativity and meaningful personal investments from subjectivity, and late modernity is depicted as a time when a 'situational logic of opportunity' renders embodied dispositions and the reproduction of symbolic advantages obsolete. Maintaining Archer's focus on 'ultimate concerns' in a context of social change, this paper argues that her theory of reflexivity is established through a narrow misreading and rejection of Bourdieu's work, which ultimately creates problems for her own approach. Archer's rejection of any pre-reflexive dimensions to subjectivity and social action leaves her unable to sociologically explain the genesis of 'ultimate concerns', and creates an empirically dubious narrative of the consequences of social change. Through a focus on Archer's concept of 'fractured reflexivity', the paper explores the theoretical necessity of habitus and illusio for understanding the social changes that Archer is grappling with. In late modernity, reflexivity is valorized just as the conditions for its successful operation are increasingly foreclosed, creating 'fractured reflexivity' emblematic of the complex contemporary interaction between habitus, illusio, and accelerating social change. © London School of Economics and Political Science 2015.

On reflexivity and the conduct of the self in everyday life: reflections on Bourdieu and Archer.

PubMed

Akram, Sadiya; Hogan, Anthony

2015-12-01

This article provides a critique of the concept of reflexivity in social theory today and argues against the tendency to define agency exclusively in terms of reflexivity. Margaret Archer, in particular, is highlighted as a key proponent of this thesis. Archer argues that late modernity is characterized by reflexivity but, in our view, this position neglects the impact of more enduring aspects of agency, such as the routinization of social life and the role of the taken-for-granted. These concepts were pivotal to Bourdieu and Giddens' theorization of everyday life and action and to Foucault's understanding of technologies of the self. We offer Bourdieu's habitus as a more nuanced approach to theorizing agency, and provide an alternative account of reflexivity. Whilst accepting that reflexivity is a core aspect of agency, we argue that it operates to a backdrop of the routinization of social life and operates from within and not outside of habitus. We highlight the role of the breach in reflexivity, suggesting that it opens up a critical window for agents to initiate change. The article suggests caution in over-ascribing reflexivity to agency, instead arguing that achieving reflexivity and change is a difficult and fraught process, which has emotional and moral consequences. The effect of this is that people often prefer the status quo, rather than to risk change and uncertainty. © London School of Economics and Political Science 2015.

Analysis of factors related to vagally mediated reflex bradycardia during gastrectomy.

PubMed

Kim, Duk-Kyung; Ahn, Hyun Joo; Lee, Seung Won; Choi, Ji Won

2015-12-01

Because vagally mediated reflex bradycardia occurs frequently during gastrectomy and is potentially harmful, we compared the incidence of clinically significant reflex bradycardia between patients undergoing laparoscopic gastrectomy (LG) and open gastrectomy (OG) and examined whether the type of surgery (OG vs. LG) was an independent risk factor for clinically significant reflex bradycardia. This prospective observational study evaluated 358 adult patients (age 18-70 years) who were undergoing elective OG or LG for gastric cancer resection. Symptomatic reflex bradycardia was defined as a sudden decrease in heart rate to <50 beats per minute (bpm), or to 50-59 bpm with a systolic blood pressure <70 mmHg, associated with a specific surgical maneuver. If bradycardia or hypotension developed, atropine or ephedrine was administered, in accordance with a predefined treatment protocol. The overall incidence of symptomatic reflex bradycardia was 24.6% (88/358). Univariate analysis revealed the incidence of symptomatic reflex bradycardia in the LG group was significantly lower than that in the OG group [13.0% (13/100) vs. 29.1% (75/258), p = 0.002]. Multivariate logistic regression analysis revealed that the type of surgery (OG vs. LG), advanced age, preoperative bradycardia, type of muscle relaxant (vecuronium vs. rocuronium), no use of intravenous remifentanil, and low core temperature, were independent risk factors for symptomatic reflex bradycardia (odds ratio 3.184; 95% confidence interval 1.490-6.800; p = 0.003). The LG approach was associated with a reduced risk of clinically significant reflex bradycardia compared with the OG approach.

VizieR Online Data Catalog: RefleX : X-ray-tracing code (Paltani+, 2017)

NASA Astrophysics Data System (ADS)

Paltani, S.; Ricci, C.

2017-11-01

We provide here the RefleX executable, for both Linux and MacOSX, together with the User Manual and example script file and output file Running (for instance): reflex_linux will produce the file reflex.out Note that the results may differ slightly depending on the OS, because of slight differences in some implementations numerical computations. The difference are scientifically meaningless. (5 data files).

The vestibulosympathetic reflex in humans: neural interactions between cardiovascular reflexes

NASA Technical Reports Server (NTRS)

Ray, Chester A.; Monahan, Kevin D.

2002-01-01

1. Over the past 5 years, there has been emerging evidence that the vestibular system regulates sympathetic nerve activity in humans. We have studied this issue in humans by using head-down rotation (HDR) in the prone position. 2. These studies have clearly demonstrated increases in muscle sympathetic nerve activity (MSNA) and calf vascular resistance during HDR. These responses are mediated by engagement of the otolith organs and not the semicircular canals. 3. However, differential activation of sympathetic nerve activity has been observed during HDR. Unlike MSNA, skin sympathetic nerve activity does not increase with HDR. 4. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes (i.e. barorereflexes and skeletal muscle reflexes) has shown an additive interaction for MSNA. 5. The additive interaction between the baroreflexes and vestibulosympathetic reflex suggests that the vestibular system may assist in defending against orthostatic challenges in humans by elevating MSNA beyond that of the baroreflexes. 6. In addition, the further increase in MSNA via otolith stimulation during isometric handgrip, when arterial pressure is elevated markedly, indicates that the vestibulosympathetic reflex is a powerful activator of MSNA and may contribute to blood pressure and flow regulation during dynamic exercise. 7. Future studies will help evaluate the importance of the vestibulosympathetic reflex in clinical conditions associated with orthostatic hypotension.

Adaptation to sensory-motor reflex perturbations is blind to the source of errors.

PubMed

Hudson, Todd E; Landy, Michael S

2012-01-06

In the study of visual-motor control, perhaps the most familiar findings involve adaptation to externally imposed movement errors. Theories of visual-motor adaptation based on optimal information processing suppose that the nervous system identifies the sources of errors to effect the most efficient adaptive response. We report two experiments using a novel perturbation based on stimulating a visually induced reflex in the reaching arm. Unlike adaptation to an external force, our method induces a perturbing reflex within the motor system itself, i.e., perturbing forces are self-generated. This novel method allows a test of the theory that error source information is used to generate an optimal adaptive response. If the self-generated source of the visually induced reflex perturbation is identified, the optimal response will be via reflex gain control. If the source is not identified, a compensatory force should be generated to counteract the reflex. Gain control is the optimal response to reflex perturbation, both because energy cost and movement errors are minimized. Energy is conserved because neither reflex-induced nor compensatory forces are generated. Precision is maximized because endpoint variance is proportional to force production. We find evidence against source-identified adaptation in both experiments, suggesting that sensory-motor information processing is not always optimal.

The effect of operant-conditioning balance training on the down-regulation of spinal H-reflexes in a spastic patient.

PubMed

Hoseini, Najmeh; Koceja, David M; Riley, Zachary A

2011-10-24

Spasticity in chronic hemiparetic stroke patients has primarily been treated pharmacologically. However, there is increasing evidence that physical rehabilitation can help manage hyper-excitability of reflexes (hyperreflexia), which is a primary contributor to spasticity. In the present study, one chronic hemiparetic stroke patient operantly conditioned the soleus H-reflex while training on a balance board for two weeks. The results showed a minimal decrease in the Hmax-Mmax ratio for both the affected and unaffected limb, indicating that the H-reflex was not significantly altered with training. Alternatively, paired-reflex depression (PRD), a measure of history-dependent changes in reflex excitability, could be conditioned. This was evident by the rightward shift and decreased slope of reflex excitability in the affected limb. The non-affected limb decreased as well, although the non-affected limb was very sensitive to PRD initially, whereas the affected limb was not. Based on these results, it was concluded that PRD is a better index of hyperreflexia, and this measurement could be more informative of synapse function than simple H-reflexes. This study presents a novel and non-pharmacological means of managing spasticity that warrants further investigation with the potential of being translated to the clinic. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Generalized versus partial reflex seizures: a review.

PubMed

Italiano, Domenico; Ferlazzo, Edoardo; Gasparini, Sara; Spina, Edoardo; Mondello, Stefania; Labate, Angelo; Gambardella, Antonio; Aguglia, Umberto

2014-08-01

In this review we assess our currently available knowledge about reflex seizures with special emphasis on the difference between "generalized" reflex seizures induced by visual stimuli, thinking, praxis and language tasks, and "focal" seizures induced by startle, eating, music, hot water, somatosensory stimuli and orgasm. We discuss in particular evidence from animal, clinical, neurophysiological and neuroimaging studies supporting the concept that "generalized" reflex seizures, usually occurring in the setting of IGE, should be considered as focal seizures with quick secondary generalization. We also review recent advances in genetic and therapeutic approach of reflex seizures. Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Electromechanical analogs of human reflexes.

PubMed

Littman, M G; Liker, M; Stubbeman, W; Russakow, J; McGee, C; Gelfand, J; Call, B J

1989-01-01

The conclusion to be drawn from our modeling is that the combined stretch and tendon reflexes alone can endow artificial muscle with a springlike feel as well as give it a baseline tone. In response to questions that motor physiologists often ask as to what variables the system controls, the answer here is clear: the stretch and tendon reflexes act together to maintain both a tension set-point and a length set-point, but in so doing they also give the system a springlike feel because of the existence of a servo error. The main goal of our studies is to understand the integration of reflexes, and thus far we have only begun to explore the two lowest-level spinal reflexes. We are in the process of expanding this work by developing a much more refined arm explicitly modeled after the human arm. This new arm is to be activated by a minimum of 10 muscles, each of which is reflexively driven, and it will allow us to explore the integration of higher-level reflex action such as automatic inhibition of antagonists and facilitation of synergists.

Effects of ankle joint position and submaximal muscle contraction intensity on soleus H-reflex modulation in young and older adults.

PubMed

Chen, Yung-Sheng; Zhou, Shi; Cartwright, Colleen

2014-04-01

This study investigated the effects of ankle joint position and submaximal contraction intensity on soleus (SOL) H-reflex modulation. Twenty young (25.1 ± 4.8 years) and 20 older adults (74.2 ± 5.1 years) performed plantar flexions during 10%, 30% and 50% maximal voluntary contractions (MVC) and at ankle positions of neutral (0°), plantar flexion (20°) and dorsiflexion (-20°) in a sitting position. The SOL H-reflex gain in older adults was relatively lower than that in young adults during 10%, 30% and 50% MVC. The SOL H-reflex gain was significantly affected by the intensity of plantar flexion in the respective ankle joint position in both age groups. The latency of H-reflex was prolonged in older adults and was ankle joint dependent in young adults. Young adults demonstrated a shorter duration of the H-reflex response than that of older adults. The results indicated that there were age-related changes in the SOL H-reflex during the ankle plantar flexors activities.

Acoustic Reflexes in Normal-Hearing Adults, Typically Developing Children, and Children with Suspected Auditory Processing Disorder: Thresholds, Real-Ear Corrections, and the Role of Static Compliance on Estimates.

PubMed

Saxena, Udit; Allan, Chris; Allen, Prudence

2017-06-01

Previous studies have suggested elevated reflex thresholds in children with auditory processing disorders (APDs). However, some aspects of the child's ear such as ear canal volume and static compliance of the middle ear could possibly affect the measurements of reflex thresholds and thus impact its interpretation. Sound levels used to elicit reflexes in a child's ear may be higher than predicted by calibration in a standard 2-cc coupler, and lower static compliance could make visualization of very small changes in impedance at threshold difficult. For this purpose, it is important to evaluate threshold data with consideration of differences between children and adults. A set of studies were conducted. The first compared reflex thresholds obtained using standard clinical procedures in children with suspected APD to that of typically developing children and adults to test the replicability of previous studies. The second study examined the impact of ear canal volume on estimates of reflex thresholds by applying real-ear corrections. Lastly, the relationship between static compliance and reflex threshold estimates was explored. The research is a set of case-control studies with a repeated measures design. The first study included data from 20 normal-hearing adults, 28 typically developing children, and 66 children suspected of having an APD. The second study included 28 normal-hearing adults and 30 typically developing children. In the first study, crossed and uncrossed reflex thresholds were measured in 5-dB step size. Reflex thresholds were analyzed using repeated measures analysis of variance (RM-ANOVA). In the second study, uncrossed reflex thresholds, real-ear correction, ear canal volume, and static compliance were measured. Reflex thresholds were measured using a 1-dB step size. The effect of real-ear correction and static compliance on reflex threshold was examined using RM-ANOVA and Pearson correlation coefficient, respectively. Study 1 replicated previous studies showing elevated reflex thresholds in many children with suspected APD when compared to data from adults using standard clinical procedures, especially in the crossed condition. The thresholds measured in children with suspected APD tended to be higher than those measured in the typically developing children. There were no significant differences between the typically developing children and adults. However, when real-ear calibrated stimulus levels were used, it was found that children's thresholds were elicited at higher levels than in the adults. A significant relationship between reflex thresholds and static compliance was found in the adult data, showing a trend for higher thresholds in ears with lower static compliance, but no such relationship was found in the data from the children. This study suggests that reflex measures in children should be adjusted for real-ear-to-coupler differences before interpretation. The data in children with suspected APD support previous studies suggesting abnormalities in reflex thresholds. The lack of correlation between threshold and static compliance estimates in children as was observed in the adults may suggest a nonmechanical explanation for age and clinically related effects. American Academy of Audiology

What is a reflex? A guide for understanding disorders of consciousness.

PubMed

Fischer, David B; Truog, Robert D

2015-08-11

Uncertainty in diagnosing disorders of consciousness, and specifically in determining whether consciousness has been lost or retained, poses challenging scientific and ethical questions. Recent neuroimaging-based tests for consciousness have cast doubt on the reliability of behavioral criteria in assessing states of consciousness and generate new questions about the assumptions used in formulating coherent diagnostic criteria. The reflex, a foundational diagnostic tool, offers unique insight into these disorders; behaviors produced by unconscious patients are thought to be purely reflexive, whereas those produced by conscious patients can be volitional. Further investigation, however, reveals that reflexes cannot be reliably distinguished from conscious behaviors on the basis of any generalizable empirical characteristics. Ambiguity between reflexive and conscious behaviors undermines the capacity of the reflex to distinguish between disorders of consciousness and has implications for how these disorders should be conceptualized in future diagnostic criteria. © 2015 American Academy of Neurology.

When planning results in loss of control: intention-based reflexivity and working-memory

PubMed Central

Meiran, Nachshon; Cole, Michael W.; Braver, Todd S.

2012-01-01

In this review, the authors discuss the seemingly paradoxical loss of control associated with states of high readiness to execute a plan, termed “intention-based reflexivity.” The review suggests that the neuro-cognitive systems involved in the preparation of novel plans are different than those involved in preparation of practiced plans (i.e., those that have been executed beforehand). When the plans are practiced, intention-based reflexivity depends on the prior availability of response codes in long-term memory (LTM). When the plans are novel, reflexivity is observed when the plan is pending and the goal has not yet been achieved. Intention-based reflexivity also depends on the availability of working-memory (WM) limited resources and the motivation to prepare. Reflexivity is probably related to the fact that, unlike reactive control (once a plan is prepared), proactive control tends to be relatively rigid. PMID:22586382

An Intelligent Computerized Stretch Reflex Measurement System For Clinical And Investigative Neurology

NASA Astrophysics Data System (ADS)

Flanagan, P. M.; Chutkow, J. G.; Riggs, M. T.; Cristiano, V. D.

1987-05-01

We describe the design of a reliable, user-friendly preprototype system for quantifying the tendon stretch reflexes in humans and large mammals. A hand-held, instrumented reflex gun, the impactor of which contains a single force sensor, interfaces with a computer. The resulting test system can deliver sequences of reproducible stimuli at graded intensities and adjustable durations to a muscle's tendon ("tendon taps"), measure the impacting force of each tap, and record the subsequent reflex muscle contraction from the same tendon -- all automatically. The parameters of the reflex muscle contraction include latency; mechanical threshold; and peak time, peak magnitude, and settling time. The results of clinical tests presented in this paper illustrate the system's potential usefulness in detecting neurologic dysfunction affecting the tendon stretch reflexes, in documenting the course of neurologic illnesses and their response to therapy, and in clinical and laboratory neurologic research.

Spasticity therapy reacts to astrocyte GluA1 receptor upregulation following spinal cord injury

PubMed Central

Gómez-Soriano, Julio; Goiriena, Eider; Taylor, Julian

2010-01-01

For almost three decades intrathecal baclofen therapy has been the standard treatment for spinal cord injury spasticity when oral medication is ineffective or produces serious side effects. Although intrathecal baclofen therapy has a good clinical benefit-risk ratio for spinal spasticity, tolerance and the life-threatening withdrawal syndrome present serious problems for its management. Now, in an experimental model of spinal cord injury spasticity, AMPA receptor blockade with NGX424 (Tezampanel) has been shown to reduce stretch reflex activity alone and during tolerance to intrathecal baclofen therapy. These results stem from the observation that GluA1 receptors are overexpressed on reactive astrocytes following experimental ischaemic spinal cord injury. Although further validation is required, the appropriate choice of AMPA receptor antagonists for treatment of stretch hyperreflexia based on our recent understanding of reactive astrocyte neurobiology following spinal cord injury may lead to the development of a better adjunct clinical therapy for spasticity without the side effects of intrathecal baclofen therapy. LINKED ARTICLE This article is a commentary on Oshiro et al., pp. 976–985 of this issue. To view this paper visit http://dx.doi.org/10.1111/j.1476-5381.2010.00954.x PMID:20662840

AnimatLab: a 3D graphics environment for neuromechanical simulations.

PubMed

Cofer, David; Cymbalyuk, Gennady; Reid, James; Zhu, Ying; Heitler, William J; Edwards, Donald H

2010-03-30

The nervous systems of animals evolved to exert dynamic control of behavior in response to the needs of the animal and changing signals from the environment. To understand the mechanisms of dynamic control requires a means of predicting how individual neural and body elements will interact to produce the performance of the entire system. AnimatLab is a software tool that provides an approach to this problem through computer simulation. AnimatLab enables a computational model of an animal's body to be constructed from simple building blocks, situated in a virtual 3D world subject to the laws of physics, and controlled by the activity of a multicellular, multicompartment neural circuit. Sensor receptors on the body surface and inside the body respond to external and internal signals and then excite central neurons, while motor neurons activate Hill muscle models that span the joints and generate movement. AnimatLab provides a common neuromechanical simulation environment in which to construct and test models of any skeletal animal, vertebrate or invertebrate. The use of AnimatLab is demonstrated in a neuromechanical simulation of human arm flexion and the myotactic and contact-withdrawal reflexes. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Traumatic L7 articular processes fracture and spondylolisthesis following dorsal lumbosacral laminectomy in a cat

PubMed Central

Montoliu, Patricia; López, Marta; Mascort, Joan; Morales, Carles

2018-01-01

Case summary A 12-year-old neutered male domestic shorthair cat was presented to our referral hospital with a chronic history of tenesmus and lumbosacral pain. A diagnosis of degenerative lumbosacral stenosis (DLSS) was made and a standard dorsal L7–S1 laminectomy was performed uneventfully, with complete recovery within 1 month. The cat was brought back 4 months later for investigation of lumbosacral pain after having suffered a minor traumatic event. Neurological examination identified a low tail carriage, weakness, exercise intolerance, left pelvic limb lameness and diminished withdrawal reflexes in both pelvic limbs with severe sacrocaudal pain. A traumatic facet fracture of the L7 articular processes and subsequent spondylolisthesis was diagnosed. A second surgery was performed to stabilise the region. The cat was normal on neurological examination 1 month later and no further clinical signs were noted. Relevance and novel information This is the first description of a fracture and spondylolisthesis as a possible postoperative complication after L7–S1 dorsal laminectomy in a cat. The case highlights the importance of postoperative changes in the supportive structures of the lumbosacral spine in cats after surgical treatment of DLSS. PMID:29552353

Evaluation of the relation between triceps surae H-reflex, M-response latencies and thigh length in normal population.

PubMed

Khosrawi, Saeid; Fallah, Salman

2013-03-01

The H-reflex is a useful electrophysiological procedure for evaluating the status of the peripheral nervous system, especially at the proximal segment of the peripheral nerve. The purpose of this study is to investigate the relation between triceps surae H-reflex and M- response latencies and thigh length in normal population, in order to determine if there is any regression equation between them. After screening 75 volunteers by considering inclusion and exclusion criteria, 72 of them were selected to enroll into our study (34 men and 38 women with the mean age of 36.04 ± 7.7 years). In all of the subjects H-reflex and M-response latencies were recorded by standard electrophysiological techniques and thigh length was measured. Finally, our data was analyzed for its relations with respect to ages in both sexes by appropriate statistical and mathematical methods. Mean ± SD for H-reflex latency was 27.94 ± 1.6 ms. We found a significant correlation between H-reflex latency and M-latency (r = 0.28), no significant correlation was found between H-reflex latency and thigh length (r = -0.051). Finally based on our findings we introduce a new formula in this paper. We found a significant correlation among of M-response latency and other variables (H-reflex latency and thigh length). Despite this it was eliminated from our formula. The relationship between H-reflex latency and age was significant. Further studies are required to delineate the clinical usage and interpretation of the formula, which we found in this study.

Comparison of voluntary and reflex cough effectiveness in Parkinson’s disease

PubMed Central

Hegland, Karen Wheeler; Troche, Michelle S.; Brandimore, Alexandra E.; Davenport, Paul W.; Okun, Michael S.

2016-01-01

Introduction Multiple airway protective mechanisms are impacted with Parkinson’s disease (PD), including swallowing and cough. Cough serves to eject material from the lower airways, and can be produced voluntarily (on command) and reflexively in response to aspirate material or other airway irritants. Voluntary cough effectiveness is reduced in PD however it is not known whether reflex cough is affected as well. The goal of this study was to compare the effectiveness between voluntary and reflex cough in patients with idiopathic PD. Methods Twenty patients with idiopathic PD participated. Cough airflow data were recorded via facemask in line with a pneumotachograph. A side delivery port connected the nebulizer for delivery of capsaicin, which was used to induce cough. Three voluntary coughs and three reflex coughs were analyzed from each participant. A two-way repeated measures analysis of variance was used to compare voluntary versus reflex cough airflow parameters. Results Significant differences were found for peak expiratory flow rate (PEFR) and cough expired volume (CEV) between voluntary and reflex cough. Specifically, both PEFR and CEV were reduced for reflex as compared to voluntary cough. Conclusion Cough PEFR and CEV are indicative of cough effectiveness in terms of the ability to remove material from the lower airways. Differences between these two cough types likely reflect differences in the coordination of the respiratory and laryngeal subsystems. Clinicians should be aware that evaluation of cough function using voluntary cough tasks overestimates the PEFR and CEV that would be achieved during reflex cough in patients with PD. PMID:25246315

[Comparative study on the reflex responses of carotid and aortic baroreceptors in the rabbit].

PubMed

Li, Z; Ho, S Y

1989-08-01

In 81 anesthetized rabbits, the baroreflex control of heart rate (HR), hind-limb vascular resistance (HVR) and renal sympathetic nerve activity (RSNA) was observed during arterial baroreceptor loading and unloading by intravenously injecting phenylephrine (PE) and nitroprusside (NP). The results were as follows: (1) An increase of arterial pressure with PE caused reduction in HR, HVR and RSNA, while a decrease of arterial pressure with NP evoked opposite responses. These reflex responses were reproducible. (2) By either carotid baroreceptor denervation (CBRX) or aortic baroreceptor denervation (ABRX), the reflex changes of HR induced by injecting PE and NP were impaired (P less than 0.01), while the reflex responses in HVP remained unchanged. Despite of the enhanced basal RSNA following ABRX or CBRX, the magnitude of reflex inhibition in RSNA during injecting NP was similar to that before denervation, whereas that of the reflex excitation in RSNA during injecting NP was reduced (P less than 0.05). (3) After complete sino-aortic denervation (SAD), the change of arterial pressure following PE or NP injection was enhanced, but the reflex changes in HR, HVR and RSNA were significantly diminished (P less than 0.001). (4) Vagotomy abolished the residual reflex changes observed after SAD. The results indicate that the aortic and carotid baroreceptors may regulate HR in a simple additive manner, while the aortic baroreceptor seems to be more important. Furthermore, both the aortic and carotid baroreceptors may play important roles for the reflex control of HVR and RSNA, and operate mutually by the way of inhibitory summation.

Needle lost in minimally invasive surgery: management proposal and literature review.

PubMed

Medina, Luis G; Martin, Oscar; Cacciamani, Giovannni E; Ahmadi, Nariman; Castro, Juan C; Sotelo, Rene

2018-03-19

The reported incidence of intraoperative retained instruments, such as needles, hangs around 0.06-0.11%. Leaving a needle inside the abdominal cavity can have significant medical and legal consequences. In addition, the retrieval can be hampered due to the limited visualization of the scope during minimally invasive surgery. Factors associated with an increased probability for NL have been described. Prevention for this situation includes: having one needle at a time inside the cavity, effective communication between all personnel in the operating room, evaluation of the strength of the suture-needle connection, avoid parking of needles intraoperatively, and a proper needle withdrawal. Notwithstanding, no agreement has been made regarding NL management. Herein, we present a literature review, and a management proposal in which through a series of systematic steps, the surgical team can efficiently locate and retrieve a lost needle such as: examination of the surgical field, trocar visualization, trocar disassembly, and revision of the suction device. Finally, intraoperative or postoperative imaging can be utilized.

The Dynamics of Successive Induction in Larval Zebrafish

EPA Science Inventory

Charles Sherrington identified the properties of the synapse by purely behavioral means the study of reflexes -more than 100 years ago. They were subsequently confirmed neurophysiologically. Studying reflex interaction, he also showed that activating one reflex often facilitates...

Activity in the primary somatosensory cortex induced by reflexological stimulation is unaffected by pseudo-information: a functional magnetic resonance imaging study

PubMed Central

2013-01-01

Background Reflexology is an alternative medical practice that produces beneficial effects by applying pressure to specific reflex areas. Our previous study suggested that reflexological stimulation induced cortical activation in somatosensory cortex corresponding to the stimulated reflex area; however, we could not rule out the possibility of a placebo effect resulting from instructions given during the experimental task. We used functional magnetic resonance imaging (fMRI) to investigate how reflexological stimulation of the reflex area is processed in the primary somatosensory cortex when correct and pseudo-information about the reflex area is provided. Furthermore, the laterality of activation to the reflexological stimulation was investigated. Methods Thirty-two healthy Japanese volunteers participated. The experiment followed a double-blind design. Half of the subjects received correct information, that the base of the second toe was the eye reflex area, and pseudo-information, that the base of the third toe was the shoulder reflex area. The other half of the subjects received the opposite information. fMRI time series data were acquired during reflexological stimulation to both feet. The experimenter stimulated each reflex area in accordance with an auditory cue. The fMRI data were analyzed using a conventional two-stage approach. The hemodynamic responses produced by the stimulation of each reflex area were assessed using a general linear model on an intra-subject basis, and a two-way repeated-measures analysis of variance was performed on an intersubject basis to determine the effect of reflex area laterality and information accuracy. Results Our results indicated that stimulation of the eye reflex area in either foot induced activity in the left middle postcentral gyrus, the area to which tactile sensation to the face projects, as well as in the postcentral gyrus contralateral foot representation area. This activity was not affected by pseudo information. The results also indicate that the relationship between the reflex area and the projection to the primary somatosensory cortex has a lateral pattern that differs from that of the actual somatotopical representation of the body. Conclusion These findings suggest that a robust relationship exists between neural processing of somatosensory percepts for reflexological stimulation and the tactile sensation of a specific reflex area. PMID:23711332

Child-Computer Interaction at the Beginner Stage of Music Learning: Effects of Reflexive Interaction on Children's Musical Improvisation.

PubMed

Addessi, Anna Rita; Anelli, Filomena; Benghi, Diber; Friberg, Anders

2017-01-01

In this article children's musical improvisation is investigated through the "reflexive interaction" paradigm. We used a particular system, the MIROR-Impro, implemented in the framework of the MIROR project (EC-FP7), which is able to reply to the child playing a keyboard by a "reflexive" output, mirroring (with repetitions and variations) her/his inputs. The study was conducted in a public primary school, with 47 children, aged 6-7. The experimental design used the convergence procedure, based on three sample groups allowing us to verify if the reflexive interaction using the MIROR-Impro is necessary and/or sufficient to improve the children's abilities to improvise. The following conditions were used as independent variables: to play only the keyboard, the keyboard with the MIROR-Impro but with not-reflexive reply, the keyboard with the MIROR-Impro with reflexive reply. As dependent variables we estimated the children's ability to improvise in solos, and in duets. Each child carried out a training program consisting of 5 weekly individual 12 min sessions. The control group played the complete package of independent variables; Experimental Group 1 played the keyboard and the keyboard with the MIROR-Impro with not-reflexive reply; Experimental Group 2 played only the keyboard with the reflexive system. One week after, the children were asked to improvise a musical piece on the keyboard alone (Solo task), and in pairs with a friend (Duet task). Three independent judges assessed the Solo and the Duet tasks by means of a grid based on the TAI-Test for Ability to Improvise rating scale. The EG2, which trained only with the reflexive system, reached the highest average results and the difference with EG1, which did not used the reflexive system, is statistically significant when the children improvise in a duet. The results indicate that in the sample of participants the reflexive interaction alone could be sufficient to increase the improvisational skills, and necessary when they improvise in duets. However, these results are in general not statistically significant. The correlation between Reflexive Interaction and the ability to improvise is statistically significant. The results are discussed on the light of the recent literature in neuroscience and music education.

The Middle Ear Muscle Reflex in Rat: Developing a Biomarker of Auditory Nerve Degeneration.

PubMed

Chertoff, Mark E; Martz, Ashley; Sakumura, Joey T; Kamerer, Aryn M; Diaz, Francisco

The long-term goal of this research is to determine whether the middle ear muscle reflex can be used to predict the number of healthy auditory nerve fibers in hearing-impaired ears. In this study, we develop a high-impedance source and an animal model of the middle ear muscle reflex and explore the influence of signal frequency and level on parameters of the reflex to determine an optimal signal to examine auditory nerve fiber survival. A high-impedance source was developed using a hearing aid receiver attached to a 0.06 diameter 10.5-cm length tube. The impedance probe consisted of a microphone probe placed near the tip of a tube coupled to a sound source. The probe was calibrated by inserting it into a syringe of known volumes and impedances. The reflex in the anesthetized rat was measured with elicitor stimuli ranging from 3 to 16 kHz presented at levels ranging from 35 to 100 dB SPL to one ear while the reflex was measured in the opposite ear containing the probe and probe stimulus. The amplitude of the reflex increased with elicitor level and was largest at 3 kHz. The lowest threshold was approximately 54 dB SPL for the 3-kHz stimulus. The rate of decay of the reflex was greatest at 16 kHz followed by 10 and 3 kHz. The rate of decay did not change significantly with elicitor signal level for 3 and 16 kHz, but decreased as the level of the 10-kHz elicitor increased. A negative feedback model accounts for the reflex decay by having the strength of feedback dependent on auditory nerve input. The rise time of the reflex varied with frequency and changed with level for the 10- and 16-kHz signals but not significantly for the 3-kHz signal. The latency of the reflex increased with a decrease in elicitor level, and the change in latency with level was largest for the 10-kHz stimulus. Because the amplitude of the reflex in rat was largest with an elicitor signal at 3 kHz, had the lowest threshold, and yielded the least amount of decay, this may be the ideal frequency to estimate auditory nerve survival in hearing-impaired ears.

Portraying Reflexivity in Health Services Research.

PubMed

Rae, John; Green, Bill

2016-09-01

A model is proposed for supporting reflexivity in qualitative health research, informed by arguments from Bourdieu and Finlay. Bourdieu refers to mastering the subjective relation to the object at three levels-the overall social space, the field of specialists, and the scholastic universe. The model overlays Bourdieu's levels of objectivation with Finlay's three stages of research (pre-research, data collection, and data analysis). The intersections of these two ways of considering reflexivity, displayed as cells of a matrix, pose questions and offer prompts to productively challenge health researchers' reflexivity. Portraiture is used to show how these challenges and prompts can facilitate such reflexivity, as illustrated in a research project. © The Author(s) 2016.

Charitable giving and reflexive individuals: How personal reflexivity mediates between structure and agency

PubMed Central

Sanghera, Balihar

2016-01-01

This article examines how individuals are reflexive beings who interpret the world in relation to things that matter to them, and how charitable acts are evaluated and embedded in their lives with different degrees of meaning and importance. Rather than framing the discussion of charitable practices in terms of an altruism/egoism binary or imputing motivations and values to social structures, the article explains how reflexivity is an important and neglected dimension of social practices, and how it interacts with sympathy, sentiments and discourses to shape giving. The study also shows that there are different modes of reflexivity, which have varied effects on charity and volunteering. PMID:28232772

Underwater Noise and the Conservation of Divers’ Hearing: A Review. Volume 1

DTIC Science & Technology

1989-10-01

reflex attenuation, since the tensor tympani is unaffected and since Bell ’ palsy may affect the VIIIth (auditory) nerve as well as the VIlth (facial...studied acoustic reflexes in patients with acute facial nerve paralysis (Bell’s palsy ). These patients had absent stapedius reflexes on the side of the...voluntary middle ear muscle activation. 24 Bell’s palsy cases; attenuation estimated by shift in reflex amplitude- intensity functions (contralateral), re

Assessment of H reflex sensitivity with M wave alternation consequent to fatiguing contractions.

PubMed

Hwang, Ing-Shiou; Huang, Cheng-Ya; Wu, Pei-Shan; Chen, Yi-Ching; Wang, Chun-Hou

2008-09-01

The objective of this study was to examine the changes in H reflex sensitivity after neuromuscular fatigue associated with fluctuations of the M wave. In the maximal and submaximal voluntary contraction (MVC and SMVC) paradigms, subjects performed voluntary plantarflexion at 100% MVC and 40% MVC respectively until the limit of torque maintenance was reached. In the submaximal electrical stimulation (SMES) paradigm, the tricep surae was exhausted with sustained electrical stimulation of 40% of the maximal tolerable intensity at a 40-Hz stimulus rate. The H reflexes and maximal M waves (M(max)) of the soleus were recorded before and after the three fatigue paradigms, and the H reflex was standardized with M(max) to minimize possible bias due to fatigue-induced M wave fluctuation. The results showed a significant increase in the standardized H reflex due to the SMES paradigm in spite of M(max) potentiation. The SMVC paradigm led to a reduction in size of the standardized H reflex without modification of M(max), whereas the standardized H reflex was not mediated by the MVC paradigm, which contributed to a noticeable M(max) potentiation. The present study underscored the fact that the H reflex sensitivity and M wave amplitude were not necessarily suppressed consequent to neuromuscular fatigue, but varied with the activation history of a muscle for size-dependent efficacy of the Ia transmission pathways and postactivation potentiation.

Correlations between grasp-reflex strengths and serum thyroid-hormone levels depending upon sex and familial sinistrality in human neonates: importance of genetically predetermined cerebral organization.

PubMed

Tan, U

1994-03-01

Relations of grasp-reflex strengths to serum free-thyroid hormone levels were studied in human neonates. In right-dominant (RH) males and females without familial sinistrality (-FS), grasp-reflex strengths from right (R) and left (L) inversely correlated with serum triiodothyronine (T3). In RH, +FS males, grasp-reflex strengths from R and L hands directly correlated with T3 (no correlations in RH, +FS females). There was no significant correlation between grasp reflex and T3 in non-right-handed (NRH), -FS neonates. In NRH +FS neonates, there was a significant negative linear correlation between grasp reflex from left and T3 only in NRH, +FS males. The following correlations were found between grasp reflex and thyroxine (T4): direct relation in RH, +FS males and females; inverse relation in NRH, -FS females only for the right hand; inverse correlations in NRH, +FS females. The R-L grasp reflex directly correlated with T3 in RH, -FS males, and inversely correlated with T3 in RH, -FS females (no significant correlations in others). These results indicated that thyroid hormones may influence cerebral maturation and lateralization differentially according to genetically predetermined cerebral organization. The generalizations of the hormonal effects on, at least, cerebral functioning would be wrong, if the genetically predetermined main features of the brain are neglected.

The Neuroanatomical Correlates of Training-Related Perceptuo-Reflex Uncoupling in Dancers

PubMed Central

Nigmatullina, Yuliya; Hellyer, Peter J.; Nachev, Parashkev; Sharp, David J.; Seemungal, Barry M.

2015-01-01

Sensory input evokes low-order reflexes and higher-order perceptual responses. Vestibular stimulation elicits vestibular-ocular reflex (VOR) and self-motion perception (e.g., vertigo) whose response durations are normally equal. Adaptation to repeated whole-body rotations, for example, ballet training, is known to reduce vestibular responses. We investigated the neuroanatomical correlates of vestibular perceptuo-reflex adaptation in ballet dancers and controls. Dancers' vestibular-reflex and perceptual responses to whole-body yaw-plane step rotations were: (1) Briefer and (2) uncorrelated (controls' reflex and perception were correlated). Voxel-based morphometry showed a selective gray matter (GM) reduction in dancers' vestibular cerebellum correlating with ballet experience. Dancers' vestibular cerebellar GM density reduction was related to shorter perceptual responses (i.e. positively correlated) but longer VOR duration (negatively correlated). Contrastingly, controls' vestibular cerebellar GM density negatively correlated with perception and VOR. Diffusion-tensor imaging showed that cerebral cortex white matter (WM) microstructure correlated with vestibular perception but only in controls. In summary, dancers display vestibular perceptuo-reflex dissociation with the neuronatomical correlate localized to the vestibular cerebellum. Controls' robust vestibular perception correlated with a cortical WM network conspicuously absent in dancers. Since primary vestibular afferents synapse in the vestibular cerebellum, we speculate that a cerebellar gating of perceptual signals to cortical regions mediates the training-related attenuation of vestibular perception and perceptuo-reflex uncoupling. PMID:24072889

Cutaneous inputs from the back abolish locomotor-like activity and reduce spastic-like activity in the adult cat following complete spinal cord injury

PubMed Central

Frigon, Alain; Thibaudier, Yann; Johnson, Michael D.; Heckman, C.J.; Hurteau, Marie-France

2012-01-01

Spasticity is a condition that can include increased muscle tone, clonus, spasms, and hyperreflexia. In this study, we report the effect of manually stimulating the dorsal lumbosacral skin on spontaneous locomotor-like activity and on a variety of reflex responses in 5 decerebrate chronic spinal cats treated with clonidine. Cats were spinalized 1 month before the terminal experiment. Stretch reflexes were evoked by stretching the left triceps surae muscles. Crossed reflexes were elicited by electrically stimulating the right tibial or superficial peroneal nerves. Windup of reflex responses was evoked by electrically stimulating the left tibial or superficial peroneal nerves. We found that pinching the skin of the back abolished spontaneous locomotor-like activity. We also found that back pinch abolished the rhythmic activity observed during reflex testing without eliminating the reflex responses. Some of the rhythmic episodes of activity observed during reflex testing were consistent with clonus with an oscillation frequency greater than 3 Hz. Pinching the skin of the back effectively abolished rhythmic activity occurring spontaneously or evoked during reflex testing, irrespective of oscillation frequency. The results are consistent with the hypothesis that locomotion and clonus are produced by common central pattern-generators. Stimulating the skin of the back could prove helpful in managing undesired rhythmic activity in spinal cord-injured humans. PMID:22487200

Emotion, reflexivity and social change in the era of extreme fossil fuels.

PubMed

Davidson, Debra J

2018-05-09

Reflexivity is an important sociological lens through which to examine the means by which people engage in actions that contribute to social reproduction or social elaboration. Reflexivity theorists have largely overlooked the central place of emotions in reflexive processing, however, thus missing opportunities to enhance our understanding of reflexivity by capitalizing on recent scholarship on emotions emanating from other fields of inquiry. This paper explores the role of emotion in reflexivity, with a qualitative analysis of social responses to hydraulic fracturing in Alberta, Canada, utilizing narrative analysis of long-form interviews with rural landowners who have experienced direct impacts from hydraulic fracturing, and have attempted to voice their concerns in the public sphere. Based on interviews with a selection of two interview participants, the paper highlights the means by which emotions shape reflexivity in consequential ways, beginning with personal and highly individualized emotional responses to contingent situations, which then factor into the social interactions engaged in the pursuit of personal projects. The shared emotional context that emerges then plays a substantial role in shaping outcomes and their implications for social stasis or change. This study exemplifies the extent to which reflexive processing in response to breaches in the social order can be emotionally tumultuous affairs, constituting a significant personal toll that many may be unwilling to pay. © London School of Economics and Political Science 2018.

Modulation of H-Reflex Depression with Paired-Pulse Stimulation in Healthy Active Humans.

PubMed

Oza, Preeti D; Dudley-Javoroski, Shauna; Shields, Richard K

2017-01-01

Depression of the Hoffman reflex (H-reflex) is used to examine spinal control mechanisms during exercise, fatigue, and vibration and in response to training. H-reflex depression protocols frequently use trains of stimuli; this is time-consuming and prevents instantaneous assessment of motor neuronal excitability. The purpose of this study was to determine if paired-pulse H-reflex depression is reproducible and whether paired-pulse stimulation adequately estimates the depression induced by the more traditional ten-pulse train. H-reflexes were elicited via ten-pulse trains at 0.1, 0.2, 1, 2, and 5 Hz in ten neurologically intact individuals on two separate days. We measured the depression elicited by the second pulse (H2) and the mean depression elicited by pulses 2-10 (Hmean). H2 was consistent at all frequencies on both days ( r 2 = 0.97, p < 0.05, and ICC (3,1) = 0.81). H2 did not differ from Hmean ( p > 0.05). The results indicate that paired-pulse H-reflex depression has high between-day reliability and yields depression estimates that are comparable to those obtained via ten-pulse trains. Paired-pulse H-reflex depression may be especially useful for studies that require rapid assessment of motor neuronal excitability, such as during exercise, fatigue, and vibration, or to establish recovery curves following inhibition.

Estimated use of water in the United States in 2015

USGS Publications Warehouse

Dieter, Cheryl A.; Maupin, Molly A.; Caldwell, Rodney R.; Harris, Melissa A.; Ivahnenko, Tamara I.; Lovelace, John K.; Barber, Nancy L.; Linsey, Kristin S.

2018-06-19

Water use in the United States in 2015 was estimated to be about 322 billion gallons per day (Bgal/d), which was 9 percent less than in 2010. The 2015 estimates put total withdrawals at the lowest level since before 1970, following the same overall trend of decreasing total withdrawals observed from 2005 to 2010. Freshwater withdrawals were 281 Bgal/d, or 87 percent of total withdrawals, and saline-water withdrawals were 41.0 Bgal/d, or 13 percent of total withdrawals. Fresh surface-water withdrawals (198 Bgal/d) were 14 percent less than in 2010, and fresh groundwater withdrawals (82.3 Bgal/day) were about 8 percent greater than in 2010. Saline surface-water withdrawals were 38.6 Bgal/d, or 14 percent less than in 2010. Total saline groundwater withdrawals in 2015 were 2.34 Bgal/d, mostly for mining use.Thermoelectric power and irrigation remained the two largest uses of water in 2015, and total withdrawals decreased for thermoelectric power but increased for irrigation. With­drawals in 2015 for thermoelectric power were 18 percent less and withdrawals for irrigation were 2 percent greater than in 2010. Similarly, other uses showed reductions compared to 2010, specifically public supply (–7 percent), self-supplied domestic (–8 percent), self-supplied industrial (–9 percent), and aquaculture (–16 percent). In addition to irrigation (2 percent), mining (1 percent) reported larger withdrawals in 2015 than in 2010. Livestock withdrawals remained essentially the same in 2015 compared to 2010 (0 percent change). Thermoelectric power, irrigation, and public-supply withdrawals accounted for 90 percent of total withdrawals in 2015.Withdrawals for thermoelectric power were 133 Bgal/d in 2015 and represented the lowest levels since before 1970. Surface-water withdrawals accounted for more than 99 percent of total thermoelectric-power withdrawals, and 72 percent of those surface-water withdrawals were from freshwater sources. Saline surface-water withdrawals for thermoelectric power accounted for 97 percent of total saline surface-water withdrawals for all uses. Thermoelectric-power withdrawals accounted for 41 percent of total withdrawals for all uses, and freshwater withdrawals for thermoelectric power accounted for 34 percent of the total freshwater withdrawals for all uses. Total consumptive use for thermoelectric power was 4.31 Bgal/d in 2015 or 3 percent of the total thermoelectric-power withdrawals.Irrigation withdrawals were 118 Bgal/d in 2015, an increase of 2 percent from 2010 (116 Bgal/d), but were approximately equal to withdrawals estimated in the 1960s. Irrigation withdrawals, all freshwater, accounted for 42 percent of total freshwater withdrawals for all uses and 64 percent of total freshwater withdrawals for all uses excluding thermoelectric power. Surface-water withdrawals (60.9 Bgal/d) accounted for 52 percent of the total irrigation withdrawals, or about 8 percent less than in 2010. Ground­water withdrawals for irrigation were 57.2 Bgal/d in 2015, about 16 percent more than in 2010. About 63,500 thousand acres (or 63.5 million acres) were irrigated in 2015, an increase from 2010 of about 1,130 thousand acres (2 percent). The number of acres irrigated using sprinkler and microirrigation systems accounted for 63 percent of the total irrigated lands in 2015. Total consumptive use for irrigation was 73.2 Bgal/d in 2015 or 62 percent of the total use (withdrawals and reclaimed wastewater).Public-supply withdrawals in 2015 were 39.0 Bgal/d, or 7 percent less than in 2010, continuing the declines observed from 2005 to 2010. Total population in the United States increased from 312.6 million people in 2010 to 325.0 million people in 2015, an increase of 4 percent. Public-supply withdrawals accounted for 14 percent of the total freshwater withdrawals for all uses and 21 percent of freshwater with­drawals for all uses, excluding thermoelectric power. The number of people that received potable water from public-supply facilities in 2015 was 283 million, or about 87 percent of the total United States population. This percentage is 1 percent greater than in 2010. Self-supplied domestic withdrawals were 3.26 Bgal/d, or 8 percent less than in 2010. More than 98 percent of the self-supplied domestic withdrawals were from groundwater sources.Self-supplied industrial withdrawals were 14.8 Bgal/d in 2015, a 9 percent decline from 2010, continuing the downward trend since the peak of 47 Bgal/d in 1970. Total self-supplied industrial withdrawals were 5 percent of total withdrawals for all uses and 8 percent of total withdrawals for all uses, excluding thermoelectric power. Most of the total self-supplied industrial withdrawals were from surface-water sources (82 percent), and nearly all (94 percent) of those surface-water withdrawals were from freshwater sources. Nearly all of the groundwater withdrawals for self-supplied industrial use (98 percent) were from freshwater sources.Total aquaculture withdrawals were 7.55 Bgal/d in 2015, or 16 percent less than in 2010, and surface water was the primary source (79 percent). Most of the surface-water withdrawals occurred at facilities that operated flow-through raceways, which returned the water to the source directly after use. Aquaculture withdrawals accounted for 2 percent of the total withdrawals for all uses and 4 percent of the total withdrawals for all uses, excluding thermoelectric.Total mining withdrawals in 2015 were 4.00 Bgal/d, or about 1 percent of total withdrawals from all uses and 2 percent of total withdrawals from all uses, excluding thermoelectric. Mining withdrawals increased 1 percent from 2010 to 2015. Groundwater withdrawals accounted for 72 percent of the total mining withdrawals, and most of the groundwater was saline (65 percent). Most (77 percent) of the surface-water withdrawals for mining was freshwater.Livestock withdrawals in 2015 were 2.00 Bgal/d, the same as in 2010. All livestock withdrawals were from freshwater sources, mostly from groundwater (62 percent). Livestock withdrawals accounted for about 1 percent of total freshwater withdrawals for all uses, excluding thermoelectric power.In 2015, more than 50 percent of the total withdrawals in the United States were accounted for by 12 States (California, Texas, Idaho, Florida, Arkansas, New York, Illinois, Colorado, North Carolina, Michigan, Montana, and Nebraska). California accounted for almost 9 percent of the total withdrawals and 9 percent of freshwater withdrawals in the United States, predominantly for irrigation. Texas accounted for almost 7 percent of total withdrawals, predominantly for thermoelectric power, irrigation, and public supply. Florida accounted for 23 percent of the total saline-water withdrawals in the United States, mostly from surface-water sources for thermoelectric power. Texas and California accounted for 59 percent of the total saline groundwater withdrawals in the United States, mostly for mining.

Transient receptor potential ankyrin 1 mediates chronic pancreatitis pain in mice.

PubMed

Cattaruzza, Fiore; Johnson, Cali; Leggit, Alan; Grady, Eileen; Schenk, A Katrin; Cevikbas, Ferda; Cedron, Wendy; Bondada, Sandhya; Kirkwood, Rebekah; Malone, Brian; Steinhoff, Martin; Bunnett, Nigel; Kirkwood, Kimberly S

2013-06-01

Chronic pancreatitis (CP) is a devastating disease characterized by persistent and uncontrolled abdominal pain. Our lack of understanding is partially due to the lack of experimental models that mimic the human disease and also to the lack of validated behavioral measures of visceral pain. The ligand-gated cation channel transient receptor potential ankyrin 1 (TRPA1) mediates inflammation and pain in early experimental pancreatitis. It is unknown if TRPA1 causes fibrosis and sustained pancreatic pain. We induced CP by injecting the chemical agent trinitrobenzene sulfonic acid (TNBS), which causes severe acute pancreatitis, into the pancreatic duct of C57BL/6 trpa1(+/+) and trpa1(-/-) mice. Chronic inflammatory changes and pain behaviors were assessed after 2-3 wk. TNBS injection caused marked pancreatic fibrosis with increased collagen-staining intensity, atrophy, fatty replacement, monocyte infiltration, and pancreatic stellate cell activation, and these changes were reflected by increased histological damage scores. TNBS-injected animals showed mechanical hypersensitivity during von Frey filament probing of the abdomen, decreased daily voluntary wheel-running activity, and increased immobility scores during open-field testing. Pancreatic TNBS also reduced the threshold to hindpaw withdrawal to von Frey filament probing, suggesting central sensitization. Inflammatory changes and pain indexes were significantly reduced in trpa1(-/-) mice. In conclusion, we have characterized in mice a model of CP that resembles the human condition, with marked histological changes and behavioral measures of pain. We have demonstrated, using novel and objective pain measurements, that TRPA1 mediates inflammation and visceral hypersensitivity in CP and could be a therapeutic target for the treatment of sustained inflammatory abdominal pain.

Esophageal sensation in premature human neonates: temporal relationships and implications of aerodigestive reflexes and electrocortical arousals

PubMed Central

Parks, Vanessa N.; Peng, Juan; Dzodzomenyo, Samuel; Fernandez, Soledad; Shaker, Reza; Splaingard, Mark

2012-01-01

Electrocortical arousal (ECA) as an effect of visceral provocation or of its temporal relationships with aerodigestive reflexes in premature neonates is not known. We tested the hypothesis that esophageal provocation results in both esophageal reflex responses and ECAs during sleep and that ECAs are dependent on the frequency characteristics of esophageal neuromotor responses. We defined the spatiotemporal relationship of ECAs in relation to 1) spontaneous pharyngoesophageal swallow sequences and gastroesophageal reflux (GER) events and 2) sensory-motor characteristics of esophageal reflexes. Sixteen healthy premature neonates born at 27.9 ± 3.4 wk were tested at 36.8 ± 1.9 wk postmenstrual age. Ninety-five midesophageal and 31 sham stimuli were given in sleep during concurrent manometry and videopolysomnography. With stimulus onset as reference point, we scored the response latency, frequency occurrence and duration of arousals, peristaltic reflex, and upper esophageal sphincter contractile reflex (UESCR). Changes in polysomnography-respiratory patterns and esophageal sensory-motor parameters were scored by blinded observers. Significantly (for each characteristic listed, P < 0.05), swallow sequences were associated with arousals and sleep state changes, and arousals were associated with incomplete peristalsis, response delays to lower esophageal sphincter relaxation, and prolonged esophageal clearance. GER events (73.5%) provoked arousals, and arousals were associated with response delays to peristaltic reflexes or clearance, sleep state modification, and prolonged respiratory arousal. Midesophageal stimuli (54%) provoked arousals and were associated with increased frequency, prolonged latency, prolonged response duration of peristaltic reflexes and UESCR, and increased frequency of sleep state changes and respiratory arousals. In human neonates, ECAs are provoked upon esophageal stimulation; the sensory-motor characteristics of esophageal reflexes are distinct when accompanied by arousals. Aerodigestive homeostasis is defended by multiple tiers of aerodigestive safety mechanisms, and when esophageal reflexes are delayed, cortical hypervigilance (ECAs) occurs. PMID:21852361

Age-related differences in trunk muscle reflexive behaviors.

PubMed

Shojaei, Iman; Nussbaum, Maury A; Bazrgari, Babak

2016-10-03

Reports of larger passive and similar intrinsic trunk stiffness in older vs. younger populations suggest a diminishing demand for reflexive contributions of trunk muscles to spinal stability with aging. It remains unclear, though, whether such diminishing demands result in deterioration of trunk muscle reflexive behaviors. A cross-sectional study was completed to assess age-related differences in the latency and likelihood of trunk muscle reflexive responses to sudden perturbations. Sixty healthy individuals, aged 20-70 years, were recruited to form five equal-sized and gender-balanced age groups. Using a displacement-control, sudden perturbation paradigm, the latency and likelihood of trunk muscle reflexive responses to sudden perturbations were estimated, and the influences of age, gender, and level of effort (20% versus 30% of maximum voluntary exertion-MVE) were evaluated. There were no consistent age-related differences found in any of the measures of trunk muscle reflexive behavior. However, the latency of muscle response to perturbation was generally higher among older individuals, and this difference was significant in the condition involving 30% MVE effort. With an increase in level of effort (from 20% to 30% of MVE), there was a ~7% increase in the latency of trunk muscle responses to anteriorly-directed perturbations as well as ~ 15% (21%) decrease (increase) in response likelihood during anteriorly (posteriorly) directed perturbations. Furthermore, the reflexive response likelihood of trunk muscles was 28% (58%) larger (smaller) in female vs. male participants during anteriorly (posteriorly) directed perturbations. Our results did not, in general, support the hypothesis of an age-related decay in reflexive trunk muscle behaviors. Larger reflexive responses were associated with lower trunk intrinsic stiffness among females and during a lower level of effort, suggesting a secondary role for reflexive responses in spinal stability. Such secondary compensatory responses appear, however, to be consistent over a wide age range. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reflexive convention: civil partnership, marriage and family.

PubMed

Heaphy, Brian

2017-09-14

Drawing on an analysis of qualitative interview data from a study of formalized same-sex relationships (civil partnerships) this paper examines the enduring significance of marriage and family as social institutions. In doing so, it intervenes in current debates in the sociology of family and personal life about how such institutions are undermined by reflexivity or bolstered by convention. Against the backdrop of dominating sociological frames for understanding the links between the changing nature of marriage and family and same-sex relationship recognition, the paper analyses the diverse and overlapping ways (including the simple, relational, strategic, ambivalent and critical ways) in which same-sex partners reflexively constructed and engaged with marriage and family conventions. My analysis suggests that instead of viewing reflexivity and convention as mutually undermining, as some sociologists of family and personal life do, it is insightful to explore how diverse forms of reflexivity and convention interact in everyday life to reconfigure the social institutions of marriage and family, but do not undermine them as such. I argue the case for recognizing the ways in which 'reflexive convention', or reflexive investment in convention, contributes to the continuing significance of marriage and family as social institutions. © London School of Economics and Political Science 2017.

Two cases of Bezold-Jarisch reflex induced by intra-arterial nitroglycerin in critical left main coronary artery stenosis.

PubMed

Shah, Sachin P; Waxman, Sergio

2013-01-01

The Bezold-Jarisch reflex, a well-described phenomenon, occurs upon the stimulation of intracardiac mechanoreceptors and is mediated by vagal afferent nerve fibers. Several factors can sensitize the cardiovascular system to develop this reflex, including acute myocardial ischemia, natriuretic peptides, and, rarely, nitroglycerin administration in the setting of acute myocardial infarction. The development of the Bezold-Jarisch reflex in the presence of severe coronary artery stenosis, specifically left main coronary artery stenosis, has not been described. We report 2 cases of patients who underwent elective coronary angiography and were given intra-arterial nitroglycerin during radial sheath insertion to reduce radial artery spasm. In both patients, bradycardia and hypotension developed along with diaphoresis, consistent with the Bezold-Jarisch reflex. Coronary angiography revealed critical (>90%) left main coronary artery stenosis in both patients. Critical left main coronary artery stenosis might sensitize mechanoreceptors or vagal afferents to the development of the Bezold-Jarisch reflex after intra-arterial nitroglycerin use; however, the mechanism of this possible relationship is unclear. In addition to discussing our patients' cases, we review the medical literature relevant to the Bezold-Jarisch reflex.

Robotic investigation on effect of stretch reflex and crossed inhibitory response on bipedal hopping

PubMed Central

Rosendo, Andre; Ikemoto, Shuhei; Shimizu, Masahiro; Hosoda, Koh

2018-01-01

To maintain balance during dynamic locomotion, the effects of proprioceptive sensory feedback control (e.g. reflexive control) should not be ignored because of its simple sensation and fast reaction time. Scientists have identified the pathways of reflexes; however, it is difficult to investigate their effects during locomotion because locomotion is controlled by a complex neural system and current technology does not allow us to change the control pathways in living humans. To understand these effects, we construct a musculoskeletal bipedal robot, which has similar body structure and dynamics to those of a human. By conducting experiments on this robot, we investigate the effects of reflexes (stretch reflex and crossed inhibitory response) on posture during hopping, a simple and representative bouncing gait with complex dynamics. Through over 300 hopping trials, we confirm that both the stretch reflex and crossed response can contribute to reducing the lateral inclination during hopping. These reflexive pathways do not use any prior knowledge of the dynamic information of the body such as its inclination. Beyond improving the understanding of the human neural system, this study provides roboticists with biomimetic ideas for robot locomotion control. PMID:29593088

Effects of postural changes of the upper limb on reflex transmission in the lower limb. Cervicolumbar reflex interactions in man.

PubMed

Delwaide, P J; Figiel, C; Richelle, C

1977-06-01

The influence of passive changes in upper limb position on the excitability of three myotatic arc reflexes (soleus, quadriceps, and biceps femoris) of the lower limb has been explored on 42 volunteers. The results indicate that the excitability of the three myotatic arcs can be influenced at a distance by postural modifications of the upper limb. When the ipsilateral upper limb is forwards or the contralateral backwards, a facilitation of both soleus and quadriceps tendon reflexes is observed while the biceps femoris reflexes are reduced. This pattern of facilitation and inhibition is reversed when the ipsilateral upper limb is backwards or the contralateral forwards. The facilitations as well as inhibitions of proximal myotatic arc reflexes are quantitatively more marked than that of the soleus reflex. Facilitation and inhibition are not linearly related to the angle of the arm with the trunk. Effects begin at a considerable angle, become maximal at 45 degrees, and progressively disappear for greater values. It is suggested that the distinct pattern of facilitation and inhibition which is exerted in reciprocal fashion on extensor and flexor motor nuclei might depend on the long propriospinal neurones connecting cervical and lumbar enlargements.

Involvement of ERK phosphorylation in brainstem neurons in modulation of swallowing reflex in rats

PubMed Central

Tsujimura, Takanori; Kondo, Masahiro; Kitagawa, Junichi; Tsuboi, Yoshiyuki; Saito, Kimiko; Tohara, Haruka; Ueda, Koichiro; Sessle, Barry J; Iwata, Koichi

2009-01-01

In order to evaluate the neuronal mechanisms underlying functional abnormalities of swallowing in orofacial pain patients, this study investigated the effects of noxious orofacial stimulation on the swallowing reflex, phosphorylated extracellular signal-regulated kinase (pERK) and γ-aminobutyric acid (GABA) immunohistochemical features in brainstem neurons, and also analysed the effects of brainstem lesioning and of microinjection of GABA receptor agonist or antagonist into the nucleus tractus solitarii (NTS) on the swallowing reflex in anaesthetized rats. The swallowing reflex elicited by topical administration of distilled water to the pharyngolaryngeal region was inhibited after capsaicin injection into the facial (whisker pad) skin or lingual muscle. The capsaicin-induced inhibitory effect on the swallowing reflex was itself depressed after the intrathecal administration of MAPK kinase (MEK) inhibitor. No change in the capsaicin-induced inhibitory effect was observed after trigeminal spinal subnucleus caudalis lesioning, but the inhibitory effect was diminished by paratrigeminal nucleus (Pa5) lesioning. Many pERK-like immunoreactive neurons in the NTS showed GABA immunoreactivity. The local microinjection of the GABAA receptor agonist muscimol into the NTS produced a significant reduction in swallowing reflex, and the capsaicin-induced depression of the swallowing reflex was abolished by microinjection of the GABAA receptor antagonist bicuculline into the NTS. The present findings suggest that facial skin–NTS, lingual muscle–NTS and lingual muscle–Pa5–NTS pathways are involved in the modulation of swallowing reflex by facial and lingual pain, respectively, and that the activation of GABAergic NTS neurons is involved in the inhibition of the swallowing reflex following noxious stimulation of facial and intraoral structures. PMID:19124539

The cremasteric reflex and its muscle - a paragon of ongoing scientific discussion: A systematic review.

PubMed

Schwarz, Gilbert M; Hirtler, Lena

2017-05-01

The technique of triggering the cremasteric reflex and its respective signaling pathway is not described uniformly throughout the literature. As this reflex is a useful sign in diagnosing testicular torsion, orchitis, varicocele, and undescended testis, it seems desirable to identify and define the correct mechanism. Our aim was to investigate how the cremasteric reflex and its signaling pathway are described in the current literature and how the variability of the innervation of the inguinal region could affect the frequency of this reflex. Thirty-five original articles and 18 current textbooks were included after searching PubMed (MEDLINE) and Scopus for the terms "cremaster muscle," "cremasteric reflex," and "genitofemoral nerve" and after applying all exclusion criteria. This systematic review was performed according to the PRISMA Statement Rules. Eliciting the cremasteric reflex was defined either as "rubbing of the upper inner thigh" or "rubbing of the skin under the inguinal ligament." Four different afferent pathways among studies and three different pathways among textbooks were described and the frequency of an intact reflex ranged between 42.7 and 92.5% in newborns and between 61.7 and 100% in boys between 24 months and 12 years. Owing to the huge differences among the studies investigated and the lack of convincing results, it is not possible to define the correct way to elicit the cremasteric reflex. Four hypotheses about the afferent pathway are proposed on the basis of the literature. Further studies should be performed, concentrating on the afferent pathway(s) with respect to the individual innervation of the inguinal region. Clin. Anat. 30:498-507, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Effect of pinching-evoked pain on jaw-stretch reflexes and exteroceptive suppression periods in healthy subjects.

PubMed

Biasiotta, A; Peddireddy, A; Wang, K; Romaniello, A; Frati, A; Svensson, P; Arendt-Nielsen, L

2007-10-01

To investigate the influence of conditioning cutaneous nociceptive inputs by a new "pinch" model on the jaw-stretch reflex and the exteroceptive suppression periods (ES1 and ES2) in jaw muscles. The jaw-stretch reflex was evoked with the use of a custom-made muscle stretcher and electrical stimuli were used to evoke an early and late exteroceptive suppression period (ES1 and ES2) in the jaw-closing muscles. Electromyographic (EMG) activity was recorded bilaterally from the masseter and temporalis muscles. These brainstem reflexes were recorded in 19 healthy men (28.8+/-1.1 years) during three different conditions: one painful clip applied to the earlobe; one painful clip applied to the nostril, and four painful clips applied simultaneously to the earlobe, nostril, eyebrow, and lower lip. Pain intensity induced by the application of the clips was scored continuously by the subjects on a 100mm visual analogue scale (VAS). The highest VAS pain scores were evoked by placement of four clips (79+/-0.5mm). There was no significant modulation of the jaw-stretch reflex (ANOVAs: P=0.929), the ES1 (P=0.298) or ES2 (P=0.082) in any of the three painful conditions. Intense and tonic cutaneous pain could be elicited by this new "pinch" pain model; however, there was no significant modulation on either excitatory or inhibitory brainstem reflex responses. The novel observation that high-intensity pinch stimuli applied to the craniofacial region fail to modulate two different brainstem reflexes is in contrast to other experimental pain studies documented facilitation of the jaw-stretch reflexes or inhibition of exteroceptive suppression periods. The clinical implication of the present findings is that only some craniofacial pain conditions could be expected to show perturbation of the brainstem reflex responses.

Does spasticity contribute to walking dysfunction after stroke?

PubMed Central

Ada, L.; Vattanasilp, W.; O'Dwyer, N.; Crosbie, J.

1998-01-01

OBJECTIVES—Clinically, it is assumed that spasticity of the calf muscles interferes with walking after stroke. The aim was to examine this assumption by evaluating the contribution of spasticity in the gastrocnemius muscle to walking dysfunction in an ambulant stroke population several months after stroke.
METHODS—Fourteen stroke patients who were able to walk independently and 15 neurologically normal control subjects were recruited. Both resting and action stretch reflexes of the gastrocnemius muscle were investigated under conditions that simulated walking. Resting tonic stretch reflexes were measured to assess spasticity whereas action tonic stretch reflexes were measured to assess the possible contribution of spasticity to gait dysfunction.
RESULTS—Two thirds of the stroke patients exhibited resting tonic stretch reflexes which indicate spasticity, whereas none of the control subjects did. However, the stroke patients exhibited action tonic stretch reflexes that were of similar magnitude to the control subjects, suggesting that their reflex activity during walking was not different from that of control subjects. Furthermore, there was no evidence that the action stretch reflex in the stroke patients contributed a higher resistance to stretch than the control subjects.
CONCLUSIONS—Whereas most of the stroke patients exhibited spasticity when measured both clinically and physiologically, they did not exhibit an increase in resistance to dorsiflexion due to exaggerated action tonic stretch reflexes. It is concluded that it is unlikely that spasticity causes problems in walking after stroke in ambulant patients. Therefore, it seems inappropriate to routinely reduce or inhibit the reflex response to improve functional movement in stroke rehabilitation. Factors other than spasticity should be considered when analysing walking after stroke, so that appropriate treatment is provided to patients.

 PMID:9598679

Testing rocuronium-induced neuromuscular blockade at the stapedius muscle using stapedius reflex measurements.

PubMed

Sárkány, P; Tassonyi, E; Nemes, R; Timkó, A; Pongrácz, A; Fülesdi, Béla

2011-12-01

Neuromuscular monitoring prior to emergence from anaesthesia has been shown to be necessary to achieve adequate airway protection in order to decrease postoperative pulmonary complications. In the present study we hypothesized that stapedius reflex measurement allows the detection of residual neuromuscular blockade using the stapedius muscle following the administration of rocuronium. Parallel stapedius and acceleromyographic measurements were performed on 20 patients undergoing cholecystectomy. Acceleromyographic measurements were continuously performed during the course of anaesthesia, whereas the stapedius reflex was measured on different occasions: (1) after premedication but before anaesthesia induction, (2) after induction, but before administration of muscle relaxant, (3) after administration of muscle relaxant, (4) during the course of surgical anaesthesia at regular intervals, and (5) continuously performed during emergence from anaesthesia, until the stapedius reflex threshold returned to normal. The intensity of the sound energy at which the stapedius reflex is detectable was similar: 89.5 ± 9.9 dB(mean ± SD) after premedication and after anaesthetic induction. However, after administration of rocuronium, when the twitch height decreased to 5%, the stapedius reflex disappeared, indicating a total block of the stapedius muscle.During the recovery phase (twitch>10%) significantly higher sound energies compared to baseline values were necessary to evoke the reflex, indicating residual inhibition of the stapedius muscle. At the point where stapedius reflex threshold returned to normal the twitch height averaged about 50% showing low sensitivity of the tympanometry in detecting residual neuromuscular blockade. The neuromuscular effect of rocuronium on the stapedius muscle can be detected using stapedius reflex measurements. Due to its methodological limitation and low sensitivity, the method cannot be recommended for the monitoring of residual neuromuscular blockade.

Reflex regulation during sustained and intermittent submaximal contractions in humans

PubMed Central

Duchateau, Jacques; Balestra, Costantino; Carpentier, Alain; Hainaut, Karl

2002-01-01

To investigate whether the intensity and duration of a sustained contraction influences reflex regulation, we compared sustained fatiguing contractions at 25 % and 50 % of maximal voluntary contraction (MVC) force in the human abductor pollicis brevis (APB) muscle. Because the activation of motoneurones during fatigue may be reflexively controlled by the metabolic status of the muscle, we also compared reflex activities during sustained and intermittent (6 s contraction, 4 s rest) contractions at 25 % MVC for an identical duration. The short-latency Hoffmann(H) reflex and the long-latency reflex (LLR) were recorded during voluntary contractions, before, during and after the fatigue tests, with each response normalised to the compound muscle action potential (M-wave). The results showed that fatigue during sustained contractions was inversely related to the intensity, and hence the duration, of the effort. The MVC force and associated surface electromyogram (EMG) declined by 26.2 % and 35.2 %, respectively, after the sustained contraction at 50 % MVC, and by 34.2 % and 44.2 % after the sustained contraction at 25 % MVC. Although the average EMG increased progressively with time during the two sustained fatiguing contractions, the amplitudes of the H and LLR reflexes decreased significantly. Combined with previous data (Duchateau & Hainaut, 1993), the results show that the effect on the H reflex is independent of the intensity of the sustained contraction, whereas the decline in the LLR is closely related to the duration of the contraction. Because there were no changes in the intermittent test at 25 % MVC, the results indicate that the net excitatory spinal and supraspinal reflex-mediated input to the motoneurone pool is reduced. This decline in excitation to the motoneurones, however, can be temporarily compensated by an enhancement of the central drive. PMID:12068054

Roles of neuronal NK1 and NK3 receptors in synaptic transmission during motility reflexes in the guinea-pig ileum

PubMed Central

Johnson, P J; Bornstein, J C; Burcher, E

1998-01-01

The role of NK1 and NK3 receptors in synaptic transmission between myenteric neurons during motility reflexes in the guinea-pig ileum was investigated by recording intracellularly the reflex responses of the circular muscle to distension or compression of the mucosal villi. Experiments were performed in a three-chambered organ bath that enabled drugs to be selectively applied to different sites along the reflex pathways.When applied in the recording chamber, an NK1 receptor antagonist, SR140333 (100 nM), reduced by 40–50% the amplitudes of inhibitory junction potentials (i.j.ps) evoked in the circular muscle by activation of descending reflex pathways. This effect was abolished when synaptic transmission in the stimulus region was blocked with physiological saline containing 0.1 mM Ca2+ plus 10 mM Mg2+, leaving only the component of the descending reflex pathway conducted via long anally directed collaterals of intrinsic sensory neurons.SR140333 (100 nM) had no effect on descending reflex i.j.ps when applied to the stimulus region. Ascending reflexes were also unaffected by SR140333 in the stimulus region or between the stimulus and recording sites.Septide (10 nM), an NK1 receptor agonist, enhanced descending reflexes by 30–60% when in the recording chamber. [Sar9,Met(O2)11]substance P had no effect at 10 nM, but potentiated distension-evoked reflexes at 100 nM.A selective NK3 receptor antagonist, SR142801 (100 nM), when applied to the stimulus region, reduced the amplitude of descending reflex responses to compression by 40%, but had no effect on responses to distension. SR142801 (100 nM) had no effect when applied to other regions of the descending reflex pathways.SR142801 (100 nM) only inhibited ascending reflexes when applied at the recording site. However, after nicotinic transmission in the stimulus region was blocked, SR142801 (100 nM) at this site reduced responses to compression.Contractions of the circular muscle of isolated rings of ileum evoked by low concentrations of septide, but not [Sar9,Met(O2)11]substance P, were potentiated by tetrodotoxin (300 nM).Contractile responses evoked by an NK3 receptor agonist, senktide, were non-competitively inhibited by SR142801. After excitatory neuromuscular transmission was blocked, senktide produced inhibitory responses that were also antagonised by SR142801, but to a lesser extent and in an apparently competitive manner.These results indicate that tachykinins acting via NK1 receptors partly mediate transmission to inhibitory motor neurons. NK3 receptors play a role in transmission from intrinsic sensory neurons and from ascending interneurons to excitatory motor neurons during motility reflexes. PMID:9723948

The legacy of care as reflexive learning

PubMed Central

García, Marta Rodríguez; Moya, Jose Luis Medina

2016-01-01

Abstract Objective: to analyze whether the tutor's use of reflexive strategies encourages the students to reflect. The goal is to discover what type of strategies can help to achieve this and how tutors and students behave in the practical context. Method: a qualitative and ethnographic focus was adopted. Twenty-seven students and 15 tutors from three health centers participated. The latter had received specific training on reflexive clinical tutoring. The analysis was developed through constant comparisons of the categories. Results: the results demonstrate that the tutors' use of reflexive strategies such as didactic questioning, didactic empathy and pedagogical silence contributes to encourage the students' reflection and significant learning. Conclusions: reflexive practice is key to tutors' training and students' learning. PMID:27305180

Reconsidering reflexivity: introducing the case for intellectual entrepreneurship.

PubMed

Cutcliffe, John R

2003-01-01

In this article, the author reconsiders reflexivity and attempts to examine some unresolved issues by drawing particular attention to the relationship between reflexivity and certain related phenomena/processes: the researcher's a priori knowledge, values, beliefs; empathy within qualitative research; the presence and influence of the researcher's tacit knowledge, and May's "magic" in method. Given the limitations of some reflexive activity identified in this article, the author introduces the case for greater intellectual entrepreneurship within the context of qualitative research. He suggests that excessive emphasis on reflexive activity might inhibit intellectual entrepreneurship. Wherein intellectual entrepreneurship implies a conscious and deliberate attempt on the part of academics to explore the world of ideas boldly; to take more risks in theory development and to move away from being timid researchers.

How Can Hypnodontics Manage Severe Gag Reflex for Root Canal Therapy? A Case Report

PubMed Central

Ramazani, Mohsen; zarenejad, Nafiseh; Parirokh, Masoud; Zahedpasha, Samir

2016-01-01

In endodontics, severe involuntary gagging can have a severe impact on treatment procedure. There are many ways to ease the gag reflex, one of which is hypnosis. A 34-year-old male was referred for root canal treatment of a molar tooth. He had not received any dental treatments for the past nine years due to fear of severe gag reflex. Three hypnotic sessions based upon eye fixation, progressive muscle relaxation and guided imagery techniques were spent for psychosomatic management. The gag reflex was controlled and reduced to a normal level, and the required dental treatments including root canal therapy and restoration were performed successfully. This report shows that hypnosis can control gag reflex for dental treatments. PMID:27141226

THE EFFECT OF PENETRATING RADIATION ON THE REFLEXES FROM INTESTINAL RECEPTORS (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dzharakyan, T.K.; Fakhrutdinov, G.F.

1958-03-01

The reflexes from the chemo-, baro-, and thermoceptors of the small intestine were studied in acute and chronic experiments on dogs after the general action of penetrating radiation (400 r). Regular changes were revealed in the reflexes. They consisted of an increase of the vegetative components (vascular- motor, cardiac, and respiratory) and other components (movement of the head and the body) of the reflex reaction in response to the action of the stimulants of the threshold value, as well as in considerable increase of the consequent period. The changes in the reflexes appear on the 6th to 10th day aftermore » the actwon of penetrating radiation and increase with development of this disease. The intensity of these changes depend on the gravity of the radiation sickness. In the authors' opinion the changes in the reflexes are due to disturbance of the functional condition of the subcortical ganglia of the central nervous system. (tr-auth)« less

Researching Reflexively With Patients and Families: Two Studies Using Video-Reflexive Ethnography to Collaborate With Patients and Families in Patient Safety Research.

PubMed

Collier, Aileen; Wyer, Mary

2016-06-01

Patient safety research has to date offered few opportunities for patients and families to be actively involved in the research process. This article describes our collaboration with patients and families in two separate studies, involving end-of-life care and infection control in acute care. We used the collaborative methodology of video-reflexive ethnography, which has been primarily used with clinicians, to involve patients and families as active participants and collaborators in our research. The purpose of this article is to share our experiences and findings that iterative researcher reflexivity in the field was critical to the progress and success of each study. We present and analyze the complexities of reflexivity-in-the-field through a framework of multilayered reflexivity. We share our lessons here for other researchers seeking to actively involve patients and families in patient safety research using collaborative visual methods. © The Author(s) 2015.

Are the unken reflex and the aposematic colouration of Red-Bellied Toads efficient against bird predation?

PubMed Central

Caorsi, Valentina Zaffaroni; Colombo, Patrick; Abadie, Michelle; Brack, Ismael Verrastro; Dasoler, Bibiana Terra; Borges-Martins, Márcio

2018-01-01

Aposematic signals as well as body behaviours may be important anti-predator defences. Species of the genus Melanophryniscus are characterised by having toxic lipophilic alkaloids in the skin and for presenting a red ventral colouration, which can be observed when they perform the behaviour called the unken reflex. Both the reflex behaviour and the colouration pattern are described as defence mechanisms. However, there are currently no studies testing their effectiveness against predators. This study aimed to test experimentally if both ventral conspicuous colouration and the unken reflex in Melanophryniscus cambaraensis function as aposematic signals against visually oriented predators (birds). We simulated the species studied using three different clay toad models as follows: (a) in a normal position with green coloured bodies, (b) in the unken reflex position with green coloured body and extremities and (c) in the unken reflex position with a green body and red extremities. Models were distributed on a known M. cambaraensis breeding site and in the adjacent forest. More than half of the attacks on the models were from birds; however, there was no preference for any model type. Thus, just the presence of the red colour associated with the motionless unken reflex position does not seem to prevent attacks from potential predators. It is possible that the effective aposematic signal in Melanophryniscus is achieved through the unken reflex movement together with the subsequent exhibition of the warning colouration and the secretion of toxins. PMID:29596437

Neural effects of muscle stretching on the spinal reflexes in multiple lower-limb muscles.

PubMed

Masugi, Yohei; Obata, Hiroki; Inoue, Daisuke; Kawashima, Noritaka; Nakazawa, Kimitaka

2017-01-01

While previous studies have shown that muscle stretching suppresses monosynaptic spinal reflex excitability in stretched muscles, its effects on non-stretched muscles is still largely unknown. The purpose of this study was to examine the effects of muscle stretching on monosynaptic spinal reflex in non-stretched muscles. Ten healthy male subjects participated in this study. Muscle stretching of the right triceps surae muscle was performed using a motor torque device for 1 minute. Three different dorsiflexion torques (at approximately 5, 10, and 15 Nm) were applied during muscle stretching. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded in both the lower-limb muscles before, during, and at 0 and 5 min following muscle stretching. The amplitudes of the spinal reflexes in both the stretched and non-stretched muscles in the right (ipsilateral) leg were smaller during stretching compared to before, and at 0 and 5 min after stretching. Furthermore, the degree of reduction in the amplitude of the spinal reflexes in the right (ipsilateral) leg muscles increased significantly as the dorsiflexion torque (i.e., stretching of the right triceps surae muscles) increased. In contrast, reduction in the amplitude of the spinal reflexes with increasing dorsiflexion torque was not seen in the left (contralateral) leg muscles. Our results clearly indicate that muscle stretching has inhibitory effects on monosynaptic spinal reflexes, not only in stretched muscles, but also in non-stretched muscles of the ipsilateral leg.

Neural effects of muscle stretching on the spinal reflexes in multiple lower-limb muscles

PubMed Central

Obata, Hiroki; Inoue, Daisuke; Kawashima, Noritaka; Nakazawa, Kimitaka

2017-01-01

While previous studies have shown that muscle stretching suppresses monosynaptic spinal reflex excitability in stretched muscles, its effects on non-stretched muscles is still largely unknown. The purpose of this study was to examine the effects of muscle stretching on monosynaptic spinal reflex in non-stretched muscles. Ten healthy male subjects participated in this study. Muscle stretching of the right triceps surae muscle was performed using a motor torque device for 1 minute. Three different dorsiflexion torques (at approximately 5, 10, and 15 Nm) were applied during muscle stretching. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded in both the lower-limb muscles before, during, and at 0 and 5 min following muscle stretching. The amplitudes of the spinal reflexes in both the stretched and non-stretched muscles in the right (ipsilateral) leg were smaller during stretching compared to before, and at 0 and 5 min after stretching. Furthermore, the degree of reduction in the amplitude of the spinal reflexes in the right (ipsilateral) leg muscles increased significantly as the dorsiflexion torque (i.e., stretching of the right triceps surae muscles) increased. In contrast, reduction in the amplitude of the spinal reflexes with increasing dorsiflexion torque was not seen in the left (contralateral) leg muscles. Our results clearly indicate that muscle stretching has inhibitory effects on monosynaptic spinal reflexes, not only in stretched muscles, but also in non-stretched muscles of the ipsilateral leg. PMID:28662201

Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems.

PubMed

Cionni, Robert J; Pei, Ron; Dimalanta, Ramon; Lubeck, David

2015-08-01

To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery.

Effects of postural and voluntary muscle contraction on modulation of the soleus H reflex by transcranial magnetic stimulation.

PubMed

Guzmán-López, Jessica; Selvi, Aikaterini; Solà-Valls, Núria; Casanova-Molla, Jordi; Valls-Solé, Josep

2015-12-01

Modulation of spinal reflexes depends largely on the integrity of the corticospinal tract. A useful method to document the influence of descending tracts on reflexes is to examine the effects of transcranial magnetic stimulation (TMS) on the soleus H reflex elicited by posterior tibial nerve electrical stimuli (PTS). In 12 healthy volunteers, we investigated how postural or voluntary muscle contraction modified such descending modulation. We first characterized the effects of TMS at 95 % of motor threshold for leg responses on the H reflex elicited by a preceding PTS at inter-stimuli intervals (ISIs) between 0 and 120 ms at rest and, then, during voluntary plantar flexion (pf), dorsal flexion (df), and standing still (ss). During pf, there was an increase in the facilitation of the H reflex at ISIs 0-20 ms. During df, there were no effects of TMS on the H reflex. During ss, there was inhibition at ISIs 40-60 ms. Our observations suggest that muscle contraction prevails over the baseline effects of TMS on the soleus H reflex. While contraction of the antagonist (df) suppressed most of the effects, contraction of the agonist had different effects depending on the type of activity (pf or ss). The characterization of the interaction between descending corticospinal volleys and segmental peripheral inputs provides useful information on motor control for physiological research and further understanding of the effects of spinal cord lesions.

Celiac Disease Presenting with Peripheral Neuropathy in Children: A Case Report.

PubMed

Pacitto, Alessandra; Paglino, Alessandra; Di Genova, Lorenza; Leonardi, Alberto; Farinelli, Edoardo; Principi, Nicola; di Cara, Giuseppe; Esposito, Susanna

2017-07-14

Background: Clinically relevant neurological manifestations in children with celiac disease (CD) are unusual, especially when they are considered as signs of the onset of the disease. In this paper, a case of Guillain-Barrè syndrome (GBS) as the first manifestation of CD in a 23-month-old child is reported. Case presentation: We describe a case of CD onset with peripheral neuropathy in a 23-month-old Bulgarian boy presenting with a sudden refusal to walk and absence of deep tendon reflexes in both lower limbs. Neurological symptoms were preceded by two months of gastrointestinal symptoms such as vomiting, abdominal distention, and clear signs of malnutrition and weight loss. When we evaluated the child six months after the onset of the symptoms, clinical and laboratory findings showed clear signs of peripheral neuropathy associated with malnutrition. Serum deamidated gliadin and tissue transglutaminase antibodies were therefore measured. The anti-gliadin levels were more than sixteen times higher than normal and the IgA anti-transglutaminase levels were four times higher than normal. Anti-endomysium antibodies were positive, and human leukocyte antigens (HLA) II typing confirmed a genetic predisposition to CD (DQ2 positive and DQ8 negative). Given the association between the clinical evidence of the disease and the results of the celiac screening tests, a diagnosis of CD was made without biopsy confirmation of the enteropathy. The child began a restricted gluten-free diet that led to complete recovery of the peripheral neuropathy, walking, reflexes, and overall improvement after three months on the diet. Conclusion: Our case underlines the rare but possible associations between CD and peripheral neuropathy in children as an onset symptom, even in the absence of gastrointestinal manifestations, thus suggesting that CD should always be considered in the differential diagnosis of peripheral neuropathy in children. A good knowledge of the extra-intestinal manifestations of CD is essential for the rapid introduction of a gluten-free diet that could be useful for the resolution of the neurological symptoms.

The Dynamics of Successive Induction in Larval Zebrafish

ERIC Educational Resources Information Center

Staddon, J. E. R.; MacPhail, R. C.; Padilla, S.

2010-01-01

Charles Sherrington identified the properties of the synapse by purely behavioral means--the study of reflexes--more than 100 years ago. They were subsequently confirmed neurophysiologically. Studying reflex interaction, he also showed that activating one reflex often facilitates another, antagonistic one: "successive induction," which has since…

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

21 CFR 890.1450 - Powered reflex hammer.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Powered reflex hammer. 890.1450 Section 890.1450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES PHYSICAL MEDICINE DEVICES Physical Medicine Diagnostic Devices § 890.1450 Powered reflex...

Age Related Decline in Postural Control Mechanisms.

ERIC Educational Resources Information Center

Stelmach, George E.; And Others

1989-01-01

Studied voluntary and reflexive mechanisms of postural control of young (N=8) and elderly (N=8) adults through measurement of reflexive reactions to large-fast and small-slow ankle rotation postural disturbances. Found reflexive mechanisms relatively intact for both groups although elderly appeared more disadvantaged when posture was under the…

Informed Reflexivity: Enacting Epistemic Virtue

ERIC Educational Resources Information Center

Weinstock, Michael; Kienhues, Dorothe; Feucht, Florian C.; Ryan, Mary

2017-01-01

To discuss reflexive practice in relation to epistemic cognition, we posit informed reflexivity as an epistemic virtue that is informed by its particular context and purposes of knowing and action and promotes use of reliable processes to achieve epistemic aims. It involves reasoning about social relationships in which a person is embedded when…

Erecting Closets and Outing Ourselves: Uncomfortable Reflexivity and Community-Based Research

ERIC Educational Resources Information Center

Reed, Sarah J.; Miller, Robin Lin; Nnawulezi, Nkiru; Valenti, Maria T.

2012-01-01

Feminist scholars and community psychologists have argued that reflexivity is a necessary component to conducting socially conscious research. Reflexivity, however, is rarely evident in community psychology. In this article, we share the uncomfortable realities that surfaced during a community-based research project in which we adapted and…

A Movement Account of Long-Distance Reflexives

ERIC Educational Resources Information Center

McKeown, Rebecca Katherine

2013-01-01

This thesis examines reflexive pronouns, such as Icelandic "sig" (Cf. Thrainsson 2007), which may be bound from outside of an infinitive clause (which I call MD "medium distance" binding) in addition to being bound locally. I propose that such reflexives are linked to their antecedents via sisterhood followed by movement: the…

The Reflexive Imperative among High-Achieving Adolescents: A Flemish Case Study

ERIC Educational Resources Information Center

Van Lancker, Inge

2016-01-01

The socio-cultural conditions of late modernity induce a "reflexive imperative" amongst young people, which also results in metapragmatic and metalinguistic behaviour, as has been demonstrated by linguistic ethnographers (LE). However, recent LE studies on reflexivity in Western European settings have mainly focused on how groups of…

Collaborative Research in Contexts of Inequality: The Role of Social Reflexivity

ERIC Educational Resources Information Center

Leibowitz, Brenda; Bozalek, Vivienne; Farmer, Jean; Garraway, James; Herman, Nicoline; Jawitz, Jeff; McMillan, Wendy; Mistri, Gita; Ndebele, Clever; Nkonki, Vuyisile; Quinn, Lynn; van Schalkwyk, Susan; Vorster, Jo-Anne; Winberg, Chris

2017-01-01

This article reports on the role and value of social reflexivity in collaborative research in contexts of extreme inequality. Social reflexivity mediates the enablements and constraints generated by the internal and external contextual conditions impinging on the research collaboration. It fosters the ability of participants in a collaborative…

A modular telerobotic task execution system

NASA Technical Reports Server (NTRS)

Backes, Paul G.; Tso, Kam S.; Hayati, Samad; Lee, Thomas S.

1990-01-01

A telerobot task execution system is proposed to provide a general parametrizable task execution capability. The system includes communication with the calling system, e.g., a task planning system, and single- and dual-arm sensor-based task execution with monitoring and reflexing. A specific task is described by specifying the parameters to various available task execution modules including trajectory generation, compliance control, teleoperation, monitoring, and sensor fusion. Reflex action is achieved by finding the corresponding reflex action in a reflex table when an execution event has been detected with a monitor.

Role of the cerebellum and the vestibular apparatus in regulation of orthostatic reflexes in the cat

NASA Technical Reports Server (NTRS)

Doba, N.; Reis, D. J.

1974-01-01

The contribution of the fastigial nucleus and the vestibular nerves (eighth cranial nerves) to the orthostatic reflexes in anesthetized, paralyzed cats was studied. Bilateral lesions of the rostral fastigial nucleus resulted in impairment of the reflex changes in blood pressure, femoral arterial flow, and resistance evoked by head-up tilting to 30 deg or 60 deg. The rostral fastigial nucleus, which might be triggered by the vestibular apparatus, appears to participate in concert with the baroreceptors in the initiation and possibly the maintenance of the orthostatic reflexes.

[Facial diplegia with atypical paresthesia. A variant of Guillain-Barré syndrome].

PubMed

Dal Verme, Agustín; Acosta, Paula; Margan, Mercedes; Pagnini, Cecilia; Dellepiane, Eugenia; Peralta, Christian

2015-01-01

Guillain-Barré syndrome is an acute demyelinating disease which presents in a classic form with muscular weakness and the lack of reflexes. There are multiple variations and atypical forms of the disease, being facial diplegia with paresthesia one of them. Also, the absence of reflexes in this syndrome is typical but not constant, since 10% of patients present reflexes. We describe a case of atypical presentation with bilateral facial palsy, paresthesia, brisk reflexes and weakness in the lower limbs in a 33 year old woman.

[Red reflex: prevention way to blindness in childhood].

PubMed

de Aguiar, Adriana Sousa Carvalho; Cardoso, Maria Vera Lúcia Moreira Leitão; Lúcio, Ingrid Martins Leite

2007-01-01

This study had as objective to investigate the result and the colour gradation of red reflex test in newborns (NB). It is a exploratory, quantitative study and the sample was 180 NB from maternity ward in Fortaleza-CE. From this, 156 showed result "no altered" and 24 "suspect". About the aspect of red reflex, 144 NB showed the same coloration in the two eyes, in 35 of this, the colour was red, in 33, orange reddish, in 46 orange colour, in 24 light yellow, in 6 yellow with whitish stains central. Of the suspect cases, the reflex was light yellow with whitish stains with lines. The nurse trained to accomplish the red reflex test can have important role at Neonatal Unit with actions about the prevention of ocular alterations in the childhood.

Tonic blood pressure modulates the relationship between baroreceptor cardiac reflex sensitivity and cognitive performance.

PubMed

Del Paso, Gustavo A Reyes; González, M Isabel; Hernández, José Antonio; Duschek, Stefan; Gutiérrez, Nicolás

2009-09-01

This study explored the effects of tonic blood pressure on the association between baroreceptor cardiac reflex sensitivity and cognitive performance. Sixty female participants completed a mental arithmetic task. Baroreceptor reflex sensitivity was assessed using sequence analysis. An interaction was found, indicating that the relationship between baroreceptor reflex sensitivity and cognitive performance is modulated by blood pressure levels. Reflex sensitivity was inversely associated to performance indices in the subgroup of participants with systolic blood pressure above the mean, whereas the association was positive in participants with systolic values below the mean. These results are in accordance with the findings in the field of pain perception and suggest that tonic blood pressure modulates the inhibitory effects of baroreceptor stimulation on high central nervous functions.

Management of exaggerated gag reflex in dental patients using intravenous sedation with dexmedetomidine.

PubMed

Reshetnikov, Aleksei P; Kasatkin, Anton A; Urakov, Aleksandr L; Baimurzin, Dmitrii Y

2017-01-01

Pharmacological sedation is one of the effective ways of prevention of gag reflex development in patients experiencing anxiety and fright before dental treatment. We are reporting a case where we could successfully eliminate exaggerated gag reflex (intravenous [IV] Gagging Severity Index) in a dental patient using IV sedation with dexmedetomidine. IV administration of dexmedetomidine provided elimination of gag reflex at a depth of sedation for the patient with the Richmond Agitation-Sedation Scale score of -2 and -1. The patient received dexmedetomidine 1.0 μg/kg for 10 min and then a continuous infusion of dexmedetomidine 0.4 μg/kg/h. The use of dexmedetomidine for sedation may be an alternative to other pharmacological agents in patients with dental anxiety accompanied by exaggerated gag reflex.

Time course of the soleus M response and H reflex after lidocaine tibial nerve block in the rat.

PubMed

Buffenoir, Kévin; Decq, Philippe; Pérot, Chantal

2013-01-01

In spastic subjects, lidocaine is often used to induce a block predictive of the result provided by subsequent surgery. Lidocaine has been demonstrated to inhibit the Hoffmann (H) reflex to a greater extent than the direct motor (M) response induced by electrical stimulation, but the timecourse of these responses has not been investigated. An animal (rat) model of the effects of lidocaine on M and H responses was therefore developed to assess this time course. M and H responses were recorded in 18 adult rats before and after application of lidocaine to the sciatic nerve. Two to five minutes after lidocaine injection, M responses were markedly reduced (mean reduction of 44%) and H reflexes were completely abolished. Changes were observed more rapidly for the H reflex. The effects of lidocaine then persisted for 100 minutes. The effect of lidocaine was therefore more prolonged on the H reflex than on the M response. This study confirms that lidocaine blocks not only alpha motoneurons but also Ia afferent fibres responsible for the H reflex. The authors describe, for the first time, the detailed time course of the effect of lidocaine on direct or reflex activation of motoneurons in the rat.

The Relationship between MOC Reflex and Masked Threshold

PubMed Central

Garinis, Angela; Werner, Lynne; Abdala, Carolina

2011-01-01

Otoacoustic emission (OAE) amplitude can be reduced by acoustic stimulation. This effect is produced by the medial olivocochlear (MOC) reflex. Past studies have shown that the MOC reflex is related to listening in noise and attention. In the present study, the relationship between strength of the contralateral MOC reflex and masked threshold was investigated in 19 adults. Detection thresholds were determined for a 1000-Hz, 300-ms tone presented simultaneously with one repetition of a 300-ms masker in an ongoing train of 300-ms masker bursts at 600-ms intervals. Three masking conditions were tested: 1) broadband noise 2) a fixed-frequency 4-tone complex masker and 3) a random-frequency 4-tone complex masker. Broadband noise was expected to produce energetic masking and the tonal maskers were expected to produce informational masking in some listeners. DPOAEs were recorded at fine frequency interval from 500 to 4000 Hz, with and without contralateral acoustic stimulation. MOC reflex strength was estimated as a reduction in baseline level and a shift in frequency of DPOAE fine-structure maxima near 1000-Hz. MOC reflex and psychophysical testing were completed in separate sessions. Individuals with poorer thresholds in broadband noise and in random-frequency maskers were found to have stronger MOC reflexes. PMID:21878379

The role of nervus intermedius in side specific nasal responses.

PubMed

Nichani, J R; Malik, V; Woolford, T J; Ramsden, R T; Homer, J J

2010-03-02

Nervus intermedius (NI) dysfunction is common in patients who have had vestibular schwannoma (VS) surgery. Such patients have a unilateral parasympathetic-denervated nasal cavity. A number of side-specific nasal reflexes have been demonstrated in normal individuals, including hand cold-water immersion. It is not understood whether these reflexes have parasympathetic or sympathic efferent pathways. We aimed to evaluate the side specific nasal reflex to cold-water immersion in post-operative VS patients with NI dysfunction, in order to determine the nature of the efferent pathway of these reflexes. Side specific responses to cold-water immersion were tested by acoustic rhinometry in 10 normal individuals and 18 patients with NI dysfunction (proven by Schirmer s test) after VS surgery. A consistent pattern of ipsilateral congestion and contralateral decongestion after the cold-water immersion was seen in normal individuals (p smaller than 0.001). We found no consistent response in VS patients both ipsilateral and contralateral to the side of NI dysfunction. We confirm the consistent side-specific nasal reflexes to cold-water hand immersion in normal individuals. This is disturbed in patients with NI dysfunction. We have also shown unexpectantly that the contralateral side-specific reflex is disturbed in these patients. These data suggest that the reflex is parasympathetic and crosses the midline.

Effects of pirfenidone on increased cough reflex sensitivity in guinea pigs.

PubMed

Okazaki, Akihito; Ohkura, Noriyuki; Fujimura, Masaki; Katayama, Nobuyuki; Kasahara, Kazuo

2013-10-01

Pirfenidone, an antifibrotic drug with anti-inflammatory and antioxidant effects, delays fibrosis in idiopathic pulmonary fibrosis (IPF). Patients with IPF have a greater cough reflex sensitivity to inhaled capsaicin than healthy people, and cough is an independent predictor of IPF disease progression; however, the effects of pirfenidone on cough reflex sensitivity are unknown. After challenge with an aerosolized antigen in actively sensitized guinea pigs, pirfenidone was administered intraperitoneally, and the cough reflex sensitivity was measured at 48 h after the challenge. Bronchoalveolar lavage (BAL) was performed, and the tracheal tissue was collected. Pirfenidone suppressed the capsaicin-induced increase in cough reflex sensitivity in a dose-dependent manner. Additionally, increased levels of prostaglandin E2, substance P, and leukotriene B4, but not histamine, in the BAL fluid were dose dependently suppressed by pirfenidone. The decrease in neutral endopeptidase activity in the tracheal tissue was also alleviated by pirfenidone treatment. The total number of cells and components in the BAL fluid was not influenced. These results suggest that pirfenidone ameliorates isolated cough based on increased cough reflex sensitivity associated with allergic airway diseases, and potentially relieve chronic cough in IPF patients who often have increased cough reflex sensitivity. Prospective studies on cough-relieving effects of pirfenidone in patients with IPF are therefore warranted. Copyright © 2013 Elsevier Ltd. All rights reserved.

Restoring walking after spinal cord injury: operant conditioning of spinal reflexes can help.

PubMed

Thompson, Aiko K; Wolpaw, Jonathan R

2015-04-01

People with incomplete spinal cord injury (SCI) frequently suffer motor disabilities due to spasticity and poor muscle control, even after conventional therapy. Abnormal spinal reflex activity often contributes to these problems. Operant conditioning of spinal reflexes, which can target plasticity to specific reflex pathways, can enhance recovery. In rats in which a right lateral column lesion had weakened right stance and produced an asymmetrical gait, up-conditioning of the right soleus H-reflex, which increased muscle spindle afferent excitation of soleus, strengthened right stance and eliminated the asymmetry. In people with hyperreflexia due to incomplete SCI, down-conditioning of the soleus H-reflex improved walking speed and symmetry. Furthermore, modulation of electromyographic activity during walking improved bilaterally, indicating that a protocol that targets plasticity to a specific pathway can trigger widespread plasticity that improves recovery far beyond that attributable to the change in the targeted pathway. These improvements were apparent to people in their daily lives. They reported walking faster and farther, and noted less spasticity and better balance. Operant conditioning protocols could be developed to modify other spinal reflexes or corticospinal connections; and could be combined with other therapies to enhance recovery in people with SCI or other neuromuscular disorders. © The Author(s) 2014.

The behaviour of the long-latency stretch reflex in patients with Parkinson's disease

PubMed Central

Rothwell, Jc; Obeso, Ja; Traub, Mm; Marsden, Cd

1983-01-01

The size of the long-latency stretch reflex was measured in a proximal (triceps) and distal (flexor pollicis longus) muscle in 47 patients with Parkinson's disease, and was compared with that seen in a group of 12 age-matched normal control subjects. The patients were classified clinically into four groups according to the degree of rigidity at the elbow or tremor. Stretch reflexes were evaluated while the subject was exerting a small force against a constant preload supplied by a torque motor, and the size of the reflex response was measured as fractional increase over basal levels of activity. When stretches were given at random intervals by increasing the force exerted by the motor by a factor of 2 or 3, there was a clear trend for the more severely affected patients to have larger long latency responses in the triceps muscle, although there was no change in the size of the short-latency, spinal component of the response. In contrast, there was no change in the size of the long-latency response of the flexor pollicis longus in any group of patients with Parkinson's disease. Despite any differences in reflex size, the inherent muscle stiffness of both muscles appeared to be normal in all groups of patients with Parkinson's disease, since the displacement trajectory of the limb following the force increase was the same as control values in the short (25 ms) period before reflex compensation could intervene. In 20 of the patients and in seven of the control subjects, servo-controlled, ramp positional disturbances were given to the thumb. Up to a velocity of 300°/s, the size of the long-latency stretch reflex was proportional to the log velocity of stretch. This technique revealed, in both moderately and severely rigid patients, increases in the reflex sensitivity of the flexor pollicis longus, which had not been clear using step torque stretches alone. However, whether using ramp or step displacements, long latency stretch reflex gain was not closely related to rigidity; reflex size was within the normal range in many patients with severe rigidity. Enhanced long latency stretch reflexes thus contribute to, but may not be solely responsible for, rigidity in Parkinson's disease. PMID:6842198

Child–Computer Interaction at the Beginner Stage of Music Learning: Effects of Reflexive Interaction on Children’s Musical Improvisation

PubMed Central

Addessi, Anna Rita; Anelli, Filomena; Benghi, Diber; Friberg, Anders

2017-01-01

In this article children’s musical improvisation is investigated through the “reflexive interaction” paradigm. We used a particular system, the MIROR-Impro, implemented in the framework of the MIROR project (EC-FP7), which is able to reply to the child playing a keyboard by a “reflexive” output, mirroring (with repetitions and variations) her/his inputs. The study was conducted in a public primary school, with 47 children, aged 6–7. The experimental design used the convergence procedure, based on three sample groups allowing us to verify if the reflexive interaction using the MIROR-Impro is necessary and/or sufficient to improve the children’s abilities to improvise. The following conditions were used as independent variables: to play only the keyboard, the keyboard with the MIROR-Impro but with not-reflexive reply, the keyboard with the MIROR-Impro with reflexive reply. As dependent variables we estimated the children’s ability to improvise in solos, and in duets. Each child carried out a training program consisting of 5 weekly individual 12 min sessions. The control group played the complete package of independent variables; Experimental Group 1 played the keyboard and the keyboard with the MIROR-Impro with not-reflexive reply; Experimental Group 2 played only the keyboard with the reflexive system. One week after, the children were asked to improvise a musical piece on the keyboard alone (Solo task), and in pairs with a friend (Duet task). Three independent judges assessed the Solo and the Duet tasks by means of a grid based on the TAI-Test for Ability to Improvise rating scale. The EG2, which trained only with the reflexive system, reached the highest average results and the difference with EG1, which did not used the reflexive system, is statistically significant when the children improvise in a duet. The results indicate that in the sample of participants the reflexive interaction alone could be sufficient to increase the improvisational skills, and necessary when they improvise in duets. However, these results are in general not statistically significant. The correlation between Reflexive Interaction and the ability to improvise is statistically significant. The results are discussed on the light of the recent literature in neuroscience and music education. PMID:28184205

Spastic long-lasting reflexes in the awake rat after sacral spinal cord injury.

PubMed

Bennett, D J; Sanelli, L; Cooke, C L; Harvey, P J; Gorassini, M A

2004-05-01

Following chronic sacral spinal cord transection in rats the affected tail muscles exhibit marked spasticity, with characteristic long-lasting tail spasms evoked by mild stimulation. The purpose of the present paper was to characterize the long-lasting reflex seen in tail muscles in response to electrical stimulation of the tail nerves in the awake spastic rat, including its development with time and relation to spasticity. Before and after sacral spinal transection, surface electrodes were placed on the tail for electrical stimulation of the caudal nerve trunk (mixed nerve) and for recording EMG from segmental tail muscles. In normal and acute spinal rats caudal nerve trunk stimulation evoked little or no EMG reflex. By 2 wk after injury, the same stimulation evoked long-lasting reflexes that were 1) very low threshold, 2) evoked from rest without prior EMG activity, 3) of polysynaptic latency with >6 ms central delay, 4) about 2 s long, and 5) enhanced by repeated stimulation (windup). These reflexes produced powerful whole tail contractions (spasms) and developed gradually over the weeks after the injury (< or =52 wk tested), in close parallel to the development of spasticity. Pure low-threshold cutaneous stimulation, from electrical stimulation of the tip of the tail, also evoked long-lasting spastic reflexes, not seen in acute spinal or normal rats. In acute spinal rats a strong C-fiber stimulation of the tip of the tail (20 x T) could evoke a weak EMG response lasting about 1 s. Interestingly, when this C-fiber stimulation was used as a conditioning stimulation to depolarize the motoneuron pool in acute spinal rats, a subsequent low-threshold stimulation of the caudal nerve trunk evoked a 300-500 ms long reflex, similar to the onset of the long-lasting reflex in chronic spinal rats. A similar conditioned reflex was not seen in normal rats. Thus there is an unusually long low-threshold polysynaptic input to the motoneurons (pEPSP) that is normally inhibited by descending control. This pEPSP is released from inhibition immediately after injury but does not produce a long-lasting reflex because of a lack of motoneuron excitability. With chronic injury the motoneuron excitability is increased markedly, and the pEPSP then triggers sustained motoneuron discharges associated with long-lasting reflexes and muscle spasms.

Motor impairment: a new ethanol withdrawal phenotype in mice

PubMed Central

Philibin, Scott D.; Cameron, Andy J.; Metten, Pamela; Crabbe, John C.

2015-01-01

Alcoholism is a complex disorder with genetic and environmental risk factors. The presence of withdrawal symptoms is one criterion for alcohol dependence. Genetic animal models have followed a reductionist approach by quantifying various effects of ethanol withdrawal separately. Different ethanol withdrawal symptoms may have distinct genetic etiologies, and therefore differentiating distinct neurobiological mechanisms related to separate signs of withdrawal would increase our understanding of various aspects of the complex phenotype. This study establishes motor incoordination as a new phenotype of alcohol withdrawal in mice. Mice were made physically dependent on ethanol by exposure to ethanol vapor for 72 h. The effects of ethanol withdrawal in mice from different genetic backgrounds were measured on the accelerating rotarod, a simple motor task. Ethanol withdrawal disrupted accelerating rotarod behavior in mice. The disruptive effects of withdrawal suggest a performance rather than a learning deficit. Inbred strain comparisons suggest genetic differences in magnitude of this withdrawal phenotype. The withdrawal-induced deficits were not correlated with the selection response difference in handling convulsion severity in selectively bred Withdrawal Seizure-Prone and Withdrawal Seizure-Resistant lines. The accelerating rotarod seems to be a simple behavioral measure of ethanol withdrawal that is suitable for comparing genotypes. PMID:18690115

Withdrawal: Expanding a Key Addiction Construct

PubMed Central

2015-01-01

Withdrawal is an essential component of classical addiction theory; it is a vital manifestation of dependence and motivates relapse. However, the traditional conceptualization of withdrawal as a cohesive collection of symptoms that emerge during drug deprivation and decline with either the passage of time or reinstatement of drug use, may be inadequate to explain scientific findings or fit with modern theories of addiction. This article expands the current understanding of tobacco withdrawal by examining: (1) withdrawal variability; (2) underlying causes of withdrawal variability, including biological and person factors, environmental influences, and the influence of highly routinized behavioral patterns; (3) new withdrawal symptoms that allow for enhanced characterization of the withdrawal experience; and (4) withdrawal-related cognitive processes. These topics provide guidance regarding the optimal assessment of withdrawal and illustrate the potential impact modern withdrawal conceptualization and assessment could have on identifying treatment targets. PMID:25744958

Modulation of ethanol withdrawal-induced anxiety-like behavior during later withdrawals by treatment of early withdrawals with benzodiazepine/gamma-aminobutyric acid ligands.

PubMed

Knapp, Darin J; Overstreet, David H; Breese, George R

2005-04-01

Anxiety states, including those arising during acute or protracted withdrawal periods, may be precipitating factors in alcoholic relapse. Given the cyclical nature of ethanol withdrawal associated with repeated cycles of ethanol intake and abstinence in a pattern that often spans years, meaningful attempts to model ethanol withdrawal-associated anxiety should incorporate cycled ethanol treatments. The studies reported herein examined the effects of gamma-aminobutyric acid-modulating drugs on social interaction behavior-an established model of anxiety-in rats exposed to repeated cycles of ethanol treatment and withdrawal. Rats were exposed to 8 to 12 g/kg/day ethanol during three 7-day dietary cycles (5 days on ethanol diet followed by 2 days on control diet). Ethanol was administered either at hour 4 of withdrawal after cessation of each of the first 2 ethanol cycles or during the final withdrawal only. In other groups, the early withdrawals were treated with alphaxalone, diazepam, PK11159, or flumazenil to block anxiety-like behavior during an untreated later (third) withdrawal. The benzodiazepine inverse agonist DMCM (methyl-6, 7-dymerhoxy-4-ethyl-beta-carboline-3-carboxylate) was also given repeatedly to determine whether it would sensitize anxiety-like behavior during a future withdrawal. Finally, the effects of all drugs on deficits in locomotor behavior were assessed. Pretreatment of earlier withdrawals with alphaxalone, diazepam, ethanol, or flumazenil reduced social interaction deficits during a later withdrawal, but pretreatment with PK11195 did not. In contrast, DMCM administered in lieu of early withdrawals increased social interaction deficits during an untreated later withdrawal. Locomotor deficits were significantly reversed only by the acute ethanol and diazepam treatment during the final withdrawal. Single-dose administration of drugs that enhance or diminish activity at benzodiazepine-gamma-aminobutyric acid- receptors during earlier withdrawals reduced or potentiated, respectively, anxiety-like behavior during later, drug-free withdrawals. These results support the potential of the novel strategy of using prophylactic therapy administered during early withdrawals to ameliorate symptoms of later withdrawals.

Opioid modulation of reflex versus operant responses following stress in the rat.

PubMed

King, C D; Devine, D P; Vierck, C J; Mauderli, A; Yezierski, R P

2007-06-15

In pre-clinical models intended to evaluate nociceptive processing, acute stress suppresses reflex responses to thermal stimulation, an effect previously described as stress-induced "analgesia." Suggestions that endogenous opioids mediate this effect are based on demonstrations that stress-induced hyporeflexia is enhanced by high dose morphine (>5 mg/kg) and is reversed by naloxone. However, reflexes and pain sensations can be modulated differentially. Therefore, in the present study direct comparisons were made of opioid agonist and antagonist actions, independently and in combination with acute restraint stress in Long Evans rats, on reflex lick-guard (L/G) and operant escape responses to nociceptive thermal stimulation (44.5 degrees C). A high dose of morphine (>8 mg/kg) was required to reduce reflex responding, but a moderate dose of morphine (1 mg/kg) significantly reduced escape responding. The same moderate dose (and also 5 mg/kg) of morphine significantly enhanced reflex responding. Naloxone (3 mg/kg) significantly enhanced escape responding but did not affect L/G responding. Restraint stress significantly suppressed L/G reflexes (hyporeflexia) but enhanced escape responses (hyperalgesia). Stress-induced hyperalgesia was significantly reduced by morphine and enhanced by naloxone. In contrast, stress-induced hyporeflexia was blocked by both naloxone and 1 mg/kg of morphine. Thus, stress-induced hyperalgesia was opposed by endogenous opioid release and by administration of morphine. Stress-induced hyporeflexia was dependent upon endogenous opioid release but was counteracted by a moderate dose of morphine. These data demonstrate a differential modulation of reflex and operant outcome measures by stress and by separate or combined opioid antagonism or administration of morphine.

OPERANT CONDITIONING OF A SPINAL REFLEX CAN IMPROVE LOCOMOTION AFTER SPINAL CORD INJURY IN HUMANS

PubMed Central

Thompson, Aiko K.; Pomerantz, Ferne; Wolpaw, Jonathan R.

2013-01-01

Operant conditioning protocols can modify the activity of specific spinal cord pathways and can thereby affect behaviors that use these pathways. To explore the therapeutic application of these protocols, we studied the impact of down-conditioning the soleus H-reflex in people with impaired locomotion caused by chronic incomplete spinal cord injury. After a baseline period in which soleus H-reflex size was measured and locomotion was assessed, subjects completed either 30 H-reflex down-conditioning sessions (DC subjects) or 30 sessions in which the H-reflex was simply measured (Unconditioned (UC) subjects), and locomotion was reassessed. Over the 30 sessions, the soleus H-reflex decreased in two-thirds of the DC subjects (a success rate similar to that in normal subjects) and remained smaller several months later. In these subjects, locomotion became faster and more symmetrical, and the modulation of EMG activity across the step-cycle increased bilaterally. Furthermore, beginning about halfway through the conditioning sessions, all of these subjects commented spontaneously that they were walking faster and farther in their daily lives, and several noted less clonus, easier stepping, and/or other improvements. The H-reflex did not decrease in the other DC subjects or in any of the UC subjects; and their locomotion did not improve. These results suggest that reflex conditioning protocols can enhance recovery of function after incomplete spinal cord injuries and possibly in other disorders as well. Because they are able to target specific spinal pathways, these protocols could be designed to address each individual’s particular deficits, and might thereby complement other rehabilitation methods. PMID:23392666

[Developing team reflexivity as a learning and working tool for medical teams].

PubMed

Riskin, Arieh; Bamberger, Peter

2014-01-01

Team reflexivity is a collective activity in which team members review their previous work, and develop ideas on how to modify their work behavior in order to achieve better future results. It is an important learning tool and a key factor in explaining the varying effectiveness of teams. Team reflexivity encompasses both self-awareness and agency, and includes three main activities: reflection, planning, and adaptation. The model of briefing-debriefing cycles promotes team reflexivity. Its key elements include: Pre-action briefing--setting objectives, roles, and strategies the mission, as well as proposing adaptations based on what was previously learnt from similar procedures; Post-action debriefing--reflecting on the procedure performed and reviewing the extent to which objectives were met, and what can be learnt for future tasks. Given the widespread attention to team-based work systems and organizational learning, efforts should be made toward ntroducing team reflexivity in health administration systems. Implementation could be difficult because most teams in hospitals are short-lived action teams formed for a particular event, with limited time and opportunity to consciously reflect upon their actions. But it is precisely in these contexts that reflexive processes have the most to offer instead of the natural impulsive collective logics. Team reflexivity suggests a potential solution to the major problems of iatorgenesis--avoidable medical errors, as it forces all team members to participate in a reflexive process together. Briefing-debriefing technology was studied mainly in surgical teams and was shown to enhance team-based learning and to improve quality-related outcomes and safety.

Evaluating Red Reflex and Surgeon Preference Between Nearly-Collimated and Focused Beam Microscope Illumination Systems

PubMed Central

Cionni, Robert J.; Pei, Ron; Dimalanta, Ramon; Lubeck, David

2015-01-01

Purpose To evaluate the intensity and stability of the red reflex produced by ophthalmic surgical microscopes with nearly-collimated versus focused illumination systems and to assess surgeon preference in a simulated surgical setting. Methods This two-part evaluation consisted of postproduction surgical video analysis of red reflex intensity and a microscope use and preference survey completed by 13 experienced cataract surgeons. Survey responses were based on bench testing and experience in a simulated surgical setting. A microscope with nearly-collimated beam illumination and two focused beam microscopes were assessed. Results Red reflex intensity and stability were greater with the nearly-collimated microscope illumination system. In the bench testing survey, surgeons reported that the red reflex was maintained over significantly greater distances away from pupillary center, and depth of focus was numerically greater with nearly-collimated illumination relative to focused illumination. Most participating surgeons (≥64%) reported a preference for the microscope with nearly-collimated illumination with regard to red reflex stability, depth of focus, visualization, surgical working distance, and perceived patient comfort. Conclusions The microscope with nearly-collimated illumination produced a more intense and significantly more stable red reflex and was preferred overall by more surgeons. Translational Relevance This is the first report of an attempt to quantify red reflex intensity and stability and to evaluate surgically-relevant parameters between microscope systems. The data and methods presented here may provide a basis for future studies attempting to quantify differences between surgical microscopes that may affect surgeon preference and microscope use in ophthalmic surgery. PMID:26290778

Contribution of the maculo-ocular reflex to gaze stability in the rabbit.

PubMed

Pettorossi, V E; Errico, P; Santarelli, R M

1991-01-01

The contribution of the maculo-ocular reflex to gaze stability was studied in 10 pigmented rabbits by rolling the animals at various angles of sagittal inclination of the rotation and/or longitudinal animal axes. At low frequencies (0.005-0.01 Hz) of sinusoidal stimulation the vestibulo-ocular reflex (VOR) was due to macular activation, while at intermediate and high frequencies it was mainly due to ampullar activation. The following results were obtained: 1) maculo-ocular reflex gain decreased as a function of the cosine of the angle between the rotation axis and the earth's horizontal plane. No change in gain was observed when longitudinal animal axis alone was inclined. 2) At 0 degrees of rotation axis and with the animal's longitudinal axis inclination also set at 0 degrees, the maculo-ocular reflex was oriented about 20 degrees forward and upward with respect to the earth's vertical axis. This orientation remained constant with sagittal inclinations of the rotation and/or longitudinal animal axes ranging from approximately 5 degrees upward to 30 degrees downward. When the longitudinal animal axis was inclined beyond these limits, the eye trajectory tended to follow the axis inclination. In the upside down position, the maculo-ocular reflex was anticompensatory, oblique and fixed with respect to orbital coordinates. 3) Ampullo-ocular reflex gain did not change with inclinations of the rotation and/or longitudinal animal axes. The ocular responses were consistently oriented to the stimulus plane. At intermediate frequencies the eye movement trajectory was elliptic because of directional differences between the ampullo- and maculo-ocular reflexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Alterations of brain network hubs in reflex syncope: Evidence from a graph theoretical analysis based on DTI.

PubMed

Park, Bong Soo; Lee, Yoo Jin; Park, Jin-Han; Kim, Il Hwan; Park, Si Hyung; Lee, Ho-Joon; Park, Kang Min

2018-06-01

We evaluated global topology and organization of regional hubs in the brain networks and microstructural abnormalities in the white matter of patients with reflex syncope. Twenty patients with reflex syncope and thirty healthy subjects were recruited, and they underwent diffusion tensor imaging (DTI) scans. Graph theory was applied to obtain network measures based on extracted DTI data, using DSI Studio. We then investigated differences in the network measures between the patients with reflex syncope and the healthy subjects. We also analyzed microstructural abnormalities of white matter using tract-based spatial statistics analysis (TBSS). Measures of global topology were not different between patients with reflex syncope and healthy subjects. However, in reflex syncope patients, the strength measures of the right angular, left inferior frontal, left middle orbitofrontal, left superior medial frontal, and left middle temporal gyrus were lower than in healthy subjects. The betweenness centrality measures of the left middle orbitofrontal, left fusiform, and left lingual gyrus in patients were lower than those in healthy subjects. The PageRank centrality measures of the right angular, left middle orbitofrontal, and left superior medial frontal gyrus in patients were lower than those in healthy subjects. Regarding the analysis of the white matter microstructure, there were no differences in the fractional anisotropy and mean diffusivity values between the two groups. We have identified a reorganization of network hubs in the brain network of patients with reflex syncope. These alterations in brain network may play a role in the pathophysiologic mechanism underlying reflex syncope. © 2018 The Authors. Brain and Behavior published by Wiley Periodicals, Inc.

Avian reflex and electroencephalogram responses in different states of consciousness.

PubMed

Sandercock, Dale A; Auckburally, Adam; Flaherty, Derek; Sandilands, Victoria; McKeegan, Dorothy E F

2014-06-22

Defining states of clinical consciousness in animals is important in veterinary anaesthesia and in studies of euthanasia and welfare assessment at slaughter. The aim of this study was to validate readily observable reflex responses in relation to different conscious states, as confirmed by EEG analysis, in two species of birds under laboratory conditions (35-week-old layer hens (n=12) and 11-week-old turkeys (n=10)). We evaluated clinical reflexes and characterised electroencephalograph (EEG) activity (as a measure of brain function) using spectral analyses in four different clinical states of consciousness: conscious (fully awake), semi-conscious (sedated), unconscious-optimal (general anaesthesia), unconscious-sub optimal (deep hypnotic state), as well as assessment immediately following euthanasia. Jaw or neck muscle tone was the most reliable reflex measure distinguishing between conscious and unconscious states. Pupillary reflex was consistently observed until respiratory arrest. Nictitating membrane reflex persisted for a short time (<1 min) after respiratory arrest and brain death (isoelectric EEG). The results confirm that the nictitating membrane reflex is a conservative measure of death in poultry. Using spectral analyses of the EEG waveforms it was possible to readily distinguish between the different states of clinical consciousness. In all cases, when birds progressed from a conscious to unconscious state; total spectral power (PTOT) significantly increased, whereas median (F50) and spectral edge (F95) frequencies significantly decreased. This study demonstrates that EEG analysis can differentiate between clinical states (and loss of brain function at death) in birds and provides a unique integration of reflex responses and EEG activity. Copyright © 2014 Elsevier Inc. All rights reserved.

Oxygen-conserving reflexes of the brain: the current molecular knowledge.

PubMed

Schaller, B; Cornelius, J F; Sandu, N; Ottaviani, G; Perez-Pinzon, M A

2009-04-01

The trigemino-cardiac reflex (TCR) may be classified as a sub-phenomenon in the group of the so-called 'oxygen-conserving reflexes'. Within seconds after the initiation of such a reflex, there is neither a powerful and differentiated activation of the sympathetic system with subsequent elevation in regional cerebral blood flow (CBF) with no changes in the cerebral metabolic rate of oxygen (CMRO(2)) or in the cerebral metabolic rate of glucose (CMRglc). Such an increase in regional CBF without a change of CMRO(2) or CMRglc provides the brain with oxygen rapidly and efficiently and gives substantial evidence that the TCR is an oxygen-conserving reflex. This system, which mediates reflex protection projects via currently undefined pathways from the rostral ventrolateral medulla oblongata to the upper brainstem and/or thalamus which finally engage a small population of neurons in the cortex. This cortical centre appears to be dedicated to reflexively transduce a neuronal signal into cerebral vasodilatation and synchronization of electrocortical activity. Sympathetic excitation is mediated by cortical-spinal projection to spinal pre-ganglionic sympathetic neurons whereas bradycardia is mediated via projections to cardiovagal motor medullary neurons. The integrated reflex response serves to redistribute blood from viscera to brain in response to a challenge to cerebral metabolism, but seems also to initiate a preconditioning mechanism. Better and more detailed knowledge of the cascades, transmitters and molecules engaged in such endogenous (neuro) protection may provide new insights into novel therapeutic options for a range of disorders characterized by neuronal death and into cortical organization of the brain.

Attenuation of Morphine-Induced Tolerance and Dependence by Pretreatment with Cerebrolysin in Male rats.

PubMed

Ghavimi, Hamed; Darvishi, Sara; Ghanbarzadeh, Saeed

2018-01-01

Dependence and tolerance to morphine are major problems which limit its chronic clinical application. This study was aimed to investigate the attenuation effect of Cerebrolysin, a mixture of potent growth factors (BDNF, GDNF, NGF, CNTF etc,), on the development of Morphine-induced dependence and tolerance. Male Wistar rats were selected randomly and divided into different groups (n=8) including: a control group, groups received additive doses of morphine (5-25 mg/kg, ip, at an interval of 12 h until tolerance completion), and groups pretreated with Cerebrolysin (40, 80 and 160 mg/kg, ip, before morphine administration). Development of tolerance was assessed by tail-flick test and the attenuation effect of Cerebrolysin on morphine-induced dependence was evaluated after injection of naloxone (4 mg/kg, ip, 12 h after the morning dose of morphine). Seven distinct withdrawal signs including: jumping, rearing, genital grooming, abdominal writhing, wet dog shake and teeth grinding were recorded for 45 min and total withdrawal score (TWS) was calculated. Results showed that administration of Cerebrolysin could prolonged development (10 and 14 days in administration of 80 mg/kg and 160 mg/kg Cerebrolysin) and completion (4, 10 and 14 days in administration of 40, 80 and 160 mg/kg Cerebrolysin, respectively) of tolerance. Results also indicated that administration of Cerebrolysin (40, 80 and 160 mg/kg) could significantly decreased the TWS value (62±2, 77±4 and 85±6%, respectively). In conclusion, it was found that pretreatment with Cerebrolysin could attenuated morphine-induced tolerance and dependence. © Georg Thieme Verlag KG Stuttgart · New York.

Improvements of mean body mass index and body weight in preobese and overweight Japanese adults with black Chinese tea (Pu-Erh) water extract.

PubMed

Kubota, Kazumitsu; Sumi, Shunichiro; Tojo, Hideaki; Sumi-Inoue, Yukiko; I-Chin, Hou; Oi, Yasuyuki; Fujita, Hiroyuki; Urata, Hidenori

2011-06-01

Water-soluble black Chinese (Pu-Erh) tea extract (BTE), which contains high gallic acid content, has been demonstrated to elicit antiobese effects in animals. Because gallic acid is related with the reduction of visceral fat and cholesterol contents and improvement of obesity in animals, we investigated the effects of BTE intake on 36 preobese Japanese adults (body mass index [BMI], >25- <30 kg/m(2)) in a 12-week double-blind, randomized, placebo-controlled group comparison study using powdered barley tea with or without (placebo) BTE. A follow-up 4-week period after BTE intake termination was monitored to observe the withdrawal effect. All subjects ingested barley tea with or without BTE (333 mg) before each of the 3 daily meals. In the BTE-treated group, the mean pretreament values of body weight and BMI significantly decreased after intake and after BTE withdrawal. However, the corresponding values scored significant differences only from 8 weeks after intake (vs the placebo-treated group). The mean values of the waist circumference indicated a similar tendency. Furthermore, coronal navel section (same anatomical position) images of computed tomography of all BTE- and non-BTE-treated subjects revealed that the visceral fat areas (cm(2)) were significantly (P < .05) less in the former 12 weeks after BTE ingestion. Measured biochemical parameters did not indicate significant differences, and BTE-treated subjects did not complain of any adverse effects (abdominal distension, etc). Ingestion of BTE exhibited significant effects in reducing the mean waist circumference, BMI, and visceral fat values and might be useful for weight control and prevention of obesity development (or metabolic syndrome) in humans. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Encouraging Reflexivity in Urban Geography Fieldwork: Study Abroad Experiences in Singapore and Malaysia

ERIC Educational Resources Information Center

Glass, Michael R.

2014-01-01

Fieldwork in urban geography courses can encourage reflexivity among students regarding the cities they encounter. This article outlines how student reflexivity was encouraged within a new international field research course in Singapore and Malaysia. Drawing on examples from students' field exercises written during an intensive and occasionally…

Iris Pigmentation and Fractionated Reaction and Reflex Time.

ERIC Educational Resources Information Center

Hale, Bruce D.; And Others

Behavioral measures, fractionated reaction and reflex times by means of electromyography, were used to determine if the eye color differences are found in the central or peripheral regions of the nervous system. The purpose of this research was to determine the truth of the hypothesis that dark-eyed individuals have faster reflex and reaction time…

Approaches to Reflexivity: Navigating Educational and Career Pathways

ERIC Educational Resources Information Center

Dyke, Martin; Johnston, Brenda; Fuller, Alison

2012-01-01

This paper provides a critical appraisal of approaches to reflexivity in sociology. It uses data from social network research to argue that Archer's approach to reflexivity provides a valuable lens with which to understand how people navigate their education and career pathways. The paper is also critical of Archer's methodology and typology of…

"Madam, Are You One of Them?" "Reflexivities of Discomfort" in Researching an "Illicit" Subject

ERIC Educational Resources Information Center

Namatende-Sakwa, Lydia

2018-01-01

Informed largely by Affect theory (2004), this paper takes up "reflexivities of discomfort" to reflexively engage with my affective struggles as a Christian, heterosexual, mother, educator, undertaking a study on homosexuality, which is a thorny issue in Uganda. It a methodological prologue, reflecting my thoughts and struggles before I…

Favouring Reflexivity in Technology-Enhanced Learning Systems: Towards Smart Uses of Traces

ERIC Educational Resources Information Center

George, Sébastien; Michel, Christine; Ollagnier-Beldame, Magali

2016-01-01

During learning activities, reflexive processes allow learners to realise what they have done, understand why, decide on new actions and gain motivation. They help learners to regulate their actions by themselves, that is, to develop metacognitive regulation skills. Computer environments can support reflexive processes to support human learning,…

Changes in Soleus H-Reflex Modulation after Treadmill Training in Children with Cerebral Palsy

ERIC Educational Resources Information Center

Hodapp, Maike; Vry, Julia; Mall, Volker; Faist, Michael

2009-01-01

In healthy children, short latency leg muscle reflexes are profoundly modulated throughout the step cycle in a functionally meaningful way and contribute to the electromyographic (EMG) pattern observed during gait. With maturation of the corticospinal tract, the reflex amplitudes are depressed via supraspinal inhibitory mechanisms. In the soleus…

F response and H reflex analysis of physiological unity of gravity and antigravity muscles in man.

PubMed

García, H A; Fisher, M A

1977-01-01

Observational differences between reflex (H reflex) and antidromic (F response) activation of segmental motoneurons by a peripheral electrical stimulus are described. In contrast to H reflexes, the percentage of F responses found after a series of stimuli is directly related to the pick-up field of the recording electrode consistent with this response being due to the variable activation of a small fraction of the available motoneuron pool. Despite the differing physiological mechanisms, both F responses and H reflexes can be used to demonstrate similar relative "central excitatory states" for antigravity muscles (i.e. extensors in the lower extremity and flexors in the upper extremity) and their antagonist gravity muscles. H reflexes were elicited not only in their usual location in certain antigravity muscles but also in unusual locations by length/tension changes in agonist and antagonist groups as well as by passive stretch. The data argue for the physiological unity of similarly acting gravity and antigravity muscles as well as supporting a meaningful role of group II afferents in normal segmental motoneuron pool excitability.

Effect of cervicolabyrinthine impulsation on the spinal reflex apparatus

NASA Technical Reports Server (NTRS)

Yarotskiy, A. I.

1980-01-01

In view of the fact that the convergence effect of vestibular impulsation may both stimulate and inhibit intra and intersystemic coordination of physiological processes, an attempt was made to define the physiological effect on the spinal reflex apparatus of the convergence of cervicolabyrinthine impulsation on a model of the unconditioned motor reflex as a mechanism of the common final pathway conditioning the formation and realization of a focused beneficial result of human motor activities. More than 100 persons subjected to rolling effect and angular acceleration during complexly coordinated muscular loading were divided according to typical variants of the functional structure of the patella reflex in an experiment requiring 30 rapid counterclockwise head revolutions at 2/sec with synchronous recording of a 20 item series of patella reflex acts. A knee jerk coefficient was used in calculations. In 85 percent of the cases 2 patellar reflexograms show typical braking and release of knee reflex and 1 shows an extreme local variant. The diagnostic and prognostic value of these tests is suggested for determining adaptive possibilities of functional systems in respect to acceleration and proprioceptive stimuli.

Contraction induced h reflexes in the diagnosis of cervical radiculopathy.

PubMed

Bodofsky, Elliot B; Campellone, Joseph V; Cohen, Stephen J; Caten, Holly N; Schindelheim, Adam M

2015-06-01

To determine whether Contraction Induced H Reflexes (CIHR) can accurately detect cervical radiculopathy. Comparison of CIHR results with Needle Electromyography at academic outpatient Electromyography/Nerve Conduction laboratories. Participants were all patients over 18 with a needle electromyography diagnosis of cervical radiculopathy. Patients were tested for CIHR in at least two upper extremity muscles in electromyographically proven myotomes bilaterally. Patients were requested to perform a moderate contraction while stimulus was applied proximally (elbow or Erb's point). Outcome measures included H Reflex onset latency and side-to-side latency differences. These were compared against previously established normal values. Overall, 10 of 15 patients who met criteria for cervical radiculopathy showed CIHR abnormalities (sensitivity = 67%; 95% confidence interval, 43-91). Counting each side and level separately, CIHR identified 16/27 radiculopathies (sensitivity = 59.2%; 95% confidence interval, 40.6-77.8). Contraction Induced H Reflexes identified 1 possible radiculopathy not seen on electromyography (specificity = 98%; 95% confidence interval, 95-100). Contraction induced H Reflexes have a sensitivity and specificity for cervical radiculopathy similar to the resting Gastroc-Soleus H Reflex.

19 CFR 144.27 - Withdrawal from warehouse by transferee.

Code of Federal Regulations, 2012 CFR

2012-04-01

...; DEPARTMENT OF THE TREASURY (CONTINUED) WAREHOUSE AND REWAREHOUSE ENTRIES AND WITHDRAWALS Transfer of Right To Withdraw Merchandise from Warehouse § 144.27 Withdrawal from warehouse by transferee. At any time within... withdraw all or part of the merchandise covered by the transfer by filing any authorized kind of withdrawal...

19 CFR 144.27 - Withdrawal from warehouse by transferee.

Code of Federal Regulations, 2010 CFR

2010-04-01

...; DEPARTMENT OF THE TREASURY (CONTINUED) WAREHOUSE AND REWAREHOUSE ENTRIES AND WITHDRAWALS Transfer of Right To Withdraw Merchandise from Warehouse § 144.27 Withdrawal from warehouse by transferee. At any time within... withdraw all or part of the merchandise covered by the transfer by filing any authorized kind of withdrawal...

Unusual Presentation of Spasm of Near Reflex Mimicking Large-Angle Acute Acquired Comitant Esotropia

PubMed Central

Shanker, Varshini; Nigam, Vishal

2015-01-01

Abstract We report the case of an 11-year-old boy who presented with sudden esotropia, binocular diplopia, and blurred vision. The patient was neurologically normal. He had a large, constant, comitant, alternating esotropia associated with minimal accommodative spasm. Ocular motility and pupillary reactions were normal. He was diagnosed to have spasm of the near reflex presenting as acute onset of esotropia. The esotropia was persistent despite treatment and eventually resolved with prolonged cycloplegic therapy. This unusual case illustrates that spasm of the near reflex can have unique and variable presentations. Spasm of the near reflex needs to be considered in the differential diagnosis of every case of acute, acquired, comitant esotropia. This is the first case of spasm of the near reflex where persistent esotropia is reported in the absence of any neurological disorder. PMID:27928354

Modulation of spinal reflexes by sexual films of increasing intensity.

PubMed

Both, Stephanie; Boxtel, Geert; Stekelenburg, Jeroen; Everaerd, Walter; Laan, Ellen

2005-11-01

Sexual arousal can be viewed as an emotional state generating sex-specific autonomic and general somatic motor system responses that prepare for sexual action. In the present study modulation of spinal tendious (T) reflexes by sexual films of varying intensity was investigated. T reflexes were expected to increase as a function of increased film intensity. Through use of a between-subjects design, participants were exposed to three erotic films of low, moderate, and high intensity or to three films of moderate intensity. Self-report and genital data confirmed the induction of increasing versus stable levels of sexual arousal. Exposure to the films of increasing intensity resulted in increasing T reflexes. The results indicate that T reflex modulation is sensitive to varying levels of sexual arousal and may be of use in research on behavioral mechanisms underlying appetitive motivation.

Acoustic Reflex Testing in Neonatal Hearing Screening and Subsequent Audiological Evaluation.

PubMed

Jacob-Corteletti, Lilian Cássia Bórnia; Araújo, Eliene Silva; Duarte, Josilene Luciene; Zucki, Fernanda; Alvarenga, Kátia de Freitas

2018-06-18

The aims of the study were to examine the acoustic reflex screening and threshold in healthy neonates and those at risk of hearing loss and to determine the effect of birth weight and gestational age on acoustic stapedial reflex (ASR). We assessed 18 healthy neonates (Group I) and 16 with at least 1 risk factor for hearing loss (Group II); all of them passed the transient evoked otoacoustic emission test that assessed neonatal hearing. The test battery included an acoustic reflex screening with activators of 0.5, 1, 2, and 4 kHz and broadband noise and an acoustic reflex threshold test with all of them, except for the broadband noise activator. In the evaluated neonates, the main risk factors were the gestational age at birth and a low birth weight; hence, these were further analyzed. The lower the gestational age at birth and birth weight, the less likely that an acoustic reflex would be elicited by pure-tone activators. This effect was significant at the frequencies of 0.5, 1, and 2 kHz for gestational age at birth and at the frequencies of 1 and 2 kHz for birth weight. When the broadband noise stimulus was used, a response was elicited in all neonates in both groups. When the pure-tone stimulus was used, the Group II showed the highest acoustic reflex thresholds and the highest percentage of cases with an absent ASR. The ASR threshold varied from 50 to 100 dB HL in both groups. Group II presented higher mean ASR thresholds than Group I, this difference being significant at frequencies of 1, 2, and 4 kHz. Birth weight and gestational age at birth were related to the elicitation of the acoustic reflex. Neonates with these risk factors for hearing impairment were less likely to exhibit the acoustic reflex and had higher thresholds.

Role of the flocculus of the cerebellum in motor learning of the vestibulo-ocular reflex

NASA Technical Reports Server (NTRS)

Highstein, S. M.

1998-01-01

Structure-function studies at the systems level are an effective method for understanding the relationship of the central nervous system to behavior. Motor learning or adaptation of the vestibulo-ocular reflex is a clear example wherein this approach has been productive. During a vestibulo-ocular reflex the brain converts a head velocity signal, transduced through the vestibular semicircular canals, into an eye movement command delivered to the extraocular muscles. If the viewed target remains on the fovea of the retina, the reflex is compensatory, and its gain, eye velocity/head velocity, is one. When the image of the viewed object slips across the retina, visual acuity decreases, and the gain of the reflex, which is no longer one, is plastically adapted or adjusted until retinal stability is restored. The anatomic substrate for this plasticity thus involves brain structures in which visual-vestibular interaction can potentially occur, as well as vestibular and visual sensory and oculomotor motor structures. Further, it has been known for many years that removal of the flocculus of the cerebellum permanently precludes further vestibulo-ocular reflex adaptation, demonstrating the involvement of the cerebellum in this behavior. Maekawa and Simpson (J Neurophysiol 1973;36: 649-66) discovered that one visual input to the flocculus involved the accessory optic system and the inferior olive. Ensuing work has demonstrated that the visual signals used to adapt the vestibulo-ocular reflex are transmitted by this accessory optic system to the flocculus and subsequently to brain stem structures involved in vestibulo-ocular reflex plasticity. Presently the inclusive list of anatomic sites involved in vestibulo-ocular reflex circuitry and its adaptive plasticity is small. Our laboratory continues to believe that this behavior should be caused by interactions within this small class of neurons. By studying each class of identified neuron and its interactions with others within the list, we hope to ultimately understand the mechanisms used by the brain in the expression of this behavior.

Mechanical Characteristics of Reflex Durign Upright Posture in Paralyzed Subjects

NASA Astrophysics Data System (ADS)

Kim, Yongchul; Youm, Youngil; Lee, Bumsuk; Kim, Youngho; Choi, Hyeonki

The characteristics of flexor reflexes have been investigated in the previous studies with human subjects who were seated or supine position. However, researchers did not describe how the spinal circuits are used in different hip angles for paralyzed subjects, such as the standing position with walker or cane. In upright posture the compatibility between a flexor reflex of leg and body balance is a special problem for lower limb injured subjects. Therefore, the purpose of this study was to investigate the effects of hip angle change on the flexor reflex evoked in standing paralyzed subjects supported by walker. In this study, six spinal cord injured and four stroke subjects were recruited through the inpatient physical therapy clinics of Korea national rehabilitation hospital. A single axis electronic goniometer was mounted on the lateral side of the hip joint of the impaired limb to record movements in the sagittal plane at this joint. The electronic goniometer was connected to a data acquisition system, through amplifiers to a computer. Since subject' posture influenced characteristics of the flexion reflex response, the subjects were supported in an upright posture by the help of parallelogram walder. Two series of tests were performed on each leg. The first series of the tests investigated the influence of hip angle during stationary standing posture on flexion reflex response. The hip angle was adjusted by the foot plate. The second examined the effect of the voluntary action of subject on swing motion during the gait. The electrically induced flexion reflex simultaneously produced the flexion of the hip, knee and dorsiflexion of the ankle enabling the swing phase of walking. Form the experimental results we observed that the reflex response of hip joint was largerwith the hip in the extended position than in the flexed position during standing posture. Under voluntary movement on flexion reflex during gaint, the peak hip angle induced by stimulation was increased in spinal cord injury and stroke patients by subject' voluntary movement.

Gender differences in self-reported withdrawal symptoms and reducing or quitting smoking three years later: A prospective, longitudinal examination of U.S. adults

PubMed Central

Weinberger, Andrea H.; Platt, Jonathan; Shuter, Jonathan; Goodwin, Renee D.

2016-01-01

Background Little is known about gender differences in withdrawal symptoms among smokers in the community. This study used longitudinal epidemiologic data to examine gender differences in current smokers’ report of withdrawal symptoms during past quit attempts and the relationship between withdrawal symptoms and the odds of reducing or quitting smoking three years later. Methods Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC; Wave 1, 2001–2001, n=43,093; Wave 2, 2004–2005, n=34,653). Analyses were conducted on respondents who reported current daily cigarette smoking at Wave 1 (n=6,911). Withdrawal symptoms during past quit attempts were assessed at Wave 1. Current smoking status was assessed at Wave 2. Results Wave 1 current smoking women, compared to men, were more likely to endorse any withdrawal symptoms, withdrawal-related discomfort, and withdrawal-related relapse (ps<0.0001). Women endorsed a greater number of withdrawal symptoms than men (M=2.37, SE=0.05 versus M=1.78, SE=0.04; p<0.0001). The odds of reducing and quitting smoking were significantly lower for respondents who reported any Wave 1 withdrawal symptoms, withdrawal-related discomfort, and withdrawal-related relapse. These relationships did not differ for women versus men. Among men, the odds of reducing smoking at Wave 2 decreased significantly with each cumulative withdrawal symptom compared to women (β interaction= 0.87; p=0.01). Conclusions Women were more likely to report withdrawal while the relationship between withdrawal symptoms and decreased likelihood of reducing smoking was stronger in men. Identifying gender differences in withdrawal can help develop strategies to help reduce withdrawal for both men and women. PMID:27350655

Interaction between the vestibulo-collic reflex and the cervico-collic stretch reflex in the decerebrate cat.

PubMed Central

Dutia, M B; Price, R F

1987-01-01

1. Interactions between the sagittal vestibulo-collic reflex (v.c.r.) and the cervico-collic stretch reflex (c.c.r.) have been studied in the neck extensor muscles biventer cervicis (b.c.) in the decerebrate cat. The v.c.r. was evoked by a 'standard' vestibular stimulus consisting of a sinusoidal nose-up, nose-down head movement of 6-8 deg amplitude at 1 Hz. The c.c.r. was evoked by sinusoidal stretching of the b.c. muscles at 1 Hz. The amplitude of muscle stretching, and its phase in relation to head movement, were systematically varied. 2. When muscle stretching was applied in phase with head movement (so that the muscles were stretched as the head moved in the nose-down direction), the gain of the combined (v.c.r. + c.c.r.) reflex in the b.c. muscles increased above that of the v.c.r. If the muscle stretching was applied out of phase with head movement (so that the muscles shortened as the head moved downward), the gain of the combined reflex was reduced to a value below that of the v.c.r. 3. The effects on the gain of the combined reflex varied in proportion to the amplitude of muscle stretching. The gain and phase of the combined reflex is modelled reasonably well by a linear vectorial addition between the v.c.r. and the c.c.r. over a wide range of amplitudes of muscle stretching. The linear summation model contains a proportionality constant K, which may represent a factor by which the two reflexes are 'calibrated' against each other. 4. If one of the b.c. muscles was held at a fixed length and the other stretched sinusoidally, the c.c.r. was evoked only in the stimulated muscle. Vestibular stimulation then summed with the c.c.r in the stimulated muscle, while on the contralateral side the reflex response was the same as that of the v.c.r. alone. It would appear therefore that the motoneurone pools of the b.c. muscles are organized as independent entities without mutually excitatory or inhibitory reflex linkages. This arrangement presumably allows flexibility in the supraspinal control of the b.c. muscles, which are often used either as synergists during sagittal head movement or as antagonists during horizontal or roll movements of the head. 5. The interaction between the v.c.r. and the c.c.r. results in an apparent 'servo-assistance' role for the muscle afferent feed-back from the b.c. muscles, amplifying or attenuating the reflex response of the muscles to a given head movement.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3498829

29 CFR 4219.12 - Employers liable upon mass withdrawal.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Employers liable upon mass withdrawal. 4219.12 Section 4219... Redetermination of Withdrawal Liability Upon Mass Withdrawal § 4219.12 Employers liable upon mass withdrawal. (a... experiences successive mass withdrawals, an employer that has been determined to be liable under this subpart...

29 CFR 4219.12 - Employers liable upon mass withdrawal.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 9 2011-07-01 2011-07-01 false Employers liable upon mass withdrawal. 4219.12 Section 4219... Redetermination of Withdrawal Liability Upon Mass Withdrawal § 4219.12 Employers liable upon mass withdrawal. (a... experiences successive mass withdrawals, an employer that has been determined to be liable under this subpart...

Value of the pinnal-pedal reflex in the diagnosis of canine scabies.

PubMed

Mueller, R S; Bettenay, S V; Shipstone, M

2001-05-19

The potential value of the pinnal-pedal scratch reflex as an aid to diagnosing canine scabies was assessed in 588 dogs with skin disease. The reflex was assessed by vigorously rubbing the tip of one earflap on to the base of the ear for five seconds, and it was considered positive if the ipsilateral hind leg made a scratching movement. A diagnosis of scabies was based on the dog's history, a physical examination and either positive skin scrapings or the complete resolution of pruritus and dermatitis after treatment with ivermectin or milbemycin, with no relapse for at least 12 months. Scabies was diagnosed in 55 of the dogs, allergic skin disease in 463, and 70 had other miscellaneous skin diseases. There was a positive pinnal-pedal scratch reflex in 45 (82 per cent) of the 55 dogs with scabies. Forty (73 per cent) of the dogs with scabies had pinnal dermatitis, and 36 (90 per cent) of these had a positive pinnal-pedal scratch reflex. There was a positive pinnal-pedal scratch reflex in 33 (6.2 per cent) of the other 533 dogs. On the basis of these results, the specificity of testing for scabies by the pinnal-pedal scratch reflex was 93.8 per cent, and the sensitivity was 81.8 per cent The test's positive predictive value was 0.57 and its negative predictive value was 0.98.

Knee joint effusion following ipsilateral hip surgery.

PubMed

Christodoulou, A G; Givissis, P; Antonarakos, P D; Petsatodis, G E; Hatzokos, I; Pournaras, J D

2010-12-01

To correlate patellar reflex inhibition with sympathetic knee joint effusion. 65 women and 40 men aged 45 to 75 (mean, 65) years underwent hip surgery. The surgery entailed dynamic hip screw fixation using the lateral approach with reflection of the vastus lateralis for pertrochantric fractures (n = 49), and hip hemiarthroplasty or total hip replacement using the Watson-Jones approach (n = 38) or hip hemiarthroplasty using the posterior approach (n = 18) for subcapital femoral fractures (n = 28) or osteoarthritis (n = 28). Knee joint effusion, patellar reflex, and thigh circumference were assessed in both legs before and after surgery (at day 0.5, 2, 7, 14, 30, and 45). Time-sequence plots were used for chronological analysis, and correlation between patellar reflex inhibition and knee joint effusion was tested. In the time-sequence plot, the peak frequency of patellar reflex inhibition (on day 0.5) preceded that of the knee joint effusion and the thigh circumference increase (on day 2). Patellar reflex inhibition correlated positively with the knee joint effusion (r = 0.843, p = 0.035). These 2 factors correlated significantly for all 3 surgical approaches (p < 0.0005). All 3 approaches were associated with patellar reflex inhibition on day 0.5 (p = 0.033) and knee joint effusion on day 2 (p = 0.051). Surgical trauma of the thigh may cause patellar reflex inhibition and subsequently knee joint effusion.

Cannabinoid-induced effects on the nociceptive system: a neurophysiological study in patients with secondary progressive multiple sclerosis.

PubMed

Conte, Antonella; Bettolo, Chiara Marini; Onesti, Emanuela; Frasca, Vittorio; Iacovelli, Elisa; Gilio, Francesca; Giacomelli, Elena; Gabriele, Maria; Aragona, Massimiliano; Tomassini, Valentina; Pantano, Patrizia; Pozzilli, Carlo; Inghilleri, Maurizio

2009-05-01

Although clinical studies show that cannabinoids improve central pain in patients with multiple sclerosis (MS) neurophysiological studies are lacking to investigate whether they also suppress these patients' electrophysiological responses to noxious stimulation. The flexion reflex (FR) in humans is a widely used technique for assessing the pain threshold and for studying spinal and supraspinal pain pathways and the neurotransmitter system involved in pain control. In a randomized, double-blind, placebo-controlled, cross-over study we investigated cannabinoid-induced changes in RIII reflex variables (threshold, latency and area) in a group of 18 patients with secondary progressive MS. To investigate whether cannabinoids act indirectly on the nociceptive reflex by modulating lower motoneuron excitability we also evaluated the H-reflex size after tibial nerve stimulation and calculated the H wave/M wave (H/M) ratio. Of the 18 patients recruited and randomized 17 completed the study. After patients used a commercial delta-9-tetrahydrocannabinol (THC) and cannabidiol mixture as an oromucosal spray the RIII reflex threshold increased and RIII reflex area decreased. The visual analogue scale score for pain also decreased, though not significantly. Conversely, the H/M ratio measured before patients received cannabinoids remained unchanged after therapy. In conclusion, the cannabinoid-induced changes in the RIII reflex threshold and area in patients with MS provide objective neurophysiological evidence that cannabinoids modulate the nociceptive system in patients with MS.

Effect of angular velocity on soleus and medial gastrocnemius H-reflex during maximal concentric and eccentric muscle contraction.

PubMed

Duclay, Julien; Robbe, Alice; Pousson, Michel; Martin, Alain

2009-10-01

At rest, the H-reflex is lower during lengthening than shortening actions. During passive lengthening, both soleus (SOL) and medial gastrocnemius (MG) H-reflex amplitudes decrease with increasing angular velocity. This study was designed to investigate whether H-reflex amplitude is affected by angular velocity during concentric and eccentric maximal voluntary contraction (MVC). Experiments were performed on nine healthy men. At a constant angular velocity of 60 degrees /s and 20 degrees /s, maximal H-reflex and M-wave potentials were evoked at rest (i.e., H(max) and M(max), respectively) and during concentric and eccentric MVC (i.e., H(sup) and M(sup), respectively). Regardless of the muscle, H(max)/M(max) was lower during lengthening than shortening actions and the H(sup)/M(sup) ratio was higher than H(max)/M(max) during lengthening actions. Whereas no action type and angular velocity effects on the MG H(sup)/M(sup) were found, the SOL H(sup)/M(sup) was lower during eccentric than concentric MVC and this depression was increased with higher angular velocity. Our findings indicate that the depression of the H-reflex amplitude during eccentric compared to concentric MVC depends mainly on the amount of inhibition induced by lengthening action. In conclusion, H-reflex should be evoked during both passive and active dynamic trials to evaluate the plasticity of the spinal loop.

Neuromuscular performance of lower limbs during voluntary and reflex activity in power- and endurance-trained athletes.

PubMed

Kyröläinen, H; Komi, P V

1994-01-01

Neural, mechanical and muscle factors influence muscle force production. This study was therefore, designed to compare possible differences in the function of the neuromuscular system among differently adapted subjects. A group of 11 power-trained athletes and 10 endurance-trained athletes volunteered as subjects for this study. Maximal voluntary isometric force and the rate of force production of the knee extensor and the plantar flexor muscles were measured. In addition, basic reflex function was measured in the two experimental conditions. The power athletes produced higher voluntary forces (P < 0.01-0.001) with higher rates for force production (P < 0.001) by both muscle groups measured. Unexpectedly, however, no differences were noticed in the electromyogram time curves between the groups. During reflex activity, the endurance group demonstrated higher sensitivity to the mechanical stimuli, i.e. the higher reflex amplitude caused a higher rate of reflex force development, and the reflex amplitude correlated with the averaged angular velocity. The differences in the isometric conditions could be explained by obviously different muscle fibre distribution, by different amounts of muscle mass, by possible differences in the force transmission from individual myofibrils to the skeletal muscle and by specificity of training. In addition, differences in nervous system structure and muscle spindle properties could explain the observed differences in reflex activity between the two groups.

Subspace methods for identification of human ankle joint stiffness.

PubMed

Zhao, Y; Westwick, D T; Kearney, R E

2011-11-01

Joint stiffness, the dynamic relationship between the angular position of a joint and the torque acting about it, describes the dynamic, mechanical behavior of a joint during posture and movement. Joint stiffness arises from both intrinsic and reflex mechanisms, but the torques due to these mechanisms cannot be measured separately experimentally, since they appear and change together. Therefore, the direct estimation of the intrinsic and reflex stiffnesses is difficult. In this paper, we present a new, two-step procedure to estimate the intrinsic and reflex components of ankle stiffness. In the first step, a discrete-time, subspace-based method is used to estimate a state-space model for overall stiffness from the measured overall torque and then predict the intrinsic and reflex torques. In the second step, continuous-time models for the intrinsic and reflex stiffnesses are estimated from the predicted intrinsic and reflex torques. Simulations and experimental results demonstrate that the algorithm estimates the intrinsic and reflex stiffnesses accurately. The new subspace-based algorithm has three advantages over previous algorithms: 1) It does not require iteration, and therefore, will always converge to an optimal solution; 2) it provides better estimates for data with high noise or short sample lengths; and 3) it provides much more accurate results for data acquired under the closed-loop conditions, that prevail when subjects interact with compliant loads.

Next generation control system for reflexive aerostructures

NASA Astrophysics Data System (ADS)

Maddux, Michael R.; Meents, Elizabeth P.; Barnell, Thomas J.; Cable, Kristin M.; Hemmelgarn, Christopher; Margraf, Thomas W.; Havens, Ernie

2010-04-01

Cornerstone Research Group Inc. (CRG) has developed and demonstrated a composite structural solution called reflexive composites for aerospace applications featuring CRG's healable shape memory polymer (SMP) matrix. In reflexive composites, an integrated structural health monitoring (SHM) system autonomously monitors the structural health of composite aerospace structures, while integrated intelligent controls monitor data from the SHM system to characterize damage and initiate healing when damage is detected. Development of next generation intelligent controls for reflexive composites were initiated for the purpose of integrating prognostic health monitoring capabilities into the reflexive composite structural solution. Initial efforts involved data generation through physical inspections and mechanical testing. Compression after impact (CAI) testing was conducted on composite-reinforced shape memory polymer samples to induce damage and investigate the effectiveness of matrix healing on mechanical performance. Non-destructive evaluation (NDE) techniques were employed to observe and characterize material damage. Restoration of mechanical performance was demonstrated through healing, while NDE data showed location and size of damage and verified mitigation of damage post-healing. Data generated was used in the development of next generation reflexive controls software. Data output from the intelligent controls could serve as input to Integrated Vehicle Health Management (IVHM) systems and Integrated Resilient Aircraft Controls (IRAC). Reflexive composite technology has the ability to reduce maintenance required on composite structures through healing, offering potential to significantly extend service life of aerospace vehicles and reduce operating and lifecycle costs.

Auditory Brainstem Circuits That Mediate the Middle Ear Muscle Reflex

PubMed Central

Mukerji, Sudeep; Windsor, Alanna Marie; Lee, Daniel J.

2010-01-01

The middle ear muscle (MEM) reflex is one of two major descending systems to the auditory periphery. There are two middle ear muscles (MEMs): the stapedius and the tensor tympani. In man, the stapedius contracts in response to intense low frequency acoustic stimuli, exerting forces perpendicular to the stapes superstructure, increasing middle ear impedance and attenuating the intensity of sound energy reaching the inner ear (cochlea). The tensor tympani is believed to contract in response to self-generated noise (chewing, swallowing) and nonauditory stimuli. The MEM reflex pathways begin with sound presented to the ear. Transduction of sound occurs in the cochlea, resulting in an action potential that is transmitted along the auditory nerve to the cochlear nucleus in the brainstem (the first relay station for all ascending sound information originating in the ear). Unknown interneurons in the ventral cochlear nucleus project either directly or indirectly to MEM motoneurons located elsewhere in the brainstem. Motoneurons provide efferent innervation to the MEMs. Although the ascending and descending limbs of these reflex pathways have been well characterized, the identity of the reflex interneurons is not known, as are the source of modulatory inputs to these pathways. The aim of this article is to (a) provide an overview of MEM reflex anatomy and physiology, (b) present new data on MEM reflex anatomy and physiology from our laboratory and others, and (c) describe the clinical implications of our research. PMID:20870664

Eye movement abnormalities in essential tremor

PubMed Central

Plinta, Klaudia; Krzak-Kubica, Agnieszka; Zajdel, Katarzyna; Falkiewicz, Marcel; Dylak, Jacek; Ober, Jan; Szczudlik, Andrzej; Rudzińska, Monika

2016-01-01

Abstract Essential tremor (ET) is the most prevalent movement disorder, characterized mainly by an action tremor of the arms. Only a few studies published as yet have assessed oculomotor abnormalities in ET and their results are unequivocal. The aim of this study was to assess the oculomotor abnormalities in ET patients compared with the control group and to find the relationship between oculomotor abnormalities and clinical features of ET patients. We studied 50 ET patients and 42 matched by age and gender healthy controls. Saccadometer Advanced (Ober Consulting, Poland) was used to investigate reflexive, pace-induced and cued saccades and conventional electrooculography for evaluation of smooth pursuit and fixation. The severity of the tremor was assessed by the Clinical Rating Scale for Tremor. Significant differences between ET patients and controls were found for the incidence of reflexive saccades dysmetria and deficit of smooth pursuit. Reflexive saccades dysmetria was more frequent in patients in the second and third phase of ET compared to the first phase. The reflexive saccades latency increase was correlated with severity of the tremor. In conclusion, oculomotor abnormalities were significantly more common in ET patients than in healthy subjects. The most common oculomotor disturbances in ET were reflexive saccades dysmetria and slowing of smooth pursuit. The frequency of reflexive saccades dysmetria increased with progression of ET. The reflexive saccades latency increase was related to the severity of tremor. PMID:28149393

Effects of acute alcohol withdrawal on nest building in mice selectively bred for alcohol withdrawal severity

PubMed Central

Greenberg, Gian D.; Phillips, Tamara J.; Crabbe, John C.

2017-01-01

Nest building has been used to assess thermoregulatory behavior and positive motivational states in mice. There are known genetic influences on ethanol withdrawal severity as well as individual/thermoregulatory nest building. Withdrawal Seizure-Prone (WSP-1, WSP-2) and Withdrawal Seizure-Resistant (WSR-1, WSR-2) mice were selectively bred for high vs low handling-induced convulsion (HIC) severity, respectively, during withdrawal from chronic ethanol vapor inhalation. They also differ in HIC severity during withdrawal from an acute, 4 g/kg ethanol injection. In our initial study, withdrawal from an acute dose of ethanol dose-dependently impaired nest building over the initial 24 h of withdrawal in genetically segregating Withdrawal Seizure Control (WSC) mice. In two further studies, acute ethanol withdrawal suppressed nest building for up to two days in WSP-1 females. Deficits in nest building from ethanol were limited to the initial 10 h of withdrawal in WSR-1 females and to the initial 24 h of withdrawal in WSP-1 and WSR-1 males. Effects of ethanol on nest building for up to two days were found in WSP-2 and WSR-2 mice of both sexes. Nest building deficits in female mice from the first replicate could not be explained by a general decrease in locomotor behavior. These results suggest that nest building is a novel behavioral phenotype for indexing the severity of acute ethanol withdrawal, and that genes contributing to this trait differ from those affecting acute withdrawal HIC severity. PMID:27503811

Postrenal acute kidney injury in a patient with unilateral ureteral obstruction caused by urolithiasis: A case report.

PubMed

Kazama, Itsuro; Nakajima, Toshiyuki

2017-10-01

In patients with bilateral ureteral obstruction, the serum creatinine levels are often elevated, sometimes causing postrenal acute kidney injury (AKI). In contrast, those with unilateral ureteral obstruction present normal serum creatinine levels, as long as their contralateral kidneys are preserved intact. However, the unilateral obstruction of the ureter could affect the renal function, as it humorally influences the renal hemodynamics. A 66-year-old man with a past medical history of hypertension and diabetes mellitus came to our outpatient clinic because of right abdominal dullness. Unilateral ureteral obstruction caused by a radio-opaque calculus in the right upper ureter and a secondary renal dysfunction. As oral hydration and the use of calcium antagonists failed to allow the spontaneous stone passage, extracorporeal shock wave lithotripsy (ESWL) was performed. Immediately after the passage of the stone, the number of red blood cells in the urine was dramatically decreased and the serum creatinine level almost returned to the normal range with the significant increase in glomerular filtration rate. Unilateral ureteral obstruction by the calculus, which caused reflex vascular constriction and ureteral spasm in the contralateral kidney, was thought to be responsible for the deteriorating renal function.

[A case of severe bradycardia and AV block during administration of propofol].

PubMed

Takase, Hajime; Kudoh, Akira; Takazawa, Tomoko

2003-09-01

A 69-yr-old man underwent emergency laparotomy. He was in endotoxic shock. Preoperative evaluation including a full blood count, chest X-ray and ECG were normal. Body temperature was 37.4 degrees C. Preoperative arterial pressure was 140/80 mmHg and heart rate 65 bpm. Anesthesia was induced with ketamine 100 mg, propofol 20 mg, fentanyl 50 micrograms and vecuronium 4 mg and maintained with propofol 4 mg.kg-1.hr-1 and fentanyl. Soon after opening the abdominal peritoneum, severe bradycardia (< 20 bpm) occurred, but it was effectively treated by ephedrine 16 mg. After that, surgery was performed uneventfully. In the intensive care unit (ICU), the patient developed four episodes of severe atrioventricular (AV) block after stimulation of the trachea by suction drainage under sedation with propofol, although there was no AV block during sedation with ketamine and propofol. After stopping propofol, the AV block was no longer observed. He was discharged from the ICU on the 12th postoperative day. Postoperative Holter ECG and echocardiography showed no abnormalities. It is likely that stimulation of the trachea triggered vagovagal reflex and propofol prolonged AV conduction, causing the AV block.

[Monitoring depth of anesthesia: a comparision between electroencephalographic nonlinear index and bispectral index].

PubMed

Yu, Hai; Yang, Xiao-Yun; Zhu, Da; Du, Run-Zi; Yin, Yan; Zhou, Rong-Hua; Liu, Bin

2010-01-01

To compare the efficiency and accuracy of electroencephalographic nonlinear index (ENI) and bispectral index (BIS) in monitoring depth of anesthesia during general anesthesia. Thirty patients undergoing elective abdominal surgery were recruited. The ability of ENI and BIS to distinguish between the anesthetic states (awake, loss of eyelash reflex, loss of response, steady anesthesia, first reaction and extubation) was analyzed with prediction probability (Pk). Correlation between ENI and BIS was tested by nonparametric Spearman rank correlation analysis, with data paired from awake through to extubation. The clinical performances of ENI and BIS were evaluated with success rate, responsiveness, and recovery time. ENI and BIS were better than mean arterial pressure (MAP) and heart rate (HR) for distinguishing between the states of anesthesia. ENI correlated strongly with BIS from the stage of awake through to extubation (r = 0.93). No differences were found between ENI and BIS in success rate and responsiveness; but the recovery time was shorter with ENI than with BIS. ENI and BIS provide similar information reflecting the states of anesthesia, which allows accurate distinguishment between different states of anesthesia. The clinical performance of ENI is better than that of BIS.

Bourdieu's Reflexive Sociology and "Spaces of Points of View": Whose Reflexivity, Which Perspective?

ERIC Educational Resources Information Center

Kenway, Jane; McLeod, Julie

2004-01-01

This paper considers Bourdieu's concepts of perspectivism and reflexivity, looking particularly at how he develops arguments about these in his recent work, The Weight of the World (1999) and Pascalian Meditations (2000b). We explicate Bourdieu's distinctive purposes and deployment of these terms and approaches, and discuss how this compares with…

Processing Reflexives in a Second Language: The Timing of Structural and Discourse-Level Constraints

ERIC Educational Resources Information Center

Felser, Claudia; Cunnings, Ian

2012-01-01

We report the results from two eye-movement monitoring experiments examining the processing of reflexive pronouns by proficient German-speaking learners of second language (L2) English. Our results show that the nonnative speakers initially tried to link English argument reflexives to a discourse-prominent but structurally inaccessible antecedent,…

Reflexive Management Learning: An Integrative Review and a Conceptual Typology

ERIC Educational Resources Information Center

Cotter, Richard J.; Cullen, John G.

2012-01-01

The scale and reach of the recent global financial has created a fresh wave of interest in exploring more sustainable forms of management. A central thrust behind this trend in the practice of management development and education has been the accentuation of reflexivity. There are many variations in how reflexivity is understood, and this article…

Reflexive Language and Ethnic Minority Activism in Hong Kong: A Trajectory-Based Analysis

ERIC Educational Resources Information Center

Pérez-Milans, Miguel; Soto, Carlos

2016-01-01

This article engages with Archer's call to further research on reflexivity and social change under conditions of late modernity (2007, 2010, 2012) from the perspective of existing work on reflexive discourse in the language disciplines (Silverstein 1976, Lucy 1993). Drawing from a linguistic ethnography of the networked trajectories of a group of…

More than Meets the Eye: The Use of Videonarratives to Facilitate Doctoral Students' Reflexivity on Their Doctoral Journeys

ERIC Educational Resources Information Center

Taylor, Carol A.

2011-01-01

This article discusses findings from a UK Higher Education Academy project, which used digital video to promote doctoral students' reflexivity. The project aimed to facilitate doctoral students' research skills through the making of videonarratives; create spaces for reflexivity on the relations between research, narrative and identity; and…

Reflexivity and the Politics of Knowledge: Researchers as "Brokers" and "Translators" of Educational Development

ERIC Educational Resources Information Center

Sriprakash, Arathi; Mukhopadhyay, Rahul

2015-01-01

This paper interrogates the ways in which "reflexivity" has proliferated as a normative methodological discourse in the field of international and comparative education. We argue that the dominant approach to reflexivity foregrounds the standpoints of researchers and their subjects in a way that does not attend to the situated,…

Bourdieu and Science Studies: Toward a Reflexive Sociology

ERIC Educational Resources Information Center

Hess, David J.

2011-01-01

Two of Bourdieu's fundamental contributions to science studies--the reflexive analysis of the social and human sciences and the concept of an intellectual field--are used to frame a reflexive study of the history and social studies of science and technology as an intellectual field in the United States. The universe of large, Ph.D.-granting…

A Comparison of Statistical Models for Calculating Reliability of the Hoffmann Reflex

ERIC Educational Resources Information Center

Christie, A.; Kamen, G.; Boucher, Jean P.; Inglis, J. Greig; Gabriel, David A.

2010-01-01

The Hoffmann reflex is obtained through surface electromyographic recordings, and it is one of the most common neurophysiological techniques in exercise science. Measurement and evaluation of the peak-to-peak amplitude of the Hoffmann reflex has been guided by the observation that it is a variable response that requires multiple trials to obtain a…

Withdrawal: Expanding a Key Addiction Construct.

PubMed

Piper, Megan E

2015-12-01

Withdrawal is an essential component of classical addiction theory; it is a vital manifestation of dependence and motivates relapse. However, the traditional conceptualization of withdrawal as a cohesive collection of symptoms that emerge during drug deprivation and decline with either the passage of time or reinstatement of drug use, may be inadequate to explain scientific findings or fit with modern theories of addiction. This article expands the current understanding of tobacco withdrawal by examining: (1) withdrawal variability; (2) underlying causes of withdrawal variability, including biological and person factors, environmental influences, and the influence of highly routinized behavioral patterns; (3) new withdrawal symptoms that allow for enhanced characterization of the withdrawal experience; and (4) withdrawal-related cognitive processes. These topics provide guidance regarding the optimal assessment of withdrawal and illustrate the potential impact modern withdrawal conceptualization and assessment could have on identifying treatment targets. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Stretch reflex excitability of the anti-gravity ankle extensor muscle in elderly humans.

PubMed

Kawashima, N; Nakazawa, K; Yamamoto, S-I; Nozaki, D; Akai, M; Yano, H

2004-01-01

To examine whether the stretch reflex excitability of the soleus muscle changes with age, stretch reflexes at rest (REST) and during weak voluntary contractions (ACT) were elicited in 18 older and 14 younger subjects. The amplitude of the stretch reflex responses and gain, defined as the gradient of the regression line for the relation between stretch reflex responses against the angular velocity of the applied perturbation, were evaluated in each short-latency (M1) and two long-latency components (M2 and M3). It was found that in the older group, both the amplitude and gain of the M1 component did not change from the REST to the ACT conditions, whereas in the younger group both variables significantly increased from the REST to ACT conditions. The latency of the M1 component was significantly shorter under the REST condition (older vs. younger: 51.8 +/- 7.37 vs. 55.1 +/- 8.69 ms), while no group differences were found in those variables under the ACT condition, suggesting that the muscle-tendon complexes of SOL muscles of the older subjects were less elastic and had less slack, probably due to age-related histochemical alterations. Further, the Hoffman reflex (H-reflex), elicited during the REST condition in 10 older and 11 younger subjects showed no significant differences, suggesting that the soleus motoneuron response to the Ia input was comparable between the two subject groups. The histochemical alterations occurring with the ageing process might augment the short-latency stretch reflex in the SOL muscle without enhancement of motoneuronal excitability, and this effect might be masked when the muscle is voluntarily activated.

The subject-fixated coaxially sighted corneal light reflex: a clinical marker for centration of refractive treatments and devices.

PubMed

Chang, Daniel H; Waring, George O

2014-11-01

To describe the inconsistencies in definition, application, and usage of the ocular reference axes (optical axis, visual axis, line of sight, pupillary axis, and topographic axis) and angles (angle kappa, lambda, and alpha) and to propose a precise, reproducible, clinically defined reference marker and axis for centration of refractive treatments and devices. Perspective. Literature review of papers dealing with ocular reference axes, angles, and centration. The inconsistent definitions and usage of the current ocular axes, as derived from eye models, limit their clinical utility. With a clear understanding of Purkinje images and a defined alignment of the observer, light source/fixation target, and subject eye, the subject-fixated coaxially sighted corneal light reflex can be a clinically useful reference marker. The axis formed by connecting the subject-fixated coaxially sighted corneal light reflex and the fixation point, the subject-fixated coaxially sighted corneal light reflex axis, is independent of pupillary dilation and phakic status of the eye. The relationship of the subject-fixated coaxially sighted corneal light reflex axis to a refined definition of the visual axis without reference to nodal points, the foveal-fixation axis, is discussed. The displacement between the subject-fixated coaxially sighted corneal light reflex and pupil center is described not by an angle, but by a chord, here termed chord mu. The application of the subject-fixated coaxially sighted corneal light reflex to the surgical centration of refractive treatments and devices is discussed. As a clinically defined reference marker, the subject-fixated coaxially sighted corneal light reflex avoids the shortcomings of current ocular axes for clinical application and may contribute to better consensus in the literature and improved patient outcomes. Copyright © 2014 Elsevier Inc. All rights reserved.

Arm Dominance Affects Feedforward Strategy more than Feedback Sensitivity during a Postural Task

PubMed Central

Walker, Elise H. E.; Perreault, Eric J.

2015-01-01

Handedness is a feature of human motor control that is still not fully understood. Recent work has demonstrated that the dominant and nondominant arm each excel at different behaviors, and has proposed that this behavioral asymmetry arises from lateralization in the cerebral cortex: the dominant side specializes in predictive trajectory control, while the nondominant side is specialized for impedance control. Long-latency stretch reflexes are an automatic mechanism for regulating posture, and have been shown to contribute to limb impedance. To determine whether long-latency reflexes also contribute to asymmetric motor behavior in the upper limbs, we investigated the effect of arm dominance on stretch reflexes during a postural task that required varying degrees of impedance control. Our results demonstrated slightly but significantly larger reflex responses in the biarticular muscles of the nondominant arm, as would be consistent with increased impedance control. These differences were attributed solely to higher levels of voluntary background activity in the nondominant biarticular muscles, indicating that feedforward strategies for postural stability may differ between arms. Reflex sensitivity, which was defined as the magnitude of the reflex response for matched levels of background activity, was not significantly different between arms for a broad subject population ranging from 23–51 years of age. These results indicate that inter-arm differences in feedforward strategies are more influential during posture than differences in feedback sensitivity, in a broad subject population. Interestingly, restricting our analysis to subjects under 40 years of age revealed a small increase in long-latency reflex sensitivity in the nondominant arm relative to the dominant arm. Though our subject numbers were small for this secondary analysis, it suggests that further studies may be required to assess the influence of reflex lateralization throughout development. PMID:25850407

Comprehensive neuromechanical assessment in stroke patients: reliability and responsiveness of a protocol to measure neural and non-neural wrist properties.

PubMed

van der Krogt, Hanneke; Klomp, Asbjørn; de Groot, Jurriaan H; de Vlugt, Erwin; van der Helm, Frans Ct; Meskers, Carel Gm; Arendzen, J Hans

2015-03-13

Understanding movement disorder after stroke and providing targeted treatment for post stroke patients requires valid and reliable identification of biomechanical (passive) and neural (active and reflexive) contributors. Aim of this study was to assess test-retest reliability of passive, active and reflexive parameters and to determine clinical responsiveness in a cohort of stroke patients with upper extremity impairments and healthy volunteers. Thirty-two community-residing chronic stroke patients with an impairment of an upper limb and fourteen healthy volunteers were assessed with a comprehensive neuromechanical assessment protocol consisting of active and passive tasks and different stretch reflex-eliciting measuring velocities, using a haptic manipulator and surface electromyography of wrist flexor and extensor muscles (Netherlands Trial Registry number NTR1424). Intraclass correlation coefficients (ICC) and Standard Error of Measurement were calculated to establish relative and absolute test-retest reliability of passive, active and reflexive parameters. Clinical responsiveness was tested with Kruskal Wallis test for differences between groups. ICC of passive parameters were fair to excellent (0.45 to 0.91). ICC of active parameters were excellent (0.88-0.99). ICC of reflexive parameters were fair to good (0.50-0.74). Only the reflexive loop time of the extensor muscles performed poor (ICC 0.18). Significant differences between chronic stroke patients and healthy volunteers were found in ten out of fourteen parameters. Passive, active and reflexive parameters can be assessed with high reliability in post-stroke patients. Parameters were responsive to clinical status. The next step is longitudinal measurement of passive, active and reflexive parameters to establish their predictive value for functional outcome after stroke.

Arm dominance affects feedforward strategy more than feedback sensitivity during a postural task.

PubMed

Walker, Elise H E; Perreault, Eric J

2015-07-01

Handedness is a feature of human motor control that is still not fully understood. Recent work has demonstrated that the dominant and nondominant arm each excel at different behaviors and has proposed that this behavioral asymmetry arises from lateralization in the cerebral cortex: the dominant side specializes in predictive trajectory control, while the nondominant side is specialized for impedance control. Long-latency stretch reflexes are an automatic mechanism for regulating posture and have been shown to contribute to limb impedance. To determine whether long-latency reflexes also contribute to asymmetric motor behavior in the upper limbs, we investigated the effect of arm dominance on stretch reflexes during a postural task that required varying degrees of impedance control. Our results demonstrated slightly but significantly larger reflex responses in the biarticular muscles of the nondominant arm, as would be consistent with increased impedance control. These differences were attributed solely to higher levels of voluntary background activity in the nondominant biarticular muscles, indicating that feedforward strategies for postural stability may differ between arms. Reflex sensitivity, which was defined as the magnitude of the reflex response for matched levels of background activity, was not significantly different between arms for a broad subject population ranging from 23 to 51 years of age. These results indicate that inter-arm differences in feedforward strategies are more influential during posture than differences in feedback sensitivity, in a broad subject population. Interestingly, restricting our analysis to subjects under 40 years of age revealed a small increase in long-latency reflex sensitivity in the nondominant arm relative to the dominant arm. Though our subject numbers were small for this secondary analysis, it suggests that further studies may be required to assess the influence of reflex lateralization throughout development.

Pre- and post-alpha motoneuronal control of the soleus H-reflex during sinusoidal hip movements in human spinal cord injury

PubMed Central

Knikou, Maria; Chaudhuri, Debjani; Kay, Elizabeth; Schmit, Brian D.

2006-01-01

The aim of this study was to establish the contribution of hip-mediated sensory feedback to spinal interneuronal circuits during dynamic conditions in people with incomplete spinal cord injury (SCI). Specifically, we investigated the effects of synergistic and antagonistic group I afferents on the soleus H-reflex during imposed sinusoidal hip movements. The soleus H-reflex was conditioned by stimulating the common peroneal nerve (CPN) at short (2, 3, and 4 ms) and long (80, 100, and 120 ms) conditioning test (C-T) intervals to assess the reciprocal and pre-synaptic inhibition of the soleus H-reflex, respectively. The soleus H-reflex was also conditioned by medial gastrocnemius (MG) nerve stimulation at C-T intervals ranging from 4 to 7 ms to assess changes in autogenic Ib inhibition during hip movement. Sinusoidal hip movements were imposed to the right hip joint at 0.2 Hz by the Biodex system while subjects were supine. The effects of sinusoidal hip movement on five leg muscles along with hip, knee, and ankle joint torques were also established during sensorimotor conditioning of the reflex. Phase-dependent modulation of antagonistic and synergistic muscle afferents was present during hip movement, with the reciprocal, pre-synaptic, and Ib inhibition to be significantly reduced during hip extension and reinforced during hip flexion. Reflexive muscle and joint torque responses – induced by the hip movement – were entrained to specific phases of hip movement. This study provides evidence that hip-mediated input acts as a controlling signal of pre- and post-alpha motoneuronal control of the soleus H-reflex. The expression of these spinal interneuronal circuits during imposed sinusoidal hip movements is discussed with respect to motor recovery in humans after SCI. PMID:16782072

Estimated Withdrawals and Other Elements of Water Use in the Great Lakes Basin of the United States in 2005

USGS Publications Warehouse

Mills, Patrick C.; Sharpe, Jennifer B.

2010-01-01

Estimates of water withdrawals in the United States part of the Great Lakes Basin and 107 of its watersheds designated by the 8-digit hydrologic unit code (HUCs) indicate that about 30.3 billion gallons per day (Bgal/d) were withdrawn for practically all categories of use in 2005. Virtually all water withdrawn was freshwater. Surface-water withdrawals totaled 28.8 Bgal/d, or 95 percent of total withdrawals; about 24 Bgal/d was withdrawn from the Great Lakes or their connecting channels. Total withdrawals, and total surface-water withdrawals, decreased 7 percent from 1995 to 2005, generally following the withdrawal trends of industrial use and that of the largest use-thermoelectric power. Groundwater withdrawals increased 3 percent from 1995 to 2005 and 33 percent during 1985-2005. The substantial increase since 1985 results primarily from increases in irrigation and self-supplied domestic withdrawals. In 2005, withdrawals for public supply, domestic, and irrigation use accounted for 81 percent of groundwater withdrawals. About 21.9 Bgal/d, or 72 percent of total withdrawals for 2005, was used for thermoelectric power. Virtually all of this water was derived from surface water and used for once-through cooling at powerplants. As such, the reuse potential of this water in the basin is high, with the majority of the withdrawn water returned to its surface-water source. Public-supply withdrawals were 3.81 Bgal/d (13 percent), with withdrawals declining by about 13 percent from 1995 to 2005. In 2005, about 77 percent of the population in the Great Lakes Basin obtained drinking water from public suppliers, compared to about 78 percent in 1995 and 83 percent in 1985. Surface water consistently provided about 88 percent of the total withdrawals for public supply since 1985. Self-supplied industrial withdrawals in 2005 totaled 2.93 Bgal/d (10 percent), possibly as much as 30 percent less than in 1995. Surface water was the source for 95 percent of industrial withdrawals. Combined withdrawals for mining, irrigation, domestic, aquaculture, and livestock use (in order of decreasing rate) were 1.63 Bgal/d, or only 5 percent of total withdrawals; the withdrawals were distributed almost equally between surface-water and groundwater sources. Withdrawals for each of these uses, except livestock, increased almost continuously during 1985-2005. Withdrawals for mining increased 103 percent and for irrigation 94 percent during 1985-2005; livestock withdrawals decreased 25 percent from their peak in 1990. The number of irrigated acres increased 56 percent since 1985, totaling 750,000 acres in 2005. No use of reclaimed wastewater for industrial or irrigation applications was reported; however, sources of information regarding its use were sparse. Within the basin, the Lake Michigan watershed accounted for 15.0 Bgal/d, or 49 percent, of total water withdrawals for 2005; an estimated 12.3 Bgal/d was withdrawn directly from Lake Michigan. The State of Michigan accounted for 38 percent of total water withdrawals, representing the largest surface-water withdrawals (primarily for thermoelectric power use) and groundwater withdrawals (primarily for public supply and self-supplied domestic use). A disproportionately large percentage of surface-water withdrawals (6 percent, 1.80 Bgal/d) were in Illinois, given this state represents less than 1 percent of the land area of the basin. Ninety percent of the Illinois population served by the water withdrawn from Lake Michigan for public supply resides outside the basin. Within land-based HUCs, the Lower Maumee (04100009) of Ohio accounted for the largest total withdrawal and total surface-water withdrawal (about 0.75 Bgal/d). The St. Joseph (04050001) of Michigan and Indiana accounted for the largest total groundwater withdrawal (0.25 Bgal/d).

Modulation of Ethanol Withdrawal–Induced Anxiety-Like Behavior During Later Withdrawals by Treatment of Early Withdrawals With Benzodiazepine/γ-Aminobutyric Acid Ligands

PubMed Central

Knapp, Darin J.; Overstreet, David H.; Breese, George R.

2010-01-01

Background Anxiety states, including those arising during acute or protracted withdrawal periods, may be precipitating factors in alcoholic relapse. Given the cyclical nature of ethanol withdrawal associated with repeated cycles of ethanol intake and abstinence in a pattern that often spans years, meaningful attempts to model ethanol withdrawal–associated anxiety should incorporate cycled ethanol treatments. The studies reported herein examined the effects of γ-aminobutyric acid–modulating drugs on social interaction behavior—an established model of anxiety—in rats exposed to repeated cycles of ethanol treatment and withdrawal. Methods Rats were exposed to 8 to 12 g/kg/day ethanol during three 7-day dietary cycles (5 days on ethanol diet followed by 2 days on control diet). Ethanol was administered either at hour 4 of withdrawal after cessation of each of the first 2 ethanol cycles or during the final withdrawal only. In other groups, the early withdrawals were treated with alphaxalone, diazepam, PK11159, or flumazenil to block anxiety-like behavior during an untreated later (third) withdrawal. The benzodiazepine inverse agonist DMCM (methyl–6, 7–dymerhoxy–4–ethyl–beta–carboline–3–carboxylate) was also given repeatedly to determine whether it would sensitize anxiety-like behavior during a future withdrawal. Finally, the effects of all drugs on deficits in locomotor behavior were assessed. Results Pretreatment of earlier withdrawals with alphaxalone, diazepam, ethanol, or flumazenil reduced social interaction deficits during a later withdrawal, but pretreatment with PK11195 did not. In contrast, DMCM administered in lieu of early withdrawals increased social interaction deficits during an untreated later withdrawal. Locomotor deficits were significantly reversed only by the acute ethanol and diazepam treatment during the final withdrawal. Conclusions Single-dose administration of drugs that enhance or diminish activity at benzodiazepine–γ-aminobutyric acid- receptors during earlier withdrawals reduced or potentiated, respectively, anxiety-like behavior during later, drug-free withdrawals. These results support the potential of the novel strategy of using prophylactic therapy administered during early withdrawals to ameliorate symptoms of later withdrawals. PMID:15834220

Reflexive Research Ethics in Fetal Tissue Xenotransplantation Research

PubMed Central

Panikkar, Bindu; Smith, Natasha; Brown, Phil

2013-01-01

For biomedical research in which the only involvement of the human subject is the provision of tissue or organ samples, a blanket consent, i.e. consent to use the tissue for anything researchers wish to do, is considered by many to be adequate for legal and IRB requirements. Alternatively, a detailed informed consent provides patients or study participants with more thorough information about the research topic. We document here the beliefs and opinions of the research staff on informed consent and the discussion-based reflexive research ethics process that we employed in our fetal tissue xenotransplantion research on the impact of environmental exposures on fetal development. Reflexive research ethics entails the continued adjustment of research practice according to relational and reflexive understandings of what might be beneficent or harmful. Such reflexivity is not solely an individual endeavor, but rather a collective relationship between all actors in the research process. PMID:23074992

Charge state distribution and emission characteristics in a table top reflex discharge - Effect of ion confinement and electrons accelerated across the sheath

DOE PAGES

Kumar, Deepak; Englesbe, Alexander; Parman, Matthew; ...

2015-11-05

Tabletop reflex discharges in a Penning geometry have many applications including ion sources and eXtreme Ultra-Violet (XUV) sources. The presence of primary electrons accelerated across the cathode sheaths is responsible for the distribution of ion charge states and of the unusually high XUV brightness of these plasmas. Absolutely calibrated space resolved XUV spectra from a table top reflex discharge operating with Al cathodes and Ne gas are presented. The spectra are analyzed with a new and complete model for ion charge distribution in similar reflex discharges. The plasma in the discharge was found to have a density of ~10 18mmore » –3 with a significant fraction >0.01 of fast primary electrons. As a result, the implications of the new model on the ion states achievable in a tabletop reflex plasma discharge are also discussed.« less

Effects of acute alcohol withdrawal on nest building in mice selectively bred for alcohol withdrawal severity.

PubMed

Greenberg, Gian D; Phillips, Tamara J; Crabbe, John C

2016-10-15

Nest building has been used to assess thermoregulatory behavior and positive motivational states in mice. There are known genetic influences on ethanol withdrawal severity as well as individual/thermoregulatory nest building. Withdrawal Seizure-Prone (WSP-1, WSP-2) and Withdrawal Seizure-Resistant (WSR-1, WSR-2) mice were selectively bred for high vs low handling-induced convulsion (HIC) severity, respectively, during withdrawal from chronic ethanol vapor inhalation. They also differ in HIC severity during withdrawal from an acute, 4g/kg ethanol injection. In our initial study, withdrawal from an acute dose of ethanol dose-dependently impaired nest building over the initial 24h of withdrawal in genetically segregating Withdrawal Seizure Control (WSC) mice. In two further studies, acute ethanol withdrawal suppressed nest building for up to two days in WSP-1 females. Deficits in nest building from ethanol were limited to the initial 10h of withdrawal in WSR-1 females and to the initial 24h of withdrawal in WSP-1 and WSR-1 males. Effects of ethanol on nest building for up to two days were found in WSP-2 and WSR-2 mice of both sexes. Nest building deficits in female mice from the first replicate could not be explained by a general decrease in locomotor behavior. These results suggest that nest building is a novel behavioral phenotype for indexing the severity of acute ethanol withdrawal, and that genes contributing to this trait differ from those affecting acute withdrawal HIC severity. Published by Elsevier Inc.

[The prevalence of obesity and metabolic syndrome in paediatric patients with epilepsy treated in monotherapy with valproic acid].

PubMed

Carmona-Vazquez, C R; Ruiz-Garcia, M; Pena-Landin, D M; Diaz-Garcia, L; Greenawalt, S R

2015-09-01

Valproic acid (VPA) is a useful antiepileptic drug for controlling different types of epilepsy. It has several side effects and is associated to increased body weight, as well as metabolic and endocrine disorders, including metabolic syndrome. To determine the prevalence of obesity and metabolic syndrome among paediatric patients with epilepsy treated in monotherapy with VPA. The study was cross-sectional, observational and analytical. A sample of patients treated with VPA between 2010-2014 were studied and the body mass index (BMI), abdominal perimeter, arterial blood pressure, glucose, triglycerides and high density lipoproteins (HDL) were studied in search of obesity and metabolic syndrome. Obesity was defined as a BMI above the 95th percentile, and metabolic syndrome was considered if at least three of the following criteria were fulfilled: abdominal perimeter above the 90th percentile, systolic arterial pressure above the 90th percentile, triglycerides above 110 mg/dL and HDL below 40 mg/dL. A total of 47 patients with a mean age of 10.1 ± 4 years were studied; 51.06% were males. Eight (17%) of them developed obesity and, of those, two (25%) had metabolic syndrome. Three patients went on to become overweight (6%). Statistically significant differences were observed in the mean age in comparison to the BMI groups, where the obese patients were adolescents (ANOVA, p = 0.0001) and those who took more VPA per day were the obese (ANOVA, p = 0.024). Patients treated with VPA who become obese may go on to develop metabolic syndrome. They require careful monitoring and, if they are seen to put on weight, withdrawal of the drug should be considered.

Effect of intravenous ascorbic acid infusion on blood loss during laparoscopic myomectomy: a randomized, double-blind, placebo-controlled trial.

PubMed

Lee, Banghyun; Kim, Kidong; Cho, Hye Yon; Yang, Eun Joo; Suh, Dong Hoon; No, Jae Hong; Lee, Jung Ryeol; Hwang, Jung Won; Do, Sang Hwan; Kim, Yong Beom

2016-04-01

Most interventions aimed at reducing bleeding during myomectomy lack sufficient evidence regarding their effectiveness. Recently, it was reported that intraoperative ascorbic acid administration effectively reduced blood loss during abdominal myomectomy. Therefore, this study aimed to investigate whether intravenous ascorbic acid infusion would affect intraoperative blood loss in women undergoing laparoscopic myomectomy. A randomized, double-blind, parallel-group, placebo-controlled trial including 50 women undergoing laparoscopic myomectomy was conducted. Women with ≤4 myomas, ≤9cm in maximum diameter were eligible. The study:control group ratio was 1:1. Starting 30minutes before anesthesia, 2g of ascorbic acid or a placebo were administered for 2hours intraoperatively. Intraoperative blood loss, the primary endpoint, was calculated as the difference between the volume of fluids acquired from suction and that used for irrigation of the abdominal cavity during surgery using constant values. Among the 50 randomized women, 1 and 3 in the study and control groups, respectively, were excluded due to withdrawal of consent, cancelation of surgery, or non-measurement of the primary endpoint. The baseline and operative characteristics were similar between the study and control groups, as was the intraoperative blood loss (193±204mL vs. 159±193mL, P=0.52). In addition, the operating time (95±29min vs. 110±52min; P=0.50) and decrease in hemoglobin level after surgery (1.9±1.31g/dL vs. 1.4±1.4g/dL; P=0.24) were similar between the study and control groups. Intravenous ascorbic acid infusion did not reduce intraoperative blood loss in women undergoing laparoscopic myomectomy. ClinicalTrials.gov, www.clinicaltrials.gov, NCT01715597. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

SSRI and SNRI withdrawal symptoms reported on an internet forum.

PubMed

Stockmann, Tom; Odegbaro, Dolapo; Timimi, Sami; Moncrieff, Joanna

2018-05-09

Antidepressant withdrawal symptoms are well-recognised, but their potential duration remains uncertain. We aimed to describe the characteristics of withdrawal associated with two popular classes of antidepressants, including duration. We analysed the content of a sample of posts on an antidepressant withdrawal website. We compared the characteristics of withdrawal associated with SSRIs and SNRIs, including time of onset, duration and nature of symptoms. 110 posts about SSRI withdrawal, and 63 concerning SNRI withdrawal, were analysed. The mean duration of withdrawal symptoms was significantly longer with SSRIs than SNRIs: 90.5 weeks (standard deviation, SD, 150.0) and 50.8 weeks (SD 76.0) respectively; p = 0.043). Neurological symptoms, such as 'brain zaps,' were more common among SNRI users (p = 0.023). Psychosexual/genitourinary symptoms may be more common among SSRI users (p = 0.054). The website aims to help people with antidepressant withdrawal, and is therefore likely to attract people who have difficulties. Length of prior use of antidepressants was long, with a mean of 252.2 weeks (SD 250.8). People accessing antidepressant withdrawal websites report experiencing protracted withdrawal symptoms. There are some differences in the characteristics of withdrawal associated with different classes of antidepressants.

Reconstruction of global gridded monthly sectoral water withdrawals for 1971-2010 and analysis of their spatiotemporal patterns

NASA Astrophysics Data System (ADS)

Huang, Zhongwei; Hejazi, Mohamad; Li, Xinya; Tang, Qiuhong; Vernon, Chris; Leng, Guoyong; Liu, Yaling; Döll, Petra; Eisner, Stephanie; Gerten, Dieter; Hanasaki, Naota; Wada, Yoshihide

2018-04-01

Human water withdrawal has increasingly altered the global water cycle in past decades, yet our understanding of its driving forces and patterns is limited. Reported historical estimates of sectoral water withdrawals are often sparse and incomplete, mainly restricted to water withdrawal estimates available at annual and country scales, due to a lack of observations at seasonal and local scales. In this study, through collecting and consolidating various sources of reported data and developing spatial and temporal statistical downscaling algorithms, we reconstruct a global monthly gridded (0.5°) sectoral water withdrawal dataset for the period 1971-2010, which distinguishes six water use sectors, i.e., irrigation, domestic, electricity generation (cooling of thermal power plants), livestock, mining, and manufacturing. Based on the reconstructed dataset, the spatial and temporal patterns of historical water withdrawal are analyzed. Results show that total global water withdrawal has increased significantly during 1971-2010, mainly driven by the increase in irrigation water withdrawal. Regions with high water withdrawal are those densely populated or with large irrigated cropland production, e.g., the United States (US), eastern China, India, and Europe. Seasonally, irrigation water withdrawal in summer for the major crops contributes a large percentage of total annual irrigation water withdrawal in mid- and high-latitude regions, and the dominant season of irrigation water withdrawal is also different across regions. Domestic water withdrawal is mostly characterized by a summer peak, while water withdrawal for electricity generation has a winter peak in high-latitude regions and a summer peak in low-latitude regions. Despite the overall increasing trend, irrigation in the western US and domestic water withdrawal in western Europe exhibit a decreasing trend. Our results highlight the distinct spatial pattern of human water use by sectors at the seasonal and annual timescales. The reconstructed gridded water withdrawal dataset is open access, and can be used for examining issues related to water withdrawals at fine spatial, temporal, and sectoral scales.

Reflexive Clitics in the Slavic and Romance Languages. A Comparative View from an Antipassive Perspective

ERIC Educational Resources Information Center

Medova, Lucie

2009-01-01

In this work, I offer a unified analysis of all the constructions that involve a reflexive clitic SE in Slavic and Romance languages. Next to canonical constructions, in which the reflexive clitic semantically identifies the two arguments of a transitive verb, cf. "John" SE "wash" means "John washes himself," there are constructions in which it is…

Leveraging Researcher Reflexivity to Consider a Classroom Event over Time: Reflexive Discourse Analysis of "What Counts"

ERIC Educational Resources Information Center

Anderson, Kate T.

2017-01-01

This article presents a reflexive and critical discourse analysis of classroom events that grew out of a cross-cultural partnership with a secondary school teacher in Singapore. I aim to illuminate how differences between researcher and teacher assumptions about what participation in classroom activities should look like came into high relief when…

Second Language Acquisition of Reflexive Verbs in Russian by L1 Speakers of English

ERIC Educational Resources Information Center

Alexieva, Petia Dimitrova

2012-01-01

This dissertation examines the process of acquisition of semantic classes of reflexive verbs (RVs) in Russian by L2 learners with a native language English. The purpose of this study is to bridge the gap between current linguistic knowledge and the pedagogical literature existing in English on reflexives in Russian. RVs are taught partially and…

Navigating the Tides of Change: Revisiting the Notion of Reflexivity in the Context of Social Learning for Transboundary Collective Experimentation

ERIC Educational Resources Information Center

Bastrup-Birk, Henriette; Wildemeersch, Danny

2011-01-01

Social learning theory in the context of multi-actor engagement tends to relate reflexivity primarily to critical questioning of theories-in-use. We argue that viewing suspensive dialogue and imaginative envisioning as additional stages of reflexivity will serve at least three purposes: prevent over-emphasis on instrumental rationality focusing on…

Role of stretch reflex in voluntary movements. [of human foot

NASA Technical Reports Server (NTRS)

Gottlieb, G. L.; Agarwal, G. C.

1975-01-01

The stretch reflex is often described as a spinal servomechanism, a device for assisting in the regulation of muscle length. Observation of the EMG response to mechanical interruption of voluntary movements fails to demonstrate a significant role for spinal reflexes at 40 msec latency. Two functional responses with latencies of 120 msec and 200 msec, implying supraspinal mediation, are observed.

[The role of the somatosensory cortex in the development of reflex analgesia].

PubMed

Kukushkin, M L; Reshetniak, V K; Durinian, R A

1986-06-01

The effects of reflex stimulation on the changes of nociception thresholds in animals before and after ablation of the somatosensory cortex were studied in behavioural experiments on adult cats. Electroacupuncture stimulation (EAP) was shown to increase nociception thresholds at all levels of the conventional scale. The ablation of both the first (S1) and the second (S2) somatosensory cortex led to EAP inefficiency at the side opposite to the ablation. Partial lesion of the lateral and suprasylvian gyri, used as control, did not affect the efficiency of reflex analgesia. It is concluded that somatosensory areas of the cortex, especially 2, are involved in reflex analgesia.

Do reflex seizures and spontaneous seizures form a continuum? - triggering factors and possible common mechanisms.

PubMed

Irmen, Friederike; Wehner, Tim; Lemieux, Louis

2015-02-01

Recent changes in the understanding and classification of reflex seizures have fuelled a debate on triggering mechanisms of seizures and their conceptual organization. Previous studies and patient reports have listed extrinsic and intrinsic triggers, albeit their multifactorial and dynamic nature is poorly understood. This paper aims to review literature on extrinsic and intrinsic seizure triggers and to discuss common mechanisms among them. Among self-reported seizure triggers, emotional stress is most frequently named. Reflex seizures are typically associated with extrinsic sensory triggers; however, intrinsic cognitive or proprioceptive triggers have also been assessed. The identification of a trigger underlying a seizure may be more difficult if it is intrinsic and complex, and if triggering mechanisms are multifactorial. Therefore, since observability of triggers varies and triggers are also found in non-reflex seizures, the present concept of reflex seizures may be questioned. We suggest the possibility of a conceptual continuum between reflex and spontaneous seizures rather than a dichotomy and discuss evidence to the notion that to some extent most seizures might be triggered. Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Extinction of the soleus H reflex induced by conditioning stimulus given after test stimulus.

PubMed

Hiraoka, Koichi

2002-02-01

To quantify the extinction of the soleus H reflex induced by a conditioning stimulus above the motor threshold to the post-tibial nerve applied 10-12 ms after a test stimulus (S2 method). Ten healthy subjects participated. The sizes of extinction induced by a test stimulus above the motor threshold (conventional method) and by the S2 method were measured. The size of the conditioned H reflex decreased as the intensity of the S2 conditioning stimulus increased. The decrease was less than that induced by the conventional method. The difference between the two methods correlated highly with the amount of orthodromically activated recurrent inhibition. When the S2 conditioning stimulus evoked an M wave that was roughly half of the maximum M wave, the decrease in the size of the conditioned H reflex depended on the size of the unconditioned H reflex. The S2 method allows us to observe extinction without changing the intensity of the test stimulus. The amount of the extinction depends partially on the size of the unconditioned H reflex. The difference in the sizes of extinction between the S2 and conventional methods should relate to recurrent inhibition.

Could the Use of Acoustic Reflexes Prior to Administering Distortion Product Otoacoustic Emissions (DPOAEs) Affect the Results of DPOAEs?

PubMed

Garrette, Rachel; Jones, Alisha L; Wilson, Martha W

2018-05-15

The purpose of this study is to investigate whether acoustic reflex threshold testing before administration of distortion product otoacoustic emissions can affect the results of the distortion product otoacoustic emissions testing using an automated protocol. Fifteen young adults with normal hearing ranging in age from 19 to 25 years participated in the study. All participants had clear external ear canals and normal Jerger Type A tympanograms and had passed a hearing screening. Testing was performed using the Interacoustics Titan acoustic reflex threshold and distortion product otoacoustic emissions protocol. Participants underwent baseline distortion product otoacoustic emissions. A paired-samples t test was conducted for both the right and left ears to assess within-group differences between baseline distortion product otoacoustic emissions and repeated distortion product otoacoustic emissions measures. No significant differences were found in distortion product otoacoustic emission measures following administration of acoustic reflexes. The use of a protocol when using an automated system that includes both acoustic reflexes and distortion product otoacoustic emissions is important. Overall, presentation of acoustic reflexes prior to measuring distortion product otoacoustic emission did not affect distortion product otoacoustic emission results; therefore, test sequence can be modified as needed.

Orthodontic treatment-induced temporal alteration of jaw-opening reflex excitability.

PubMed

Sasaki, Au; Hasegawa, Naoya; Adachi, Kazunori; Sakagami, Hiroshi; Suda, Naoto

2017-10-01

The impairment of orofacial motor function during orthodontic treatment needs to be addressed, because most orthodontic patients experience pain and motor excitability would be affected by pain. In the present study, the temporal alteration of the jaw-opening reflex excitability was investigated to determine if orthodontic treatment affects orofacial motor function. The excitability of jaw-opening reflex evoked by electrical stimulation on the gingiva and recorded bilaterally in the anterior digastric muscles was evaluated at 1 (D1), 3 (D3), and 7 days (D7) after orthodontic force application to the teeth of right side; morphological features (e.g., osteoclast genesis and tooth movement) were also evaluated. To clarify the underlying mechanism of orthodontic treatment-induced alteration of orofacial motor excitability, analgesics were administrated for 1 day. At D1 and D3, orthodontic treatment significantly decreased the threshold for inducing the jaw-opening reflex but significantly increased the threshold at D7. Other parameters of the jaw-opening reflex were also evaluated (e.g., latency, duration and area under the curve of anterior digastric muscles activity), and only the latency of the D1 group was significantly different from that of the other groups. Temporal alteration of the jaw-opening reflex excitability was significantly correlated with changes in morphological features. Aspirin (300 mg·kg -1 ·day -1 ) significantly increased the threshold for inducing the jaw-opening reflex, whereas a lower dose (75-150 mg·kg -1 ·day -1 ) of aspirin or acetaminophen (300 mg·kg -1 ·day -1 ) failed to alter the jaw-opening reflex excitability. These results suggest that an increase of the jaw-opening reflex excitability can be induced acutely by orthodontic treatment, possibly through the cyclooxygenase activation. NEW & NOTEWORTHY It is well known that motor function is affected by pain, but the effect of orthodontic treatment-related pain on the trigeminal motor excitability has not been fully understood. We found that, during orthodontic treatment, trigeminal motor excitability is acutely increased and then decreased in a week. Because alteration of trigeminal motor function can be evaluated quantitatively by jaw-opening reflex excitability, the present animal model may be useful to search for alternative approaches to attenuate orthodontic pain. Copyright © 2017 the American Physiological Society.

A novel reflex cough testing device.

PubMed

Fujiwara, Kazunori; Kawamoto, Katsuyuki; Shimizu, Yoko; Fukuhara, Takahiro; Koyama, Satoshi; Kataoka, Hideyuki; Kitano, Hiroya; Takeuchi, Hiromi

2017-01-18

The reflex cough test is useful for detecting silent aspiration, a risk factor for aspiration pneumonia. However, assessing the risk of aspiration pneumonia requires measuring not only the cough reflex but also cough strength. Currently, no reflex cough testing device is available that can directly measure reflex cough strength. We therefore developed a new testing device that can easily and simultaneously measure cough strength and the time until the cough reflex, and verified whether screening with this new instrument is feasible for evaluating the risk of aspiration pneumonia. This device consists of a special pipe with a double lumen, a nebulizer, and an electronic spirometer. We used a solution of prescription-grade L-tartaric acid to initiate the cough reflex. The solution was inhaled through a mouthpiece as a microaerosol produced by an ultrasonic nebulizer. The peak cough flow (PCF) of the induced cough was measured with the spirometer. The 70 patients who participated in this study comprised 49 patients without a history of pneumonia (group A), 21 patients with a history of pneumonia (group B), and 10 healthy volunteers (control group). With the novel device, PCF and time until cough reflex could be measured without adverse effects. The PCF values were 118.3 ± 64.0 L/min, 47.7 ± 38.5 L/min, and 254.9 ± 83.8 L/min in group A, group B, and the control group, respectively. The PCF of group B was significantly lower than that of group A and the control group (p < 0.0001), while that of group B was significantly lower than that of the control group (p < 0.0001). The time until the cough reflex was 4.2 ± 5.9 s, 7.0 ± 7.0 s, and 1 s in group A, group B, and the control group, respectively. This duration was significantly longer for groups A and B than for the control group (A: p < 0.001, B: p < 0.001), but there was no significant difference between groups A and B (p = 0.0907). Our newly developed device can easily and simultaneously measure the time until the cough reflex and the strength of involuntary coughs for assessment of patients at risk of aspiration pneumonia.

Quantitation of Contacts Among Sensory, Motor, and Serotonergic Neurons in the Pedal Ganglion of Aplysia

PubMed Central

Zhang, Han; Wainwright, Marcy; Byrne, John H.; Cleary, Leonard J.

2003-01-01

Present models of long-term sensitization in Aplysia californica indicate that the enhanced behavioral response is due, at least in part, to outgrowth of sensory neurons mediating defensive withdrawal reflexes. Presumably, this outgrowth strengthens pre-existing connections by formation of newsynapses with follower neurons. However, the relationship between the number of sensorimotor contacts and the physiological strength of the connection has never been examined in intact ganglia. As a first step in addressing this issue, we used confocal microscopy to examine sites of contact between sensory and motor neurons in naive animals. Our results revealed relatively fewcontacts between physiologically connected cells. In addition, the number of contact sites was proportional to the amplitude of the EPSP elicited in the follower motor neuron by direct stimulation of the sensory neuron. This is the first time such a correlation has been observed in the central nervous system. Serotonin is the neurotransmitter most closely examined for its role in modulating synaptic strength at the sensorimotor synapse. However, the structural relationship of serotonergic processes and sensorimotor synapses has never been examined. Surprisingly, serotonergic processes usually made contact with sensory and motor neurons at sites located relatively distant from the sensorimotor synapse. This result implies that heterosynaptic regulation is due to nondirected release of serotonin into the neuropil. PMID:14557611

cAMP modulates multiple K+ currents, increasing spike duration and excitability in Aplysia sensory neurons.

PubMed

Goldsmith, B A; Abrams, T W

1992-12-01

Enhancement of the defensive withdrawal reflex of Aplysia involves a prolongation of the action potentials of mechanosensory neurons, which contributes to facilitation of transmitter release from these cells. Recent reports have suggested that whereas cAMP-dependent modulation of K+ current increases sensory neuron excitability, a cAMP-independent decrease in K+ current may increase the action potential duration and, thus, facilitate transmitter release. We have tested this proposal using Walsh cAMP-dependent protein kinase inhibitor or activators of the cAMP cascade and found that cAMP plays a major role in the spike-broadening effects of facilitatory transmitter; however, broadening requires higher levels of activation of the cAMP-dependent kinase than does increasing excitability. A steeply voltage-dependent transient K+ current, termed IKV,early, and the slowly activating S-type K+ (S-K+) current are both reduced by activation of the cAMP cascade, although with different sensitivities to the second messenger, enabling excitability and spike duration to be regulated independently. Differences in cAMP sensitivity also suggested that the originally described S-K+ current actually consists of two independent components, a slowly activating component and a time-independent, "steady-state" current that is activated at rest.

Repeated pulses of serotonin required for long-term facilitation activate mitogen-activated protein kinase in sensory neurons of Aplysia

PubMed Central

Michael, Dan; Martin, Kelsey C.; Seger, Rony; Ning, Ming-Ming; Baston, Rene; Kandel, Eric R.

1998-01-01

Long-term facilitation of the connections between the sensory and motor neurons of the gill-withdrawal reflex in Aplysia requires five repeated pulses of serotonin (5-HT). The repeated pulses of 5-HT initiate a cascade of gene activation that leads ultimately to the growth of new synaptic connections. Several genes in this process have been identified, including the transcriptional regulators apCREB-1, apCREB-2, apC/EBP, and the cell adhesion molecule apCAM, which is thought to be involved in the formation of new synaptic connections. Here we report that the transcriptional regulators apCREB-2 and apC/EBP, as well as a peptide derived from the cytoplasmic domain of apCAM, are phosphorylated in vitro by Aplysia mitogen-activated protein kinase (apMAPK). We have cloned the cDNA encoding apMAPK and show that apMAPK activity is increased in sensory neurons treated with repeated pulses of 5-HT and by the cAMP pathway. These results suggest that apMAPK may participate with cAMP-dependent protein kinase during long-term facilitation in sensory cells by modifying some of the key elements involved in the consolidation of short- to long-lasting changes in synaptic strength. PMID:9465108

Analgesics as Reinforcers with Chronic Pain: Evidence from Operant Studies

PubMed Central

Ewan, Eric E.; Martin, Thomas J.

2013-01-01

Previously preclinical pain research has focused on simple behavioral endpoints to assess the efficacy of analgesics in acute and chronic pain models, primarily reflexive withdrawal from an applied mechanical or thermal stimulus. However recent research has been aimed at investigating other behavioral states in the presence of pain, including spontaneous, non-elicited pain. One approach is to investigate the reinforcing effects of analgesics in animals with experimental pain, which should serve as reinforcers by virtue of their ability to alleviate the relevant subjective states induced by pain. The gold standard for assessing drug reinforcement is generally accepted to be drug self-administration, and this review highlights the ability of drugs to serve as reinforcers in animals with experimental neuropathic pain, and the extent to which this behavior is altered in chronic pain states. Additionally, intracranial self-stimulation is an operant procedure that has been used extensively to study drug reinforcement mechanisms and the manner in which neuropathic pain alters the ability of drugs to serve as reinforcers in this paradigm will also be discussed. Drug self-administration and intracranial self-stimulation have promise as tools to investigate behavioral effects of analgesics in animals with chronic pain, particularly regarding the mechanisms through which these drugs motivate consumption in a chronic pain state. PMID:23973302

Pain processing in atypical Parkinsonisms and Parkinson disease: A comparative neurophysiological study.

PubMed

Avenali, Micol; Tassorelli, Cristina; De Icco, Roberto; Perrotta, Armando; Serrao, Mariano; Fresia, Mauro; Pacchetti, Claudio; Sandrini, Giorgio

2017-10-01

Pain is a frequent non-motor feature in Parkinsonism but mechanistic data on the alteration of pain processing are insufficient to understand the possible causes and to define specifically-targeted treatments. we investigated spinal nociception through the neurophysiological measure of the threshold (TR) of nociceptive withdrawal reflex (NWR) and its temporal summation threshold (TST) comparatively in 12 Progressive Supranuclear Palsy (PSP) subjects, 11 Multiple System Atrophy (MSA) patients, 15 Parkinson's disease (PD) subjects and 24 healthy controls (HC). We also investigated the modulatory effect of L-Dopa in these three parkinsonian groups. We found a significant reduction in the TR of NWR and in the TST of NWR in PSP, MSA and PD patients compared with HC. L-Dopa induced an increase in the TR of NWR in the PSP group while TST of NWR increased in both PSP and PD. Our neurophysiological findings identify a facilitation of nociceptive processing in PSP that is broadly similar to that observed in MSA and PD. Specific peculiarities have emerged for PSP. Our data advance the knowledge of the neurophysiology of nociception in the advanced phases of parkinsonian syndromes and on the role of dopaminergic pathways in the control on pain processing. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

Time-course of the DSM-5 cannabis withdrawal symptoms in poly-substance abusers

PubMed Central

2013-01-01

Background Evidence is accumulating that a cannabis withdrawal syndrome is common, of clinical significance, and has a clear time course. Up till now, very limited data exist on the cannabis withdrawal symptoms in patients with co-morbid substance use disorders, other than cannabis use and tobacco use. Methods Symptoms of withdrawal were assessed through patient self-reports during detoxification in Danish residential rehabilitation centers. Patients (n = 90) completed booklets three times during their first month at the treatment centre. Self-reported withdrawal symptoms was rated using the DSM-5 Withdrawal Symptom Check List with withdrawal symptoms from all classes of substances, with no indication that the described symptoms should be attributed to withdrawal. Self-reported time since last use of cannabis was used as a predictor of cannabis withdrawal severity. Results With the exception of loss of appetite, time since last use of cannabis was associated with all types of withdrawal symptoms listed in the DSM-5. Only four of 19 symptoms intended to measure withdrawal from other substances were related to time since last use of cannabis, including vivid, unpleasant dreams. Conclusions The findings yield strong support to the notion of a cannabis withdrawal syndrome, and gives further evidence for the inclusion of the criterion of vivid, unpleasant dreams. Further, the findings speak against the significance of demand characteristics in determining the course of the symptoms of cannabis withdrawal. PMID:24118963

Trigeminocardiac reflex during endoscopic juvenile nasopharyngeal angiofibroma surgery: an appraisal.

PubMed

Sharma, Shilpee Bhatia; Janakiram, Trichy Narayanan; Baxi, Hina; Chinnasamy, Balamurugan

2017-07-01

Juvenile nasopharyngeal angiofibroma is a locally aggressive benign tumour which has propensity to erode the skull base. The tumour spreads along the pathways of least resistance and is in close proximity to the extracranial part of trigeminal nerve. Advancements in expanded approaches for endoscopic excision of tumours in infratemporal fossa and pterygopalatine fossa increase the vulnerability for the trigeminocardiac reflex. The manipulation of nerve and its branches during tumour dissection can lead to sensory stimulation and thus inciting the reflex. The aim of our study is to report the occurrence of trigeminocardiac reflex in endoscopic excision of juvenile nasopharyngeal angiofibroma. To describe the occurence of trigeminocardiac reflex during endoscopic endonasal excision of juvenile nasopharyngeal angiofibroma. We studied the occurrence of TCR in 15 patients (out of 242 primary cases and 52 revision cases) operated for endoscopic endonasal excision of JNA. The drop in mean arterial blood pressure and heart rate were observed and measured. To the best of our knowledge of English literature, this is the first case series reporting TCR as complication in endoscopic excision of JNA. occurence of this reflex has been mentioned in various occular, maxillofacial surgeries but its occurence during endoscopic excision of JNA has never been reported before. Manifestation of trigeminocardiac reflex during surgery can alter the course of the surgery and is a potential threat to life. It is essential for the anesthetist and surgeons to be familiar with the presentations, preventive measures and management protocols.

Losing touch: age-related changes in plantar skin sensitivity, lower limb cutaneous reflex strength, and postural stability in older adults

PubMed Central

Peters, Ryan M.; McKeown, Monica D.; Carpenter, Mark G.

2016-01-01

Age-related changes in the density, morphology, and physiology of plantar cutaneous receptors negatively impact the quality and quantity of balance-relevant information arising from the foot soles. Plantar perceptual sensitivity declines with age and may predict postural instability; however, alteration in lower limb cutaneous reflex strength may also explain greater instability in older adults and has yet to be investigated. We replicated the age-related decline in sensitivity by assessing monofilament and vibrotactile (30 and 250 Hz) detection thresholds near the first metatarsal head bilaterally in healthy young and older adults. We additionally applied continuous 30- and 250-Hz vibration to drive mechanically evoked reflex responses in the tibialis anterior muscle, measured via surface electromyography. To investigate potential relationships between plantar sensitivity, cutaneous reflex strength, and postural stability, we performed posturography in subjects during quiet standing without vision. Anteroposterior and mediolateral postural stability decreased with age, and increases in postural sway amplitude and frequency were significantly correlated with increases in plantar detection thresholds. With 30-Hz vibration, cutaneous reflexes were observed in 95% of young adults but in only 53% of older adults, and reflex gain, coherence, and cumulant density at 30 Hz were lower in older adults. Reflexes were not observed with 250-Hz vibration, suggesting this high-frequency cutaneous input is filtered out by motoneurons innervating tibialis anterior. Our findings have important implications for assessing the risk of balance impairment in older adults. PMID:27489366

Volitional control of reflex cough

PubMed Central

Bolser, Donald C.; Davenport, Paul W.

2012-01-01

Multiple studies suggest a role for the cerebral cortex in the generation of reflex cough in awake humans. Reflex cough is preceded by detection of an urge to cough; strokes specifically within the cerebral cortex can affect parameters of reflex cough, and reflex cough can be voluntarily suppressed. However, it is not known to what extent healthy, awake humans can volitionally modulate the cough reflex, aside from suppression. The aims of this study were to determine whether conscious humans can volitionally modify their reflexive cough and, if so, to determine what parameters of the cough waveform and corresponding muscle activity can be modified. Twenty adults (18–40 yr, 4 men) volunteered for study participation and gave verbal and written informed consent. Participants were seated and outfitted with a facemask and pneumotacograph, and two surface EMG electrodes were positioned over expiratory muscles. Capsaicin (200 μM) was delivered via dosimeter and one-way (inspiratory) valve attached to a side port between the facemask and pneumotachograph. Cough airflow and surface EMG activity were recorded across tasks including 1) baseline, 2) small cough (cough smaller or softer than normal), 3) long cough (cough longer or louder than normal), and 4) not cough (alternative behavior). All participants coughed in response to 200 μM capsaicin and were able to modify the cough. Variables exhibiting changes include those related to the peak airflow during the expiratory phase. Results demonstrate that it is possible to volitionally modify cough motor output characteristics. PMID:22492938

Sexually stimulated testosterone release in male mice (Mus musculus): roles of genotype and sexual arousal.

PubMed

James, Peter J; Nyby, John G; Saviolakis, George A

2006-09-01

In virtually every mammalian species examined, some males exhibit reflexive testosterone release upon encountering a novel female (or female-related stimulus). At the same time, not every individual male (or every published study) provides evidence for reflexive testosterone release. Four experiments using house mice (Mus musculus) examined the hypothesis that both the male's genotype and his degree of sexual arousal (as indexed by ultrasonic mating calls) are related to such variability. In Experiment 1, CF-1 males exhibited reflexive testosterone elevations 30 min after encountering female urine. CK males, on the other hand, did not exhibit testosterone elevations 20, 30, 50, 60, or 80 min after encountering female urine (Experiments 1 and 2) suggesting this strain incapable of reflexive release. In Experiment 3, we measured both mating calls and reflexive testosterone release in response to female urine in CF-1 and CK males. Most males of both strains called vigorously to female urine but not to water. But, only CF-1 males exhibited significant testosterone elevations to female urine. In Experiment 4, DBA/2J males called vigorously to females followed by testosterone elevations 30 min later. The first 3 experiments support the hypothesis that male genotype is an important variable underlying mammalian reflexive testosterone release. Statistically significant correlations between mating calls in the first minute after stimulus exposure and testosterone elevations 30 min later (Experiments 3 and 4) support the hypothesis that, in capable males, reflexive testosterone release is related to the male's initial sexual arousal.

Effects of reflex-based self-defence training on police performance in simulated high-pressure arrest situations.

PubMed

Renden, Peter G; Savelsbergh, Geert J P; Oudejans, Raôul R D

2017-05-01

We investigated the effects of reflex-based self-defence training on police performance in simulated high-pressure arrest situations. Police officers received this training as well as a regular police arrest and self-defence skills training (control training) in a crossover design. Officers' performance was tested on several variables in six reality-based scenarios before and after each training intervention. Results showed improved performance after the reflex-based training, while there was no such effect of the regular police training. Improved performance could be attributed to better communication, situational awareness (scanning area, alertness), assertiveness, resolution, proportionality, control and converting primary responses into tactical movements. As officers trained complete violent situations (and not just physical skills), they learned to use their actions before physical contact for de-escalation but also for anticipation on possible attacks. Furthermore, they learned to respond against attacks with skills based on their primary reflexes. The results of this study seem to suggest that reflex-based self-defence training better prepares officers for performing in high-pressure arrest situations than the current form of police arrest and self-defence skills training. Practitioner Summary: Police officers' performance in high-pressure arrest situations improved after a reflex-based self-defence training, while there was no such effect of a regular police training. As officers learned to anticipate on possible attacks and to respond with skills based on their primary reflexes, they were better able to perform effectively.

Human H-reflexes are smaller in difficult beam walking than in normal treadmill walking.

PubMed

Llewellyn, M; Yang, J F; Prochazka, A

1990-01-01

Hoffman (H) reflexes were elicited from the soleus (SOL) muscle while subjects walked on a treadmill and on a narrow beam (3.5 cm wide, raised 34 cm from the floor). The speed of walking on the treadmill was selected for each subject to match the background activation level of their SOL muscle during beam walking. The normal reciprocal activation pattern of the tibialis anterior and SOL muscles in treadmill walking was replaced by a pattern dominated by co-contraction on the beam. In addition, the step cycle duration was more variable and the time spent in the swing phase was reduced on the beam. The H-reflexes were highly modulated in both tasks, the amplitude being high in the stance phase and low in the swing phase. The H-reflex amplitude was on average 40% lower during beam walking than treadmill walking. The relationship between the H-reflex amplitude and the SOL EMG level was quantified by a regression line relating the two variables. The slope of this line was on average 41% lower in beam walking than treadmill walking. The lower H-reflex gain observed in this study and the high level of fusimotor drive observed in cats performing similar tasks suggest that the two mechanisms which control the excitability of this reflex pathway (i.e. fusimotor action and control of transmission at the muscle spindle to moto-neuron synapse) may be controlled independently.

Compensatory increase of the cervico-ocular reflex with age in healthy humans

PubMed Central

Kelders, W P A; Kleinrensink, G J; van der Geest, J N; Feenstra, L; de Zeeuw, C I; Frens, M A

2003-01-01

The cervico-ocular reflex (COR) is an ocular stabilization reflex that is elicited by rotation of the neck. It works in conjunction with the vestibulo-ocular reflex (VOR) and the optokinetic reflex (OKR) in order to prevent visual slip over the retina due to self-motion. The gains of the VOR and OKR are known to decrease with age. We have investigated whether the COR, a reflexive eye movement elicited by rotation of the neck, shows a compensatory increase and whether a synergy exists between the COR and the other ocular stabilization reflexes. In the present study 35 healthy subjects of varying age (20–86 years) were rotated in the dark in a trunk-to-head manner (the head fixed in spaced with the body passively rotated under it) at peak velocities between 2.1 and 12.6 deg s−1 as a COR stimulus. Another 15 were subjected to COR, VOR and OKR stimuli at frequencies between 0.04 and 0.1 Hz. Three subjects participated in both tests. The position of the eyes was recorded with an infrared recording technique. We found that the COR-gain increases with increasing age and that there is a significant covariation between the gains of the VOR and COR, meaning that when VOR increases, COR decreases and vice versa. A nearly constant phase lag between the COR and the VOR of about 25 deg existed at all stimulus frequencies. PMID:12949226

Three-dimensional vestibular eye and head reflexes of the chameleon: characteristics of gain and phase and effects of eye position on orientation of ocular rotation axes during stimulation in yaw direction.

PubMed

Haker, H; Misslisch, H; Ott, M; Frens, M A; Henn, V; Hess, K; Sándor, P S

2003-07-01

We investigated gaze-stabilizing reflexes in the chameleon using the three-dimensional search-coil technique. Animals were rotated sinusoidally around an earth-vertical axis under head-fixed and head-free conditions, in the dark and in the light. Gain, phase and the influence of eye position on vestibulo-ocular reflex rotation axes were studied. During head-restrained stimulation in the dark, vestibulo-ocular reflex gaze gains were low (0.1-0.3) and phase lead decreased with increasing frequencies (from 100 degrees at 0.04 Hz to < 30 degrees at 1 Hz). Gaze gains were larger during stimulation in the light (0.1-0.8) with a smaller phase lead (< 30 degrees) and were close to unity during the head-free conditions (around 0.6 in the dark, around 0.8 in the light) with small phase leads. These results confirm earlier findings that chameleons have a low vestibulo-ocular reflex gain during head-fixed conditions and stimulation in the dark and higher gains during head-free stimulation in the light. Vestibulo-ocular reflex eye rotation axes were roughly aligned with the head's rotation axis and did not systematically tilt when the animals were looking eccentrically, up- or downward (as predicted by Listing's Law). Therefore, vestibulo-ocular reflex responses in the chameleon follow a strategy, which optimally stabilizes the entire retinal images, a result previously found in non-human primates.

Effect of Maturation of the Magnitude of Mechanosensitive and Chemosensitive Reflexes in the Premature Human Esophagus

PubMed Central

Jadcherla, Sudarshan Rao; Hoffmann, Raymond G.; Shaker, Reza

2014-01-01

Objectives To investigate the effect of esophageal mechanosensitive and chemosensitive stimulation on the magnitude and recruitment of peristaltic reflexes and upper esophageal sphincter (UES)-contractile reflex in premature infants. Study design Esophageal manometry and provocation testing were performed in the same 18 neonates at 33 and 36 weeks postmenstrual age (PMA). Mechanoreceptor and chemoreceptor stimulation were performed using graded volumes of air, water, and apple juice (pH 3.7), respectively. The frequency and magnitude of the resulting esophago-deglutition response (EDR) or secondary peristalsis (SP), and esophago-UES-contractile reflex (EUCR) were quantified. Results Threshold volumes to evoke EDR, SP, or EUCR were similar. The recruitment and magnitude of SP and EUCR increased with volume increments of air and water in either study (P < .05). However, apple juice infusions resulted in increased recruitment of EDR in the 33 weeks group (P < .05), and SP in the 36 weeks group (P < .05). The magnitude of EUCR was also volume responsive (all media, P < .05), and significant differences between media were noted (P < .05). At maximal stimulation (1 mL, all media), sensory-motor characteristics of peristaltic and EUCR reflexes were different (P < .05) between media and groups. Conclusions Mechano- and chemosensitive stimuli evoke volume-dependent specific peristaltic and UES reflexes at 33 and 36 weeks PMA. The recruitment and magnitude of these reflexes are dependent on the physicochemical properties of the stimuli in healthy premature infants. PMID:16860132

Lower Amplitude of the Hoffmann Reflex in Women With Patellofemoral Pain: Thinking Beyond Proximal, Local, and Distal Factors.

PubMed

de Oliveira Silva, Danilo; Magalhães, Fernando Henrique; Faria, Nathálie Clara; Pazzinatto, Marcella Ferraz; Ferrari, Deisi; Pappas, Evangelos; de Azevedo, Fábio Mícolis

2016-07-01

To investigate whether vastus medialis (VM) Hoffmann reflexes (H-reflexes) differ on the basis of the presence or absence of patellofemoral pain (PFP) and to assess the capability of VM H-reflex measurements in accurately discriminating between women with and without PFP. Cross-sectional study. Laboratory of biomechanics and motor control. Women (N=30) aged 18 to 35 years were recruited, consisting of 2 groups: women with PFP (n=15) and asymptomatic controls (n=15). Not applicable. Maximum evoked responses were obtained by electrical stimulation applied to the femoral nerve, and peak-to-peak amplitudes of maximal Hoffmann reflex (Hmax) and maximal motor wave (Mmax) ratios were calculated. Independent samples t tests were performed to identify differences between groups, and a receiver operating characteristic curve was constructed to assess the discriminatory capability of VM H-reflex measurements. VM Hmax/Mmax ratios were significantly lower in participants with PFP than in pain-free participants (P=.007). In addition, the VM Hmax/Mmax ratios presented large and balanced discriminatory capability values (sensitivity, 73%; specificity, 67%). This study is the first to show that VM H-reflexes are lower in women with PFP than in asymptomatic controls. Therefore, increasing the excitation of the spinal cord in PFP participants may be essential to maintaining the gains acquired during the rehabilitation programs. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

[Measuring the effect of eyeglasses on determination of squint angle with Purkinje reflexes and the prism cover test].

PubMed

Barry, J C; Backes, A

1998-04-01

The alternating prism and cover test is the conventional test for the measurement of the angle of strabismus. The error induced by the prismatic effect of glasses is typically about 27-30%/10 D. Alternatively, the angle of strabismus can be measured with methods based on Purkinje reflex positions. This study examines the differences between three such options, taking into account the influence of glasses. The studied system comprised the eyes with or without glasses, a fixation object and a device for recording the eye position: in the case of the alternate prism and cover test, a prism bar was required; in the case of a Purkinje reflex based device, light sources for generation of reflexes and a camera for the documentation of the reflex positions were used. Measurements performed on model eyes and computer ray traces were used to analyze and compare the options. When a single corneal reflex is used, the misalignment of the corneal axis can be measured; the error in this measurement due to the prismatic effect of glasses was 7.6%/10 D, the smallest found in this study. The individual Hirschberg ratio can be determined by monocular measurements in three gaze directions. The angle of strabismus can be measured with Purkinje reflex based methods if the fundamental differences between these methods and the alternate prism and cover test, and if the influence of glasses and other sources of error are accounted for.

[Treatment with sympathetic intravenous block with reserpine in work-related reflex sympathetic dystrophy].

PubMed

Morros, C; Cedo, F

1994-01-01

To assess the results obtained in treatment of sympathetic reflex dystrophy by sympathetic endovenous blockades with reserpine in working patients. We reviewed 170 diagnoses of sympathetic reflex dystrophy in 165 patients. One hundred seven were located in the foot, 13 were in the knee and 50 were in the hand. All were treated once a week for 3 weeks with local sympathetic endovenous blocks with reserpine (1 mg in the upper extremity and 1.5 mg in the lower extremity). We analyzed the location, etiology, course, X-rays, gammagrams, psychological state, other treatments, associated conditions, number of blocks received and side effects. The results were classified as excellent, good, fair and nil. We particularly reviewed sympathetic reflex dystrophy associated to Colles' fractures. Five hundred forty endovenous sympathetic blocks with reserpine were performed. Results obtained were excellent in 57 (34%) patients, good in 77 (45%), fair in 29 (17%) and nil in 7 (4%). Sympathetic reflex dystrophy leads to loss of 215 +/- 91 working days. In patients with Colles' fracture without sympathetic reflex dystrophy the loss is 96 +/- 31 days, although this period lengthens to 115 +/- 15 days if the two conditions are associated in stage I and to loss of 193 +/- 71 days if the association is in stage II. Results of treating sympathetic reflex dystrophy with sympathetic endovenous blocks with reserpine are satisfactory, particularly when diagnosis and treatment are early, clearly demonstrating the usefulness of this technique in workplace medicine.

Reflex epileptic mechanisms in humans: Lessons about natural ictogenesis.

PubMed

Wolf, Peter

2017-06-01

The definition of reflex epileptic seizures is that specific seizure types can be triggered by certain sensory or cognitive stimuli. Simple triggers are sensory (most often visual, more rarely tactile or proprioceptive; simple audiogenic triggers in humans are practically nonexistent) and act within seconds, whereas complex triggers like praxis, reading and talking, and music are mostly cognitive and work within minutes. The constant relation between a qualitatively, often even quantitatively, well-defined stimulus and a specific epileptic response provides unique possibilities to investigate seizure generation in natural human epilepsies. For several reflex epileptic mechanisms (REMs), this has been done. Reflex epileptic mechanisms have been reported less often in focal lesional epilepsies than in idiopathic "generalized" epilepsies (IGEs) which are primarily genetically determined. The key syndrome of IGE is juvenile myoclonic epilepsy (JME), where more than half of the patients present reflex epileptic traits (photosensitivity, eye closure sensitivity, praxis induction, and language-induced orofacial reflex myocloni). Findings with multimodal investigations of cerebral function concur to indicate that ictogenic mechanisms in IGEs largely (ab)use preexisting functional anatomic networks (CNS subsystems) normally serving highly complex physiological functions (e.g., deliberate complex actions and linguistic communication) which supports the concept of system epilepsy. Whereas REMs in IGEs, thus, are primarily function-related, in focal epilepsies, they are primarily localization-related. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic". Copyright © 2015 Elsevier Inc. All rights reserved.

Respiratory reflexes in response to nasal administration of halothane to anesthetized, spontaneously breathing dogs.

PubMed

Mutoh, T; Kanamaru, A; Tsubone, H; Nishimura, R; Sasaki, N

2000-03-01

To characterize and determine the sensory innervation of respiratory reflexes elicited by nasal administration of halothane to dogs. 10 healthy Beagles. Dogs underwent permanent tracheostomy and, 2 to 3 weeks later, were anesthetized with thiopental and alpha-chloralose administered IV. The nasal passages were functionally isolated so that halothane could be administered to the nasal passages while dogs were breathing 100% O2 via the tracheostomy. Respiratory reflexes in response to administration of halothane at concentrations of 1.25, 1.75, and 2.5 times the minimum alveolar concentration (MAC), and 5% (administered in 100% O2 at a flow rate of 5 L/min) were recorded. Reflexes in response to administration of 5% halothane were also recorded following transection of the infraorbital nerve, transection of the caudal nasal nerve, and nasal administration of lidocaine. Nasal administration of halothane induced an inhibition of breathing characterized by a dose-dependent increase in expiratory time and a resultant decrease in expired volume per unit time. Effects were noticeable immediately after the onset of halothane administration and lasted until its cessation. Reflex responses to halothane administration were attenuated by transection of the caudal nasal nerve and by nasal administration of lidocaine, but transection of the infraorbital nerve had no effect. Nasal administration of halothane at concentrations generally used for mask induction of anesthesia induces reflex inhibition of breathing. Afferent fibers in the caudal nasal nerve appear to play an important role in the reflex inhibition of breathing induced by halothane administration.

[An examination of the determinants of social withdrawal and affinity for social withdrawal].

PubMed

Watanabe, Asami; Matsui, Yutaka; Takatsuka, Yusuke

2010-12-01

This study examined the determinants of social withdrawal using data from a survey by the Tokyo Metropolitan Government Office for Youth Affairs and Public Safety (2008). In addition, this study identified young people who showed an affinity for social withdrawal although they were not in a state of withdrawal, and examined the determinants of an affinity for social withdrawal. The results of stepwise discriminant analysis showed that factors such as social phobia, depression, violence, and emotional bonds with family differentiated between the general youth group and the social withdrawal group and the "affinity group". Social phobia, violence, and refusal to be interfered in self-decision making differentiated between the social withdrawal group and the "affinity group". This study shows that an "affinity group" should be cared as well as an actual withdrawal group.

20 CFR 408.355 - Can you withdraw your application?

Code of Federal Regulations, 2010 CFR

2010-04-01

... Section 408.355 Employees' Benefits SOCIAL SECURITY ADMINISTRATION SPECIAL BENEFITS FOR CERTAIN WORLD WAR II VETERANS Filing Applications Withdrawal of Application § 408.355 Can you withdraw your application? (a) Request for withdrawal filed before a determination is made. You may withdraw your application...

"Is That A Method of Birth Control?" A Qualitative Exploration of Young Women's Use of Withdrawal.

PubMed

Arteaga, Stephanie; Gomez, Anu Manchikanti

2016-01-01

Despite its ubiquity, withdrawal is understudied as a family planning method. We investigated the context of and decision making around withdrawal use, drawing on in-depth, qualitative interviews with 38 Black and Latina women (ages 18 to 24). We examined contraceptive use histories to understand when and why participants used withdrawal. The majority of participants (n = 29; 76%) had used withdrawal in their lifetimes, though two-thirds of users mentioned withdrawal in their contraceptive histories only after interviewer prompts. Withdrawal was primarily used during transitions between contraceptive methods and when other methods were not desired. Relationship context was also an important factor, as many used withdrawal to increase intimacy with their partners; because they felt condoms were no longer necessary due to monogamy; or to fulfill their partners' preferences to increase sexual pleasure. Our findings indicate that decision making around withdrawal is embedded in situational and relational contexts. Future research should explore how health care providers and sex educators can engage young women in discussions of withdrawal's benefits and constraints. A harm reduction framework, which recognizes that optimal use of withdrawal is preferable to not using a pregnancy prevention method at all, may inform the ways that withdrawal can be addressed in clinical and educational settings.

Effects of Acute Withdrawal on Ethanol-Induced Conditioned Place Preference in DBA/2J mice

PubMed Central

Dreumont, Sarah E.; Cunningham, Christopher L.

2013-01-01

Rationale Re-exposure to ethanol during acute withdrawal might facilitate the transition to alcoholism by enhancing the rewarding effect of ethanol. Objective The conditioned place preference (CPP) procedure was used to test whether ethanol reward is enhanced during acute withdrawal. Methods DBA/2J mice were exposed to an unbiased one-compartment CPP procedure. Ethanol (0.75, 1.0 or 1.5 g/kg IP) was paired with a distinctive floor cue (CS+), whereas saline was paired with a different floor cue (CS−). The Withdrawal (W) group received CS+ trials during acute withdrawal produced by a large dose of ethanol (4 g/kg) given 8 h before each trial. The No Withdrawal (NW) group did not experience acute withdrawal during conditioning trials, but was matched for acute withdrawal experience. Floor preference was tested in the absence of ethanol or acute withdrawal. Results All groups eventually showed a dose-dependent preference for the ethanol-paired cue, but development of CPP was generally more rapid and stable in the W groups than in the NW groups. Acute withdrawal suppressed the normal activating effect of ethanol during CS+ trials, but there were no group differences in test activity. Conclusions Acute withdrawal enhanced ethanol’s rewarding effect as indexed by CPP. Since this effect depended on ethanol exposure during acute withdrawal, the enhancement of ethanol reward was likely mediated by the alleviation of acute withdrawal, i.e., negative reinforcement. Enhancement of ethanol reward during acute withdrawal may be a key component in the shift from episodic to chronic ethanol consumption that characterizes alcoholism. PMID:24096534

A genetic perspective on the proposed inclusion of cannabis withdrawal in DSM-5.

PubMed

Verweij, K J H; Agrawal, A; Nat, N O; Creemers, H E; Huizink, A C; Martin, N G; Lynskey, M T

2013-08-01

Various studies support the inclusion of cannabis withdrawal in the diagnosis of cannabis use disorder (CUD) in the upcoming DSM-5. The aims of the current study were to (1) estimate the prevalence of DSM-5 cannabis withdrawal (criterion B), (2) estimate the role of genetic and environmental influences on individual differences in cannabis withdrawal and (3) determine the extent to which genetic and environmental influences on cannabis withdrawal overlap with those on DSM-IV-defined abuse/dependence. The sample included 2276 lifetime cannabis-using adult Australian twins. Cannabis withdrawal was defined in accordance with criterion B of the proposed DSM-5 revisions. Cannabis abuse/dependence was defined as endorsing one or more DSM-IV criteria of abuse or three or more dependence criteria. The classical twin model was used to estimate the genetic and environmental influences on variation in cannabis withdrawal, along with its covariation with abuse/dependence. Of all the cannabis users, 11.9% met criteria for cannabis withdrawal. Around 50% of between-individual variation in withdrawal could be attributed to additive genetic variation, and the rest of the variation was mostly due to non-shared environmental influences. Importantly, the genetic influences on cannabis withdrawal almost completely (99%) overlapped with those on abuse/dependence. We have shown that cannabis withdrawal symptoms exist among cannabis users, and that cannabis withdrawal is moderately heritable. Genetic influences on cannabis withdrawal are the same as those affecting abuse/dependence. These results add to the wealth of literature that recommends the addition of cannabis withdrawal to the diagnosis of DSM-5 CUD.

Worldwide withdrawal of medicinal products because of adverse drug reactions: a systematic review and analysis.

PubMed

Onakpoya, Igho J; Heneghan, Carl J; Aronson, Jeffrey K

2016-07-01

We have systematically identified medicinal products withdrawn worldwide because of adverse drug reactions, assessed the level of evidence used for making the withdrawal decisions, and explored the patterns of withdrawals over time. We searched PubMed, the WHO database of withdrawn products, and selected texts. We included products that were withdrawn after launch from 1950 onwards, excluding non-human and over-the-counter medicines. We assessed the levels of evidence on which withdrawals were based using the Oxford Center for Evidence Based Medicine Levels of Evidence. Of 353 medicinal products withdrawn from any country, only 40 were withdrawn worldwide. Anecdotal reports were cited as evidence for withdrawal in 30 (75%) and deaths occurred in 27 (68%). Hepatic, cardiac, and nervous system toxicity accounted for over 60% of withdrawals. In 28 cases, the first withdrawal was initiated by the manufacturer. The median interval between the first report of an adverse drug reaction that led to withdrawal and the first withdrawal was 1 year (range 0-43 years). Worldwide withdrawals occurred within 1 year after the first withdrawal in any country. In conclusion, the time it takes for drugs to be withdrawn worldwide after reports of adverse drug reactions has shortened over time. However, there are inconsistencies in current withdrawal procedures when adverse drug reactions are suspected. A uniform method for establishing worldwide withdrawal of approved medicinal products when adverse drug reactions are suspected should be developed, to facilitate global withdrawals. Rapid synthesis of the evidence on harms should be a priority when serious adverse reactions are suspected.

A genetic perspective on the proposed inclusion of cannabis withdrawal in the DSM-5

PubMed Central

Verweij, K.J.H.; Agrawal, A.; Nat, N.O.; Creemers, H.E.; Huizink, A.C.; Martin, N.G.; Lynskey, M.T.

2013-01-01

Background Various studies support the inclusion of cannabis withdrawal to the diagnosis of cannabis use disorders in the upcoming DSM-5. The aims of the current study were to (1) estimate the prevalence of DSM-5 cannabis withdrawal (Criterion B), (2) estimate the role of genetic and environmental influences on individual differences in cannabis withdrawal, and (3) determine the extent to which genetic and environmental influences on cannabis withdrawal overlap with those on DSM-IV defined abuse/dependence. Methods The sample included 2276 lifetime cannabis-using adult Australian twins. Cannabis withdrawal was defined in accordance with Criterion B of the proposed DSM-5 revisions. Cannabis abuse/dependence was defined as endorsing one or more DSM-IV criteria of abuse or three or more dependence criteria. The classical twin model was used to estimate the genetic and environmental influences on variation in cannabis withdrawal, as well as its covariation with abuse/dependence. Results Of all cannabis users 11.9% met criteria for cannabis withdrawal. Around 50% of between-individual variation in withdrawal could be attributed to additive genetic variation, and the rest of the variation was mostly due to non-shared environmental influences. Importantly, the genetic influences on cannabis withdrawal almost completely (99%) overlapped with those on abuse/dependence. Conclusions We showed that cannabis withdrawal symptoms exist among cannabis users, and that cannabis withdrawal is moderately heritable. Genetic influences on cannabis withdrawal are the same as those influencing abuse/dependence. These results add to the wealth of literature that recommends the addition of cannabis withdrawal to the diagnosis of DSM-5 cannabis use disorders. PMID:23194657

Ethical Mindfulness and Reflexivity: Managing a Research Relationship with Children and Young People in a 14-Year Qualitative Longitudinal Research (QLR) Study

ERIC Educational Resources Information Center

Warin, Jo

2011-01-01

This article draws on the articulation of a value for reflexivity that has accumulated within qualitative methods debates in the past decade. It demonstrates how reflexivity is interwoven with the concept of ethical mindfulness. The argument has developed from a consideration of the ethical dilemmas that were a salient aspect of an ongoing…

Discontinuation of reflex testing of stool samples for vancomycin-resistant enterococci resulted in increased prevalence.

PubMed

Bodily, Mandy; McMullen, Kathleen M; Russo, Anthony J; Kittur, Nupur D; Hoppe-Bauer, Joan; Warren, David K

2013-08-01

Discontinuation of reflex testing of stool submitted for Clostridium difficile testing for vancomycin-resistant enterococci (VRE) led to an increase in the number of patients with healthcare-associated VRE bacteremia and bacteriuria (0.21 vs 0.36 cases per 1,000 patient-days; P<.01). Cost-benefit analysis showed reflex screening and isolation of VRE reduced hospital costs.

Reflex Responses to Ligament Loading: Implications for Knee Joint Stability

DTIC Science & Technology

2001-10-25

white noise approach", Prentice-Hall".:, 1978. [15] B. Grenfield and B. Wyke, "Reflex innervation of the temporo - mandibular joint .". Nature. 211(52...selective, depending on the magnitude of the angular perturbation. Keywords - Reflex, Periarticular tissue afferents, Joint stability I...INTRODUCTION Traditionally, joint stability has been considered to be purely mechanical in origin, with little or no consideration of neuromuscular

Reflex responses of paraspinal muscles to tapping

PubMed Central

Dimitrijevic, M R; Gregoric, M R; Sherwood, A M; Spencer, W A

1980-01-01

Erector spinae reflex studies in healthy subjects revealed two responses: a 12·0±1·6 ms latency, oligosynaptic response, and a 30 to 50 ms latency response with polysynaptic reflex characteristics. There was a silent period after the first and second responses. The effect of limb position, trunk, neck, postural changes, Jendrassik manoeuvre and vibration on both responses were also evaluated. PMID:7217957

Reflexes from pulmonary arterial baroreceptors in dogs: interaction with carotid sinus baroreceptors

PubMed Central

Moore, Jonathan P; Hainsworth, Roger; Drinkhill, Mark J

2011-01-01

Abstract In contrast to the reflex vasodilatation occurring in response to stimulation of baroreceptors in the aortic arch, carotid sinuses and coronary arteries, stimulation of receptors in the wall of pulmonary arteries results in reflex systemic vasoconstriction. It is rare for interventions to activate only one reflexogenic region, therefore we investigated how these two types of reflexes interact. In anaesthetized dogs connected to cardiopulmonary bypass, reflexogenic areas of the carotid sinuses, aortic arch and coronary arteries and the pulmonary artery were subjected to independently controlled pressures. Systemic perfusion pressure (SPP) measured in the descending aorta (constant flow) provided an index of systemic vascular resistance. In other experiments, sympathetic efferent neural activity was recorded in fibres dissected from the renal nerve (RSNA). Physiological increases in pulmonary arterial pressure (PAP) induced significant increases in SPP (+39.1 ± 10.4 mmHg) and RSNA (+17.6 ± 2.2 impulses s−1) whereas increases in carotid sinus pressure (CSP) induced significant decreases in SPP (−42.6 ± 10.8 mmHg) and RSNA (−42.8 ± 18.2 impulses s−1) (P < 0.05 for each comparison; paired t test). To examine possible interactions, PAP was changed at different levels of CSP in both studies. With CSP controlled at 124 ± 2 mmHg, the threshold, ‘set point’ and saturation pressures of the PAP–SPP relationship were higher than those with CSP at 60 ± 1 mmHg; this rightward shift was associated with a significant decrease in the reflex gain. Similarly, increasing CSP produced a rightward shift of the PAP–RSNA relationship, although the effect on reflex gain was inconsistent. Furthermore, the responses to changes in CSP were influenced by setting PAP at different levels; increasing the level of PAP from 5 ± 1 to 33 ± 3 mmHg significantly increased the set point and threshold pressures of the CSP–SPP relationship; the reflex gain was not affected. These results indicate the existence of interaction between pulmonary arterial and carotid sinus baroreceptor reflexes; physiological and pathological states that alter the stimulus to one may alter the reflex responses from the other. PMID:21690195

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2014 CFR

2014-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2013 CFR

2013-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2012 CFR

2012-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2011 CFR

2011-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

40 CFR 74.18 - Withdrawal.

Code of Federal Regulations, 2010 CFR

2010-07-01

... opt-in source may request to withdraw from the Acid Rain Program by submitting an administrative... paragraph (f)(1) of this section. (b) Requesting withdrawal. To withdraw from the Acid Rain Program, the...-in source's prior violations. An opt-in source that withdraws from the Acid Rain Program shall comply...

Estimated Use of Water in the United States in 2000

USGS Publications Warehouse

Hutson, Susan S.; Barber, Nancy L.; Kenny, Joan F.; Linsey, Kristin S.; Lumia, Deborah S.; Maupin, Molly A.

2004-01-01

Estimates of water use in the United States indicate that about 408 billion gallons per day (one thousand million gallons per day, abbreviated Bgal/d) were withdrawn for all uses during 2000. This total has varied less than 3 percent since 1985 as withdrawals have stabilized for the two largest uses?thermoelectric power and irrigation. Fresh ground-water withdrawals (83.3 Bgal/d) during 2000 were 14 percent more than during 1985. Fresh surface-water withdrawals for 2000 were 262 Bgal/d, varying less than 2 percent since 1985. About 195 Bgal/d, or 48 percent of all freshwater and saline-water withdrawals for 2000, were used for thermoelectric power. Most of this water was derived from surface water and used for once-through cooling at power plants. About 52 percent of fresh surface-water withdrawals and about 96 percent of saline-water withdrawals were for thermoelectric-power use. Withdrawals for thermoelectric power have been relatively stable since 1985. Irrigation remained the largest use of freshwater in the United States and totaled 137 Bgal/d for 2000. Since 1950, irrigation has accounted for about 65 percent of total water withdrawals, excluding those for thermoelectric power. Historically, more surface water than ground water has been used for irrigation. However, the percentage of total irrigation withdrawals from ground water has continued to increase, from 23 percent in 1950 to 42 percent in 2000. Total irrigation withdrawals were 2 percent more for 2000 than for 1995, because of a 16-percent increase in ground-water withdrawals and a small decrease in surface-water withdrawals. Irrigated acreage more than doubled between 1950 and 1980, then remained constant before increasing nearly 7 percent between 1995 and 2000. The number of acres irrigated with sprinkler and microirrigation systems has continued to increase and now comprises more than one-half the total irrigated acreage. Public-supply withdrawals were more than 43 Bgal/d for 2000. Public-supply withdrawals during 1950 were 14 Bgal/d. During 2000, about 85 percent of the population in the United States obtained drinking water from public suppliers, compared to 62 percent during 1950. Surface water provided 63 percent of the total during 2000, whereas surface water provided 74 percent during 1950. Self-supplied industrial withdrawals totaled nearly 20 Bgal/d in 2000, or 12 percent less than in 1995. Compared to 1985, industrial self-supplied withdrawals declined by 24 percent. Estimates of industrial water use in the United States were largest during the years from 1965 to 1980, but during 2000, estimates were at the lowest level since reporting began in 1950. Combined withdrawals for self-supplied domestic, livestock, aquaculture, and mining were less than 13 Bgal/d for 2000, and represented about 3 percent of total withdrawals. California, Texas, and Florida accounted for one-fourth of all water withdrawals for 2000. States with the largest surface-water withdrawals were California, which had large withdrawals for irrigation and thermoelectric power, and Texas, which had large withdrawals for thermoelectric power. States with the largest ground-water withdrawals were California, Texas, and Nebraska, all of which had large withdrawals for irrigation.

Spinal anaesthesia with gamma hydroxybutyrate. A study in a rat model.

PubMed

Chanimov, M; Bahar, M; Cohen, M L; Brenner, R; Koifman, I; Grinshpon, Y

1999-05-01

Gamma hydroxybutyric acid, a central inhibitory neurotransmitter and a cerebral metabolite of gamma-aminobutyric acid, is present in high concentrations in the mammalian hypothalamus and basal ganglia. Its sodium salt gamma hydroxybutyrate has been effectively used as an intravenous anaesthetic agent, and as an oral sedative, and in the management of the alcohol withdrawal syndrome. In an animal model, using 72 Wistar strain rats allocated to one of six groups of 12 animals each, with implanted lumbar intrathecal catheters, we examined whether gamma hydroxybutyrate, 20% 40 microL (32 mg kg-1) administered alone or combined with fentanyl, gamma hydroxybutyrate 20% 20 microL (16 mg kg-1), fentanyl 0.005% 20 microL (4 mg kg-1) as an intrathecal bolus, provides intraoperative anaesthesia, comparable with that produced by intrathecal lignocaine. We demonstrated that gamma hydroxybutyrate, given by an intrathecal bolus in the rat model, produced reversible segmental antinociception, together with muscular relaxation of the abdominal wall and rear limbs. This is accompanied by moderate sedation without haemodynamic or respiratory depression. This agent may thus be promising for use as a spinal anaesthetic drug.

8 CFR 235.4 - Withdrawal of application for admission.

Code of Federal Regulations, 2010 CFR

2010-01-01

... right to withdraw his or her application for admission. Permission to withdraw an application for... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Withdrawal of application for admission... INSPECTION OF PERSONS APPLYING FOR ADMISSION § 235.4 Withdrawal of application for admission. The Attorney...

Groundwater withdrawals and associated well descriptions for the Nevada National Security Site, Nye County, Nevada, 1951-2008

USGS Publications Warehouse

Elliott, Peggy E.; Moreo, Michael T.

2011-01-01

From 1951 to 2008, groundwater withdrawals totaled more than 25,000 million gallons from wells on and directly adjacent to the Nevada National Security Site. Total annual groundwater withdrawals ranged from about 30 million gallons in 1951 to as much as 1,100 million gallons in 1989. Annual withdrawals from individual wells ranged from 0 million gallons to more than 325 million gallons. Monthly withdrawal data for the wells were compiled in a Microsoft(copyright) Excel 2003 spreadsheet. Groundwater withdrawal data are a compilation of measured and estimated withdrawals obtained from published and unpublished reports, U.S. Geological Survey files, and/or data reported by other agencies. The withdrawal data were collected from 42 wells completed in 33 boreholes. A history of each well is presented in terms of its well construction, borehole lithology, withdrawals, and water levels.

Blocking microglial pannexin-1 channels alleviates morphine withdrawal in rodents.

PubMed

Burma, Nicole E; Bonin, Robert P; Leduc-Pessah, Heather; Baimel, Corey; Cairncross, Zoe F; Mousseau, Michael; Shankara, Jhenkruthi Vijaya; Stemkowski, Patrick L; Baimoukhametova, Dinara; Bains, Jaideep S; Antle, Michael C; Zamponi, Gerald W; Cahill, Catherine M; Borgland, Stephanie L; De Koninck, Yves; Trang, Tuan

2017-03-01

Opiates are essential for treating pain, but termination of opiate therapy can cause a debilitating withdrawal syndrome in chronic users. To alleviate or avoid the aversive symptoms of withdrawal, many of these individuals continue to use opiates. Withdrawal is therefore a key determinant of opiate use in dependent individuals, yet its underlying mechanisms are poorly understood and effective therapies are lacking. Here, we identify the pannexin-1 (Panx1) channel as a therapeutic target in opiate withdrawal. We show that withdrawal from morphine induces long-term synaptic facilitation in lamina I and II neurons within the rodent spinal dorsal horn, a principal site of action for opiate analgesia. Genetic ablation of Panx1 in microglia abolished the spinal synaptic facilitation and ameliorated the sequelae of morphine withdrawal. Panx1 is unique in its permeability to molecules up to 1 kDa in size and its release of ATP. We show that Panx1 activation drives ATP release from microglia during morphine withdrawal and that degrading endogenous spinal ATP by administering apyrase produces a reduction in withdrawal behaviors. Conversely, we found that pharmacological inhibition of ATP breakdown exacerbates withdrawal. Treatment with a Panx1-blocking peptide ( 10 panx) or the clinically used broad-spectrum Panx1 blockers, mefloquine or probenecid, suppressed ATP release and reduced withdrawal severity. Our results demonstrate that Panx1-mediated ATP release from microglia is required for morphine withdrawal in rodents and that blocking Panx1 alleviates the severity of withdrawal without affecting opiate analgesia.

Reconstruction of global gridded monthly sectoral water withdrawals for 1971–2010 and analysis of their spatiotemporal patterns

DOE PAGES

Huang, Zhongwei; Hejazi, Mohamad; Li, Xinya; ...

2018-04-06

Human water withdrawal has increasingly altered the global water cycle in past decades, yet our understanding of its driving forces and patterns is limited. Reported historical estimates of sectoral water withdrawals are often sparse and incomplete, mainly restricted to water withdrawal estimates available at annual and country scales, due to a lack of observations at seasonal and local scales. In this study, through collecting and consolidating various sources of reported data and developing spatial and temporal statistical downscaling algorithms, we reconstruct a global monthly gridded (0.5°) sectoral water withdrawal dataset for the period 1971–2010, which distinguishes six water use sectors, i.e., irrigation,more » domestic, electricity generation (cooling of thermal power plants), livestock, mining, and manufacturing. Based on the reconstructed dataset, the spatial and temporal patterns of historical water withdrawal are analyzed. Results show that total global water withdrawal has increased significantly during 1971–2010, mainly driven by the increase in irrigation water withdrawal. Regions with high water withdrawal are those densely populated or with large irrigated cropland production, e.g., the United States (US), eastern China, India, and Europe. Seasonally, irrigation water withdrawal in summer for the major crops contributes a large percentage of total annual irrigation water withdrawal in mid- and high-latitude regions, and the dominant season of irrigation water withdrawal is also different across regions. Domestic water withdrawal is mostly characterized by a summer peak, while water withdrawal for electricity generation has a winter peak in high-latitude regions and a summer peak in low-latitude regions. Despite the overall increasing trend, irrigation in the western US and domestic water withdrawal in western Europe exhibit a decreasing trend. Our results highlight the distinct spatial pattern of human water use by sectors at the seasonal and annual timescales. Here, the reconstructed gridded water withdrawal dataset is open access, and can be used for examining issues related to water withdrawals at fine spatial, temporal, and sectoral scales.« less

Reconstruction of global gridded monthly sectoral water withdrawals for 1971–2010 and analysis of their spatiotemporal patterns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Zhongwei; Hejazi, Mohamad; Li, Xinya

Human water withdrawal has increasingly altered the global water cycle in past decades, yet our understanding of its driving forces and patterns is limited. Reported historical estimates of sectoral water withdrawals are often sparse and incomplete, mainly restricted to water withdrawal estimates available at annual and country scales, due to a lack of observations at seasonal and local scales. In this study, through collecting and consolidating various sources of reported data and developing spatial and temporal statistical downscaling algorithms, we reconstruct a global monthly gridded (0.5°) sectoral water withdrawal dataset for the period 1971–2010, which distinguishes six water use sectors, i.e., irrigation,more » domestic, electricity generation (cooling of thermal power plants), livestock, mining, and manufacturing. Based on the reconstructed dataset, the spatial and temporal patterns of historical water withdrawal are analyzed. Results show that total global water withdrawal has increased significantly during 1971–2010, mainly driven by the increase in irrigation water withdrawal. Regions with high water withdrawal are those densely populated or with large irrigated cropland production, e.g., the United States (US), eastern China, India, and Europe. Seasonally, irrigation water withdrawal in summer for the major crops contributes a large percentage of total annual irrigation water withdrawal in mid- and high-latitude regions, and the dominant season of irrigation water withdrawal is also different across regions. Domestic water withdrawal is mostly characterized by a summer peak, while water withdrawal for electricity generation has a winter peak in high-latitude regions and a summer peak in low-latitude regions. Despite the overall increasing trend, irrigation in the western US and domestic water withdrawal in western Europe exhibit a decreasing trend. Our results highlight the distinct spatial pattern of human water use by sectors at the seasonal and annual timescales. Here, the reconstructed gridded water withdrawal dataset is open access, and can be used for examining issues related to water withdrawals at fine spatial, temporal, and sectoral scales.« less

Reconstruction of global gridded monthly sectoral water withdrawals for 1971–2010 and analysis of their spatiotemporal patterns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Zhongwei; Hejazi, Mohamad; Li, Xinya

Human water withdrawal has increasingly altered the global water cycle in past decades, yet our understanding of its driving forces and patterns is limited. Reported historical estimates of sectoral water withdrawals are often sparse and incomplete, mainly restricted to water withdrawal estimates available at annual and country scales, due to a lack of observations at seasonal and local scales. In this study, through collecting and consolidating various sources of reported data and developing spatial and temporal statistical downscaling algorithms, we reconstruct a global monthly gridded (0.5°) sectoral water withdrawal dataset for the period 1971–2010, which distinguishes six water use sectors, i.e., irrigation,more » domestic, electricity generation (cooling of thermal power plants), livestock, mining, and manufacturing. Based on the reconstructed dataset, the spatial and temporal patterns of historical water withdrawal are analyzed. Results show that total global water withdrawal has increased significantly during 1971–2010, mainly driven by the increase in irrigation water withdrawal. Regions with high water withdrawal are those densely populated or with large irrigated cropland production, e.g., the United States (US), eastern China, India, and Europe. Seasonally, irrigation water withdrawal in summer for the major crops contributes a large percentage of total annual irrigation water withdrawal in mid- and high-latitude regions, and the dominant season of irrigation water withdrawal is also different across regions. Domestic water withdrawal is mostly characterized by a summer peak, while water withdrawal for electricity generation has a winter peak in high-latitude regions and a summer peak in low-latitude regions. Despite the overall increasing trend, irrigation in the western US and domestic water withdrawal in western Europe exhibit a decreasing trend. Our results highlight the distinct spatial pattern of human water use by sectors at the seasonal and annual timescales. The reconstructed gridded water withdrawal dataset is open access, and can be used for examining issues related to water withdrawals at fine spatial, temporal, and sectoral scales.« less

Ocular screening tests of elementary school children

NASA Technical Reports Server (NTRS)

Richardson, J.

1983-01-01

This report presents an analysis of 507 abnormal retinal reflex images taken of Huntsville kindergarten and first grade students. The retinal reflex images were obtained by using an MSFC-developed Generated Retinal Reflex Image System (GRRIS) photorefractor. The system uses a 35 mm camera with a telephoto lens with an electronic flash attachment. Slide images of the eyes were examined for abnormalities. Of a total of 1835 students screened for ocular abnormalities, 507 were found to have abnormal retinal reflexes. The types of ocular abnormalities detected were hyperopia, myopia, astigmatism, esotropia, exotropia, strabismus, and lens obstuctions. The report shows that the use of the photorefractor screening system is an effective low-cost means of screening school children for abnormalities.

The origin of Woltman's sign of myxoedema.

PubMed

Burkholder, David B; Klaas, James P; Kumar, Neeraj; Boes, Christopher J

2013-09-01

Woltman's sign of myxoedema, named after Henry Woltman in 1956, is the delayed relaxation phase of the muscle stretch reflex in patients with myxoedema. Although a change in these reflexes was mentioned as being clinically evident possibly as early as the 1870s, no formal description was published until 1924 when William Calvert Chaney objectively quantified the change. Woltman was involved in training Chaney, and it has been proposed that he guided Chaney's study of these reflexes. Despite the attachment of Woltman's name to the eponym, little evidence exists that directly links him to the first objective study of the muscle stretch reflex in myxoedema performed by Chaney. Copyright © 2013 Elsevier Ltd. All rights reserved.

Device for rapid quantification of human carotid baroreceptor-cardiac reflex responses

NASA Technical Reports Server (NTRS)

Sprenkle, J. M.; Eckberg, D. L.; Goble, R. L.; Schelhorn, J. J.; Halliday, H. C.

1986-01-01

A new device has been designed, constructed, and evaluated to characterize the human carotid baroreceptor-cardiac reflex response relation rapidly. This system was designed for study of reflex responses of astronauts before, during, and after space travel. The system comprises a new tightly sealing silicon rubber neck chamber, a stepping motor-driven electrodeposited nickel bellows pressure system, capable of delivering sequential R-wave-triggered neck chamber pressure changes between +40 and -65 mmHg, and a microprocessor-based electronics system for control of pressure steps and analysis and display of responses. This new system provokes classic sigmoid baroreceptor-cardiac reflex responses with threshold, linear, and saturation ranges in most human volunteers during one held expiration.

Opiate and opioid withdrawal

MedlinePlus

... opiate withdrawal; Oxycontin - opiate withdrawal; Hydrocodone - opiate withdrawal; Detox - opiates; Detoxification - opiates ... facilities set up to help people with detoxification (detox). In a regular hospital, if symptoms are severe. ...

The frequency of buccopalpebral reflex in Parkinson disease.

PubMed

Eser, Hülya; Ünal, Yasemin; Kutlu, Gülnihal; Öcal, Ruhsen; İnan, Levent Ertuğrul

2016-11-17

This study aimed to define the frequency of a primitive reflex, the buccopalpebral reflex (BPR), and its association with the clinical situation in patients with Parkinson disease. Between May 2010 and May 2011, 222 patients, 115 with Parkinson disease and 107 patients without any sign of neurodegenerative disease, were included in the study. All included patients were examined for BPR and snout reflex and were also evaluated with the Mini Mental State Examination. All patients with Parkinson disease were classified with the Unified Parkinson's Disease Rating Scale (UPDRS) and the Hoehn and Yahr Score to determine their clinical severity. Sixteen patients with Parkinson disease (13.9%) had a BPR (+) and 4 patients in the control group (3.7%) (P < 0.001). The UPDRS score, UPDRS daily life activities score, and UPDRS motor system score were all higher in the group with BPR (+). All patients with a BPR also had a positive snout reflex. BPR is more frequent in patients with Parkinson disease than in patients without a neurodegenerative disease.

Intramuscular Neurotrophin-3 normalizes low threshold spinal reflexes, reduces spasms and improves mobility after bilateral corticospinal tract injury in rats.

PubMed

Kathe, Claudia; Hutson, Thomas Haynes; McMahon, Stephen Brendan; Moon, Lawrence David Falcon

2016-10-19

Brain and spinal injury reduce mobility and often impair sensorimotor processing in the spinal cord leading to spasticity. Here, we establish that complete transection of corticospinal pathways in the pyramids impairs locomotion and leads to increased spasms and excessive mono- and polysynaptic low threshold spinal reflexes in rats. Treatment of affected forelimb muscles with an adeno-associated viral vector (AAV) encoding human Neurotrophin-3 at a clinically-feasible time-point after injury reduced spasticity. Neurotrophin-3 normalized the short latency Hoffmann reflex to a treated hand muscle as well as low threshold polysynaptic spinal reflexes involving afferents from other treated muscles. Neurotrophin-3 also enhanced locomotor recovery. Furthermore, the balance of inhibitory and excitatory boutons in the spinal cord and the level of an ion co-transporter in motor neuron membranes required for normal reflexes were normalized. Our findings pave the way for Neurotrophin-3 as a therapy that treats the underlying causes of spasticity and not only its symptoms.

Does diurnal variation in cough reflex testing exist in healthy young adults?

PubMed

Perry, Sarah; Huckabee, Maggie-Lee

2017-05-01

The aim of this study was to investigate whether diurnal variation in cough reflex sensitivity exists in healthy young adults when a tidal-breathing method is used. Fifty-three participants (19-37 years) underwent cough reflex testing on two occasions: once in the morning (between 9 am - midday) and once in the afternoon (between 2-5 pm). The order of testing was counter-balanced. Within each assessment, participants inhaled successively higher citric acid concentrations via a facemask, with saline solution randomly interspersed to control for a placebo response. The lowest concentration that elicited a reflexive cough response was recorded. Morning cough thresholds (mean=0.6mol/L) were not different from afternoon cough thresholds (mean=0.6mol/L), p=0.16, T=101, r=-0.14. We found no evidence of diurnal variability in cough reflex testing. There was, however, an order effect irrespective of time of day, confirming that healthy participants are able to volitionally modulate their cough response. Copyright © 2017 Elsevier B.V. All rights reserved.

[Early diagnosis and prognosis evaluation of Bell palsy with blink reflex ].

PubMed

Xie, Dan-dan; Li, Xiao-song; Liu, Yuan-yuan

2014-11-01

To determine the value of blink reflex in early diagnosis and prognosis evaluation of Bell palsy. Blink reflex and facial nerve conduction were examined in 58 patients with Bell palsy within one week after symptom onset. The patients without response of R1 , R2 and R2 ' waves were classified as complete efferent retardarce (Group A, 30 cases), and those with response of R1 , R2 and R2 ' waves were classified as incomplete efferent anomalies (Group B, 28 cases). The clinical outcomes after three months of systemic therapy were evaluated using the House-Blackmann (H-B) scale. Efferent anomalies of blink reflex occurred in ail of the 58 patients. Abnormal results of facial nerve conduction appeared in 23 (39. 7%) patients. The three months therapy was effective in 93% patients in Group B and 70% patients in Group A (P<0. 05). Blink reflex can play a significant role in early diagnosis and prognosis evaluation of Bell palsy.

Is temporal summation of pain and spinal nociception altered during normal aging?

PubMed Central

Marouf, Rafik; Piché, Mathieu; Rainville, Pierre

2015-01-01

Abstract This study examines the effect of normal aging on temporal summation (TS) of pain and the nociceptive flexion reflex (RIII). Two groups of healthy volunteers, young and elderly, received transcutaneous electrical stimulation applied to the right sural nerve to assess pain and the nociceptive flexion reflex (RIII-reflex). Stimulus intensity was adjusted individually to 120% of RIII-reflex threshold, and shocks were delivered as a single stimulus or as a series of 5 stimuli to assess TS at 5 different frequencies (0.17, 0.33, 0.66, 1, and 2 Hz). This study shows that robust TS of pain and RIII-reflex is observable in individuals aged between 18 and 75 years and indicates that these effects are comparable between young and older individuals. These results contrast with some previous findings and imply that at least some pain regulatory processes, including TS, may not be affected by normal aging, although this may vary depending on the method. PMID:26058038

Cocaine withdrawal

MedlinePlus

... Substance use - cocaine withdrawal; Substance abuse - cocaine withdrawal; Drug abuse - cocaine withdrawal; Detox - cocaine ... Elsevier Saunders; 2016:chap 50. National Institute on Drug Abuse. What is cocaine? Updated May 2016. www.drugabuse. ...

THE PREVALENCE OF CANNABIS WITHDRAWAL AND ITS INFLUENCE ON ADOLESCENTS’ TREATMENT RESPONSE AND OUTCOMES: A 12-MONTH PROSPECTIVE INVESTIGATION

PubMed Central

Greene, M. Claire; Kelly, John F.

2014-01-01

Background Withdrawal, a diagnostic indicator of cannabis use disorder, is often minimized or ignored as a consequence of cannabis use, particularly among adolescents. This study aims to characterize cannabis withdrawal among adolescents in outpatient treatment for substance use disorder and evaluate the clinical significance of withdrawal as a predictor of substance-related outcomes. Methods Adolescent outpatients (N=127) reporting cannabis as their drug of choice (n=90) were stratified by presence of withdrawal and compared on demographic and clinical variables at treatment intake. Hierarchical linear models compared the effect of withdrawal on percent days abstinent (PDA) and related outcomes over a 1-year follow-up period. Results Adolescents reporting withdrawal (40%) were more likely to meet criteria for cannabis dependence, have higher levels of substance use severity, report more substance-related consequences, and have a mood disorder. Withdrawal was not associated with PDA over the follow-up period; however, this relationship was moderated by problem recognition such that adolescents reporting withdrawal and a drug problem improved at a greater rate with respect to PDA than those that didn’t recognize a problem with drugs and didn’t report withdrawal. Discussion Withdrawal is common among adolescent outpatients and is associated with a more clinically severe profile. In this sample, all adolescents reporting withdrawal met criteria for cannabis dependence, suggesting that withdrawal is a highly specific indicator of cannabis use disorder. While withdrawal doesn’t appear to be independently associated with substance use outcomes post-treatment, moderating factors such as drug problem recognition should be taken into account when formulating treatment and continuing care plans. PMID:25100311

Youth social withdrawal behavior (hikikomori): A systematic review of qualitative and quantitative studies.

PubMed

Li, Tim M H; Wong, Paul W C

2015-07-01

Acute and/or severe social withdrawal behavior among youth was seen as a culture-bound psychiatric syndrome in Japan, but more youth social withdrawal cases in different countries have been discovered recently. However, due to the lack of a formal definition and diagnostic tool for youth social withdrawal, cross-cultural observational and intervention studies are limited. We aimed to consolidate existing knowledge in order to understand youth social withdrawal from diverse perspectives and suggest different interventions for different trajectories of youth social withdrawal. This review examined the current available scientific information on youth social withdrawal in the academic databases: ProQuest, ScienceDirect, Web of Science and PubMed. We included quantitative and qualitative studies of socially withdrawn youths published in English and academic peer-reviewed journals. We synthesized the information into the following categories: (1) definitions of youth social withdrawal, (2) developmental theories, (3) factors associated with youth social withdrawal and (4) interventions for socially withdrawn youths. Accordingly, there are diverse and controversial definitions for youth social withdrawal. Studies of youth social withdrawal are based on models that lead to quite different conclusions. Researchers with an attachment perspective view youth social withdrawal as a negative phenomenon, whereas those who adopt Erikson's developmental theory view it more positively as a process of seeking self-knowledge. Different interventions for socially withdrawn youths have been developed, mainly in Japan, but evidence-based practice is almost non-existent. We propose a theoretical framework that views youth social withdrawal as resulting from the interplay between psychological, social and behavioral factors. Future validation of the framework will help drive forward advances in theory and interventions for youth social withdrawal as an emerging issue in developed countries. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Effect of Acceleration Frequency on Spatial Orientation Mechanisms

DTIC Science & Technology

2010-09-30

by aircraft, ground vehicle, and ship motion. Method. With controlled laboratory off-vertical axis rotation (OVAR), gaze reflexes respond to low...finding that vestibular gaze reflexes become altered at the same frequency where OVAR becomes most sickening will have important implications for...the collected data, a revised crossover rate of 0.42 Hz was extrapolated as the most probable spin frequency for inducing gaze reflex changes with the

Reflexivity in the Interstices: A Tale of Reflexivity at Work in, during, and behind the Scenes

ERIC Educational Resources Information Center

Wickens, Corrine M.; Cohen, James A.; Walther, Carol S.

2017-01-01

This article is a story of how the authors came to make sense of the significance of those words in relation to gender, race/ethnicity, and citizenship in writing a manuscript about L[subscript 1]L[subscript 2] acquisition. It is a tale about how Reflexivity wove itself into the conversations, into the writing, into the in-between spaces, the…

Studies of the vestibulo-ocular reflex on STS 4, 5 and 6

NASA Technical Reports Server (NTRS)

Thornton, William E.; Pool, Sam L.; Moore, Thomas P.; Uri, John J.

1988-01-01

The vestibulo-ocular reflex (VOR) may be altered by weightlessness. Since this reflex plays a large role in visual stabilization, it was important to document any changes caused by space flight. This is a report on findings on STS-4 through 6 and is part of a larger study of neurosensory adaptation done on STS-4 through 8. Voluntary horizontal head oscillations at 1/3 Hz with amplitude of 30 deg right and left of center were recorded by a potentiometer and compared to eye position recorded by electroculography under the following conditions: eyes open, head fixed, tracking horizontal targets switched 0, 15, and 30 degrees right and left (optokinetic reflex - OKR - and calibration); eyes open and fixed on static external target with oscillation, (vestibulo ocular reflex, eyes closed - VOR EC); eyes open and wearing opaque goggles with target fixed in imagination (vestibulo-ocular reflex, eyes shaded - VOR ES); and eyes open and fixed on a head synchronized target with head oscillation (VOR suppression). No significant changes were found in voluntary head oscillation frequency or amplitude in those with (n=5), and without (n=3), space motion sickness (SMS), with phase of flight or test condition. Variations in head oscillation were too small to have produced detectable changes in test results.