Science.gov

Sample records for diffuse noxious inhibitory

  1. Dyspnea as a noxious sensation: inspiratory threshold loading may trigger diffuse noxious inhibitory controls in humans.

    PubMed

    Morélot-Panzini, Capucine; Demoule, Alexandre; Straus, Christian; Zelter, Marc; Derenne, Jean-Philippe; Willer, Jean-Claude; Similowski, Thomas

    2007-02-01

    Dyspnea, a leading respiratory symptom, shares many clinical, physiological, and psychological features with pain. Both activate similar brain areas. The neural mechanisms of dyspnea are less well described than those of pain. The present research tested the hypothesis of common pathways between the two sensations. Six healthy men (age 30-40 yr) were studied. The spinal nociceptive flexion reflex (RIII) was first established in response to electrical sural stimulation. Dyspnea was then induced through inspiratory threshold loading, forcing the subjects to develop 70% of their maximal inspiratory pressure to inhale. This led to progressive inhibition of the RIII reflex that reached 50 +/- 12% during the fifth minute of loading (P < 0.001), was correlated to the intensity of the self-evaluated respiratory discomfort, and had recovered 5 min after removal of the load. The myotatic H-reflex was not inhibited by inspiratory loading, arguing against postsynaptic alpha motoneuron inhibition. Dyspnea, like pain, thus induced counterirritation, possibly indicating a C-fiber stimulation and activation of diffuse noxious inhibitory descending controls known to project onto spinal dorsal horn wide dynamic range neurons. This confirms the noxious nature of certain types of breathlessness, thus opening new physiological and perhaps therapeutic perspectives.

  2. Behavioral analysis of diffuse noxious inhibitory controls (DNIC): antinociception and escape reactions.

    PubMed

    Morgan, M M; Whitney, P K

    1996-08-01

    'Diffuse noxious inhibitory controls' or DNIC is the inhibition of multireceptive neurons in the dorsal horn of the spinal cord that results when a noxious stimulus is applied to a region of the body remote from the neuron's excitatory receptive field. Although this phenomenon is well-documented, the behavioral consequences of DNIC are not clear. The present study was undertaken to determine how nocifensor withdrawal reflexes evoked by a noxious stimulus are altered by application of a second noxious stimulus to a distant part of the body. The tail flick or hindpaw withdrawal reflex of lightly anesthetized (0.6-1.0% halothane) rats was measured before, during and after another appendage was placed in water ranging in temperature from 45 to 54 degrees C. When the forepaw or hindpaw was placed in water exceeding 49 degrees C the tail flick reflex to acute noxious radiant heat was inhibited. In contrast, noxious conditioning stimuli, regardless of temperature or location, had no effect on the latency for hindpaw withdrawal evoked by an acute noxious stimulus, but did produce a change in reflex topography from flexion to extension. These results, along with previous research on DNIC, suggest that intense noxious stimuli: (1) inhibit the tail flick reflex via inhibition of multireceptive neurons in the dorsal horn; (2) disinhibit hindpaw extensor motoneurons by inhibiting the activity of multireceptive neurons involved in hindlimb flexion; and (3) reduce pain sensation by inhibiting multireceptive neurons projecting to the brain (see Model in Discussion).

  3. Diffuse noxious inhibitory controls and nerve injury: restoring an imbalance between descending monoamine inhibitions and facilitations.

    PubMed

    Bannister, Kirsty; Patel, Ryan; Goncalves, Leonor; Townson, Louisa; Dickenson, Anthony H

    2015-09-01

    Diffuse noxious inhibitory controls (DNICs) utilize descending inhibitory controls through poorly understood brain stem pathways. The human counterpart, conditioned pain modulation, is reduced in patients with neuropathy aligned with animal data showing a loss of descending inhibitory noradrenaline controls together with a gain of 5-HT3 receptor-mediated facilitations after neuropathy. We investigated the pharmacological basis of DNIC and whether it can be restored after neuropathy. Deep dorsal horn neurons were activated by von Frey filaments applied to the hind paw, and DNIC was induced by a pinch applied to the ear in isoflurane-anaesthetized animals. Spinal nerve ligation was the model of neuropathy. Diffuse noxious inhibitory control was present in control rats but abolished after neuropathy. α2 adrenoceptor mechanisms underlie DNIC because the antagonists, yohimbine and atipamezole, markedly attenuated this descending inhibition. We restored DNIC in spinal nerve ligated animals by blocking 5-HT3 descending facilitations with the antagonist ondansetron or by enhancing norepinephrine modulation through the use of reboxetine (a norepinephrine reuptake inhibitor, NRI) or tapentadol (μ-opioid receptor agonist and NRI). Additionally, ondansetron enhanced DNIC in normal animals. Diffuse noxious inhibitory controls are reduced after peripheral nerve injury illustrating the central impact of neuropathy, leading to an imbalance in descending excitations and inhibitions. Underlying noradrenergic mechanisms explain the relationship between conditioned pain modulation and the use of tapentadol and duloxetine (a serotonin, NRI) in patients. We suggest that pharmacological strategies through manipulation of the monoamine system could be used to enhance DNIC in patients by blocking descending facilitations with ondansetron or enhancing norepinephrine inhibitions, so possibly reducing chronic pain.

  4. [C fiber is not necessary in electroacupuncture analgesia, but necessary in diffuse noxious inhibitory controls (DNIC)].

    PubMed

    Bao, H; Zhou, Z; Yu, Y; Han, J

    1991-01-01

    Experiments were carried on rats. We applied capsaicin topically on sciatic nerve and used the techniques of extracellular recording and nerve trunk recording, Our results showed that the size of C compound action potentials in nerve trunk and C fiber response of spinal cord WDR neurons were decreased by at least 70% (mean) after topical application of capsaicin (250 micrograms) on the nerve, but A compound action potentials and A fiber response did not change significantly. It indicated that capsaicin blocked C fiber conduction selectively. Electroacupuncture (EA: 100 Hz, 0.1 ms, 3V) applied on left Zusanli (S36) and Sanyinjiao (Sp6) points inhibited C fiber response of spinal WDR neurons in the right side. The effect was similar to animal behavior analgesia elicited by EA. After applying capsaicin (250 micrograms) topically on left sciatic nerve, the inhibitory effect of EA on WDR neurons remained essentially intact (from 61.3 +/- 12.0% to 59.0 +/- 11.6%, n = 6, P greater than 0.05). It indicated that C fiber was not important in EA analgesia. Noxious heat (NH) applied on left hind paw by immersing the hind paw into 52 degrees C water inhibited C fiber response of spinal WDR neurons in the right side. It was called diffuse noxious inhibitory controls (DNIC). After applying capsaicin (250 micrograms) topically on left sciatic nerve, the inhibitory effect of NH on WDR neurons was dramatically decreased (from 77.7 +/- 8.5% to 8.1 +/- 8.9%, n = 6, P less than 0.001). It indicated that C fiber was important in DNIC. Both inhibitory effects of NH and EA were not changed by vehicle treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Diffuse noxious inhibitory control evoked by tonic craniofacial pain in humans.

    PubMed

    Sowman, P F; Wang, K; Svensson, P; Arendt-Nielsen, L

    2011-02-01

    Tonic pain in one body segment can inhibit the perception of pain in another body segment. This phenomenon is mediated by diffuse noxious inhibitory controls (DNIC), and its efficacy in craniofacial regions is investigated in this study. A compressive device that evoked a tonic, moderate/severe, headache-like, conditioning pain (∼8/10 on a visual analogue scale) was applied for 15min. Eleven males participated in the study. Pressure pain threshold (PPT) and pressure pain tolerance (PPTol) at multiple heterosegmental body sites (right masseter, splenius capitis, second intermediate phalange, brachioradialis and tibialis anterior) were measured before, during and at multiple time points (5, 20 and 35min) after the termination of the conditioning pain. PPTs and PPTols were compared within participants across two experimental sessions; one that included painful conditioning stimulation, and a separate control session on a different day. Painful conditioning increased PPT significantly during pain over the masseter (p<0.05) and over the tibialis anterior (p<0.01). PPTol was unchanged. In the period after the painful conditioning stimulation PPT was depressed compared to control. This study shows that pain evoked from the craniofacial region evokes DNIC-like mechanisms on segmental as well as heterosegmental sites.

  6. Depression of activities of dorsal horn convergent neurones by propriospinal mechanisms triggered by noxious inputs; comparison with diffuse noxious inhibitory controls (DNIC).

    PubMed

    Cadden, S W; Villanueva, L; Chitour, D; Le Bars, D

    1983-09-19

    The ability of heterotopic noxious stimuli to inhibit the activity of dorsal horn convergent neurones was investigated in both intact anesthetized, and spinal unanesthetized rats. Forty-four convergent neurones in lumbar dorsal horn were recognized by their ability to respond to both noxious and non-noxious natural stimuli and by their characteristic responses corresponding to A- and C-fibre activity following electrical stimulation of their cutaneous excitatory receptive fields on the ipsilateral hindpaw. The application of a sustained pinch to the excitatory receptive field resulted in an initial phasic activation of the neurone, which adapted to a stable tonic level of activity (mean 31.8 +/- 2.2 spikes/s). The levels of activity produced in this fashion were not appreciably different between the two types of preparation. In the intact anesthetized rat, the tonic activity produced by the sustained pinch could be strongly depressed by noxious conditioning stimuli applied to various parts of the body for all 10 neurones studied: heating the tail or pinching the contralateral hindpaw, the tail or a forepaw during 30 s each resulted in comparable inhibitions which had mean values in the order of 80% and which were always marked by post-effects lasting for upwards of 30 s. These inhibitory effects have been called Diffuse Noxious Inhibitory Controls (DNIC). In the spinal unanesthetized rat, the tonic activity was depressed to some extent by the same conditioning stimuli, for only 16/34 neurones studied. By comparison with the intact animals these inhibitions were weak, adapted to base-line levels within 30 s and were more marked for conditioning stimuli applied to structures proximal (tail, contralateral hindpaw) to the excitatory receptive field than for stimuli applied more distally (forepaws). The differences between the inhibitions found in the intact and spinal preparations were subsequently confirmed in a series of experiments in which single convergent

  7. Involvement of the dorsolateral funiculus in the descending spinal projections responsible for diffuse noxious inhibitory controls in the rat.

    PubMed

    Villanueva, L; Chitour, D; Le Bars, D

    1986-10-01

    Recordings were made from convergent neurons in the lumbar dorsal horn of the spinal cord of the rat. These neurons were activated by both innocuous and noxious mechanical stimuli applied to their excitatory receptive fields located on the extremity of the hindpaw. Transcutaneous application of suprathreshold 2-ms square-wave electrical stimuli to the center of the excitatory field, resulted in responses to C-fiber activation being observed. This type of response was inhibited by applying a noxious thermal conditioning stimulus on the muzzle. The immersion of the muzzle in a 52 degrees C waterbath resulted in a strong reduction of the response during the application of the noxious conditioning stimulus and this was followed by long lasting poststimulus effects. Such inhibitory processes have been termed diffuse noxious inhibitory controls (DNIC). The effects on these inhibitions of lesions including the dorsolateral funiculus (DLF) were investigated in acute experiments: tests were performed before and at least 30 min after the DLF lesion. A lesion including the DLF ipsilateral to the neuron under study completely abolished the inhibitory processes triggered from the muzzle. Concomitantly, a facilitation of C-fiber responses was observed. Nevertheless, DNIC was still impaired even using a juxtathreshold current to elicit a weak C-fiber response. To ascertain further the main, if not entire, participation of the ipsilateral DLF in the descending projections responsible for the heterotopic inhibitory processes, the effects of a lesion of the contralateral DLF were investigated. Neither the inhibitory processes nor the unconditioned C-fiber responses were altered by this procedure. Again, a second lesion including the ipsilateral DLF induced a blockade of DNIC. It is concluded that the descending projections involved in the triggering of DNIC are mainly, if not entirely, confined to the DLF ipsilateral to the neuron under study. The contralateral DLF did not appear to

  8. Painful conditioning stimuli of the craniofacial region evokes diffuse noxious inhibitory controls in men and women.

    PubMed

    Wang, Kelun; Svensson, Peter; Sessle, Barry J; Cairns, Brian E; Arendt-Nielsen, Lars

    2010-01-01

    different between men and women at any test site (unpaired t-test: P > .446). This study has documented that mechanical and thermal painful tonic stimuli applied to the craniofacial region can evoke diffuse noxious inhibitory control (DNIC)-like effects in the craniofacial region as well as spinally innervated areas, but without sex differences.

  9. Ascending pathways in the spinal cord involved in triggering of diffuse noxious inhibitory controls in the rat.

    PubMed

    Villanueva, L; Peschanski, M; Calvino, B; Le Bars, D

    1986-01-01

    Recordings were made from convergent neurons in trigeminal nucleus caudalis of the rat. These neurons were activated by both innocuous and noxious mechanical stimuli applied to their excitatory receptive fields located on the ipsilateral part of the muzzle. Transcutaneous application of suprathreshold 2-ms square-wave electrical stimuli to the center of the excitatory field resulted in responses to C-fiber activation being observed (mean latencies 63.6 +/- 5.5 ms). This type of response was inhibited by applying noxious conditioning stimuli to heterotopic body areas, namely immersing either the left or right hindpaw in a 52 degrees C water bath. A virtually total block of the response was observed during the application of the noxious conditioning stimulus, and this was followed by long-lasting poststimulus effects. Such inhibitory processes have been termed diffuse noxious inhibitory controls (DNIC) (39, 40). The effects on these inhibitions of various transverse lesions of the cervical spinal cord were investigated in acute experiments; tests were performed before and at least 30 min after the spinal section. While the unconditioned C-fiber responses were unaltered, the inhibitory processes could be impaired by the cervical lesions, although these effects depended on the part of the cervical cord destroyed and the side of application of the conditioning stimulus. Lesioning dorsal, dorsolateral, and ventromedial parts of the cervical cord was found not to affect inhibitory processes triggered from either hindpaw. The overlapping of the regions of these ineffective lesions revealed that two remaining regions were not destroyed, that is, the left and right ventrolateral quadrants. In experiments where the left anterolateral quadrant was affected by the surgical procedure the inhibition triggered from the right hindpaw was strongly reduced, whereas that elicited by left hindpaw stimulation was not diminished. The loss of inhibitory effects was characterized by a

  10. Pain modulation as a function of hypnotizability: Diffuse noxious inhibitory control induced by cold pressor test vs explicit suggestions of analgesia.

    PubMed

    Fidanza, Fabrizia; Varanini, Maurizio; Ciaramella, Antonella; Carli, Giancarlo; Santarcangelo, Enrica L

    2017-03-15

    The aim of the present study was to compare the effects of explicit suggestions of analgesia and of the activation of the Diffuse Noxious Inhibitory Control (DNIC) by cold pressor test on pain perception and heart rate in healthy participants with high (highs, N=18), low (lows, N=18) and intermediate scores of hypnotizability (mediums, N=15) out of hypnosis. Pain reports and the stimulus-locked heart rate changes induced by electrical nociceptive stimulation of the left hand were studied in the absence of concomitant stimuli (Control), during suggestions of analgesia (SUGG, glove analgesia) and during cold pressor test used as a conditioning stimulus to the right hand (DNIC, water temperature=10-12°C) in the REAL session. Participants were submitted also to a SHAM session in which the DNIC water temperature was 30°C and the suggestions for analgesia were substituted with weather forecast information. Both suggestions and DNIC reduced pain significantly in all subjects; however, the percentage of reduction was significantly larger in highs (pain intensity=55% of the control condition) than in mediums (70%) and lows (80%) independently of the REAL/SHAM session and of the specific pain manipulation. Heart rate was not modulated consistently with pain experience. Findings indicate that both suggestions and DNIC influence pain experience as a function of hypnotizability and suggest that both sensory and cognitive mechanisms co-operate in DNIC induced analgesia. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Centralization of noxious stimulus-induced analgesia (NSIA) is related to activity at inhibitory synapses in the spinal cord.

    PubMed

    Tambeli, Claudia H; Levine, Jon D; Gear, Robert W

    2009-06-01

    The duration of noxious stimulus-induced antinociception (NSIA) has been shown to outlast the pain stimulus that elicited it, however, the mechanism that determines the duration of analgesia is unknown. We evaluated the role of spinal excitatory and inhibitory receptors (NMDA, mGluR(5), mu-opioid, GABA(A), and GABA(B)), previously implicated in NSIA initiation, in its maintenance. As in our previous studies, the supraspinal trigeminal jaw-opening reflex (JOR) in the rat was used for nociceptive testing because of its remoteness from the region of drug application, the lumbar spinal cord. NSIA was reversed by antagonists for two inhibitory receptors (GABA(B) and mu-opioid) but not by antagonists for either of the two excitatory receptors (NMDA and mGluR(5)), indicating that NSIA is maintained by ongoing activity at inhibitory synapses in the spinal cord. Furthermore, spinal administration of the GABA(B) agonist baclofen mimicked NSIA in that it could be blocked by prior injection of the mu-opioid receptor antagonist H-D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP) in nucleus accumbens. CTAP also blocked baclofen antinociception when administered in the spinal cord. We conclude that analgesia induced by noxious stimulation is maintained by activity in spinal inhibitory receptors.

  12. Diffusion dynamics of synaptic molecules during inhibitory postsynaptic plasticity

    PubMed Central

    Petrini, Enrica Maria; Barberis, Andrea

    2014-01-01

    The plasticity of inhibitory transmission is expected to play a key role in the modulation of neuronal excitability and network function. Over the last two decades, the investigation of the determinants of inhibitory synaptic plasticity has allowed distinguishing presynaptic and postsynaptic mechanisms. While there has been a remarkable progress in the characterization of presynaptically-expressed plasticity of inhibition, the postsynaptic mechanisms of inhibitory long-term synaptic plasticity only begin to be unraveled. At postsynaptic level, the expression of inhibitory synaptic plasticity involves the rearrangement of the postsynaptic molecular components of the GABAergic synapse, including GABAA receptors, scaffold proteins and structural molecules. This implies a dynamic modulation of receptor intracellular trafficking and receptor surface lateral diffusion, along with regulation of the availability and distribution of scaffold proteins. This Review will focus on the mechanisms of the multifaceted molecular reorganization of the inhibitory synapse during postsynaptic plasticity, with special emphasis on the key role of protein dynamics to ensure prompt and reliable activity-dependent adjustments of synaptic strength. PMID:25294987

  13. Expression of macrophage migration inhibitory factor in diffuse systemic sclerosis

    PubMed Central

    Selvi, E; Tripodi, S; Catenaccio, M; Lorenzini, S; Chindamo, D; Manganelli, S; Romagnoli, R; Ietta, F; Paulesu, L; Miracco, C; Cintorino, M; Marcolongo, R

    2003-01-01

    Objective: To evaluate whether, in patients with the diffuse form of systemic sclerosis (dSSc), macrophage migration inhibitory factor (MIF) production is dysregulated. Methods: 10 patients with dSSc and 10 healthy controls, matched for age and sex, were studied. MIF expression was evaluated by immunohistochemistry on formalin fixed skin biopsies of patients with dSSc and controls. MIF levels were assayed in the sera and in the supernatants of skin cultured fibroblasts by a colorimetric sandwich enzyme linked immunosorbent assay (ELISA). MIF concentrations in culture medium samples and in serum samples were compared by Student's two tailed t test for unpaired data. Results: Anti-MIF antibody immunostained the basal and mainly suprabasal keratinocytes. Small perivascular clusters of infiltrating mononuclear cells were positive; scattered spindle fibroblast-like cells were immunostained in superficial and deep dermal layers. The serum concentrations of MIF in patients with dSSc (mean (SD) 10705.6 (9311) pg/ml) were significantly higher than in controls (2157.5 (1288.6) pg/ml; p=0.011); MIF levels from dSSc fibroblast cultures (mean (SD) 1.74 (0.16) ng/2x105 cells) were also significantly higher than in controls (0.6 (0.2) ng/2x105 cells; p=0.008). Conclusion: These results suggest that MIF may be involved in the amplifying proinflammatory loop leading to scleroderma tissue remodelling. PMID:12695161

  14. Toxicological Assessment of Noxious Inhalants

    PubMed Central

    Kleinsasser, N. H.; Sassen, A. W.; Wallner, B. W.; Staudenmaier, R.; Harréus, U. A.; Richter, E.

    2004-01-01

    In the past centuries mankind has been exposed to various forms of air pollution not only at his occupational but also in his social environment. He mainly gets exposed with these pollutants through the respiratory organs and partially absorbs them into the body. Many of these airborne substances can be harmful for humans and some of them may account for tumorigenic effects. The following essay describes the main features of toxicological assessment of inhalative environmental and workplace xenobiotics. The essay also explains relevant characteristics and limit values of noxious compounds and gases and depicts modern testing methods. To this end, emphasis is given on methods characterizing the different stages of tumorigenic processes. Various test systems have been developed which can be used in vivo, ex vivo or in vitro. They are to a great part based on the evidence of changes in DNA or particular genes of cells. Among others they have highlighted the impact of interindividual variability on enzymatic activation of xenobiotics and on susceptibility of the host to tumor diseases. Unfortunately, for many inhalative environmental noxious agents no sufficient risk profiles have been developed. The completion of these profiles should be the goal of toxicological assessment in order to allow reasonable socioeconomic or individual-based risk reduction. PMID:22073045

  15. Noxious mechanical heterotopic stimulation induces inhibition of the spinal dorsal horn neuronal network: analysis of spinal somatosensory-evoked potentials.

    PubMed

    Meléndez-Gallardo, J; Eblen-Zajjur, A

    2016-09-01

    Most of the endogenous pain modulation (EPM) involves the spinal dorsal horn (SDH). EPM including diffuse noxious inhibitory controls have been extensively described in oligoneuronal electrophysiological recordings but less attention had been paid to responses of the SDH neuronal population to heterotopic noxious stimulation (HNS). Spinal somatosensory-evoked potentials (SEP) offer the possibility to evaluate the neuronal network behavior, reflecting the incoming afferent volleys along the entry root, SDH interneuron activities and the primary afferent depolarization. SEP from de lumbar cord dorsum were evaluated during mechanical heterotopic noxious stimuli. Sprague-Dawley rats (n = 12) were Laminectomized (T10-L3). The sural nerve of the left hind paw was electrically stimulated (5 mA, 0.5 ms, 0.05 Hz) to induce lumbar SEP. The HNS (mechanic clamp) was applied sequentially to the tail, right hind paw, right forepaw, muzzle and left forepaw during sural stimulation. N wave amplitude decreases (-16.6 %) compared to control conditions when HNS was applied to all areas of stimulation. This effect was more intense for muzzle stimulation (-23.5 %). N wave duration also decreased by -23.6 %. HNS did not change neither the amplitude nor the duration of the P wave but dramatically increases the dispersion of these two parameters. The results of the present study strongly suggest that a HNS applied to different parts of the body is able to reduce the integrated electrical response of the SDH, suggesting that not only wide dynamic range neurons but many others in the SDH are modulated by the EPM.

  16. Differential susceptibility of cortical and subcortical inhibitory neurons and astrocytes in the long term following diffuse traumatic brain injury.

    PubMed

    Carron, Simone F; Yan, Edwin B; Alwis, Dasuni S; Rajan, Ramesh

    2016-12-01

    Long-term diffuse traumatic brain injury (dTBI) causes neuronal hyperexcitation in supragranular layers in sensory cortex, likely through reduced inhibition. Other forms of TBI affect inhibitory interneurons in subcortical areas but it is unknown if this occurs in cortex, or in any brain area in dTBI. We investigated dTBI effects on inhibitory neurons and astrocytes in somatosensory and motor cortex, and hippocampus, 8 weeks post-TBI. Brains were labeled with antibodies against calbindin (CB), parvalbumin (PV), calretinin (CR) and neuropeptide Y (NPY), and somatostatin (SOM) and glial fibrillary acidic protein (GFAP), a marker for astrogliosis during neurodegeneration. Despite persistent behavioral deficits in rotarod performance up to the time of brain extraction (TBI = 73.13 ± 5.23% mean ± SEM, Sham = 92.29 ± 5.56%, P < 0.01), motor cortex showed only a significant increase, in NPY neurons in supragranular layers (mean cells/mm(2) ± SEM, Sham = 16 ± 0.971, TBI = 25 ± 1.51, P = 0.001). In somatosensory cortex, only CR(+) neurons showed changes, being decreased in supragranular (TBI = 19 ± 1.18, Sham = 25 ± 1.10, P < 0.01) and increased in infragranular (TBI = 28 ± 1.35, Sham = 24 ± 1.07, P < 0.05) layers. Heterogeneous changes were seen in hippocampal staining: CB(+) decreased in dentate gyrus (TBI = 2 ± 0.382, Sham = 4 ± 0.383, P < 0.01), PV(+) increased in CA1 (TBI = 39 ± 1.26, Sham = 33 ± 1.69, P < 0.05) and CA2/3 (TBI = 26 ± 2.10, Sham = 20 ± 1.49, P < 0.05), and CR(+) decreased in CA1 (TBI = 10 ± 1.02, Sham = 14 ± 1.14, P < 0.05). Astrogliosis significantly increased in corpus callosum (TBI = 6.7 ± 0.69, Sham = 2.5 ± 0.38; P = 0.007). While dTBI effects on inhibitory neurons appear region- and type-specific, a common feature in all cases of decrease was that changes occurred in dendrite targeting interneurons involved in neuronal integration. J. Comp. Neurol. 524:3530-3560, 2016. © 2016 Wiley Periodicals, Inc.

  17. 7 CFR 201.16 - Noxious-weed seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Noxious-weed seeds. 201.16 Section 201.16 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.16 Noxious-weed seeds. (a) Except for those kinds of noxious-weed seeds shown in paragraph (b) of this section, the names of the kinds of noxious-weed seeds and the...

  18. 7 CFR 201.16 - Noxious-weed seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Noxious-weed seeds. 201.16 Section 201.16 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.16 Noxious-weed seeds. (a) Except for those kinds of noxious-weed seeds shown in paragraph (b) of this section, the names of the kinds of noxious-weed seeds and the...

  19. 7 CFR 201.16 - Noxious-weed seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Noxious-weed seeds. 201.16 Section 201.16 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.16 Noxious-weed seeds. (a) Except for those kinds of noxious-weed seeds shown in paragraph (b) of this section, the names of the kinds of noxious-weed seeds and the...

  20. 7 CFR 201.16 - Noxious-weed seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Noxious-weed seeds. 201.16 Section 201.16 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.16 Noxious-weed seeds. (a) Except for those kinds of noxious-weed seeds shown in paragraph (b) of this section, the names of the kinds of noxious-weed seeds and the...

  1. 7 CFR 201.52 - Noxious-weed seeds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture... REGULATIONS Purity Analysis in the Administration of the Act § 201.52 Noxious-weed seeds. (a) The determination of the number of seeds, bulblets, or tubers of individual noxious weeds present per unit...

  2. 46 CFR 4.03-60 - Noxious liquid substance (NLS).

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Noxious liquid substance (NLS). 4.03-60 Section 4.03-60 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC MARINE CASUALTIES AND INVESTIGATIONS Definitions § 4.03-60 Noxious liquid substance (NLS). Noxious liquid substance...

  3. 46 CFR 4.03-60 - Noxious liquid substance (NLS).

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Noxious liquid substance (NLS). 4.03-60 Section 4.03-60 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC MARINE CASUALTIES AND INVESTIGATIONS Definitions § 4.03-60 Noxious liquid substance (NLS). Noxious liquid substance...

  4. 46 CFR 4.03-60 - Noxious liquid substance (NLS).

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Noxious liquid substance (NLS). 4.03-60 Section 4.03-60 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC MARINE CASUALTIES AND INVESTIGATIONS Definitions § 4.03-60 Noxious liquid substance (NLS). Noxious liquid substance...

  5. 46 CFR 4.03-60 - Noxious liquid substance (NLS).

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Noxious liquid substance (NLS). 4.03-60 Section 4.03-60 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC MARINE CASUALTIES AND INVESTIGATIONS Definitions § 4.03-60 Noxious liquid substance (NLS). Noxious liquid substance...

  6. 46 CFR 4.03-60 - Noxious liquid substance (NLS).

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Noxious liquid substance (NLS). 4.03-60 Section 4.03-60 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC MARINE CASUALTIES AND INVESTIGATIONS Definitions § 4.03-60 Noxious liquid substance (NLS). Noxious liquid substance...

  7. Serum levels, tissue expression and cellular secretion of macrophage migration inhibitory factor in limited and diffuse systemic sclerosis.

    PubMed

    Corallo, Claudio; Paulesu, Luana; Cutolo, Maurizio; Ietta, Francesca; Carotenuto, Claudio; Mannelli, Chiara; Romagnoli, Roberta; Nuti, Ranuccio; Giordano, Nicola

    2015-01-01

    To investigate serum levels, tissue/cellular expression of macrophage migration inhibitory factor (MIF) in patients with limited (lSSc) and diffuse (dSSc) systemic sclerosis. 10 lSSc-patients, 10 dSSc-patients and 10 controls were enrolled. MIF serum levels were assayed by ELISA. MIF and its receptors CD74/CD44 were evaluated by immunohistochemistry on skin biopsies from patients with dSSc, lSSc (affected and not-affected skin) and controls. MIF levels were assessed (ELISA) in supernatants of healthy dermal microvascular endothelial cells (MVECs) and in control (CTR), non-affected SSc (NA) and affected (SSc) fibroblasts treated for 48 h with 10% control serum and 10% SSc-serum. MIF supernatant (ELISA) and mRNA (quantitative real-time PCR) levels were determined in SSc dermal fibroblasts and in control dermal fibroblasts untreated or stimulated at 6 h-24 h-48 h with bleomycin (50 mU/ml). Serum MIF was significantly higher in dSSc (18.7±4.1 ng/ml, p<0.001) and in lSSc (10.4±4.4 ng/ml, p<0.001) patients respect to controls (2.6±1.4 ng/ml). Enhanced MIF immunoreactivity was found in keratinocytes, fibroblasts, endothelium, sebaceous/sweat glands from lSSc/dSSc affected skin. Faint MIF immunoreactivity was found in control skin and not-affected skin of lSSc patients. No differences were found in CD74/CD44 receptors' analysis among control and dSSc/lSSc affected and non-affected skin. MVECs and fibroblasts (CTR, NA and SSc) produced significantly more MIF, when stimulated with SSc serum respect to control-serum (p<0.001). Finally, MIF mRNA levels significantly increased at 6h (p<0.001) and decreased at 48 h (p<0.001) in control fibroblasts treated with bleomycin compared to control untreated. Simultaneously, MIF supernatant protein levels increased after 48 h (p<0.01) in bleomycin-treated fibroblasts respect to untreated ones. These results suggest that MIF could be implicated in the pathogenesis of SSc, probably acting as protective factor against the SSc stressful

  8. The ability of inhibitory controls to 'switch-off' activity in dorsal horn convergent neurones in the rat.

    PubMed

    Cadden, S W

    1993-11-19

    Unitary extracellular recordings were made from 51 convergent neurones in the dorsal horn of the lumbar spinal cords of urethane anaesthetized rats. All the cells tested responded to sustained noxious mechanical stimulation of their receptive fields on the ipsilateral hindpaw, but only 26/49 gave tonic responses lasting for more than 5 min. In all 26 cells, these tonic responses were depressed by diffuse noxious inhibitory controls (DNIC) triggered by applying noxious conditioning stimuli elsewhere on the body. In seven cells, the inhibitory effects could involve a complete abolition of activity and in five cells, when this occurred, activity did not return during 2.5-6-min periods of observation following removal of the conditioning stimuli. However, in those cases, activity could be restored to pre-conditioning levels by further manipulations of the receptive field-either removal and re-application of the original stimulus or brief application of an additional stimulus. These results show that inhibitory controls can 'switch-off' activity in at least a small proportion of dorsal horn convergent neurones. One possible explanation would be that in these neurones, responses to sustained noxious stimuli may depend on activity in a positive feedback circuit within the central nervous system, which when interrupted, may be restored only by additional afferent inputs. The existence of such a loop could also explain the finding of convergent convergent neurones which initially were not spontaneously active but which after stimulation of their receptive fields, developed on-going discharges which could be switched-off by DNIC.

  9. Comparison between the antimicrobial susceptibility of Burkholderia pseudomallei to trimethoprim-sulfamethoxazole by standard disk diffusion method and by minimal inhibitory concentration determination.

    PubMed

    Lumbiganon, P; Tattawasatra, U; Chetchotisakd, P; Wongratanacheewin, S; Thinkhamrop, B

    2000-08-01

    Melioidosis, an infection caused by Burkholderia pseudomallei, usually occurs in immunocompromised patients and requires prolonged antibiotic therapy. Previously, oral trimethoprim-sulfamethoxazole (TM/SM), an inexpensive and effective drug has been used as a maintenance therapy. The susceptibility of B. pseudomallei to TM/SM by the standard disk diffusion method is very low. However, some patients who were treated with TM/SM as a maintenance therapy despite the in vitro resistance showed good clinical responses. There were no data comparing the susceptibility of B. pseudomallei by the standard disk diffusion method with other quantitative susceptibility tests. The objective of this study was to determine the agreement between the antimicrobial susceptibility of B. pseudomallei to TM/SM by standard disk diffusion and minimal inhibitory concentration determination (MIC). We performed the susceptibility test of 144 strains of B. pseudomallei to TM/SM by both the standard disk diffusion and microbroth dilution MIC. The sensitivity results were 53.5 per cent and 84.0 per cent respectively. The agreement between the 2 tests was very poor (Kappa = 0.14; 95% CI = -0.01 to 0.29). The false resistant rate by the standard disk diffusion test was 67.9 per cent. Further in vitro susceptibility and clinical study are needed to define the interpretive criteria that correlate with clinical response.

  10. Guidelines for management of noxious weeds at Hanford

    SciTech Connect

    Roos, R.C.; Malady, M.B.

    1995-10-27

    Integrated Pest Management Services is responsible for management and control of noxious weeds on the Hanford Site. Weed species and populations are prioritized and objective defined, according to potential site and regional impact. Population controls are implemented according to priority. An integrated approach is planned for noxious weed control in which several management options are considered and implemented separately or in coordination to best meet management objectives. Noxious weeds are inventories and monitored to provide information for planning and program review.

  11. Rat defensive behavior: burying noxious food.

    PubMed Central

    Wilkie, D M; MacLennan, A J; Pinel, J P

    1979-01-01

    In Experiment 1, rats living in chambers containing bedding material were injected with a toxicosis-producing dose of lithium chloride shortly after their initial taste of sweetened condensed milk. They consumed no additional milk and used the bedding to bury the spout through which the milk had been delivered, although they did not bury a concurrently available water spout. In another control condition, rats did not bury a spout containing a novel solution (saccharin) not paired with toxicosis. In Experiment 2, rats did not bury a milk spout until milk consumption was followed by toxicosis. In Experiment 3, rats buried a spout containing Tabasco pepper sauce but not a concurrently available water spout. Thus, burying the food source appears to be an integral component of the rat's defensive reaction to noxious food. PMID:572863

  12. Rat defensive behavior: burying noxious food.

    PubMed

    Wilkie, D M; MacLennan, A J; Pinel, J P

    1979-05-01

    In Experiment 1, rats living in chambers containing bedding material were injected with a toxicosis-producing dose of lithium chloride shortly after their initial taste of sweetened condensed milk. They consumed no additional milk and used the bedding to bury the spout through which the milk had been delivered, although they did not bury a concurrently available water spout. In another control condition, rats did not bury a spout containing a novel solution (saccharin) not paired with toxicosis. In Experiment 2, rats did not bury a milk spout until milk consumption was followed by toxicosis. In Experiment 3, rats buried a spout containing Tabasco pepper sauce but not a concurrently available water spout. Thus, burying the food source appears to be an integral component of the rat's defensive reaction to noxious food.

  13. 7 CFR 201.52 - Noxious-weed seeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the Administration of the Act § 201.52 Noxious-weed seeds. (a) The...

  14. 7 CFR 201.52 - Noxious-weed seeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the Administration of the Act § 201.52 Noxious-weed seeds. (a) The...

  15. 7 CFR 201.52 - Noxious-weed seeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the Administration of the Act § 201.52 Noxious-weed seeds. (a) The...

  16. 7 CFR 201.52 - Noxious-weed seeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Noxious-weed seeds. 201.52 Section 201.52 Agriculture..., Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Purity Analysis in the Administration of the Act § 201.52 Noxious-weed seeds. (a) The...

  17. Bonneville Power Administration, Lower Columbia Region: Noxious Weed Management, 1996 Annual Report.

    SciTech Connect

    United States. Bonneville Power Administration, Portland, OR; Oregon Department of Agriculture Noxious Weed Control Program

    1996-01-01

    During the 1996 season ODA executed the contract between BPA and ODA. Execution of this contract included the following activities: Survey for target noxious weeds, such as Gorse; collection and redistribution of biological control agents, for example, Apion seed weevils for Scotch broom, bioagents for diffuse and spotted knapweed, Gorse spider mite, and gall fly releases for control of Canada thistle and bull thistle; and control of isolated infestations of Gorse on BPA rights-of-way. Training was provided for line crews at the Chemawa, Alevy and North Bend districts. The purpose of the program is to assist BPA in the integrated prevention and control of noxious weed species on BPA transmission line maintenance right-of-ways.

  18. Acute intravenous administration of dietary constituent theanine suppresses noxious neuronal transmission of trigeminal spinal nucleus caudalis in rats.

    PubMed

    Takehana, Shiori; Kubota, Yoshiko; Uotsu, Nobuo; Yui, Kei; Shimazu, Yoshihito; Takeda, Mamoru

    2017-03-15

    Theanine is a non-dietary amino acid linked to the modulation of synaptic transmission in the central nervous system, although the acute effects of theanine in vivo, particularly on nociceptive transmission in the trigeminal system, remain to be determined. The present study investigated whether acute intravenous theanine administration to rats attenuates the excitability of wide dynamic range (WDR) spinal trigeminal nucleus caudalis (SpVc) neurons in response to nociceptive and non-nociceptive mechanical stimulation in vivo. Extracellular single unit recordings were made from 15 SpVc neurons in response to orofacial mechanical stimulation of pentobarbital-anesthetized rats, and responses to non-noxious and noxious mechanical stimuli were analyzed. The mean firing frequency of SpVc WDR neurons in response to all mechanical stimuli was dose-dependently inhibited by theanine (10, 50, and 100mM, i.v.) with the maximum inhibition of discharge frequency reached within 5min. These inhibitory effects were reversed after approximately 10min. The relative magnitude of theanine's inhibition of SpVc WDR neuronal discharge frequency was significantly greater for noxious than non-noxious stimulation. Iontophoretic application of l-glutamate induced the mean firing frequency of SpVc WDR neuron responding to noxious mechanical stimulation was also inhibited by intravenous administration of 100mM theanine. These results suggest that acute intravenous theanine administration suppresses glutaminergic noxious synaptic transmission in the SpVc, implicating theanine as a potential complementary and alternative therapeutic agent for the treatment of trigeminal nociceptive pain.

  19. The neurologic effects of noxious marine creatures.

    PubMed

    Southcott, R V

    1975-01-01

    The concept of the sea as a source of noxious agents is perhaps not a familiar one to clinical neurologists, judging by the lack of reference to these agents in standard textbooks. Chemical, physiologic, and pharmacologic laboratories are increasingly investigating the properties of marine toxins, finding in them compounds with interesting and novel structures or unusual physiologic effects. Such substances are seen as possible agents for biologic and, more particularly, physiologic research, and as possible sources of new pharmaceuticals. These include hormone-like substances and antiviral or antitumor agents. Despite these specialized developments, which are in large measure a consequence of the technological advances of the present century, the clinician is at times directly concerned with the effects of marine toxic substances. For example, in Japan, puffer fish or tetrodotoxic poisoning is one of the major causes of deaths from food poisoning. Another marine toxin that has caused many explosive outbreaks of food poisoning. with many deaths in various parts of the world, comes from clams or mussels. This toxin, saxitoxin, is produced by species of marine protozoa including Gonyaulax, and is concentrated in filter-feeding molluscs. These two examples were of significant interest in medicine long before the technologic developments of the twentieth century. In the last few decades, entirely new problems of marine intoxication have arisen as a result of marine pollution from the disposal of industrial wastes in the sea. The most striking example of a man-made marine intoxication has been the outbreak of Minamata disease. In Minamata, Japan, the disposal of mercury-contaminated industrial wastes from a plastics factory into an enclosed bay, followed by human consumption of the contaminated fishes, crabs, or shellfish, led to many instances of acute cerebral degeneration. With the increasing exploration of the sea for both pleasure and economic exploitation, which

  20. 7 CFR 360.305 - Disposal of noxious weeds when permits are canceled.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Disposal of noxious weeds when permits are canceled... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.305 Disposal of noxious weeds when permits are canceled. When a permit for the movement of a noxious weed is...

  1. 7 CFR 360.305 - Disposal of noxious weeds when permits are canceled.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Disposal of noxious weeds when permits are canceled... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.305 Disposal of noxious weeds when permits are canceled. When a permit for the movement of a noxious weed is...

  2. 7 CFR 360.300 - Notice of restrictions on movement of noxious weeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Notice of restrictions on movement of noxious weeds... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.300 Notice of restrictions on movement of noxious weeds. No person may move a Federal noxious weed into or...

  3. 7 CFR 360.300 - Notice of restrictions on movement of noxious weeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Notice of restrictions on movement of noxious weeds... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.300 Notice of restrictions on movement of noxious weeds. No person may move a Federal noxious weed into or...

  4. 7 CFR 360.300 - Notice of restrictions on movement of noxious weeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Notice of restrictions on movement of noxious weeds... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.300 Notice of restrictions on movement of noxious weeds. No person may move a Federal noxious weed into or...

  5. 7 CFR 360.305 - Disposal of noxious weeds when permits are canceled.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Disposal of noxious weeds when permits are canceled... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.305 Disposal of noxious weeds when permits are canceled. When a permit for the movement of a noxious weed is...

  6. 7 CFR 360.300 - Notice of restrictions on movement of noxious weeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Notice of restrictions on movement of noxious weeds... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.300 Notice of restrictions on movement of noxious weeds. No person may move a Federal noxious weed into or...

  7. 7 CFR 360.305 - Disposal of noxious weeds when permits are canceled.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Disposal of noxious weeds when permits are canceled... AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.305 Disposal of noxious weeds when permits are canceled. When a permit for the movement of a noxious weed is...

  8. Activation of rostral ventromedial medulla neurons by noxious stimulation of cutaneous and deep craniofacial tissues

    PubMed Central

    Khasabov, Sergey G.; Malecha, Patrick; Noack, Joseph; Tabakov, Janneta; Okamoto, Keiichiro; Bereiter, David A.

    2014-01-01

    The rostral ventromedial medulla (RVM) projects to the medullary and spinal dorsal horns and is a major source of descending modulation of nociceptive transmission. Traditionally, neurons in the RVM are classified functionally as ON, OFF, and NEUTRAL cells on the basis of responses to noxious cutaneous stimulation of the tail or hind paw. ON cells facilitate nociceptive transmission, OFF cells are inhibitory, whereas NEUTRAL cells are unresponsive to noxious stimuli and their role in pain modulation is unclear. Classification of RVM neurons with respect to stimulation of craniofacial tissues is not well defined. In isoflurane-anesthetized male rats, RVM neurons first were classified as ON (25.5%), OFF (25.5%), or NEUTRAL (49%) cells by noxious pinch applied to the hind paw. Pinching the skin overlying the temporomandibular joint (TMJ) altered the proportions of ON (39.2%), OFF (42.2%), and NEUTRAL (19.6%) cells. To assess the response of RVM cells to specialized craniofacial inputs, adenosine triphosphate (ATP; 0.01–1 mM) was injected into the TMJ and capsaicin (0.1%) was applied to the ocular surface. TMJ and ocular surface stimulation also resulted in a reduced proportion of NEUTRAL cells compared with hind paw pinch. Dose-effect analyses revealed that ON and OFF cells encoded the intra-TMJ concentration of ATP. These results suggest that somatotopy plays a significant role in the functional classification of RVM cells and support the notion that NEUTRAL cells likely are subgroups of ON and OFF cells. It is suggested that a portion of RVM neurons serve different functions in modulating craniofacial and spinal pain conditions. PMID:25185804

  9. Activation of rostral ventromedial medulla neurons by noxious stimulation of cutaneous and deep craniofacial tissues.

    PubMed

    Khasabov, Sergey G; Malecha, Patrick; Noack, Joseph; Tabakov, Janneta; Okamoto, Keiichiro; Bereiter, David A; Simone, Donald A

    2015-01-01

    The rostral ventromedial medulla (RVM) projects to the medullary and spinal dorsal horns and is a major source of descending modulation of nociceptive transmission. Traditionally, neurons in the RVM are classified functionally as on, off, and neutral cells on the basis of responses to noxious cutaneous stimulation of the tail or hind paw. On cells facilitate nociceptive transmission, off cells are inhibitory, whereas neutral cells are unresponsive to noxious stimuli and their role in pain modulation is unclear. Classification of RVM neurons with respect to stimulation of craniofacial tissues is not well defined. In isoflurane-anesthetized male rats, RVM neurons first were classified as on (25.5%), off (25.5%), or neutral (49%) cells by noxious pinch applied to the hind paw. Pinching the skin overlying the temporomandibular joint (TMJ) altered the proportions of on (39.2%), off (42.2%), and neutral (19.6%) cells. To assess the response of RVM cells to specialized craniofacial inputs, adenosine triphosphate (ATP; 0.01-1 mM) was injected into the TMJ and capsaicin (0.1%) was applied to the ocular surface. TMJ and ocular surface stimulation also resulted in a reduced proportion of neutral cells compared with hind paw pinch. Dose-effect analyses revealed that on and off cells encoded the intra-TMJ concentration of ATP. These results suggest that somatotopy plays a significant role in the functional classification of RVM cells and support the notion that neutral cells likely are subgroups of on and off cells. It is suggested that a portion of RVM neurons serve different functions in modulating craniofacial and spinal pain conditions.

  10. Human brain stem structures respond differentially to noxious heat.

    PubMed

    Ritter, Alexander; Franz, Marcel; Dietrich, Caroline; Miltner, Wolfgang H R; Weiss, Thomas

    2013-01-01

    Concerning the physiological correlates of pain, the brain stem is considered to be one core region that is activated by noxious input. In animal studies, different slopes of skin heating (SSH) with noxious heat led to activation in different columns of the midbrain periaqueductal gray (PAG). The present study aimed at finding a method for differentiating structures in PAG and other brain stem structures, which are associated with different qualities of pain in humans according to the structures that were associated with different behavioral significances to noxious thermal stimulation in animals. Brain activity was studied by functional MRI in healthy subjects in response to steep and shallow SSH with noxious heat. We found differential activation to different SSH in the PAG and the rostral ventromedial medulla (RVM). In a second experiment, we demonstrate that the different SSH were associated with different pain qualities. Our experiments provide evidence that brainstem structures, i.e., the PAG and the RVM, become differentially activated by different SSH. Therefore, different SSH can be utilized when brain stem structures are investigated and when it is aimed to activate these structures differentially. Moreover, percepts of first pain were elicited by shallow SSH whereas percepts of second pain were elicited by steep SSH. The stronger activation of these brain stem structures to SSH, eliciting percepts of second vs. first pain, might be of relevance for activating different coping strategies in response to the noxious input with the two types of SSH.

  11. KCa3.1 channels modulate the processing of noxious chemical stimuli in mice.

    PubMed

    Lu, Ruirui; Flauaus, Cathrin; Kennel, Lea; Petersen, Jonas; Drees, Oliver; Kallenborn-Gerhardt, Wiebke; Ruth, Peter; Lukowski, Robert; Schmidtko, Achim

    2017-10-01

    Intermediate conductance calcium-activated potassium channels (KCa3.1) have been recently implicated in pain processing. However, the functional role and localization of KCa3.1 in the nociceptive system are largely unknown. We here characterized the behavior of mice lacking KCa3.1 (KCa3.1(-/-)) in various pain models and analyzed the expression pattern of KCa3.1 in dorsal root ganglia (DRG) and the spinal cord. KCa3.1(-/-) mice demonstrated normal behavioral responses in models of acute nociceptive, persistent inflammatory, and persistent neuropathic pain. However, their behavioral responses to noxious chemical stimuli such as formalin and capsaicin were increased. Accordingly, formalin-induced nociceptive behavior was increased in wild-type mice after administration of the KCa3.1 inhibitor TRAM-34. In situ hybridization experiments detected KCa3.1 in most DRG satellite glial cells, in a minority of DRG neurons, and in ependymal cells lining the central canal of the spinal cord. Together, our data point to a specific inhibitory role of KCa3.1 for the processing of noxious chemical stimuli. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Behavioral responses to noxious stimuli shape the perception of pain

    PubMed Central

    May, Elisabeth S.; Tiemann, Laura; Schmidt, Paul; Nickel, Moritz M.; Wiedemann, Nina; Dresel, Christian; Sorg, Christian; Ploner, Markus

    2017-01-01

    Pain serves vital protective functions. To fulfill these functions, a noxious stimulus might induce a percept which, in turn, induces a behavioral response. Here, we investigated an alternative view in which behavioral responses do not exclusively depend on but themselves shape perception. We tested this hypothesis in an experiment in which healthy human subjects performed a reaction time task and provided perceptual ratings of noxious and tactile stimuli. A multi-level moderated mediation analysis revealed that behavioral responses are significantly involved in the translation of a stimulus into perception. This involvement was significantly stronger for noxious than for tactile stimuli. These findings show that the influence of behavioral responses on perception is particularly strong for pain which likely reflects the utmost relevance of behavioral responses to protect the body. These observations parallel recent concepts of emotions and entail implications for the understanding and treatment of pain. PMID:28276487

  13. Behavioral responses to noxious stimuli shape the perception of pain.

    PubMed

    May, Elisabeth S; Tiemann, Laura; Schmidt, Paul; Nickel, Moritz M; Wiedemann, Nina; Dresel, Christian; Sorg, Christian; Ploner, Markus

    2017-03-09

    Pain serves vital protective functions. To fulfill these functions, a noxious stimulus might induce a percept which, in turn, induces a behavioral response. Here, we investigated an alternative view in which behavioral responses do not exclusively depend on but themselves shape perception. We tested this hypothesis in an experiment in which healthy human subjects performed a reaction time task and provided perceptual ratings of noxious and tactile stimuli. A multi-level moderated mediation analysis revealed that behavioral responses are significantly involved in the translation of a stimulus into perception. This involvement was significantly stronger for noxious than for tactile stimuli. These findings show that the influence of behavioral responses on perception is particularly strong for pain which likely reflects the utmost relevance of behavioral responses to protect the body. These observations parallel recent concepts of emotions and entail implications for the understanding and treatment of pain.

  14. Process for the preparation of solutions from environmentally noxious substances

    SciTech Connect

    Frenken, H.; Friedsam, J.; Voss, K.

    1984-01-24

    The invention relates to a process for the automatic preparation of solutions from environmentally noxious substances in solvents whereby the noxious substance is brought on a receiver and by means of an airtight adapter and a feed connection into a hermetical sealed, storage bin, an exact quantity of the substance is dosed into a measuring and mixing vessel by means of a dosing screw after the solvent is dosed into this vessel, the substance is mixed and dissolved maintained at a certain temperature filtered and delivered to a storage vessel in an automatic sequence.

  15. Analgesic antidepressants promote the responsiveness of locus coeruleus neurons to noxious stimulation: implications for neuropathic pain.

    PubMed

    Alba-Delgado, Cristina; Mico, Juan Antonio; Sánchez-Blázquez, Pilar; Berrocoso, Esther

    2012-07-01

    Antidepressants that block the reuptake of noradrenaline and/or serotonin are among the first-line treatments for neuropathic pain, although the mechanisms underlying this analgesia remain unclear. The noradrenergic locus coeruleus is an essential element of both the ascending and descending pain modulator systems regulated by these antidepressants. Hence, we investigated the effect of analgesic antidepressants on locus coeruleus activity in Sprague-Dawley rats subjected to chronic constriction injury (CCI), a model of neuropathic pain. In vivo extracellular recordings of locus coeruleus revealed that CCI did not modify the basal tonic activity of this nucleus, although its sensory-evoked response to noxious stimuli was significantly altered. Under normal conditions, noxious stimulation evokes an early response, corresponding to the activation of myelinated A fibers, which is followed by an inhibitory period and a subsequent late capsaicin-sensitive response, consistent with the activation of unmyelinated C fibers. CCI provokes an enhanced excitatory early response in the animals and the loss of the late response. Antidepressant administration over 7 days (desipramine, 10mg/kg/day or duloxetine, 5mg/kg/day, delivered by osmotic minipumps) decreased the excitatory firing rate of the early response in the CCI group. Moreover, in all animals, these antidepressants reduced the inhibitory period and augmented the late response. We propose that N-methyl-d-aspartate and alpha-2-adrenoceptors are involved in the analgesic effect of antidepressants. Antidepressant-mediated changes were correlated with behavioral effects indicative of analgesia in healthy and neuropathic rats. Copyright © 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  16. Relationship between mechano-receptive fields of dorsal horn convergent neurons and the response to noxious immersion of the ipsilateral hindpaw in rats.

    PubMed

    McGaraughty, S; Henry, J L

    1997-04-01

    This study examines the relationship between mechano-receptive fields (inhibitory and excitatory, located on the ipsilateral hindpaw) of convergent dorsal horn neurons, and the responses of the neurons to noxious immersion of an entire paw in noxious hot water. In pentobarbital anesthetized rats with intact spinal cords and in unanesthetized decerebrate-spinalized rats, rat hindpaws were immersed in 50 degrees C water for 10 s after the mechano-receptive fields had been delineated using 5-s noxious pinches. Convergent neurons were either excited or inhibited by noxious immersion of the hindpaw. In both groups, a significant association (chi2, P < 0.01) was found between the make-up of the mechano-receptive field and the response of the neuron to immersion. Immersion-inhibited neurons (intact = 27, spinalized = 13), always had both an excitatory and an inhibitory mechano-receptive field on the same hindpaw. Additionally, when the hindpaw was removed from the noxious water, these immersion-inhibited cells displayed a strong afterdischarge which was immediately inhibited once the paw was reimmersed. Pinch-induced and immersion-induced inhibition were found in both spinalized and intact rats suggesting spinal mechanisms were sufficient to mediate this effect. The majority of immersion-excited cells showed only an excitatory mechano-receptive field on the hindpaw (intact rats = 18/23 or 78.3%, spinalized rats = 24/36 or 66.7%). However, other immersion-excited cells had both an inhibitory and an excitatory mechano-receptive field on the hindpaw (intact rats = 5/23 or 21.7%, spinalized rats = 12/36 or 33.3%). The response of a convergent neuron, which has its excitatory receptive field located on a paw, to noxious immersion of the entire paw can be predicted by the make-up of the mechano-receptive fields. Additionally, since noxious paw immersion affects ipsilateral convergent neurons in two opposite manners, it suggests that other effects, such as heterotopic actions

  17. The ability of humans to localise noxious stimuli.

    PubMed

    Koltzenburg, M; Handwerker, H O; Torebjörk, H E

    1993-02-19

    We have investigated the ability of humans to localise noxious stimuli on the dorsum of the hand. Pin-prick (non-penetrating needle prick), noxious heat (round 1 cm2 copper probe heated to 50 degrees C), mustard oil (100% applied topically in a small cotton ball, diameter 5 mm) and histamine (iontophoresis of 20 mC delivered to an area of 75 mm2) were applied to skin with intact innervation and during a differential nerve compression block of the superficial radial nerve when only C-fibres were conducting. The mean mislocalisation (+/- S.E.M.; n = 8) of all stimuli was 9.5 +/- 0.8 mm with normal nerve conduction and 8.9 +/- 1.2 during the differential nerve block. There was no significant difference between the noxious submodalities. By contrast, when nerve conduction was intact, purely tactile stimulation (7 mN von Frey hair) was significantly better localised having a mean error of 5.5 +/- 0.4 mm. We conclude that focal stimuli evoking itch or pain can be localised with high precision which is only marginally worse than for tactile stimuli. This suggests the existence of a somatotopical representation for noxious inputs in the brain similar to that found for tactile stimuli.

  18. Select noxious stimuli induce changes on corneal nerve morphology.

    PubMed

    Hegarty, Deborah M; Hermes, Sam M; Yang, Katherine; Aicher, Sue A

    2017-06-01

    The surface of the cornea contains the highest density of nociceptive nerves of any tissue in the body. These nerves are responsive to a variety of modalities of noxious stimuli and can signal pain even when activated by low threshold stimulation. Injury of corneal nerves can lead to altered nerve morphology, including neuropathic changes which can be associated with chronic pain. Emerging technologies that allow imaging of corneal nerves in vivo are spawning questions regarding the relationship between corneal nerve density, morphology, and function. We tested whether noxious stimulation of the corneal surface can alter nerve morphology and neurochemistry. We used concentrations of menthol, capsaicin, and hypertonic saline that evoked comparable levels of nocifensive eye wipe behaviors when applied to the ocular surface of an awake rat. Animals were sacrificed and corneal nerves were examined using immunocytochemistry and three-dimensional volumetric analyses. We found that menthol and capsaicin both caused a significant reduction in corneal nerve density as detected with β-tubulin immunoreactivity 2 hr after stimulation. Hypertonic saline did not reduce nerve density, but did cause qualitative changes in nerves including enlarged varicosities that were also seen following capsaicin and menthol stimulation. All three types of noxious stimuli caused a depletion of CGRP from corneal nerves, indicating that all modalities of noxious stimuli evoked peptide release. Our findings suggest that studies aimed at understanding the relationship between corneal nerve morphology and chronic disease may also need to consider the effects of acute stimulation on corneal nerve morphology.

  19. Brain mediators of the effects of noxious heat on pain.

    PubMed

    Atlas, Lauren Y; Lindquist, Martin A; Bolger, Niall; Wager, Tor D

    2014-08-01

    Recent human neuroimaging studies have investigated the neural correlates of either noxious stimulus intensity or reported pain. Although useful, analyzing brain relationships with stimulus intensity and behavior separately does not address how sensation and pain are linked in the central nervous system. In this study, we used multi-level mediation analysis to identify brain mediators of pain--regions in which trial-by-trial responses to heat explained variability in the relationship between noxious stimulus intensity (across 4 levels) and pain. This approach has the potential to identify multiple circuits with complementary roles in pain genesis. Brain mediators of noxious heat effects on pain included targets of ascending nociceptive pathways (anterior cingulate, insula, SII, and medial thalamus) and also prefrontal and subcortical regions not associated with nociceptive pathways per se. Cluster analysis revealed that mediators were grouped into several distinct functional networks, including the following: somatosensory, paralimbic, and striatal-cerebellar networks that increased with stimulus intensity; and 2 networks co-localized with "default mode" regions in which stimulus intensity-related decreases mediated increased pain. We also identified "thermosensory" regions that responded to increasing noxious heat but did not predict pain reports. Finally, several regions did not respond to noxious input, but their activity predicted pain; these included ventromedial prefrontal cortex, dorsolateral prefrontal cortex, cerebellar regions, and supplementary motor cortices. These regions likely underlie both nociceptive and non-nociceptive processes that contribute to pain, such as attention and decision-making processes. Overall, these results elucidate how multiple distinct brain systems jointly contribute to the central generation of pain.

  20. [Effects of noxious coldness and non-noxious warmth on the magnitude of cerebral cortex activation during intraoral stimulation with water].

    PubMed

    Xiuwen, Yang; Hongchen, Liu; Ke, Li; Zhen, Jin; Gang, Liu

    2014-12-01

    We used functional magnetic resonance imaging (fMRI) to explore the effects of noxious coldness and non-noxious warmth on the magnitude of cerebral cortex activation during intraoral stimulation with water. Six male and female subjects were subjected to whole-brain fMRI during the phasic delivery of non-noxious hot (23 °C) and no- xious cold (4 °C) water intraoral stimulation. A block-design blood oxygenation level-dependent fMRI scan covering the entire brain was also carried out. The activated cortical areas were as follows: left pre-/post-central gyrus, insula/operculum, anterior cingulate cortex (ACC), orbital frontal cortex (OFC), midbrain red nucleus, and thalamus. The activated cortical areas under cold condition were as follows: left occipital lobe, premotor cortex/Brodmann area (BA) 6, right motor language area BA44, lingual gyrus, parietal lobule (BA7, 40), and primary somatosensory cortex S I. Comparisons of the regional cerebral blood flow response magnitude were made among stereotactically concordant brain regions that showed significant responses under the two conditions of this study. Compared with non-noxious warmth, more regions were activated in noxious coldness, and the magnitude of activation in areas produced after non-noxious warm stimulation significantly increased. However, ACC only significantly increased the magnitude of activation under noxious coldness stimulation. Results suggested that a similar network of regions was activated common to the perception of pain and no-pain produced by either non-noxious warmth or noxious coldness stimulation. Non-noxious warmth also activated more brain regions and significantly increased the response magnitude of cerebral-cortex activation compared with noxious coldness. Noxious coldness stimulation further significantly increased the magnitude of activation in ACC areas compared with noxious warmth.

  1. 7 CFR 201.17 - Noxious-weed seeds in the District of Columbia.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Noxious-weed seeds in the District of Columbia. 201.17... ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.17 Noxious-weed seeds in the District of Columbia. (a) Noxious-weed seeds in the District of Columbia are: Quackgrass (Elytrigia repens...

  2. 7 CFR 201.65 - Noxious weed seeds in interstate commerce.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Noxious weed seeds in interstate commerce. 201.65... ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.65 Noxious weed seeds in interstate commerce. Tolerances for rates of occurrence of noxious-weed seeds shall be recognized and shall be applied to the...

  3. 7 CFR 201.17 - Noxious-weed seeds in the District of Columbia.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Noxious-weed seeds in the District of Columbia. 201.17... ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.17 Noxious-weed seeds in the District of Columbia. (a) Noxious-weed seeds in the District of Columbia are: Quackgrass (Elytrigia repens...

  4. 7 CFR 201.65 - Noxious-weed seeds in interstate commerce.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Noxious-weed seeds in interstate commerce. 201.65... ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.65 Noxious-weed seeds in interstate commerce. Tolerances for rates of occurrence of noxious-weed seeds shall be recognized and shall be applied to the...

  5. 7 CFR 360.501 - Petitions to remove a taxon from the noxious weed lists.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Petitions to remove a taxon from the noxious weed...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.501 Petitions to remove a taxon from the noxious weed lists. A person may petition the Administrator to remove a...

  6. 7 CFR 201.17 - Noxious-weed seeds in the District of Columbia.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Noxious-weed seeds in the District of Columbia. 201.17... ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.17 Noxious-weed seeds in the District of Columbia. (a) Noxious-weed seeds in the District of Columbia are: Quackgrass (Elytrigia repens...

  7. 7 CFR 360.501 - Petitions to remove a taxon from the noxious weed lists.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Petitions to remove a taxon from the noxious weed...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.501 Petitions to remove a taxon from the noxious weed lists. A person may petition the Administrator to remove a...

  8. 7 CFR 360.301 - Information required for applications for permits to move noxious weeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... move noxious weeds. 360.301 Section 360.301 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.301 Information required for applications for permits to move noxious weeds. (a) Permit to import...

  9. 7 CFR 360.301 - Information required for applications for permits to move noxious weeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... move noxious weeds. 360.301 Section 360.301 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.301 Information required for applications for permits to move noxious weeds. (a) Permit to import...

  10. 7 CFR 201.65 - Noxious-weed seeds in interstate commerce.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Noxious-weed seeds in interstate commerce. 201.65... ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.65 Noxious-weed seeds in interstate commerce. Tolerances for rates of occurrence of noxious-weed seeds shall be recognized and shall be applied to the...

  11. 7 CFR 201.65 - Noxious-weed seeds in interstate commerce.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Noxious-weed seeds in interstate commerce. 201.65... ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.65 Noxious-weed seeds in interstate commerce. Tolerances for rates of occurrence of noxious-weed seeds shall be recognized and shall be applied to the...

  12. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... noxious weeds. 360.302 Section 360.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.302 Consideration of applications for permits to move noxious weeds. Upon the receipt of an application made in...

  13. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... noxious weeds. 360.302 Section 360.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.302 Consideration of applications for permits to move noxious weeds. Upon the receipt of an application made in...

  14. 7 CFR 360.301 - Information required for applications for permits to move noxious weeds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... move noxious weeds. 360.301 Section 360.301 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.301 Information required for applications for permits to move noxious weeds. (a) Permit to import...

  15. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... noxious weeds. 360.302 Section 360.302 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.302 Consideration of applications for permits to move noxious weeds. Upon the receipt of an application made in...

  16. 7 CFR 360.301 - Information required for applications for permits to move noxious weeds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... move noxious weeds. 360.301 Section 360.301 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.301 Information required for applications for permits to move noxious weeds. (a) Permit to import...

  17. 7 CFR 201.17 - Noxious-weed seeds in the District of Columbia.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Noxious-weed seeds in the District of Columbia. 201.17... ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.17 Noxious-weed seeds in the District of Columbia. (a) Noxious-weed seeds in the District of Columbia are: Quackgrass (Elytrigia repens...

  18. 7 CFR 360.501 - Petitions to remove a taxon from the noxious weed lists.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Petitions to remove a taxon from the noxious weed...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.501 Petitions to remove a taxon from the noxious weed lists. A person may petition the Administrator to remove a...

  19. 7 CFR 201.17 - Noxious-weed seeds in the District of Columbia.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious-weed seeds in the District of Columbia. 201.17... ACT FEDERAL SEED ACT REGULATIONS Labeling Agricultural Seeds § 201.17 Noxious-weed seeds in the District of Columbia. (a) Noxious-weed seeds in the District of Columbia are: Quackgrass (Elytrigia...

  20. 7 CFR 201.65 - Noxious weed seeds in interstate commerce.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Noxious weed seeds in interstate commerce. 201.65... ACT FEDERAL SEED ACT REGULATIONS Tolerances § 201.65 Noxious weed seeds in interstate commerce. Tolerances for rates of occurrence of noxious-weed seeds shall be recognized and shall be applied to...

  1. 46 CFR 125.120 - Carriage of noxious liquid substances in bulk.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Carriage of noxious liquid substances in bulk. 125.120... GENERAL § 125.120 Carriage of noxious liquid substances in bulk. (a) Except as provided by this section, no OSV may carry a noxious liquid substance (NLS) in bulk without the approval of the Commandant...

  2. 46 CFR 125.120 - Carriage of noxious liquid substances in bulk.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Carriage of noxious liquid substances in bulk. 125.120... GENERAL § 125.120 Carriage of noxious liquid substances in bulk. (a) Except as provided by this section, no OSV may carry a noxious liquid substance (NLS) in bulk without the approval of the Commandant...

  3. 46 CFR 125.120 - Carriage of noxious liquid substances in bulk.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carriage of noxious liquid substances in bulk. 125.120... GENERAL § 125.120 Carriage of noxious liquid substances in bulk. (a) Except as provided by this section, no OSV may carry a noxious liquid substance (NLS) in bulk without the approval of the Commandant...

  4. 46 CFR 125.120 - Carriage of noxious liquid substances in bulk.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Carriage of noxious liquid substances in bulk. 125.120... GENERAL § 125.120 Carriage of noxious liquid substances in bulk. (a) Except as provided by this section, no OSV may carry a noxious liquid substance (NLS) in bulk without the approval of the Commandant...

  5. 7 CFR 360.500 - Petitions to add a taxon to the noxious weed list.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Petitions to add a taxon to the noxious weed list. 360... to add a taxon to the noxious weed list. A person may petition the Administrator to have a taxon added to the noxious weeds lists in § 360.200. Details of the petitioning process for adding a taxon...

  6. Modulation of jaw reflexes induced by noxious stimulation to the muscle in anesthetized rats.

    PubMed

    Kurose, Masayuki; Yamamura, Kensuke; Noguchi, Makiko; Inoue, Makoto; Ootaki, Sachiko; Yamada, Yoshiaki

    2005-04-11

    Previous studies have shown that jaw reflexes and activity patterns of the jaw muscles were modulated in the presence of jaw muscle pain. However, there is no study comparing the modulatory effects on the jaw reflexes induced by noxious stimulation to the jaw muscle. To clarify this, effects of the application of mustard oil (MO), an inflammatory irritant, into the temporalis (jaw-closing) muscle on (1) jaw-opening reflex evoked by tooth pulp stimulation (TP-evoked JOR) as a nociceptive reflex, (2) jaw-opening reflex evoked by inferior alveolar nerve stimulation as a non-nociceptive reflex and (3) jaw-closing reflex evoked by trigeminal mesencephalic nucleus stimulation as a proprioceptive reflex were investigated in anesthetized rats. The MO application induced suppression of all reflexes, and the effect on the TP-evoked JOR was more prominent than on the other reflexes. To elucidate the involvement of endogenous opioid system for the suppressive effect, a systemic administration of naloxone following the MO application was conducted. The MO-induced suppressive effect on the TP-evoked JOR was reversed by the naloxone administration. The results suggest that noxious stimulation to the jaw muscle modulate jaw reflexes particularly for the nociceptive jaw-opening reflex, and the modulatory effect includes both facilitatory and inhibitory aspects. The results also suggest that pain modulatory systems such as the endogenous opioid system play a crucial role in the suppression of the nociceptive transmissions related to nociceptive reflexes, and in some pathological states, defense reflexes may not be evoked properly.

  7. Modulation of jaw reflexes by remote noxious stimulation and mental state: possible association with psychological measurements of mental stress and occupation.

    PubMed

    Cadden, S W; Van Der Glas, H W; Van Der Bilt, A

    1999-12-01

    Combined electrophysiological and psychophysical experiments were performed on 15 human subjects to investigate the possible effects of perceived stress or mental occupation on jaw reflexes. Electromyographic recordings were made from the masseter and anterior temporalis muscles, of the series of excitatory and inhibitory reflexes evoked by tapping on an upper incisor tooth. The reflexes were modified by application of painful cold (3 degrees C) stimuli to the subject's hand (remote noxious stimulation) or by the subject undertaking mental exercises (the 17 times table). The resulting changes in the reflexes usually involved transient increases in EMG activity around the interfaces between successive inhibitory and excitatory responses. Both the remote noxious stimuli and the mental exercises usually produced increases in both stress and mental occupation as assessed using visual analogue scales. However, correlations between these psychological effects and the effects on the reflexes were generally weak or absent. We conclude that the modulation of jaw reflexes by remote noxious stimuli or mental activity is not likely to be dependent on an individual's conscious awareness of a change in mental state. On the other hand, data from a related study suggest that the effects on the reflex may be more closely related to the autonomic responses to stress.

  8. Race, ethnicity, and noxious facilities: Environmental racism re- examined

    SciTech Connect

    Nieves, A.L. |; Nieves, L.A.

    1992-10-01

    The charge has been made that hazardous facilities tend to be located in proximity to minority populations. This study uses a facility density measure for three categories of noxious facilities to examine the relationship between facilities and minority population concentrations. County-level data are used in a correlation analysis for African Americans, Hispanics, and Asians in the four major regions of the US. Even controlling for income and housing value, and limiting the data set to urban areas, consistent patterns of moderate to strong association of facility densities with minority population percentages are found.

  9. 7 CFR 360.300 - General prohibitions and restrictions on the movement of noxious weeds; permits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED... determines that such movement, under conditions specified in the permit, would not involve a danger...

  10. 7 CFR 360.500 - Petitions to add a taxon to the noxious weed list.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.500 Petitions... suitability in the United States (predicted ecological range); (2) Dispersal potential...

  11. 7 CFR 360.500 - Petitions to add a taxon to the noxious weed list.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.500 Petitions... suitability in the United States (predicted ecological range); (2) Dispersal potential...

  12. 7 CFR 360.500 - Petitions to add a taxon to the noxious weed list.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.500 Petitions... suitability in the United States (predicted ecological range); (2) Dispersal potential...

  13. 7 CFR 360.304 - Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... noxious weed; cancelation of a permit to move a noxious weed. 360.304 Section 360.304 Agriculture..., DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.304 Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a noxious weed. (a) The Administrator may deny an...

  14. 7 CFR 360.304 - Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... noxious weed; cancelation of a permit to move a noxious weed. 360.304 Section 360.304 Agriculture..., DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.304 Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a noxious weed. (a) The Administrator may deny an...

  15. 7 CFR 360.304 - Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... noxious weed; cancelation of a permit to move a noxious weed. 360.304 Section 360.304 Agriculture..., DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.304 Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a noxious weed. (a) The Administrator may deny an...

  16. 7 CFR 360.304 - Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... noxious weed; cancelation of a permit to move a noxious weed. 360.304 Section 360.304 Agriculture..., DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.304 Denial of an application for a permit to move a noxious weed; cancelation of a permit to move a noxious weed. (a) The Administrator may deny an...

  17. TRPA1 mediates the noxious effects of natural sesquiterpene deterrents.

    PubMed

    Escalera, Jasmine; von Hehn, Christian A; Bessac, Bret F; Sivula, Michael; Jordt, Sven-Eric

    2008-08-29

    Plants, fungi, and animals generate a diverse array of deterrent natural products that induce avoidance behavior in biological adversaries. The largest known chemical family of deterrents are terpenes characterized by reactive alpha,beta-unsaturated dialdehyde moieties, including the drimane sesquiterpenes and other terpene species. Deterrent sesquiterpenes are potent activators of mammalian peripheral chemosensory neurons, causing pain and neurogenic inflammation. Despite their wide-spread synthesis and medicinal use as desensitizing analgesics, their molecular targets remain unknown. Here we show that isovelleral, a noxious fungal sesquiterpene, excites sensory neurons through activation of TPRA1, an ion channel involved in inflammatory pain signaling. TRPA1 is also activated by polygodial, a drimane sesquiterpene synthesized by plants and animals. TRPA1-deficient mice show greatly reduced nocifensive behavior in response to isovelleral, indicating that TRPA1 is the major receptor for deterrent sesquiterpenes in vivo. Isovelleral and polygodial represent the first fungal and animal small molecule agonists of nociceptive transient receptor potential channels.

  18. 75 FR 23151 - Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-03

    ... Inspection Service 7 CFR Parts 360 and 361 Noxious Weeds; Old World Climbing Fern and Maidenhair Creeper... noxious weed regulations by adding Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown... Old World climbing fern (Lygodium microphyllum (Cavanilles) R. Brown) and maidenhair creeper (Lygodium...

  19. Dalmatian toadflax, an invasive exotic noxious weed, threatens Flagstaff pennyroyal community following prescribed fire

    Treesearch

    Barbara Goodrich Phillips; Debra Crisp

    2001-01-01

    Many noxious weed infestations are initiated or increased by soil disturbance. With the recent emphasis on reintroduction of fire into natural ecosystems there has been increased interest in the effects of noxious weeds following fires. This paper discusses the effects of fire on Flagstaff pennyroyal, a Forest Service Region 3 sensitive plant, and the subsequent...

  20. Dynamic switching between escape and avoidance regimes reduces Caenorhabditis elegans exposure to noxious heat.

    PubMed

    Schild, Lisa C; Glauser, Dominique A

    2013-01-01

    To survive, animals need to minimize exposure to damaging agents. They can either stay away from noxious stimuli (defined as avoidance), requiring the detection of remote warning cues, or run away upon exposure to noxious stimuli (defined as escape). Here we combine behavioural quantitative analyses, simulations and genetics to determine how Caenorhabditis elegans minimizes exposure to noxious heat when navigating in thermogradients. We find that worms use both escape and avoidance strategies, each involving the modulation of multiple parameters like speed and the frequency of steering and withdrawal behaviours. As some behavioural parameters promote escape while impairing avoidance, and vice versa, worms need to dynamically tune those parameters according to temperature. Furthermore, selectively disrupting avoidance or escape, through mutations affecting neuropeptide or TRPV channel signalling, increases exposure to heat. We conclude that dynamically switching between avoidance and escape regimes along the innocuous-noxious temperature continuum efficiently minimizes exposure to noxious heat.

  1. Fos induction in lamina I projection neurons in response to noxious thermal stimuli.

    PubMed

    Todd, A J; Spike, R C; Young, S; Puskár, Z

    2005-01-01

    Lamina I of the spinal cord contains many projection neurons: the majority of these are activated by noxious stimulation, although some respond to other stimuli, such as innocuous cooling. In the rat, approximately 80% of lamina I projection neurons express the neurokinin 1 (NK1) receptor, on which substance P acts. Lamina I neurons can be classified into three main morphological classes: pyramidal, fusiform and multipolar cells. It has been reported that in the cat, pyramidal cells respond to innocuous cooling, and whilst both fusiform and multipolar cells are activated by noxious mechanical and heat stimuli, only cells in the latter group respond to noxious cold [Nat Neurosci 1 (1998) 218]. However, we have previously shown that NK1 receptor-immunoreactive projection neurons belonging to each morphological class are equally likely to up-regulate the transcription factor Fos after noxious chemical stimulation, and that the density of innervation by substance P-containing (nociceptive) afferents is similar for cells of each type [J Neurosci 22 (2002) 4103]. This suggests that the morphological-physiological correlation that has been reported in the cat may not apply in the rat. We have tested this further by examining Fos expression in lamina I spinoparabrachial neurons in the rat after application of noxious heat or noxious cold stimuli under general anesthesia. Following noxious heat, 57-69% of NK1 receptor-immunoreactive spinoparabrachial neurons expressed Fos, and the proportion did not differ significantly between morphological groups. However, after noxious cold stimulation Fos was present in 63% of multipolar neurons, but only 19-26% of fusiform or pyramidal cells. These results suggest that although most NK1 receptor-expressing spinoparabrachial neurons are activated by noxious stimuli, responsiveness to noxious cold is significantly more common in those of the multipolar type. There therefore appears to be a correlation between morphology and function for

  2. 77 FR 3729 - Notice of Request for Extension of Approval of an Information Collection; Plant Pest, Noxious...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... Approval of an Information Collection; Plant Pest, Noxious Weed, and Garbage Regulations AGENCY: Animal and... information collection associated with plant pest, noxious weed, and garbage regulations. DATES: We will...: For information regarding plant pest, noxious weed, and garbage regulations, contact Dr. Shirley...

  3. The Dominant Inhibitory Chalcone Synthase Allele C2-Idf (Inhibitor diffuse) From Zea mays (L.) Acts via an Endogenous RNA Silencing Mechanism

    PubMed Central

    Della Vedova, Chris B.; Lorbiecke, René; Kirsch, Helene; Schulte, Michael B.; Scheets, Kay; Borchert, Lutz M.; Scheffler, Brian E.; Wienand, Udo; Cone, Karen C.; Birchler, James A.

    2005-01-01

    The flavonoid pigment pathway in plants has been used as a model system for studying gene regulatory mechanisms. C2-Idf is a stable dominant mutation of the chalcone synthase gene, c2, which encodes the first dedicated enzyme in this biosynthetic pathway of maize. Homozygous C2-Idf plants show no pigmentation. This allele also inhibits expression of functional C2 alleles in heterozygotes, producing a less pigmented condition instead of the normal deeply pigmented phenotype. To explore the nature of this effect, the C2-Idf allele was cloned. The gene structure of the C2-Idf haplotype differs substantially from that of the normal c2 gene in that three copies are present. Two of these are located in close proximity to each other in a head-to-head orientation and the third is closely linked. Previous experiments showed that the lower level of pigmentation in heterozygotes is correlated with reduced enzyme activity and low steady-state mRNA levels. We found that c2 transcription occurs in nuclei of C2-Idf/C2 heterozygotes, but mRNA does not accumulate, suggesting that the inhibition is mediated by RNA silencing. Infection of C2-Idf/C2 heterozygotes with viruses that carry suppressors of RNA silencing relieved the phenotypic inhibition, restoring pigment production and mRNA levels. Finally, we detected small interfering RNAs (siRNAs) in plants carrying C2-Idf, but not in plants homozygous for the wild-type C2 allele. Together, our results indicate that the inhibitory effect of C2-Idf occurs through RNA silencing. PMID:15956664

  4. Not in whose backyard Minority population concentrations and noxious facility sites

    SciTech Connect

    Nieves, L.A.

    1992-01-01

    The NIMBY (not in may backyard) syndrome has become the nemesis of facility siting efforts in the USA. Given people's reluctance to live near noxious facilities, in whose backyard are such facilities located This study employs US county-level data to examine relative concentrations of minorities living near noxious facilities. Facility types analyzed include electric generating plants, manufacturing plants, Superfund sites, and radioactive waste disposal sites. While this study does not address which cam first, the minority population concentration or the noxious facilities, it documents their current degree of association.

  5. Not in whose backyard? Minority population concentrations and noxious facility sites

    SciTech Connect

    Nieves, L.A.

    1992-04-01

    The NIMBY (not in may backyard) syndrome has become the nemesis of facility siting efforts in the USA. Given people`s reluctance to live near noxious facilities, in whose backyard are such facilities located? This study employs US county-level data to examine relative concentrations of minorities living near noxious facilities. Facility types analyzed include electric generating plants, manufacturing plants, Superfund sites, and radioactive waste disposal sites. While this study does not address which cam first, the minority population concentration or the noxious facilities, it documents their current degree of association.

  6. Sympathetic Responses to Noxious Stimulation of Muscle and Skin

    PubMed Central

    Burton, Alexander R.; Fazalbhoy, Azharuddin; Macefield, Vaughan G.

    2016-01-01

    Acute pain triggers adaptive physiological responses that serve as protective mechanisms that prevent continuing damage to tissues and cause the individual to react to remove or escape the painful stimulus. However, an extension of the pain response beyond signaling tissue damage and healing, such as in chronic pain states, serves no particular biological function; it is maladaptive. The increasing number of chronic pain sufferers is concerning, and the associated disease burden is putting healthcare systems around the world under significant pressure. The incapacitating effects of long-lasting pain are not just psychological – reflexes driven by nociceptors during the establishment of chronic pain may cause serious physiological consequences on regulation of other body systems. The sympathetic nervous system is inherently involved in a host of physiological responses evoked by noxious stimulation. Experimental animal and human models demonstrate a diverse array of heterogeneous reactions to nociception. The purpose of this review is to understand how pain affects the sympathetic nervous system by investigating the reflex cardiovascular and neural responses to acute pain and the long-lasting physiological responses to prolonged (tonic) pain. By observing the sympathetic responses to long-lasting pain, we can begin to understand the physiological consequences of long-term pain on cardiovascular regulation. PMID:27445972

  7. Compensation or inhibitory failure? Testing hypotheses of age-related right frontal lobe involvement in verbal memory ability using structural and diffusion MRI.

    PubMed

    Cox, Simon R; Bastin, Mark E; Ferguson, Karen J; Allerhand, Mike; Royle, Natalie A; Maniega, Susanna Muñoz; Starr, John M; MacLullich, Alasdair M J; Wardlaw, Joanna M; Deary, Ian J; MacPherson, Sarah E

    2015-02-01

    Functional neuroimaging studies report increased right prefrontal cortex (PFC) involvement during verbal memory tasks amongst low-scoring older individuals, compared to younger controls and their higher-scoring contemporaries. Some propose that this reflects inefficient use of neural resources through failure of the left PFC to inhibit non-task-related right PFC activity, via the anterior corpus callosum (CC). For others, it indicates partial compensation - that is, the right PFC cannot completely supplement the failing neural network, but contributes positively to performance. We propose that combining structural and diffusion brain MRI can be used to test predictions from these theories which have arisen from fMRI studies. We test these hypotheses in immediate and delayed verbal memory ability amongst 90 healthy older adults of mean age 73 years. Right hippocampus and left dorsolateral prefrontal cortex (DLPFC) volumes, and fractional anisotropy (FA) in the splenium made unique contributions to verbal memory ability in the whole group. There was no significant effect of anterior callosal white matter integrity on performance. Rather, segmented linear regression indicated that right DLPFC volume was a significantly stronger positive predictor of verbal memory for lower-scorers than higher-scorers, supporting a compensatory explanation for the differential involvement of the right frontal lobe in verbal memory tasks in older age.

  8. Compensation or inhibitory failure? Testing hypotheses of age-related right frontal lobe involvement in verbal memory ability using structural and diffusion MRI

    PubMed Central

    Cox, Simon R.; Bastin, Mark E.; Ferguson, Karen J.; Allerhand, Mike; Royle, Natalie A.; Maniega, Susanna Muñoz; Starr, John M.; MacLullich, Alasdair M.J.; Wardlaw, Joanna M.; Deary, Ian J.; MacPherson, Sarah E.

    2015-01-01

    Functional neuroimaging studies report increased right prefrontal cortex (PFC) involvement during verbal memory tasks amongst low-scoring older individuals, compared to younger controls and their higher-scoring contemporaries. Some propose that this reflects inefficient use of neural resources through failure of the left PFC to inhibit non-task-related right PFC activity, via the anterior corpus callosum (CC). For others, it indicates partial compensation – that is, the right PFC cannot completely supplement the failing neural network, but contributes positively to performance. We propose that combining structural and diffusion brain MRI can be used to test predictions from these theories which have arisen from fMRI studies. We test these hypotheses in immediate and delayed verbal memory ability amongst 90 healthy older adults of mean age 73 years. Right hippocampus and left dorsolateral prefrontal cortex (DLPFC) volumes, and fractional anisotropy (FA) in the splenium made unique contributions to verbal memory ability in the whole group. There was no significant effect of anterior callosal white matter integrity on performance. Rather, segmented linear regression indicated that right DLPFC volume was a significantly stronger positive predictor of verbal memory for lower-scorers than higher-scorers, supporting a compensatory explanation for the differential involvement of the right frontal lobe in verbal memory tasks in older age. PMID:25241394

  9. Diffusible substances from lactic acid bacterial cultures exert strong inhibitory effects on Listeria monocytogenes and Salmonella enterica serovar enteritidis in a co-culture model.

    PubMed

    Mariam, Solomon H; Zegeye, Nigus; Aseffa, Abraham; Howe, Rawleigh

    2017-02-15

    Food-borne infections cause huge economic and human life losses. Listeria monocytogenes and Salmonella enterica serovar Enteritidis are among the top ranking pathogens causing such losses. Control of such infections is hampered by persistent contamination of foods and food-processing environments, resistance of pathogens to sanitizing agents, existence of heterogeneous populations of pathogens (including culturable and viable but non-culturable cells) within the same food items, and inability to detect all such pathogens by culture-based methods. Modern methods such as flow cytometry allow analyses of cells at the single cell level within a short time and enable better and faster detection of such pathogens and distinctions between live and dead cells. Such methods should be complemented by control strategies including the use of beneficial bacteria that produce metabolites capable of inhibiting food-borne pathogens. In this study, broth cultures of lactic acid bacteria (LAB) isolated from fermented milk were tested for production of substances capable of inhibiting L. monocytogenes and S. Enteritidis in co-culture with LAB by assessment of colony-forming units (CFU) and live:dead cell populations by flow cytometry. The LAB isolates belonged to the species Lactococcus lactis, Enterococcus faecalis and Enterococcus faecium. Some LAB were effective in inhibition. Plating indicated up to 99% reduction in CFU from co-cultures compared to control cultures. Most of the bacteria in both cultures were in the viable but non-culturable state. The flow data showed that there were significantly higher dead cell numbers in co-cultures than in control cultures, indicating that such killing was caused by diffusible substances produced by the LAB cultures. This study showed that metabolites from selected local LAB species can be used to significantly reduce pathogen load. However, conditions of use and application need to be further investigated and optimized for large

  10. Nitric oxide mediates Fos expression in the spinal cord induced by mechanical noxious stimulation.

    PubMed

    Lee, J H; Wilcox, G L; Beitz, A J

    1992-10-01

    Immunocytochemical localization of Fos protein was used to analyze the involvement of nitric oxide (NO) in the expression of Fos in the spinal cord, induced by mechanical noxious stimulation (NS). Mechanical NS was applied to the left hindpaw 30 minutes after intrathecal administration of the NO synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME) and the resulting Fos expression in the spinal cord dorsal horn was compared with that obtained in rats exposed only to the mechanical NS. Pretreatment with L-NAME but not its stereoisomer N omega-nitro-D-arginine methyl ester (D-NAME), produced a dose-dependent suppression of Fos expression induced by mechanical noxious stimulation. These results indicate that NO modulates the expression of Fos in the dorsal horn induced by mechanical noxious stimulation and further support the hypothesis that NO is involved in nociceptive events occurring in the spinal cord in response to a peripheral noxious stimulus.

  11. 7 CFR 360.302 - Consideration of applications for permits to move noxious weeds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... consult with other Federal agencies or entities, States or political subdivisions of States, national... international associations, and other persons for views on the danger of noxious weed dissemination into the...

  12. Transient receptor potential channel A1 and noxious cold responses in rat cutaneous nociceptors

    PubMed Central

    Dunham, J.P.; Leith, J.L.; Lumb, B.M.; Donaldson, L.F.

    2010-01-01

    The role of transient receptor potential channel A1 (TRPA1) in noxious cold sensation remains unclear. Some data support the hypothesis that TRPA1 is a transducer of noxious cold whilst other data contest it. In this study we investigated the role of TRPA1 in cold detection in cutaneous nociceptors in vivo using complementary experimental approaches. We used noxious withdrawal reflex electromyography, and single fibre recordings in vivo, to test the hypothesis that TRPA1-expressing primary afferents mediate noxious cold responses in anaesthetised rats. TRPV1 and TRPM8 agonists sensitise their cognate receptors to heat and cold stimuli respectively. Herein we show that the TRPA1 agonist cinnamaldehyde applied to the skin in anaesthetised rats did not sensitise noxious cold evoked hind limb withdrawal. In contrast, cinnamaldehyde did sensitise the C fibre-mediated noxious heat withdrawal, indicated by a significant drop in the withdrawal temperature. TRPA1 agonist thus sensitised the noxious reflex withdrawal to heat, but not cold. Thermal stimuli also sensitise transient receptor potential (TRP) channels to agonist. Activity evoked by capsaicin in teased primary afferent fibres showed a significant positive correlation with receptive field temperature, in both normal and Freund's complete adjuvant-induced cutaneous inflammation. Altering the temperature of the receptive field did not modulate TRPA1 agonist evoked-activity in cutaneous primary afferents, in either normal or inflamed skin. In addition, block of the TRPA1 channel with Ruthenium Red did not inhibit cold evoked activity in either cinnamaldehyde sensitive or insensitive cold responsive nociceptors. In cinnamaldehyde-sensitive–cold-sensitive afferents, although TRPA1 agonist-evoked activity was totally abolished by Ruthenium Red, cold evoked activity was unaffected by channel blockade. We conclude that these results do not support the hypothesis that TRPA1-expressing cutaneous afferents play an important

  13. Transient receptor potential channel A1 and noxious cold responses in rat cutaneous nociceptors.

    PubMed

    Dunham, J P; Leith, J L; Lumb, B M; Donaldson, L F

    2010-02-17

    The role of transient receptor potential channel A1 (TRPA1) in noxious cold sensation remains unclear. Some data support the hypothesis that TRPA1 is a transducer of noxious cold whilst other data contest it. In this study we investigated the role of TRPA1 in cold detection in cutaneous nociceptors in vivo using complementary experimental approaches. We used noxious withdrawal reflex electromyography, and single fibre recordings in vivo, to test the hypothesis that TRPA1-expressing primary afferents mediate noxious cold responses in anaesthetised rats. TRPV1 and TRPM8 agonists sensitise their cognate receptors to heat and cold stimuli respectively. Herein we show that the TRPA1 agonist cinnamaldehyde applied to the skin in anaesthetised rats did not sensitise noxious cold evoked hind limb withdrawal. In contrast, cinnamaldehyde did sensitise the C fibre-mediated noxious heat withdrawal, indicated by a significant drop in the withdrawal temperature. TRPA1 agonist thus sensitised the noxious reflex withdrawal to heat, but not cold. Thermal stimuli also sensitise transient receptor potential (TRP) channels to agonist. Activity evoked by capsaicin in teased primary afferent fibres showed a significant positive correlation with receptive field temperature, in both normal and Freund's complete adjuvant-induced cutaneous inflammation. Altering the temperature of the receptive field did not modulate TRPA1 agonist evoked-activity in cutaneous primary afferents, in either normal or inflamed skin. In addition, block of the TRPA1 channel with Ruthenium Red did not inhibit cold evoked activity in either cinnamaldehyde sensitive or insensitive cold responsive nociceptors. In cinnamaldehyde-sensitive-cold-sensitive afferents, although TRPA1 agonist-evoked activity was totally abolished by Ruthenium Red, cold evoked activity was unaffected by channel blockade. We conclude that these results do not support the hypothesis that TRPA1-expressing cutaneous afferents play an important

  14. Large Intercalated Neurons of Amygdala Relay Noxious Sensory Information

    PubMed Central

    Bienvenu, Thomas C.M.; Busti, Daniela; Micklem, Benjamin R.; Mansouri, Mahnaz; Magill, Peter J.

    2015-01-01

    Various GABAergic neuron types of the amygdala cooperate to control principal cell firing during fear-related and other behaviors, and understanding their specialized roles is important. Among GABAergic neurons, the so-called intercalated cells (ITCcs) are critically involved in the expression and extinction of fear memory. Tightly clustered small-sized spiny neurons constitute the majority of ITCcs, but they are surrounded by sparse, larger neurons (L-ITCcs) for which very little information is known. We report here a detailed neurochemical, structural and physiological characterization of rat L-ITCcs, as identified with juxtacellular recording/labeling in vivo. We supplement these data with anatomical and neurochemical analyses of nonrecorded L-ITCcs. We demonstrate that L-ITCcs are GABAergic, and strongly express metabotropic glutamate receptor 1α and GABAA receptor α1 subunit, together with moderate levels of parvalbumin. Furthermore, L-ITCcs are innervated by fibers enriched with metabotropic glutamate receptors 7a and/or 8a. In contrast to small-sized spiny ITCcs, L-ITCcs possess thick, aspiny dendrites, have highly branched, long-range axonal projections, and innervate interneurons in the basolateral amygdaloid complex. The axons of L-ITCcs also project to distant brain areas, such as the perirhinal, entorhinal, and endopiriform cortices. In vivo recorded L-ITCcs are strongly activated by noxious stimuli, such as hindpaw pinches or electrical footshocks. Consistent with this, we observed synaptic contacts on L-ITCc dendrites from nociceptive intralaminar thalamic nuclei. We propose that, during salient sensory stimulation, L-ITCcs disinhibit local and distant principal neurons, acting as “hub cells,” to orchestrate the activity of a distributed network. PMID:25653362

  15. A comparison of noxious facilities` impacts for home owners versus renters

    SciTech Connect

    Clark, D.E. |; Nieves, L.A.

    1995-01-01

    The siting of noxious facilities, such as hazardous waste facilities, is often vigorously opposed by local residents, and thus it is now common for local residents to be compensated for the presence of the facility. One technique that has been employed to implicitly value noxious facilities is the intercity hedonic approach, which examines the wage and land rent premia between cities that result from the presence of the facility. However, most of the focus has been on the behavior of home owners as opposed to renters. Since these two groups of residents vary on numerous dimensions such as marital status, age, sex, and personal mobility, it would not be surprising to find different marginal valuations of local site characteristics. The authors use 1980 Census data to derive separate estimates for owners and renters of the implicit value placed on eight different types of noxious facilities. They find that renters and owners differ in their response to noxious facilities, although the differences are not systematic. Furthermore, the differences between owners and renters are not primarily due to differential mobility or socio-demographic factors. Controlling those factors decreases the differences between renters` and owners` implicit valuations of noxious facilities by less than 10%. Unmeasured differences between the two groups, such as tastes, risk aversion, or commitment to the community, must account for the remaining difference in valuations. These findings suggest that policymakers should separately consider the responses of owners and renters when estimating noxious facility impacts.

  16. 7 CFR 360.303 - Approval of an application for a permit to move a noxious weed; conditions specified in permit.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... noxious weed; conditions specified in permit. 360.303 Section 360.303 Agriculture Regulations of the... NOXIOUS WEED REGULATIONS § 360.303 Approval of an application for a permit to move a noxious weed... noxious weed. If the application is approved, the Administrator will issue the permit including any...

  17. 7 CFR 360.303 - Approval of an application for a permit to move a noxious weed; conditions specified in permit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... noxious weed; conditions specified in permit. 360.303 Section 360.303 Agriculture Regulations of the... NOXIOUS WEED REGULATIONS § 360.303 Approval of an application for a permit to move a noxious weed... noxious weed. If the application is approved, the Administrator will issue the permit including any...

  18. 7 CFR 360.303 - Approval of an application for a permit to move a noxious weed; conditions specified in permit.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... noxious weed; conditions specified in permit. 360.303 Section 360.303 Agriculture Regulations of the... NOXIOUS WEED REGULATIONS § 360.303 Approval of an application for a permit to move a noxious weed... noxious weed. If the application is approved, the Administrator will issue the permit including any...

  19. 7 CFR 360.303 - Approval of an application for a permit to move a noxious weed; conditions specified in permit.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... noxious weed; conditions specified in permit. 360.303 Section 360.303 Agriculture Regulations of the... NOXIOUS WEED REGULATIONS § 360.303 Approval of an application for a permit to move a noxious weed... noxious weed. If the application is approved, the Administrator will issue the permit including any...

  20. Electrophysiological properties of ventromedial medulla neurons in response to noxious and non-noxious stimuli in the awake, freely moving rat: a single-unit study.

    PubMed

    Oliveras, J L; Vos, B; Martin, G; Montagne, J

    1989-05-01

    The spontaneous and evoked activities of ventromedial medulla (VMM) neurons have been recorded in the chronic, awake, freely moving rat. The vast majority of neurons located at the level of the nucleus raphé magnus exhibited an irregular and variable (2-16 Hz) spontaneous activity and were activated by either cutaneous or auditory stimuli. Within this convergent neuronal class the neurons were activated by either cutaneous noxious and non-noxious inputs. The threshold for cutaneous activation was likely very low since a majority of units responded to air puffs, but the application of controlled brushing and pin-prick revealed that the VMM convergent neurons responded more for the noxious mechanical stimulation. Similar findings were found with pinch application. For both innocuous and noxious stimuli, the cutaneous receptive field was extremely extensive (almost all of the body); however, the application of the controlled brushing showed that for this innocuous stimulation, the most sensitive regions were the tail, back, snout and vibrissae and, to a lesser extent, the flank and paws. Preliminary experiments indicated that both the spontaneous and evoked activities of VMM convergent neurons were inhibited during stressful manipulations such as scruff lifting or defense reactions. These data contrast with other studies on VMM single unit recordings in anesthetized rats since the majority of these studies did not emphasize the VMM convergent group; in addition, with one exception, we did not find neurons exclusively driven by noxious inputs. Without excluding a role of the VMM convergent group in pain descending control systems, we proposed that this neuronal class is perhaps also involved in pain transmission or in general processess such as alertness and stress. Experiments are proposed in order to precisely determine the involvement of the VMM convergent neurons in alertness versus sensory discriminative aspects of nociception in the awake, freely moving rat.

  1. Involvement of spinal α2 -adrenoceptors in prolonged modulation of hind limb withdrawal reflexes following acute noxious stimulation in the anaesthetized rabbit.

    PubMed

    Harris, John

    2016-03-01

    The role of spinal α2 -adrenoceptors in mediating long-lasting modulation of hind limb withdrawal reflexes following acute noxious chemical stimulation of distant heterotopic and local homotopic locations has been investigated in pentobarbitone-anaesthetized rabbits. Reflexes evoked in the ankle extensor muscle medial gastrocnemius (MG) by electrical stimulation of the ipsilateral heel, and reflexes elicited in the ankle flexor tibialis anterior and the knee flexor semitendinosus by stimulation at the base of the ipsilateral toes, could be inhibited for over 1 h after mustard oil (20%) was applied to either the snout or into the contralateral MG. The heel-MG response was also inhibited after applying mustard oil across the plantar metatarsophalangeal joints of the ipsilateral foot, whereas this homotopic stimulus facilitated both flexor responses. Mustard oil also caused a significant pressor effect when applied to any of the three test sites. The selective α2 -adrenoceptor antagonist, RX 821002 (100-300 μg, intrathecally), had no effect on reflexes per se, but did cause a decrease in mean arterial blood pressure. In the presence of the α2 -blocker, inhibitory and facilitatory effects of mustard oil on reflexes were completely abolished. These data imply that long-lasting inhibition of spinal reflexes following acute noxious stimulation of distant locations involves activation of supraspinal noradrenergic pathways, the effects of which are dependent on an intact α2 -adrenoceptor system at the spinal level. These pathways and receptors also appear to be involved in facilitation (sensitization) as well as inhibition of reflexes following a noxious stimulus applied to the same limb.

  2. The economic impacts of noxious facilities on wages and property values: An exploratory analysis

    SciTech Connect

    Nieves, L.A.; Hemphill, R.C.; Clark, D.E.

    1991-05-01

    Recent assessments of socioeconomic impacts resulting from the location of potentially hazardous facilities have concentrated on the issue of negative public perceptions and their resulting economic consequences. This report presents an analysis designed to answer the question: Can economic impacts resulting from negative perceptions of ``noxious facilities`` be identified and measured? To identify the impacts of negative perceptions, data on noxious facilities sited throughout the United States were compiled, and secondary economic and demographic data sufficient to analyze the economic impacts on the surrounding study areas were assembled. This study uses wage rate and property value differentials to measure impacts on social welfare so that the extent to which noxious facilities and their associated activities have affected surrounding areas can be determined.

  3. The economic impacts of noxious facilities on wages and property values: An exploratory analysis

    SciTech Connect

    Nieves, L.A.; Hemphill, R.C.; Clark, D.E.

    1991-05-01

    Recent assessments of socioeconomic impacts resulting from the location of potentially hazardous facilities have concentrated on the issue of negative public perceptions and their resulting economic consequences. This report presents an analysis designed to answer the question: Can economic impacts resulting from negative perceptions of noxious facilities'' be identified and measured To identify the impacts of negative perceptions, data on noxious facilities sited throughout the United States were compiled, and secondary economic and demographic data sufficient to analyze the economic impacts on the surrounding study areas were assembled. This study uses wage rate and property value differentials to measure impacts on social welfare so that the extent to which noxious facilities and their associated activities have affected surrounding areas can be determined.

  4. Variable sensitivity to noxious heat is mediated by differential expression of the CGRP gene

    SciTech Connect

    Chesler, Elissa J; Mogil, Jeffrey; Miermeister, Frank; Frank, Seifert; Strasburg, Kate; Zimmermann, Katharina; Reinold, Heiko; Austin, Jean; Bernardini, Nadia

    2005-01-01

    Heat sensitivity shows considerable functional variability in humans and laboratory animals, and is fundamental to inflammatory and possibly neuropathic pain. In the mouse, at least, much of this variability is genetic because inbred strains differ robustly in their behavioral sensitivity to noxious heat. These strain differences are shown here to reflect differential responsiveness of primary afferent thermal nociceptors to heat stimuli. We further present convergent behavioral and electrophysiological evidence that the variable responses to noxious heat are due to strain-dependence of CGRP expression and sensitivity. Strain differences in behavioral response to noxious heat could be abolished by peripheral injection of CGRP, blockade of cutaneous and spinal CGRP receptors, or long-term inactivation of CGRP with a CGRP-binding Spiegelmer. Linkage mapping supports the contention that the genetic variant determining variable heat pain sensitivity across mouse strains affects the expression of the Calca gene that codes for CGRP

  5. The effects of noxious heat on responses of spinocervical units to low intensity cutaneous stimuli.

    PubMed

    King, G W; Ebner, T J; Bloedel, J R

    1981-10-05

    The responses of spinocervical neurons to sinusoidal hair displacements were studied during and in the absence of radiant heating of parts of the hindpaw to noxious levels (45-65 degrees C). Noxious heat usually increased background discharge and lowered the signal-to-noise ratio at low frequencies of hair displacement. At higher frequencies over 20 Hz, this ratio was slightly depressed for half of the cells, and dramatically increased for the others. Similar effects were found when the heating was off the receptive field for hair displacement, which suggests a central cause for these effects.

  6. 36 CFR 222.8 - Cooperation in control of estray or unbranded livestock, animal diseases, noxious farm weeds, and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... estray or unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. 222.8 Section... unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. (a) Insofar as it involves... application and enforcement of all laws and regulations relating to livestock diseases, sanitation and...

  7. 36 CFR 222.8 - Cooperation in control of estray or unbranded livestock, animal diseases, noxious farm weeds, and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... estray or unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. 222.8 Section... unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. (a) Insofar as it involves... application and enforcement of all laws and regulations relating to livestock diseases, sanitation and...

  8. 36 CFR 222.8 - Cooperation in control of estray or unbranded livestock, animal diseases, noxious farm weeds, and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... estray or unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. 222.8 Section... unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. (a) Insofar as it involves... application and enforcement of all laws and regulations relating to livestock diseases, sanitation and...

  9. 36 CFR 222.8 - Cooperation in control of estray or unbranded livestock, animal diseases, noxious farm weeds, and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... estray or unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. 222.8 Section... unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. (a) Insofar as it involves... application and enforcement of all laws and regulations relating to livestock diseases, sanitation and...

  10. 36 CFR 222.8 - Cooperation in control of estray or unbranded livestock, animal diseases, noxious farm weeds, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... estray or unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. 222.8 Section... unbranded livestock, animal diseases, noxious farm weeds, and use of pesticides. (a) Insofar as it involves... application and enforcement of all laws and regulations relating to livestock diseases, sanitation and...

  11. 76 FR 43706 - Final Supplementary Rules To Require the Use of Certified Noxious-Weed-Free Forage and Straw on...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-21

    ... Bureau of Land Management Final Supplementary Rules To Require the Use of Certified Noxious-Weed-Free... straw on BLM-administered land in Idaho to use certified noxious-weed-free forage and straw. Restoration, rehabilitation, and stabilization projects also will be required to use weed-free straw bales and mulch for...

  12. 7 CFR 360.501 - Petitions to remove a taxon from the noxious weed lists.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE NOXIOUS WEED REGULATIONS § 360.501... from the lists are available at http://www.aphis.usda.gov/plant_health/plant_pest_info/weeds/downloads... potential negative impacts on the economy or environment of the United States. (d) List of references....

  13. The Effects of Noxious Subliminal Suggestion upon Smoking Attitudes and Behavior.

    ERIC Educational Resources Information Center

    Dutto, Franklin N.; Galli, Nicholas

    The efforts of smoking cessation programs have met with various degrees of success and fresh approaches to the problem are needed. An innovative technique that interrupts the psychogenic drives of smokers was employed to determine the effect of noxious subliminal suggestion on smoking attitudes and behavior. Adult smokers (N=60) were shown…

  14. 76 FR 70954 - Idaho Panhandle National Forests, Idaho; Idaho Panhandle National Forest Noxious Weed Treatment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ..., establishment and/or spread of NNIP. The use of registered herbicides is one of the various treatment methods... noxious weed-free hay; biological control agents such as pathogens and insects; and herbicides that target specific invasive plant species. The application of herbicides would be ] ground based only. No...

  15. Early Detection Rapid Response Program Targets New Noxious Weed Species in Washington State

    ERIC Educational Resources Information Center

    Andreas, Jennifer E.; Halpern, Alison D.; DesCamp, Wendy C.; Miller, Timothy W.

    2015-01-01

    Early detection, rapid response is a critical component of invasive plant management. It can be challenging, however, to detect new invaders before they become established if landowners cannot identify species of concern. In order to increase awareness, eye-catching postcards were developed in Washington State as part of a noxious weed educational…

  16. Early Detection Rapid Response Program Targets New Noxious Weed Species in Washington State

    ERIC Educational Resources Information Center

    Andreas, Jennifer E.; Halpern, Alison D.; DesCamp, Wendy C.; Miller, Timothy W.

    2015-01-01

    Early detection, rapid response is a critical component of invasive plant management. It can be challenging, however, to detect new invaders before they become established if landowners cannot identify species of concern. In order to increase awareness, eye-catching postcards were developed in Washington State as part of a noxious weed educational…

  17. Reduced local field potential power in the medial prefrontal cortex by noxious stimuli.

    PubMed

    Li, Ai-Ling; Yang, Xiaofei; Chiao, Jung-Chih; Peng, Yuan Bo

    2016-10-01

    Nociceptive signals produced by noxious stimuli at the periphery reach the brain through ascending pathways. These signals are processed by various brain areas and lead to activity changes in those areas. The medial prefrontal cortex (mPFC) is involved in higher cognitive functions and emotional processing. It receives projections from brain areas involved in nociception. In this study, we investigated how nociceptive input from the periphery changes the local field potential (LFP) activity in the mPFC. Three different types of noxious stimuli were applied to the hind paw contralateral to the LFP recording site. They were transcutaneous electrical stimulations, mechanical stimuli and a chemical stimulus (formalin injection). High intensity transcutaneous stimulations (10V to 50V) and noxious mechanical stimulus (pinch) significantly reduced the LFP power during the stimulating period (p<0.05), but not the low intensity subcutaneous stimulations (0.1V to 5V) and other innocuous mechanical stimuli (brush and pressure). More frequency bands were inhibited with increased intensity of transcutaneous electrical stimulation, and almost all frequency bands were inhibited by stimulations at or higher than 30v. Pinch significantly reduced the power for beta band and formalin injection significantly reduced the power of alpha and beta band. Our data demonstrated the noxious stimuli-induced reduction of LFP power in the mPFC, which indicates the active processing of nociceptive information by the mPFC.

  18. The Effects of Noxious Subliminal Suggestion upon Smoking Attitudes and Behavior.

    ERIC Educational Resources Information Center

    Dutto, Franklin N.; Galli, Nicholas

    The efforts of smoking cessation programs have met with various degrees of success and fresh approaches to the problem are needed. An innovative technique that interrupts the psychogenic drives of smokers was employed to determine the effect of noxious subliminal suggestion on smoking attitudes and behavior. Adult smokers (N=60) were shown…

  19. Aversion-related circuitry in the cerebellum: responses to noxious heat and unpleasant images.

    PubMed

    Moulton, Eric A; Elman, Igor; Pendse, Gautam; Schmahmann, Jeremy; Becerra, Lino; Borsook, David

    2011-03-09

    The cerebellum is reliably activated during both acute and chronic pain conditions, but it is unclear whether the response to aversive painful stimuli can be generalized to other aversive stimuli. We hypothesized that cerebellar activation during pain reflects higher-level encoding of aversive stimuli. We used functional magnetic resonance imaging (fMRI) to compare cerebellar responses in 11 healthy volunteers to noxious heat (46 °C) applied to the hand and to the passive viewing of images selected from the International Affective Picture System. Aversive stimuli in the form of noxious heat and unpleasant pictures (unpleasant vs neutral) activated overlapping areas in the posterior cerebellum, specifically in hemispheric lobule VI, Crus I, and VIIb. Pleasant pictures (pleasant vs neutral) did not share the same pattern of activation as observed with the aversive stimuli. Cerebellar areas that showed functional overlap with both heat pain and unpleasant picture viewing were significantly inversely correlated with fMRI signals measured in limbic system structures, including the anterior hypothalamus, subgenual anterior cingulate cortex, and the parahippocampal gyrus. Heat-specific functional connectivity was detected in many regions including primary motor cortex, secondary somatosensory cortex, anterior insula, and the periaqueductal gray. The overlap between cerebellar lobuli reactive to noxious heat and passive viewing of unpleasant images suggest that the cerebellum may contain specific regions involved in encoding generalized aversive processing. The separate cortical networks suggest that noxious heat-evoked responses in the cerebellum can be divided into sensorimotor and emotional networks.

  20. A comparison of noxious facilities` impacts for home owners versus renters

    SciTech Connect

    Clark, D.E. |; Nieves, L.A.

    1996-09-01

    The siting of noxious facilities, such as hazardous waste facilities, is often vigorously opposed by local residents. As a result, one would expect people`s residential and employment choices to reflect a desire to avoid proximity to such facilities. Ibis behavior would in turn affect labor and housing prices. One technique that has been employed to implicitly value impacts of noxious facilities is the intercity hedonic approach, which examines the wage and land rent differentials among cities that result from environmental amenities and disamenities. However, most of the research focus has been on the behavioral response of home owners as opposed to renters. Since these two groups of residents vary on numerous dimensions such as marital status, age, sex, and personal mobility, it would not be surprising to find different marginal valuations of local site characteristics. We use 1980 Census data to derive separate estimates for owners and renters of the implicit value placed on eight different types of noxious facilities. Although the magnitude of the responses of renters and owners to noxious facilities and other environmental characteristics varies, the signs are generally consistent. The differences in values between owners and renters are not primarily due to differential mobility or sociodemographic factors. Controlling those factors decreases the differences between renters` and owners` implicit valuations by less than 10%. Unmeasured differences in characteristics between the two groups, such as tastes, risk aversion, or commitment to the community, must account for the remaining difference in valuations. These findings suggest that policymakers should separately consider the responses of owners and renters when estimating noxious facility impacts.

  1. Inhibitory control of hippocampal inhibitory neurons

    PubMed Central

    Chamberland, Simon; Topolnik, Lisa

    2012-01-01

    Information processing within neuronal networks is determined by a dynamic partnership between principal neurons and local circuit inhibitory interneurons. The population of GABAergic interneurons is extremely heterogeneous and comprises, in many brain regions, cells with divergent morphological and physiological properties, distinct molecular expression profiles, and highly specialized functions. GABAergic interneurons have been studied extensively during the past two decades, especially in the hippocampus, which is a relatively simple cortical structure. Different types of hippocampal inhibitory interneurons control spike initiation [e.g., axo-axonic and basket cells (BCs)] and synaptic integration (e.g., bistratified and oriens–lacunosum moleculare interneurons) within pyramidal neurons and synchronize local network activity, providing a means for functional segregation of neuronal ensembles and proper routing of hippocampal information. Thus, it is thought that, at least in the hippocampus, GABAergic inhibitory interneurons represent critical regulating elements at all stages of information processing, from synaptic integration and spike generation to large-scale network activity. However, this raises an important question: if inhibitory interneurons are fundamental for network computations, what are the mechanisms that control the activity of the interneurons themselves? Given the essential role of synaptic inhibition in the regulation of neuronal activity, it would be logical to expect that specific inhibitory mechanisms have evolved to control the operation of interneurons. Here, we review the mechanisms of synaptic inhibition of interneurons and discuss their role in the operation of hippocampal inhibitory circuits. PMID:23162426

  2. The Effect of Intravenous Lidocaine on Brain Activation During Non-Noxious and Acute Noxious Stimulation of the Forepaw: A Functional Magnetic Resonance Imaging Study in the Rat

    PubMed Central

    Luo, Zhongchi; Yu, Mei; Smith, S. David; Kritzer, Mary; Du, Congwu; Ma, Yu; Volkow, Nora D.; Glass, Peter S.; Benveniste, Helene

    2009-01-01

    BACKGROUND Lidocaine can alleviate acute as well as chronic neuropathic pain at very low plasma concentrations in humans and laboratory animals. The mechanism(s) underlying lidocaine’s analgesic effect when administered systemically is poorly understood but clearly not related to interruption of peripheral nerve conduction. Other targets for lidocaine’s analgesic action(s) have been suggested, including sodium channels and other receptor sites in the central rather than peripheral nervous system. To our knowledge, the effect of lidocaine on the brain’s functional response to pain has never been investigated. Here, we therefore characterized the effect of systemic lidocaine on the brain’s response to innocuous and acute noxious stimulation in the rat using functional magnetic resonance imaging (fMRI). METHODS Alpha-chloralose anesthetized rats underwent fMRI to quantify brain activation patterns in response to innocuous and noxious forepaw stimulation before and after IV administration of lidocaine. RESULTS Innocuous forepaw stimulation elicited brain activation only in the contralateral primary somatosensory (S1) cortex. Acute noxious forepaw stimulation induced activation in additional brain areas associated with pain perception, including the secondary somatosensory cortex (S2), thalamus, insula and limbic regions. Lidocaine administered at IV doses of either 1 mg/kg, 4 mg/kg or 10 mg/kg did not abolish or diminish brain activation in response to innocuous or noxious stimulation. In fact, IV doses of 4 mg/kg and 10 mg/kg lidocaine enhanced S1 and S2 responses to acute nociceptive stimulation, increasing the activated cortical volume by 50%–60%. CONCLUSION The analgesic action of systemic lidocaine in acute pain is not reflected in a straightforward interruption of pain-induced fMRI brain activation as has been observed with opioids. The enhancement of cortical fMRI responses to acute pain by lidocaine observed here has also been reported for cocaine. We

  3. Interactions between tactile and noxious visceral inputs in rat nucleus gracilus.

    PubMed

    Rong, Pei-Jing; Zhang, Jian-Liang; Zhang, Hong-Qi

    2004-05-20

    Recent studies have revealed that noxious visceral inputs travel in the dorsal column pathway, and interactions between colorectal noxious and tactile inputs occur in the ventrobasal thalamus. This investigation was to test whether the somatovisceral interactions also take place at a lower level in the dorsal column nuclei. Extracellular single neuron recordings were carried out in nucleus gracilus of anesthetized rats. Forty-three neurons responsive to colorectal distension (CRD) all had excitatory responses to tactile stimuli, and their tactile responses were predominantly (31/43 units) enhanced by preceding CRD. In contrast, the neuronal responses to CRD were reduced in 22/43 units when preceded by tactile stimulation but in two units there was an enhancement. The similarity and differences in the gracile response features in comparison with the thalamic recordings suggest that somatovisceral interactions take place at multiple levels in the dorsal column-medial lemniscus system.

  4. TRPM3 is a nociceptor channel involved in the detection of noxious heat.

    PubMed

    Vriens, Joris; Owsianik, Grzegorz; Hofmann, Thomas; Philipp, Stephan E; Stab, Julia; Chen, Xiaodi; Benoit, Melissa; Xue, Fenqin; Janssens, Annelies; Kerselaers, Sara; Oberwinkler, Johannes; Vennekens, Rudi; Gudermann, Thomas; Nilius, Bernd; Voets, Thomas

    2011-05-12

    Transient receptor potential melastatin-3 (TRPM3) is a broadly expressed Ca(2+)-permeable nonselective cation channel. Previous work has demonstrated robust activation of TRPM3 by the neuroactive steroid pregnenolone sulfate (PS), but its in vivo gating mechanisms and functions remained poorly understood. Here, we provide evidence that TRPM3 functions as a chemo- and thermosensor in the somatosensory system. TRPM3 is molecularly and functionally expressed in a large subset of small-diameter sensory neurons from dorsal root and trigeminal ganglia, and mediates the aversive and nocifensive behavioral responses to PS. Moreover, we demonstrate that TRPM3 is steeply activated by heating and underlies heat sensitivity in a subset of sensory neurons. TRPM3-deficient mice exhibited clear deficits in their avoidance responses to noxious heat and in the development of inflammatory heat hyperalgesia. These experiments reveal an unanticipated role for TRPM3 as a thermosensitive nociceptor channel implicated in the detection of noxious heat.

  5. Neuronal processing of noxious thermal stimuli mediated by dendritic Ca2+ influx in Drosophila somatosensory neurons

    PubMed Central

    Terada, Shin-Ichiro; Matsubara, Daisuke; Onodera, Koun; Matsuzaki, Masanori; Uemura, Tadashi; Usui, Tadao

    2016-01-01

    Adequate responses to noxious stimuli causing tissue damages are essential for organismal survival. Class IV neurons in Drosophila larvae are polymodal nociceptors responsible for thermal, mechanical, and light sensation. Importantly, activation of Class IV provoked distinct avoidance behaviors, depending on the inputs. We found that noxious thermal stimuli, but not blue light stimulation, caused a unique pattern of Class IV, which were composed of pauses after high-frequency spike trains and a large Ca2+ rise in the dendrite (the Ca2+ transient). Both these responses depended on two TRPA channels and the L-type voltage-gated calcium channel (L-VGCC), showing that the thermosensation provokes Ca2+ influx. The precipitous fluctuation of firing rate in Class IV neurons enhanced the robust heat avoidance. We hypothesize that the Ca2+ influx can be a key signal encoding a specific modality. DOI: http://dx.doi.org/10.7554/eLife.12959.001 PMID:26880554

  6. Sensory and sympathetic nerve contributions to the cutaneous vasodilator response from a noxious heat stimulus.

    PubMed

    Carter, Stephen J; Hodges, Gary J

    2011-11-01

    We investigated the roles of sensory and noradrenergic sympathetic nerves on the cutaneous vasodilator response to a localized noxious heating stimulus. In two separate studies, four forearm skin sites were instrumented with microdialysis fibres, local heaters and laser-Doppler probes. Skin sites were locally heated from 33 to 42 °C or rapidly to 44 °C (noxious). In the first study, we tested sensory nerve involvement using EMLA cream. Treatments were as follows: (1) control 42 °C; (2) EMLA 42 °C; (3) control 44°C; and (4) EMLA 44 °C. At the EMLA-treated sites, the axon reflex was reduced compared with the control sites during heating to 42 °C (P < 0.05). There were no differences during the plateau phase (P > 0.05). At both the sites heated to 44 °C, the initial peak and nadir became indistinguishable, and the EMLA-treated sites were lower compared with the control sites during the plateau phase (P < 0.05). In the second study, we tested the involvement of noradrenergic sympathetic nerves in response to the noxious heating using bretylium tosylate (BT). Treatments were as follows: (1) control 42 °C; (2) BT 42 °C; (3) control 44 °C; and (4) BT 44 °C. Treatment with BT at the 42 °C sites resulted in a marked reduction in both the axon reflex and the secondary plateau (P < 0.05). At the 44 °C sites, there was no apparent initial peak or nadir, but the plateau phase was reduced at the BT-treated sites (P < 0.05). These data suggest that both sympathetic nerves and sensory nerves are involved during the vasodilator response to a noxious heat stimulus.

  7. General trigeminospinal central sensitization and impaired descending pain inhibitory controls contribute to migraine progression.

    PubMed

    Boyer, Nelly; Dallel, Radhouane; Artola, Alain; Monconduit, Lénaïc

    2014-07-01

    Migraine is a chronic disease with episodic manifestations. In a subgroup, attack frequency increases over time, leading to chronic migraine. One of the most important risk factors for migraine progression is frequency of headache attacks at baseline. Unfortunately, the actual effects of repeated activation of dural nociceptors are poorly known. We investigated the behavioral, anatomical, and electrophysiological changes induced by repeated low- and high-intensity stimulation of meningeal nociceptor by injecting an inflammatory soup in rats. Single high-intensity, but not low-intensity, stimulation produces a reversible cephalic allodynia. Upon repetition, however, low-intensity stimulation, too, induces a reversible cephalic allodynia, and high-intensity, reversible cephalic and extracephalic allodynia. Moreover, cephalic allodynia becomes, in part, persistent upon repeated high-intensity stimulation. Fos expression reveals that a single high-intensity stimulation already leads to widespread, trigeminal, and spinal central sensitization, and that such general central sensitization potentiates upon repetition. Trigeminovascular nociceptive neurons become persistently sensitized and their diffuse noxious inhibitory controls (DNIC) concomitantly impaired. Thus, compared with single stimulation, repeated dural nociceptor activation specifically leads to: 1) a gradual worsening of cutaneous hypersensitivity and general neuronal hyperexcitability and 2) spreading of cutaneous hypersensitivity superimposed on 3) persistent cephalic cutaneous hypersensitivity and trigeminal central sensitization. Such repetition-induced development of central sensitization and its consequence, cutaneous allodynia, may arise from both the general neuronal hyperexcitability that results from DNIC impairment and hyperexcitability that likely develops in trigeminal nociceptive neurons in response to their repetitive activation. These neuronal changes may in turn elevate the risk for

  8. Determining perception-based impacts of noxious facilities on wage rates and property values

    SciTech Connect

    Nieves, L.A.; Clark, D.E.

    1992-02-01

    This document, written for the US Department of Energy, discusses current information and the need for future research on estimating the impacts on wages and property values that could result from people's perceptions of the risks associated with noxious facilities. Psychometric studies indicate that the US population is averse to living near noxious facilities, nuclear-related facilities in particular. Contingent valuation and hedonic studies find that the net economic impacts of proximity to noxious facilities are generally negative and often substantial. Most of these studies are limited in scope, and none estimate the impacts derived from public perceptions of such facilities. This study examines the mechanisms by which negative public perceptions result in economic impacts reflected in wages and property values. On the basis of these mechanisms, it develops a predictive model of perception-based impacts and identifies the data and methods needed to implement it. The key to predicting perception-based impacts lies in combining psychometric and hedonic methods. The reliability of psychometric measures as indicators of aversive stimuli that precipitate economic impacts can be empirically tested. To test the robustness of the findings, alternative estimation methods an be employed in the hedonic analysis. Contingent valuation methods can confirm the results.

  9. Determining perception-based impacts of noxious facilities on wage rates and property values

    SciTech Connect

    Nieves, L.A.; Clark, D.E.

    1992-02-01

    This document, written for the US Department of Energy, discusses current information and the need for future research on estimating the impacts on wages and property values that could result from people`s perceptions of the risks associated with noxious facilities. Psychometric studies indicate that the US population is averse to living near noxious facilities, nuclear-related facilities in particular. Contingent valuation and hedonic studies find that the net economic impacts of proximity to noxious facilities are generally negative and often substantial. Most of these studies are limited in scope, and none estimate the impacts derived from public perceptions of such facilities. This study examines the mechanisms by which negative public perceptions result in economic impacts reflected in wages and property values. On the basis of these mechanisms, it develops a predictive model of perception-based impacts and identifies the data and methods needed to implement it. The key to predicting perception-based impacts lies in combining psychometric and hedonic methods. The reliability of psychometric measures as indicators of aversive stimuli that precipitate economic impacts can be empirically tested. To test the robustness of the findings, alternative estimation methods an be employed in the hedonic analysis. Contingent valuation methods can confirm the results.

  10. Noxious cold ion channel TRPA1 is activated by pungent compounds and bradykinin.

    PubMed

    Bandell, Michael; Story, Gina M; Hwang, Sun Wook; Viswanath, Veena; Eid, Samer R; Petrus, Matt J; Earley, Taryn J; Patapoutian, Ardem

    2004-03-25

    Six members of the mammalian transient receptor potential (TRP) ion channels respond to varied temperature thresholds. The natural compounds capsaicin and menthol activate noxious heat-sensitive TRPV1 and cold-sensitive TRPM8, respectively. The burning and cooling perception of capsaicin and menthol demonstrate that these ion channels mediate thermosensation. We show that, in addition to noxious cold, pungent natural compounds present in cinnamon oil, wintergreen oil, clove oil, mustard oil, and ginger all activate TRPA1 (ANKTM1). Bradykinin, an inflammatory peptide acting through its G protein-coupled receptor, also activates TRPA1. We further show that phospholipase C is an important signaling component for TRPA1 activation. Cinnamaldehyde, the most specific TRPA1 activator, excites a subset of sensory neurons highly enriched in cold-sensitive neurons and elicits nociceptive behavior in mice. Collectively, these data demonstrate that TRPA1 activation elicits a painful sensation and provide a potential molecular model for why noxious cold can paradoxically be perceived as burning pain.

  11. Developmental alterations in noxious-evoked EEG activity recorded from rat primary somatosensory cortex.

    PubMed

    Devonshire, I M; Greenspon, C M; Hathway, G J

    2015-10-01

    Primary somatosensory cortex (S1) contains a nociceptive map that localizes potential tissue damage on the body and encodes stimulus intensity. An objective and specific biomarker of pain however is currently lacking and is urgently required for use in non-verbal clinical populations as well as in the validation of pre-clinical pain models. Here we describe studies to see if the responses of the S1 in juvenile rats are different to those in the adult. We recorded electroencephalogram (EEG) responses from S1 of lightly-anesthetized Sprague-Dawley rats at either postnatal day 21 or postnatal day 40 during the presentation of noxious (55 °C) or innocuous (30 °C) thermal stimuli applied to the plantar surface of the left hindpaw. The total EEG power across the recording period was the same in both ages after stimulation but the frequency distribution was significantly affected by age. Noxious heat evoked a significant increase in theta band (4-8 Hz) activity in adults only (P<0.0001 compared to baseline; P<0.0001 compared to juveniles). There were no significant differences in EEG responses to innocuous thermal stimuli. These data show that there are significant alterations in the processing of nociceptive inputs within the maturing cortex and that cortical theta activity is involved only in the adult cortical response to noxious stimulation.

  12. Hypnotic analgesia: 1. Somatosensory event-related potential changes to noxious stimuli and 2. Transfer learning to reduce chronic low back pain.

    PubMed

    Crawford, H J; Knebel, T; Kaplan, L; Vendemia, J M; Xie, M; Jamison, S; Pribram, K H

    1998-01-01

    Fifteen adults with chronic low back pain (M = 4 years), age 18 to 43 years (M = 29 years), participated. All but one were moderately to highly hypnotizable (M = 7.87; modified 11-point Stanford Hypnotic Susceptibility Scale, Form C [Weitzenhoffer & Hilgard, 1962]), and significantly reduced pain perception following hypnotic analgesia instructions during cold-pressor pain training. In Part 1, somatosensory event-related potential correlates of noxious electrical stimulation were evaluated during attend and hypnotic analgesia (HA) conditions at anterior frontal (Fp1, Fp2), midfrontal (F3, F4), central (C3, C4), and parietal (P3, P4) regions. During HA, hypothesized inhibitory processing was evidenced by enhanced N140 in the anterior frontal region and by a prestimulus positive-ongoing contingent cortical potential at Fp1 only. During HA, decreased spatiotemporal perception was evidenced by reduced amplitudes of P200 (bilateral midfrontal and central, and left parietal) and P300 (right midfrontal and central). HA led to highly significant mean reductions in perceived sensory pain and distress. HA is an active process that requires inhibitory effort, dissociated from conscious awareness, where the anterior frontal cortex participates in a topographically specific inhibitory feedback circuit that cooperates in the allocation of thalamocortical activities. In Part 2, the authors document the development of self-efficacy through the successful transfer by participants of newly learned skills of experimental pain reduction to reduction of their own chronic pain. Over three experimental sessions, participants reported chronic pain reduction, increased psychological well-being, and increased sleep quality. The development of "neurosignatures of pain" can influence subsequent pain experiences (Coderre, Katz, Vaccarino, & Melzack, 1993; Melzack, 1993) and may be expanded in size and easily reactivated (Flor & Birbaumer, 1994; Melzack, 1991, 1993). Therefore, hypnosis and

  13. Chromogranin A and cortisol at intraoperative repeated noxious stimuli: Surgical stress in a dog model

    PubMed Central

    Hagman, Ragnvi; Stridsberg, Mats

    2015-01-01

    Objectives: Biomarkers representing sympathetic tone and the surgical stress response are measured to objectively evaluate surgical techniques and anaesthetic protocols. If a part of the intraoperative procedure is repeated on the contralateral organ, one animal may potentially serve as its own control and, if so, may minimize the problem of individual differences of the stress response to anaesthesia and surgery. This study aimed to investigate the use of chromogranin A for measurement of the intraoperative sympathetic tone. Additional aims were to investigate chromogranin A and cortisol as indicators of the intraoperative surgical stress response caused by repeated noxious stimuli in dogs subjected to ovariohysterectomy and thereby to investigate the possibility of one dog serving as its own control. Methods: Experiments were carried out on 10 dogs subjected to ovariohysterectomy. Perioperative blood samples (0–6) were collected after premedication, immediately before induction of anaesthesia (0), after induction of anaesthesia and before incision (1), before (2) and after (3) removal of the first ovary, after a 15-min pause before removal of the second ovary (4), after removal of the second ovary (5) and after closing the abdomen (6). Plasma chromogranin A and cortisol were analysed. Results: Plasma chromogranin A did not change. Plasma cortisol concentration did not change between before anaesthesia and opening of the abdomen. Plasma cortisol increased at removal of the first ovary. Cortisol did not change at removal of the second ovary but remained increased compared to initial sample. Conclusion: The results suggest chromogranin A is a poor indicator of intraoperative sympathetic tone during elective surgery in dogs. Cortisol measurement was useful for assessment of intraoperative noxious stimuli. However, at these test conditions, neither plasma chromogranin A nor plasma cortisol was useful for assessment of repeated intraoperative noxious stimuli where

  14. Spatial and Temporal Brain Responses to Noxious Heat Thermal Stimuli in Burning Mouth Syndrome.

    PubMed

    Shinozaki, T; Imamura, Y; Kohashi, R; Dezawa, K; Nakaya, Y; Sato, Y; Watanabe, K; Morimoto, Y; Shizukuishi, T; Abe, O; Haji, T; Tabei, K; Taira, M

    2016-09-01

    Burning mouth syndrome (BMS) is an idiopathic orofacial pain condition. Although the pathophysiology of BMS is not clearly understood, central and peripheral neuropathic mechanisms are thought to be involved. The authors compared brain response to noxious heat stimuli in 16 right-handed women with primary BMS and 15 sex- and age-matched right-handed healthy female controls. A thermal stimulus sequence of 32 °C to 40 °C to 32 °C to 49 °C was repeated 4 times in a cycle. Warm and noxious heat stimuli were delivered with a Peltier thermode placed on the right palm or right lower lip for 32 s each in a session. Functional magnetic resonance imaging data were obtained by recording echoplanar images with a block design. Statistical Parametric Mapping 8 software was used to analyze the data. Patients and controls both reported feeling more pain during palm stimulation than during lip stimulation. Repetition of noxious heat stimulus on the lower lip but not on the palm induced habituation in brain activity in the cingulate cortex without reduction in pain perception. Multiple regression analysis revealed a correlation between perceived pain intensity and suppression of brain activity in the anterior cingulate cortex when the repeated thermal sequence was applied at the lower lip. Furthermore, the response of the parahippocampal area differed in BMS patients and controls when the same repeated thermal sequence was applied at the palm. The authors' findings indicate that BMS patients show specific brain responses due to impaired function of the central and peripheral nervous systems (clinical trial registration: UMIN000015002). © International & American Associations for Dental Research 2016.

  15. An assessment of stakeholder perceptions and management of noxious alien plants in Spain.

    PubMed

    Andreu, Jara; Vilà, Montserrat; Hulme, Philip E

    2009-06-01

    Despite biological invasions being a worldwide phenomenon causing significant ecological, economic, and human welfare impacts, there is limited understanding regarding how environmental managers perceive the problem and subsequently manage alien species. Spanish environmental managers were surveyed using questionnaires to (1) analyze the extent to which they perceive plant invasions as a problem; (2) identify the status, occurrence, and impacts of noxious alien plant species; (3) assess current effort and expenditure targeting alien plant management; and, finally, (4) identify the criteria they use to set priorities for management. In comparison to other environmental concerns, plant invasions are perceived as only moderately problematic and mechanical control is the most valued and frequently used strategy to cope with plant invasions in Spain. Based on 70 questionnaires received, 193 species are considered noxious, 109 of which have been the subject of management activities. More than 90% of species are found in at least one protected area. According to respondents, the most frequently managed species are the most widespread across administrative regions and the ones perceived as causing the highest impacts. The perception of impact seems to be independent of their invasion status, since only half of the species identified as noxious are believed to be invasive in Spain, while 43% of species thought to only be casual aliens are causing a high impact. Records of management costs are poor and the few data indicate that the total actual expenditure amounted to 50,492,437 euros in the last decade. The majority of respondents stated that management measures are insufficient to control alien plants due to limited economic resources, lack of public awareness and support, and an absence of coordination among different public administrations. Managers also expressed their concern about the fact that much scientific research is concerned with the ecology of alien plants

  16. Opiates Modulate Noxious Chemical Nociception through a Complex Monoaminergic/Peptidergic Cascade

    PubMed Central

    Mills, Holly; Ortega, Amanda; Law, Wenjing; Hapiak, Vera; Summers, Philip; Clark, Tobias

    2016-01-01

    The ability to detect noxious stimuli, process the nociceptive signal, and elicit an appropriate behavioral response is essential for survival. In Caenorhabditis elegans, opioid receptor agonists, such as morphine, mimic serotonin, and suppress the overall withdrawal from noxious stimuli through a pathway requiring the opioid-like receptor, NPR-17. This serotonin- or morphine-dependent modulation can be rescued in npr-17-null animals by the expression of npr-17 or a human κ opioid receptor in the two ASI sensory neurons, with ASI opioid signaling selectively inhibiting ASI neuropeptide release. Serotonergic modulation requires peptides encoded by both nlp-3 and nlp-24, and either nlp-3 or nlp-24 overexpression mimics morphine and suppresses withdrawal. Peptides encoded by nlp-3 act differentially, with only NLP-3.3 mimicking morphine, whereas other nlp-3 peptides antagonize NLP-3.3 modulation. Together, these results demonstrate that opiates modulate nociception in Caenorhabditis elegans through a complex monoaminergic/peptidergic cascade, and suggest that this model may be useful for dissecting opiate signaling in mammals. SIGNIFICANCE STATEMENT Opiates are used extensively to treat chronic pain. In Caenorhabditis elegans, opioid receptor agonists suppress the overall withdrawal from noxious chemical stimuli through a pathway requiring an opioid-like receptor and two distinct neuropeptide-encoding genes, with individual peptides from the same gene functioning antagonistically to modulate nociception. Endogenous opioid signaling functions as part of a complex, monoaminergic/peptidergic signaling cascade and appears to selectively inhibit neuropeptide release, mediated by a α-adrenergic-like receptor, from two sensory neurons. Importantly, receptor null animals can be rescued by the expression of the human κ opioid receptor, and injection of human opioid receptor ligands mimics exogenous opiates, highlighting the utility of this model for dissecting opiate

  17. An Assessment of Stakeholder Perceptions and Management of Noxious Alien Plants in Spain

    NASA Astrophysics Data System (ADS)

    Andreu, Jara; Vilà, Montserrat; Hulme, Philip E.

    2009-06-01

    Despite biological invasions being a worldwide phenomenon causing significant ecological, economic, and human welfare impacts, there is limited understanding regarding how environmental managers perceive the problem and subsequently manage alien species. Spanish environmental managers were surveyed using questionnaires to (1) analyze the extent to which they perceive plant invasions as a problem; (2) identify the status, occurrence, and impacts of noxious alien plant species; (3) assess current effort and expenditure targeting alien plant management; and, finally, (4) identify the criteria they use to set priorities for management. In comparison to other environmental concerns, plant invasions are perceived as only moderately problematic and mechanical control is the most valued and frequently used strategy to cope with plant invasions in Spain. Based on 70 questionnaires received, 193 species are considered noxious, 109 of which have been the subject of management activities. More than 90% of species are found in at least one protected area. According to respondents, the most frequently managed species are the most widespread across administrative regions and the ones perceived as causing the highest impacts. The perception of impact seems to be independent of their invasion status, since only half of the species identified as noxious are believed to be invasive in Spain, while 43% of species thought to only be casual aliens are causing a high impact. Records of management costs are poor and the few data indicate that the total actual expenditure amounted to 50,492,437 € in the last decade. The majority of respondents stated that management measures are insufficient to control alien plants due to limited economic resources, lack of public awareness and support, and an absence of coordination among different public administrations. Managers also expressed their concern about the fact that much scientific research is concerned with the ecology of alien plants

  18. Innocuous, Not Noxious, Input Activates PKCγ Interneurons of the Spinal Dorsal Horn via Myelinated Afferent Fibers

    PubMed Central

    Braz, Joao M.; Skinner, Kate; Llewellyn-Smith, Ida J.; Basbaum, Allan I.

    2008-01-01

    Protein kinase C γ (PKCγ), which is concentrated in interneurons of the inner part of lamina II of the dorsal horn, has been implicated in injury-induced allodynia, a condition wherein pain is produced by innocuous stimuli. Although it is generally assumed that these interneurons receive input from the nonpeptidergic, IB4-positive subset of nociceptors, the fact that PKCγ cells do not express Fos in response to noxious stimulation suggests otherwise. Here, we demonstrate that the terminal field of the nonpeptidergic population of nociceptors, in fact, lies dorsal to that of PKCγ interneurons. There was also no overlap between the PKCγ-expressing interneurons and the transganglionic tracer wheat germ agglutinin which, after sciatic nerve injection, labels all unmyelinated nociceptors. However, transganglionic transport of the β-subunit of cholera toxin, which marks the medium-diameter and large-diameter myelinated afferents that transmit non-noxious information, revealed extensive overlap with the layer of PKCγ interneurons. Furthermore, expression of a transneuronal tracer in myelinated afferents resulted in labeling of PKCγ interneurons. Light and electron microscopic double labeling further showed that the VGLUT1 subtype of vesicular glutamate transmitter, which is expressed in myelinated afferents, marks synapses that are presynaptic to the PKCγ interneurons. Finally, we demonstrate that a continuous non-noxious input, generated by walking on a rotarod, induces Fos in the PKCγ interneurons. These results establish that PKCγ interneurons are activated by myelinated afferents that respond to innocuous stimuli, which suggests that injury-induced mechanical allodynia is transmitted through a circuit that involves PKCγ interneurons and non-nociceptive, VGLUT1-expressing myelinated primary afferents. PMID:18685019

  19. Remote noxious stimuli modulate jaw reflexes evoked by activation of periodontal ligament mechanoreceptors in man.

    PubMed

    Mason, Andrew G; Scott, Brendan J J; van der Glas, Hilbert W; Linden, Roger W A; Cadden, Samuel W

    2002-11-01

    The purpose of the study was to investigate whether jaw reflexes evoked by selective stimulation of periodontal ligament me canoreceptors are susceptible to modulation by remote noxious stimulation. Experiments were performed on 10 volunteer subjects. Skin surface recordings were made from the jaw-closing masseter muscle. The subjects activated the muscle to approximately 10% of maximum by biting on a rubber impression of their molar teeth while they received visual feedback of the electromyogram (EMG) of the muscle. Reflexes were produced by the application of gentle mechanical stimuli to an upper central incisor tooth. The stimuli were in the form of 'ramp and hold' forces with a 5 ms rise-time and a 1.5 N plateau which lasted 350 ma. The resulting reflexes were recorded both under control conditions and while the subjects received a remote noxious stimulus (immersion of a hand in water at 3 degrees C). In all 10 subjects, the stimuli produced a single period of inhibition of masseteric activity (latency, 12.8 t 04 ms; duration, 18.1+/-1.3 ms; means +/- S.E.M.), which was usually followed by a period of increased masseteric activity. The period of inhibition constituted a downward wave in full-wave rectified, averaged signals. The integrals of such waves were significantly smaller (by 17+/- 6.5 %; P = 0.027; Student's t test) when the reflex was evoked during remote noxious stimulation rather than under control conditions. As such reflexes are beLieved to play a modulatory role during normal oral function this finding maybe relevant to disorders of mastication associated with pain.

  20. Drosophila painless is a Ca2+-requiring channel activated by noxious heat.

    PubMed

    Sokabe, Takaaki; Tsujiuchi, Seiya; Kadowaki, Tatsuhiko; Tominaga, Makoto

    2008-10-01

    Thermal changes activate some members of the transient receptor potential (TRP) ion channel super family. They are primary sensors for detecting environmental temperatures. The Drosophila TRP channel Painless is believed responsible for avoidance of noxious heat because painless mutant flies display defects in heat sensing. However, no studies have proven its heat responsiveness. We show that Painless expressed in human embryonic kidney-derived 293 (HEK293) cells is a noxious heat-activated, Ca(2+)-permeable channel, and the function is mostly dependent on Ca(2+). In Ca(2+)-imaging, Painless mediated a robust intracellular Ca(2+) (Ca(2+)(i)) increase during heating, and it showed heat-evoked inward currents in whole-cell patch-clamp mode. Ca(2+) permeability was much higher than that of other cations. Heat-evoked currents were negligible in the absence of extracellular Ca(2+) (Ca(2+)(o)) and Ca(2+)(i), whereas 200 nm Ca(2+)(i) enabled heat activation of Painless. Activation kinetics were significantly accelerated in the presence of Ca(2+)(i). The temperature threshold for Painless activation was 42.6 degrees C in the presence of Ca(2+)(i), whereas the threshold was significantly increased to 44.1 degrees C when only Ca(2+)(o) was present. Temperature thresholds were further reduced after repetitive heating in a Ca(2+)-dependent manner. Ca(2+)-dependent heat activation of Painless was observed at the single-channel level in excised membranes. We found that a Ca(2+)-regulatory site is located in the N-terminal region of Painless. Painless-expressing HEK293 cells were insensitive to various thermosensitive TRP channel activators including allyl isothiocyanate, whereas mammalian TRPA1 inhibitors, ruthenium red, and camphor, reversibly blocked heat activation of Painless. Our results demonstrate that Painless is a direct sensor for noxious heat in Drosophila.

  1. Secondary hyperalgesia phenotypes exhibit differences in brain activation during noxious stimulation.

    PubMed

    Asghar, Mohammad Sohail; Pereira, Manuel Pedro; Werner, Mads Utke; Mårtensson, Johan; Larsson, Henrik B W; Dahl, Jørgen Berg

    2015-01-01

    Noxious stimulation of the skin with either chemical, electrical or heat stimuli leads to the development of primary hyperalgesia at the site of injury, and to secondary hyperalgesia in normal skin surrounding the injury. Secondary hyperalgesia is inducible in most individuals and is attributed to central neuronal sensitization. Some individuals develop large areas of secondary hyperalgesia (high-sensitization responders), while others develop small areas (low-sensitization responders). The magnitude of each area is reproducible within individuals, and can be regarded as a phenotypic characteristic. To study differences in the propensity to develop central sensitization we examined differences in brain activity and anatomy according to individual phenotypical expression of secondary hyperalgesia by magnetic resonance imaging. Forty healthy volunteers received a first-degree burn-injury (47 °C, 7 min, 9 cm(2)) on the non-dominant lower-leg. Areas of secondary hyperalgesia were assessed 100 min after the injury. We measured neuronal activation by recording blood-oxygen-level-dependent-signals (BOLD-signals) during mechanical noxious stimulation before burn injury and in both primary and secondary hyperalgesia areas after burn-injury. In addition, T1-weighted images were used to measure differences in gray-matter density in cortical and subcortical regions of the brain. We found significant differences in neuronal activity between high- and low-sensitization responders at baseline (before application of the burn-injury) (p < 0.05). After the burn-injury, we found significant differences between responders during noxious stimulation of both primary (p < 0.01) and secondary hyperalgesia (p ≤ 0.04) skin areas. A decreased volume of the right (p = 0.001) and left caudate nucleus (p = 0.01) was detected in high-sensitization responders in comparison to low-sensitization responders. These findings suggest that brain-structure and neuronal activation to noxious

  2. [The circulation of influenza virus in human communities subjected to the action of noxious chemical substances].

    PubMed

    Moisa, I; Petrescu, A; Pârvu, C; Bârnaure, F; Sîrbu, D

    1987-01-01

    Investigations were conducted during 1985 and 1986 years on the effect of some noxious chemicals on the influenza virus circulation in an industrial enterprise community. The presence of influenza virus type A (H1N1), A (H3N2) and B was revealed by immunofluorescence in exfoliated cells collected from nasopharynx. The kinetic of type specific hemagglutination inhibiting antibodies was followed monthly. Chick embryos were used to isolate influenza virus strains. Meaning of the results is discussed from an epidemiological point of view.

  3. Secondary Hyperalgesia Phenotypes Exhibit Differences in Brain Activation during Noxious Stimulation

    PubMed Central

    Werner, Mads Utke; Mårtensson, Johan; Larsson, Henrik B. W.; Dahl, Jørgen Berg

    2015-01-01

    Noxious stimulation of the skin with either chemical, electrical or heat stimuli leads to the development of primary hyperalgesia at the site of injury, and to secondary hyperalgesia in normal skin surrounding the injury. Secondary hyperalgesia is inducible in most individuals and is attributed to central neuronal sensitization. Some individuals develop large areas of secondary hyperalgesia (high-sensitization responders), while others develop small areas (low-sensitization responders). The magnitude of each area is reproducible within individuals, and can be regarded as a phenotypic characteristic. To study differences in the propensity to develop central sensitization we examined differences in brain activity and anatomy according to individual phenotypical expression of secondary hyperalgesia by magnetic resonance imaging. Forty healthy volunteers received a first-degree burn-injury (47°C, 7 min, 9 cm2) on the non-dominant lower-leg. Areas of secondary hyperalgesia were assessed 100 min after the injury. We measured neuronal activation by recording blood-oxygen-level-dependent-signals (BOLD-signals) during mechanical noxious stimulation before burn injury and in both primary and secondary hyperalgesia areas after burn-injury. In addition, T1-weighted images were used to measure differences in gray-matter density in cortical and subcortical regions of the brain. We found significant differences in neuronal activity between high- and low-sensitization responders at baseline (before application of the burn-injury) (p < 0.05). After the burn-injury, we found significant differences between responders during noxious stimulation of both primary (p < 0.01) and secondary hyperalgesia (p ≤ 0.04) skin areas. A decreased volume of the right (p = 0.001) and left caudate nucleus (p = 0.01) was detected in high-sensitization responders in comparison to low-sensitization responders. These findings suggest that brain-structure and neuronal activation to noxious stimulation

  4. An interregional hedonic analysis of noxious facility impacts on local wages and property values

    SciTech Connect

    Clark, D.E.; Nieves, L.A.

    1991-12-31

    Claims of property value loss are commonly raised by homeowners when noxious facilities are sited or when new information about the hazards of existing facilities is made public. While the capitalization of externalities into land values is consistent with economic theory, empirical measurement of impacts has not generated consistent results. This is true both for hedonic measurements as well as other types of econometric analyses. While it is well established that job and site risks have similar impacts on regional labor markets, there are no studies relating the presence of a broad range of noxious facilities to local wage premiums. In contrast, this study employs an interregional framework in a hedonic analysis of both wage and property markets and considers eight different facility classifications. This paper discusses the development of the hedonic model employed in this study. It develops more fully the theoretical advantages of the intercity model and alternative methods of deriving implicit prices for environmental amenities and disamenities. The unique data base and the structure of the estimated model are described. It also includes a discussion of the research findings. Major conclusions and suggestions for further research are presented.

  5. An interregional hedonic analysis of noxious facility impacts on local wages and property values

    SciTech Connect

    Clark, D.E.; Nieves, L.A.

    1991-01-01

    Claims of property value loss are commonly raised by homeowners when noxious facilities are sited or when new information about the hazards of existing facilities is made public. While the capitalization of externalities into land values is consistent with economic theory, empirical measurement of impacts has not generated consistent results. This is true both for hedonic measurements as well as other types of econometric analyses. While it is well established that job and site risks have similar impacts on regional labor markets, there are no studies relating the presence of a broad range of noxious facilities to local wage premiums. In contrast, this study employs an interregional framework in a hedonic analysis of both wage and property markets and considers eight different facility classifications. This paper discusses the development of the hedonic model employed in this study. It develops more fully the theoretical advantages of the intercity model and alternative methods of deriving implicit prices for environmental amenities and disamenities. The unique data base and the structure of the estimated model are described. It also includes a discussion of the research findings. Major conclusions and suggestions for further research are presented.

  6. Economic impacts of noxious facilities: Incorporating the effects of risk aversion

    SciTech Connect

    Nieves, L.A.

    1993-09-01

    Developing new sites for noxious facilities has become a complex process with many potential pitfalls. In addition to the need to negotiate conditions acceptable to the host community, siting success may depend on the facility proposer`s ability to identify a candidate site that not only meets technical requirements, but that is located in a community or region whose population is not highly averse to the risks associated with the type of facility being proposed. Success may also depend on the proposer accurately assessing potential impacts of the facility and offering an equitable compensation package to the people affected by it. Facility impact assessments, as typically performed, include only the effects of changes in population, employment and economic activity associated with facility construction and operation. Because of their scope, such assessments usually show a short-run, net economic benefit for the host region, making the intensely negative public reaction to some types and locations of facilities seem unreasonable. The impact component excluded from these assessments is the long-run economic effect of public perceptions of facility risk and nuisance characteristics. Recent developments in psychological and economic measurement techniques have opened the possibility of correcting this flaw by incorporating public perceptions in projections of economic impacts from noxious facilities.

  7. Ventral premotor to primary motor cortical interactions during noxious and naturalistic action observation.

    PubMed

    Lago, Angel; Koch, Giacomo; Cheeran, Binith; Márquez, Gonzalo; Sánchez, Jose Andrés; Ezquerro, Milagros; Giraldez, Manolo; Fernández-del-Olmo, Miguel

    2010-05-01

    Within the motor system, cortical areas such as the primary motor cortex (M1) and the ventral premotor cortex (PMv), are thought to be activated during the observation of actions performed by others. However, it is not known how the connections between these areas become active during action observation or whether these connections are modulated by the volitional component induced by the action observed. In this study, using a paired pulse transcranial magnetic stimulation (ppTMS) method, we evaluated the excitability of PMv-M1 connections during the observation of videos showing a human hand reaching to grasp a ball (naturalistic grasping video) or a switched on soldering iron (noxious grasping video). The results show that the observation of the naturalistic grasping action increased the M1 excitability and changed the strength of the PMv-M1 connections. The observation of the noxious grasping action did not induce any change in the excitability of the PMv-M1 connections throughout the video, but the strength of PMv-M1 connectivity was reduced. These results demonstrate that the PMv-M1 connections are modulated differently depending on whether the action observed would or would not be performed in real life. 2010. Published by Elsevier Ltd. All rights reserved.

  8. Personality traits associated with perception of noxious stimuli in women with vulvar vestibulitis syndrome.

    PubMed

    Granot, Michal

    2005-03-01

    Vulvar vestibulitis syndrome (VVS) is associated with enhanced pain sensitivity. The present study explores the role of personality on the perception of noxious stimuli among women with VVS. More specifically, the aim of the study was to explore whether the personality traits assessed by Cloninger's Tridimensional Personality Questionnaire (TPQ) (harm avoidance [HA], novelty seeking [NS], and reward dependence [RD]) are associated with the augmented pain perception in women with VVS. Quantitative sensory tests were applied to the forearm of 98 women with VVS and 135 control subjects, all of whom completed the TPQ. The women with VVS scored higher than the control subjects on HA and RD with no significant differences in NS. Linear regression analyses revealed that in the VVS group, lower pain thresholds and higher magnitude estimations of suprathreshold pain stimuli were associated with higher HA and RD scores. The enhanced pain perception among women with VVS might reflect their tendency to respond intensely to signals of reward and to elevate the perceived risk. This might lead them to avoid hazards by overestimating the level of potential harm, as represented by greater pain sensitivity. The association between personality traits assessed by Cloninger's Tridimensional Personality Questionnaire, ie, harm avoidance, novelty seeking, and reward dependence, and the enhanced perception of noxious stimuli in vulvar vestibulitis syndrome might suggest neurochemical mechanisms of pain experience affected by personality, with possible application for future treatment approaches toward pain disorders.

  9. Borneol inhibits TRPA1, a proinflammatory and noxious pain-sensing cation channel.

    PubMed

    Sherkheli, Muhammad Azhar; Schreiner, Benjamin; Haq, Rizwanul; Werner, Markus; Hatt, Hanns

    2015-07-01

    Borneol, a natural product isolated from several species of Artemisia, Blumea and Kaempferia, has a widespread use in traditional medicine. TRP ion channels are a class of nonselective cation channel proteins involved in a variety of physiological and pathological processes in mammals. TRPA1, a member of TRP family of cation channels, is involved in plethora of processes including noxious-cold, noxious-pain sensations, inflammation and the detection of irritant chemicals. Borneol is chemically related to camphor (a known inhibitor of TRPA1 ion channels); therefore, it is beneficial to investigate the effects of borneol on TRPA1. In the present investigation it was found that borneol inhibits TRPA1 mediated cationic currents in low millimolar range (IC50 0.3mM) in heterologous expression systems like Xenopus oocytes and in neurons cultured from trigeminal ganglia. Effects of nicotine, a known chemical irritant and agonist of TRPA1 are also inhibited by borneol in both systems. It is concluded that borneol, being an inhibitor of TRPA1, could be a safer therapeutic-combination in clinical situations where TRPA1 channelopathies like neuropathic-pain, trigeminal neuralgia or nicotine withdrawal treatments are involved.

  10. The noxious effects of electroimmobilization in adult Holstein cows: a pilot study.

    PubMed Central

    Pascoe, P J; McDonell, W N

    1986-01-01

    Ten adult Holstein cows were used in an experiment to determine whether the induction of electroimmobilization was a noxious event. The cows were halter trained and accustomed to being led into a set of stocks. The time taken for the cattle to walk the last ten metres into the stocks was recorded. The heart rate of the cow was recorded for a three minute period prior to a ten second exposure to a high pitched sound (the conditioning stimulus). Measurements were collected for three repetitions and then the cows were assigned to two groups of five. One group was immobilized for 30 seconds using a commercial electroimmobilizer, the other group was not treated. This procedure was repeated ten times over a period of eight days. The cows were then exposed to the conditioning stimulus and their response observed. The treated group took significantly (P less than 0.05) longer to get into the stocks and the regression slopes for heart rate were significantly different from the control group. The treated cows responded to the conditioning stimulus at five and nine months after the end of the conditioning period. Adult Holstein cows regarded electroimmobilization as a noxious event and were very strongly conditioned to this stimulus. PMID:3756681

  11. Quality discrimination for noxious stimuli in secondary somatosensory cortex: a MEG-study.

    PubMed

    Maihöfner, Christian; Kaltenhäuser, Martin

    2009-11-01

    A complex cortical network is believed to encode the multi-dimensionality of the human pain experience. In the present study, we used magnetoencephalography (MEG) to examine whether the cortical processing of noxious stimuli with different psychophysical properties differs in primary (S1) and secondary (S2) somatosensory cortices. Noxious low (condition 1) and high (condition 2) current density stimulations of equal stimulus intensities were applied at the left forearm in 12 subjects in a randomised order. Concomitantly, subjects had to evaluate the corresponding sensory-discriminative and affective-motivational pain dimensions. MEG revealed an increased activation of bilateral secondary somatosensory cortices (S2) during condition 2 compared to condition 1. Higher activations of bilateral S2 were significantly correlated with higher scores for the sensory-discriminative component during condition 2. In contrast, corresponding scores for the affective-motivational pain dimension did not differ between both conditions. Therefore, concerning the sensory dimension of the human pain experience we conclude that the S2 cortex is involved in the encoding of quality discrimination.

  12. Enhancing non-noxious perception: behavioural and neurophysiological correlates of a placebo-like manipulation.

    PubMed

    Fiorio, M; Recchia, S; Corrà, F; Simonetto, S; Garcia-Larrea, L; Tinazzi, M

    2012-08-16

    Sensory perception can be influenced by cognitive functions like attention and expectation. An emblematic case of this is the placebo effect, where a reduction in pain perception can be obtained by inducing expectation of benefit following a treatment. The current study assessed the behavioural and brain activity correlates of a placebo procedure inducing an enhancement of non-noxious somatic sensation. An experimental group was verbally suggested and surreptitiously conditioned about the effect of an inert cream in enhancing tactile perception, while a control group was informed about the actual inefficacy of the cream. Both groups received non-noxious electric shocks activating A-Beta fibres on the right index finger, before and after application of the cream in the same site. The behavioural and neurophysiological effects of this procedure were measured by a numerical rating scale of subjective perception and by recording cortical and subcortical somatosensory-evoked potentials (SEPs). Although the intensity of stimulation was physically identical in the two sessions, the experimental group reported stronger tactile sensation after cream treatment than before. In parallel, the experimental group showed enhanced somatosensory cortical responses (N140, P200) after treatment, whereas subcortical and early-cortical SEP components did not change. We suggest that these findings reflect top-down modulation on tactile perception probably due to an interplay between expectation and attention and might rely on interactions between prefrontal and parietal brain regions.

  13. Reflex modulation of ovarian estradiol secretion by noxious mechanical stimulation of a hindpaw in anesthetized rats.

    PubMed

    Uchida, Sae; Kagitani, Fusako; Hotta, Harumi

    2012-11-02

    Previously, we demonstrated that electrical stimulation of the superior ovarian nerve in rats reduces the ovarian estradiol secretion rate. In the present study, we examined the effect of noxious mechanical afferent stimulation (pinching) of a hindpaw on the ovarian estradiol secretion rate in rats. The rats were anesthetized on the day of estrus, and the ovarian venous blood was collected intermittently. The secretion rate of estradiol from the ovary was calculated from differences in the estradiol concentration between ovarian venous plasma and systemic arterial blood plasma, and from the flow rate of ovarian venous plasma. Pinching stimulation of a hindpaw for 5 min decreased the estradiol secretion rate from the ovary. A significant reduction of the estradiol secretion rate began at 5 min after the end of the stimulation and lasted for 20 min. The minimum decrease in estradiol secretion rate was 71.1 ± 14.0% of the prestimulus basal values at 15 min after the stimulation ended. The decrease responses of the ovarian estradiol secretion rate were abolished by bilateral severance of the superior ovarian nerves. The efferent activity of the superior ovarian nerves was increased following hindpaw pinching. After spinal transection at the second cervical level, the increased response of the superior ovarian nerve activity by hindpaw pinching was abolished. These results indicate that noxious mechanical stimulation of a hindpaw decreases the estradiol secretion rate from the ovary, and that the response is due to reflex activation of ovarian sympathetic nerves, mediated by supraspinal structures.

  14. Aromatization of androgens into estrogens reduces response latency to a noxious thermal stimulus in male quail.

    PubMed

    Evrard, H C; Balthazart, J

    2004-03-01

    We recently demonstrated the presence of estrogen synthase (aromatase) and of estrogen receptors in the dorsal horn (laminae I-II) throughout the rostrocaudal extent of the spinal cord in male and female Japanese quail. The spinal laminae I-II receive and process abundant sensory information elicited, among others, by acute noxious stimulation of the skin and resulting in rapid, reflex-like withdrawal behavior. In the present study, we demonstrate that systemic treatment with estradiol or testosterone markedly decreases the latency of the foot withdrawal in the hot water test. A simultaneous treatment with an aromatase inhibitor blocks the effects of testosterone demonstrating, hence, that they are mediated by a conversion of testosterone into an estrogen by aromatase. Furthermore, the testosterone- or estradiol-induced decrease in foot withdrawal latency is blocked by a treatment with the estradiol receptor antagonist, tamoxifen, indicating that the effects are largely mediated by the interaction of estradiol with estrogen receptors. Together, these data suggest that sex steroids modulate sensitivity to noxious stimuli possibly by a direct action at the level of the dorsal horn of the spinal cord.

  15. Involvement of mu opioid receptors of periaqueductal gary (PAG) in acupuncture inhibition of noxious blood pressure response in rabbits.

    PubMed

    Gao, M; Xu, W; Chen, W; He, L

    1994-01-01

    Strong electric shock stimulation of the rabbit front paw elicited a pressor blood pressure response regarded as noxious response. Ligands of mu opioid receptors were microinjected into the PAG to observe their effects on acupunture inhibition of the pressor response. (1) Ohmefentanyl (OMF), a mu agonist, significantly attenuated the pressor response. Mu antagonist TCTAP greatly enhanced the pressor response. (2) Electroacupuncture (EA) significantly inhibited the pressor response, the inhibition being readily reversed by TCTAP. The response after TCTAP was significantly greater than that of the control before EA. The results suggest that noxious stimulation is able to activate the mu opioid receptor of the PAG to modulate the noxious response and EA is able to enhance the activation.

  16. The effect of foot-shock on the noxious-evoked activity of neurons in the rostral ventral medulla.

    PubMed

    Friederich, M W; Walker, J M

    1990-04-01

    The effect of foot-shock on the noxious-evoked activity of rostral ventral medulla (RVM) neurons was investigated in anesthetized rats. Neurons were first classified as on-cells if they fired faster during noxious pinch or as off-cells if they fired slower. Exposure to a 20 Hz squarewave at 2.5 or 3.5 mA administered for two minutes decreased the noxious-evoked responses of both cell types: on-cells showed a reduced increase in firing, while off-cells showed a reduced decrease in firing. The results indicate that stress-induced analgesia is accompanied by alterations in the activity of on- and off-cells.

  17. An inhibitory corticostriatal pathway

    PubMed Central

    Rock, Crystal; Zurita, Hector; Wilson, Charles; Apicella, Alfonso junior

    2016-01-01

    Anatomical and physiological studies have led to the assumption that the dorsal striatum receives exclusively excitatory afferents from the cortex. Here we test the hypothesis that the dorsal striatum receives also GABAergic projections from the cortex. We addressed this fundamental question by taking advantage of optogenetics and directly examining the functional effects of cortical GABAergic inputs to spiny projection neurons (SPNs) of the mouse auditory and motor cortex. We found that the cortex, via corticostriatal somatostatin neurons (CS-SOM), has a direct inhibitory influence on the output of the striatum SPNs. Our results describe a corticostriatal long-range inhibitory circuit (CS-SOM inhibitory projections → striatal SPNs) underlying the control of spike timing/generation in SPNs and attributes a specific function to a genetically defined type of cortical interneuron in corticostriatal communication. DOI: http://dx.doi.org/10.7554/eLife.15890.001 PMID:27159237

  18. Cat's medullary reticulospinal and subnucleus reticularis dorsalis noxious neurons form a coupled neural circuit through collaterals of descending axons

    PubMed Central

    Leiras, Roberto; Martín-Cora, Francisco; Velo, Patricia; Liste, Tania

    2015-01-01

    Animals and human beings sense and react to real/potential dangerous stimuli. However, the supraspinal mechanisms relating noxious sensing and nocifensive behavior are mostly unknown. The collateralization and spatial organization of interrelated neurons are important determinants of coordinated network function. Here we electrophysiologically studied medial medullary reticulospinal neurons (mMRF-RSNs) antidromically identified from the cervical cord of anesthetized cats and found that 1) more than 40% (79/183) of the sampled mMRF-RSNs emitted bifurcating axons running within the dorsolateral (DLF) and ventromedial (VMF) ipsilateral fascicles; 2) more than 50% (78/151) of the tested mMRF-RSNs with axons running in the VMF collateralized to the subnucleus reticularis dorsalis (SRD) that also sent ipsilateral descending fibers bifurcating within the DLF and the VMF. This percentage of mMRF collateralization to the SRD increased to more than 81% (53/65) when considering the subpopulation of mMRF-RSNs responsive to noxiously heating the skin; 3) reciprocal monosynaptic excitatory relationships were electrophysiologically demonstrated between noxious sensitive mMRF-RSNs and SRD cells; and 4) injection of the anterograde tracer Phaseolus vulgaris leucoagglutinin evidenced mMRF to SRD and SRD to mMRF projections contacting the soma and proximal dendrites. The data demonstrated a SRD-mMRF network interconnected mainly through collaterals of descending axons running within the VMF, with the subset of noxious sensitive cells forming a reverberating circuit probably amplifying mutual outputs simultaneously regulating motor activity and spinal noxious afferent input. The results provide evidence that noxious stimulation positively engages a reticular SRD-mMRF-SRD network involved in pain-sensory-to-motor transformation and modulation. PMID:26581870

  19. Types of skin afferent fibers and spinal opioid receptors that contribute to touch-induced inhibition of heart rate changes evoked by noxious cutaneous heat stimulation.

    PubMed

    Watanabe, Nobuhiro; Piché, Mathieu; Hotta, Harumi

    2015-12-01

    In anesthetized rats and conscious humans, a gentle touch using a soft disc covered with microcones (with a texture similar to that of a finger), but not with a flat disc, inhibits nociceptive somatocardiac reflexes. Such an inhibitory effect is most reliably evoked when touch is applied to the skin ipsilateral and closest to nociceptive inputs. However, the mechanism of this inhibition is not completely elucidated. We aimed to clarify the types of cutaneous afferent fibers and spinal opioid receptors that contribute to antinociceptive effects of microcone touch. The present study comprised two experiments with urethane-anesthetized rats. In the first experiment, unitary activity of skin afferent fibers was recorded from the saphenous nerve, and responses to a 10-min touch using a microcone disc and a flat disc (control) were compared. Greater discharge rate during microcone touch was observed in low-threshold mechanoreceptive Aδ and C afferent units, whereas many Aβ afferents responded similarly to the two types of touch. In the second experiment, the effect of an intrathecal injection of opioid receptor antagonists on the inhibitory effects of microcone touch on heart rate responses to noxious heat stimulation was examined. The magnitude of the heart rate response was significantly reduced by microcone touch in rats that received saline or naltrindole (δ-opioid receptor antagonist) injections. However, such an inhibition was not observed in rats that received naloxone (non-selective opioid receptor antagonist) or Phe-Cys-Tyr-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP; μ-opioid receptor antagonist) injections. Microcone touch induced greater responses of low-threshold mechanoreceptive Aδ and C afferent units than control touch. The antinociceptive effect of microcone touch was abolished by intrathecal injection of μ-opioid receptor antagonist. These results suggest that excitation of low-threshold mechanoreceptive Aδ and C afferents produces the release of endogenous

  20. Types of skin afferent fibers and spinal opioid receptors that contribute to touch-induced inhibition of heart rate changes evoked by noxious cutaneous heat stimulation.

    PubMed

    Watanabe, Nobuhiro; Piché, Mathieu; Hotta, Harumi

    2015-02-12

    In anesthetized rats and conscious humans, a gentle touch using a soft disc covered with microcones (with a texture similar to that of a finger), but not with a flat disc, inhibits nociceptive somatocardiac reflexes. Such an inhibitory effect is most reliably evoked when touch is applied to the skin ipsilateral and closest to nociceptive inputs. However, the mechanism of this inhibition is not completely elucidated. We aimed to clarify the types of cutaneous afferent fibers and spinal opioid receptors that contribute to antinociceptive effects of microcone touch. The present study comprised two experiments with urethane-anesthetized rats. In the first experiment, unitary activity of skin afferent fibers was recorded from the saphenous nerve, and responses to a 10-min touch using a microcone disc and a flat disc (control) were compared. Greater discharge rate during microcone touch was observed in low-threshold mechanoreceptive Aδ and C afferent units, whereas many Aβ afferents responded similarly to the two types of touch. In the second experiment, the effect of an intrathecal injection of opioid receptor antagonists on the inhibitory effects of microcone touch on heart rate responses to noxious heat stimulation was examined. The magnitude of the heart rate response was significantly reduced by microcone touch in rats that received saline or naltrindole (δ-opioid receptor antagonist) injections. However, such an inhibition was not observed in rats that received naloxone (non-selective opioid receptor antagonist) or Phe-Cys-Tyr-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP; μ-opioid receptor antagonist) injections. Microcone touch induced greater responses of low-threshold mechanoreceptive Aδ and C afferent units than control touch. The antinociceptive effect of microcone touch was abolished by intrathecal injection of μ-opioid receptor antagonist. These results suggest that excitation of low-threshold mechanoreceptive Aδ and C afferents produces the release of endogenous

  1. Temperature coefficient of membrane currents induced by noxious heat in sensory neurones in the rat

    PubMed Central

    Vyklický, L; Vlachová, V; Vitásková, Z; Dittert, I; Kabát, M; Orkand, R K

    1999-01-01

    Membrane currents induced by noxious heat (Iheat) were studied in cultured dorsal root ganglion (DRG) neurones from newborn rats using ramps of increasing temperature of superfusing solutions. Iheat was observed in about 70 % of small (< 25 μm) DRG neurones. At -60 mV, Iheat exhibited a threshold at about 43 °C and reached its maximum, sometimes exceeding 1 nA, at 52 °C (716 ± 121 pA; n = 39). Iheat exhibited a strong temperature sensitivity (temperature coefficient over a 10 °C temperature range (Q10) = 17·8 ± 2·1, mean ± s.d., in the range 47-51 °C; n = 41), distinguishing it from the currents induced by capsaicin (1 μM), bradykinin (5 μM) and weak acid (pH 6·1 or 6·3), which exhibited Q10 values of 1·6-2·8 over the whole temperature range (23-52 °C). Repeated heat ramps resulted in a decrease of the maximum Iheat and the current was evoked at lower temperatures. A single ramp exceeding 57 °C resulted in an irreversible change in Iheat. In a subsequent trial, maximum Iheat was decreased to less than 50 %, its threshold was lowered to a temperature just above that in the bath and its maximum Q10 was markedly lower (5·6 ± 0·8; n = 8). DRG neurones that exhibited Iheat were sensitive to capsaicin. However, four capsaicin-sensitive neurones out of 41 were insensitive to noxious heat. There was no correlation between the amplitude of capsaicin-induced responses and Iheat. In the absence of extracellular Ca2+, Q10 for Iheat was lowered from 25·3 ± 7·5 to 4·2 ± 0·4 (n = 7) in the range 41-50 °C. The tachyphylaxis, however, was still observed. A high Q10 of Iheat suggests a profound, rapid and reversible change in a protein structure in the plasma membrane of heat-sensitive nociceptors. It is hypothesized that this protein complex possesses a high net free energy of stabilization (possibly due to ionic bonds) and undergoes disassembly when exposed to noxious heat. The liberated components activate distinct cationic channels to generate Iheat

  2. Neonatal local noxious insult affects gene expression in the spinal dorsal horn of adult rats.

    PubMed

    Ren, Ke; Novikova, Svetlana I; He, Fang; Dubner, Ronald; Lidow, Michael S

    2005-09-22

    Neonatal noxious insult produces a long-term effect on pain processing in adults. Rats subjected to carrageenan (CAR) injection in one hindpaw within the sensitive period develop bilateral hypoalgesia as adults. In the same rats, inflammation of the hindpaw, which was the site of the neonatal injury, induces a localized enhanced hyperalgesia limited to this paw. To gain an insight into the long-term molecular changes involved in the above-described long-term nociceptive effects of neonatal noxious insult at the spinal level, we performed DNA microarray analysis (using microarrays containing oligo-probes for 205 genes encoding receptors and transporters for glutamate, GABA, and amine neurotransmitters, precursors and receptors for neuropeptides, and neurotrophins, cytokines and their receptors) to compare gene expression profiles in the lumbar spinal dorsal horn (LDH) of adult (P60) male rats that received neonatal CAR treatment within (at postnatal day 3; P3) and outside (at postnatal 12; P12) of the sensitive period. The data were obtained both without inflammation (at baseline) and during complete Freund's adjuvant induced inflammation of the neonatally injured paw. The observed changes were verified by real-time RT-PCR. This study revealed significant basal and inflammation-associated aberrations in the expression of multiple genes in the LDH of adult animals receiving CAR injection at P3 as compared to their expression levels in the LDH of animals receiving either no injections or CAR injection at P12. In particular, at baseline, twelve genes (representing GABA, serotonin, adenosine, neuropeptide Y, cholecystokinin, opioid, tachykinin and interleukin systems) were up-regulated in the bilateral LDH of the former animals. The baseline condition in these animals was also characterized by up-regulation of seven genes (encoding members of GABA, cholecystokinin, histamine, serotonin, and neurotensin systems) in the LDH ipsilateral to the neonatally-injured paw. The

  3. TRPA1 Mediates the Noxious Effects of Natural Sesquiterpene Deterrents*S⃞

    PubMed Central

    Escalera, Jasmine; von Hehn, Christian A.; Bessac, Bret F.; Sivula, Michael; Jordt, Sven-Eric

    2008-01-01

    Plants, fungi, and animals generate a diverse array of deterrent natural products that induce avoidance behavior in biological adversaries. The largest known chemical family of deterrents are terpenes characterized by reactive α,β-unsaturated dialdehyde moieties, including the drimane sesquiterpenes and other terpene species. Deterrent sesquiterpenes are potent activators of mammalian peripheral chemosensory neurons, causing pain and neurogenic inflammation. Despite their wide-spread synthesis and medicinal use as desensitizing analgesics, their molecular targets remain unknown. Here we show that isovelleral, a noxious fungal sesquiterpene, excites sensory neurons through activation of TPRA1, an ion channel involved in inflammatory pain signaling. TRPA1 is also activated by polygodial, a drimane sesquiterpene synthesized by plants and animals. TRPA1-deficient mice show greatly reduced nocifensive behavior in response to isovelleral, indicating that TRPA1 is the major receptor for deterrent sesquiterpenes in vivo. Isovelleral and polygodial represent the first fungal and animal small molecule agonists of nociceptive transient receptor potential channels. PMID:18550530

  4. [Toxicological effects of weapons of mass destruction and noxious agents in modern warfare and terrorism].

    PubMed

    Vucemilović, Ante

    2010-06-01

    Weapons of mass destruction (WMD) best portray the twisted use of technological achievements against the human species. Despite arm control efforts, WMD threat continues to exist and even proliferate. This in turn calls for improvement in defensive measures against this threat. The modern soldier is exposed to a number of chemical, biological, and radiological agents in military and peace operations, while civilians are mainly exposed to terrorist attacks. Regardless of origin or mode of action, WMDs and other noxious agents aim for the same - to make an organism dysfunctional. Because their effects are often delayed, these agents are hard to spot on time and treat. This review presents a biomedical aspect of agents used in warfare and terrorism, including polonium-210, depleted uranium, salmonella, anthrax, genetically modified bacteria, cobweb-like polymer fibre, sarin, and mustard gas.

  5. Race, region and risk: An examination of minority proximity to noxious facilities

    SciTech Connect

    Nieves, A.L. |; Nieves, L.A.

    1996-04-01

    The past decade has given rise to terms like environmental racism, eco-racism, and environmental inequities to characterize a disproportional distribution of environmental disamenities among minority communities. Much of the literature supports the contention that racial and ethnic minorities and low-income groups bear a disproportionate burden of risk from hazardous activities and substances in the environment. This study expands the scope of prior studies by employing county-level data for the entire nation and including a broad range of facility types associated with environmental disamenities. In addition, it addresses the issue of the distribution of noxious facilities among white and non-white populations in an attempt to determine the relative exposure to risk among different racial and ethnic groups. In addition, the authors also explore the relative importance of nonurban versus urban residence.

  6. The Correlation between Thermal and Noxious Gas Environments, Pig Productivity and Behavioral Responses of Growing Pigs

    PubMed Central

    Choi, Hong Lim; Han, Sang Hwa; Albright, Louis D.; Chang, Won Kyung

    2011-01-01

    Correlations between environmental parameters (thermal range and noxious gas levels) and the status (productivity, physiological, and behavioral) of growing pigs were examined for the benefit of pig welfare and precision farming. The livestock experiment was conducted at a Seoul National University station in South Korea. Many variations were applied and the physiological and behavioral responses of the growing pigs were closely observed. Thermal and gas environment parameters were different during the summer and winter seasons, and the environments in the treatments were controlled in different manners. In the end, this study finds that factors such as Average Daily Gain (ADG), Adrenocorticotropic Hormone (ACTH), stress, posture, and eating habits were all affected by the controlled environmental parameters and that appropriate control of the foregoing could contribute to the improvement of precision farming and pig welfare. PMID:22016700

  7. Multifrequency Radar Imagery and Characterization of Hazardous and Noxious Substances at Sea

    NASA Astrophysics Data System (ADS)

    Angelliaume, S.; Minchew, B.; Chataing, S.; Martineau, Ph.; Miegebielle, V.

    2016-08-01

    Maritime pollution by chemical products occurs at much lower frequency than spills of oil, however the consequences of a chemical spill can be more wide-reaching than those of oil. While detection and characterization of hydrocarbons have been the subject of numerous studies, detection of other chemical products at sea using remote sensing has been little studied and is still an open subject of research. To address this knowledge gap, an experiment was conducted in May 2015 over the Mediterranean Sea during which controlled releases of hazardous and noxious substances were imaged by an airborne SAR sensor at X- and L-band simultaneously.In this paper we discuss the experimental procedure and report the main results from the airborne radar imaging campaign.

  8. Pre-stimulus alpha power affects vertex N2-P2 potentials evoked by noxious stimuli.

    PubMed

    Babiloni, Claudio; Del Percio, Claudio; Brancucci, Alfredo; Capotosto, Paolo; Le Pera, Domenica; Marzano, Nicola; Valeriani, Massimiliano; Romani, Gian Luca; Arendt-Nielsen, Lars; Rossini, Paolo Maria

    2008-03-28

    It is well known that scalp potentials evoked by nonpainful visual and auditory stimuli are enhanced in amplitude when preceded by pre-stimulus low-amplitude alpha rhythms. This study tested the hypothesis that the same holds for the amplitude of vertex N2-P2 potentials evoked by brief noxious laser stimuli, an issue of interest for clinical perspective. EEG data were recorded in 10 subjects from 30 electrodes during laser noxious stimulation. The artifact-free vertex N2-P2 complex was spatially enhanced by surface Laplacian transformation. Pre-stimulus alpha power was computed at three alpha sub-bands according to subject's individual alpha frequency peak (i.e. about 6-8Hz for alpha 1, 8-10Hz for alpha 2 and 10-12Hz for alpha 3 sub-band). Individual EEG single trials were divided in two sub-groups. The strong-alpha sub-group (high band power) included halfway of all EEG single trials, namely those having the highest pre-stimulus alpha power. Weak-alpha sub-group (low band power) included the remaining trials. Averaging procedure provided laser evoked potentials for both trial sub-groups. No significant effect was found for alpha 1 and alpha 2 sub-bands. Conversely, compared to strong-alpha 3 sub-group, weak-alpha 3 sub-group showed vertex N2-P2 potentials having significantly higher amplitude (p<0.05). These results extend to the later phases of pain processing systems the notion that generation mechanisms of pre-stimulus alpha rhythms and (laser) evoked potentials are intrinsically related and subjected to fluctuating "noise". That "noise" could explain the trial-by-trial variability of laser evoked potentials and perception.

  9. Distinct temporal filtering mechanisms are engaged during dynamic increases and decreases of noxious stimulus intensity

    PubMed Central

    Mørch, Carsten Dahl; Frahm, Ken Steffen; Coghill, Robert C.; Arendt-Nielsen, Lars; Andersen, Ole Kæseler

    2015-01-01

    Abstract Physical stimuli are subject to pronounced temporal filtering during afferent processing such that changes occurring at certain rates are amplified and others are diminished. Temporal filtering of nociceptive information remains poorly understood. However, the phenomenon of offset analgesia, where a disproportional drop in perceived pain intensity is caused by a slight drop in noxious heat stimulation, indicates potent temporal filtering in the pain pathways. To develop a better understanding of how dynamic changes in a physical stimulus are constructed into an experience of pain, a transfer function between the skin temperature and the perceived pain intensity was modeled. Ten seconds of temperature-controlled near-infrared (970 nm) laser stimulations above the pain threshold with a 1°C increment, decrement, or constant temperature were applied to the dorsum of the hand of healthy human volunteers. The skin temperature was assessed by an infrared camera. Offset analgesia was evoked by laser heat stimulation. The estimated transfer functions showed shorter latencies when the temperature was increased by 1°C (0.53 seconds [0.52-0.54 seconds]) than when decreased by 1°C (1.15 seconds [1.12-1.18 seconds]) and smaller gains (increase: 0.89 [0.82-0.97]; decrease: 2.61 [1.91-3.31]). The maximal gain was observed at rates around 0.06 Hz. These results show that temperature changes occurring around 0.06 Hz are best perceived and that a temperature decrease is associated with a larger but slower change in pain perception than a comparable temperature increase. These psychophysical findings confirm the existence of differential mechanisms involved in temporal filtering of dynamic increases and decreases in noxious stimulus intensity. PMID:26035254

  10. Chronic Lateral Epicondylalgia Does Not Exhibit Mechanical Pain Modulation in Response to Noxious Conditioning Heat Stimulus.

    PubMed

    Lim, Edwin Choon Wyn; Sterling, Michele; Vicenzino, Bill

    2017-10-01

    The impaired attenuation of pain by the application of a noxious conditioning stimulus at a segmentally distinct site, known as conditioned pain modulation (CPM), has been implicated in clinical pain states. Chronic lateral epicondylalgia (LE), which is characterized by lower pressure pain thresholds (PPTs) at sites remote to the affected elbow and spinal cord hyperexcitability, is a clinical pain state that might plausibly involve less efficacious CPM. This study aimed to determine whether LE exhibits a less efficacious CPM compared with that in pain-free controls. Results: Twenty participants with LE, aged 50.7 years (SD=7.05) and who had their condition for 10.2 months (range: 2 to 80 mo), were matched by age and sex to 22 pain-free participants. All participants indicated their PPT over the lateral epicondyle(s) before and during a conditioning noxious heat stimulus that was applied over the calf. A CPM score was calculated as the difference between the PPT before and during the heat pain-conditioning stimulus expressed as a percentage of PPT before the heat pain-conditioning stimulus. The condition (LE vs. control) by side (affected vs. unaffected) analysis of variance revealed a significant condition effect (P=0.001), but not side effect (P=0.192) or side-by-condition interaction effect (P=0.951). Follow-up tests for the effect of condition revealed a mean deficit in CPM of -24.5% (95% confidence interval, -38.0 to -11.0) in LE compared with that in pain-free participants. The results that suggest an impaired ability to modulate pain might be associated with the previously observed spinal cord hyperexcitability and the mechanical hyperalgesia that characterizes LE.

  11. Reduced cortical responses to noxious heat in patients with rheumatoid arthritis

    PubMed Central

    Jones, A; Derbyshire, S

    1997-01-01

    OBJECTIVES—To test the hypothesis that patients with chronic inflammatory pain develop adaptive cortical responses to noxious stimulation characterised by reduced anterior cingulate responses.
METHODS—Positron emission tomography was used to measure changes in regional cerebral blood flow (rCBF) in response to an acute experimental pain stimulus in six patients with rheumatoid arthritis (RA) in comparison to six age and sex matched controls. A standardised and reproducible non-painful and painful phasic heat stimulus was delivered by a thermal probe to the back of the right hand during six two minute periods during which time rCBF measurements were made. The effects of non-painful heat were subtracted from those of painful heat to weight the analysis towards the non-discriminatory or `suffering' components of pain processing. Significance maps of pain processing were generated and compared in each group and contrasted with results obtained in a group of patients with atypical facial pain (AFP) that have been previously published.
RESULTS—The RA patients showed remarkably damped cortical and subcortical responses to pain compared with the control group. Significant differences between the two groups were observed in the prefrontal (BA 10) and anterior cingulate (BA 24 ) and cingulofrontal transition cortical (BA 32) areas. The reduced anterior cingulate responses to standardised heat pain were compared with the increased cingulate responses seen in patients with psychogenically maintained pain (AFP) who had both lower pain tolerance and mood than the RA group.
CONCLUSIONS—Major cortical adaptive responses to standardised noxious heat can be measured and contrasted in patients with different types of chronic pain. The different pattern of cingulate and frontal cortical responses in the patients with inflammatory and non-nociceptive pain suggest that different mechanisms are operating, possibly at a thalamocortical level. Implications for treatment

  12. Distinct temporal filtering mechanisms are engaged during dynamic increases and decreases of noxious stimulus intensity.

    PubMed

    Mørch, Carsten Dahl; Frahm, Ken Steffen; Coghill, Robert C; Arendt-Nielsen, Lars; Andersen, Ole Kæseler

    2015-10-01

    Physical stimuli are subject to pronounced temporal filtering during afferent processing such that changes occurring at certain rates are amplified and others are diminished. Temporal filtering of nociceptive information remains poorly understood. However, the phenomenon of offset analgesia, where a disproportional drop in perceived pain intensity is caused by a slight drop in noxious heat stimulation, indicates potent temporal filtering in the pain pathways. To develop a better understanding of how dynamic changes in a physical stimulus are constructed into an experience of pain, a transfer function between the skin temperature and the perceived pain intensity was modeled. Ten seconds of temperature-controlled near-infrared (970 nm) laser stimulations above the pain threshold with a 1°C increment, decrement, or constant temperature were applied to the dorsum of the hand of healthy human volunteers. The skin temperature was assessed by an infrared camera. Offset analgesia was evoked by laser heat stimulation. The estimated transfer functions showed shorter latencies when the temperature was increased by 1°C (0.53 seconds [0.52-0.54 seconds]) than when decreased by 1°C (1.15 seconds [1.12-1.18 seconds]) and smaller gains (increase: 0.89 [0.82-0.97]; decrease: 2.61 [1.91-3.31]). The maximal gain was observed at rates around 0.06 Hz. These results show that temperature changes occurring around 0.06 Hz are best perceived and that a temperature decrease is associated with a larger but slower change in pain perception than a comparable temperature increase. These psychophysical findings confirm the existence of differential mechanisms involved in temporal filtering of dynamic increases and decreases in noxious stimulus intensity.

  13. Nitric oxide modulates the hyperalgesic response to mechanical noxious stimuli in sleep-deprived rats

    PubMed Central

    2013-01-01

    Background Sleep restriction alters pain perception in animals and humans, and many studies have indicated that paradoxical sleep deprivation (PSD) promotes hyperalgesia. The hyperalgesia observed after mechanical nociceptive stimulus is reversed through nitric oxide synthase (NOS) inhibition. Both nitric oxide (NO) and the dorsolateral periaqueductal gray matter (dlPAG) area of the brainstem are involved in hyperalgesia. Thus, in this work, we investigated the pain-related behavior response after mechanical noxious stimuli (electronic von Frey test), and the activity of nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d), an indicator of NOS activity, within the dlPAG of paradoxical sleep-deprived rats. We also evaluated the effects of pre-treatment with L-NAME on these parameters. Results These data revealed that PSD reduced the hindpaw withdrawal threshold (−47%, p < 0.0001) confirming the hyperalgesic effect of this condition. In addition, there were more NADPH-d positive cells in dlPAG after PSD than in control rats (+ 59%, p < 0.0001). L-NAME treatment prevented the reduction in the hindpaw withdrawal threshold (+ 93%, p < 0.0001) and the increase in the NADPH-d positive cells number in the dlPAG of PSD-treated rats (−36%, p < 0.0001). Conclusion These data suggest that the hyperalgesic response to mechanical noxious stimuli in paradoxical sleep-deprived rats is associated with increased NOS activity in the dlPAG, which presumably influences the descending antinociceptive pathway. PMID:23987566

  14. A field guide for forest indicator plants, sensitive plants, and noxious weeds of the Shoshone National Forest, Wyoming

    Treesearch

    Kent E. Houston; Walter J. Hartung; Carol J. Hartung

    2001-01-01

    This field guide was designed for people with minimal botanical training. It is an identification aid to plant species that have ecological indicator value, are on sensitive species lists, or are considered noxious weeds. It contains illustrations and simplified taxonomic descriptions.

  15. Differential induction of c-Fos and phosphorylated ERK by a noxious stimulus after peripheral nerve injury.

    PubMed

    Tabata, Mitsuyasu; Terayama, Ryuji; Maruhama, Kotaro; Iida, Seiji; Sugimoto, Tomosada

    2017-10-02

    In this study, we compared induction of c-Fos and phosphorylated extracellular signal-regulated kinase (p-ERK) in the spinal dorsal horn after peripheral nerve injury. We examined the spinal dorsal horn for noxious heat-induced c-Fos and p-ERK protein-like immunoreactive (c-Fos- and p-ERK-IR) neuron profiles after tibial nerve injury. The effect of administration of a MEK 1/2 inhibitor (PD98059) on noxious heat-induced c-Fos expression was also examined after tibial nerve injury. A large number of c-Fos- and p-ERK-IR neuron profiles were induced by noxious heat stimulation to the hindpaw in sham-operated animals. A marked reduction in the number of c-Fos- and p-ERK-IR neuron profiles was observed in the medial 1/3 (tibial territory) of the dorsal horn at 3 and 7 days after nerve injury. Although c-Fos-IR neuron profiles had reappeared by 14 days after injury, the number of p-ERK-IR neuron profiles remained decreased in the tibial territory of the superficial dorsal horn. Double immunofluorescence labeling for c-Fos and p-ERK induced by noxious heat stimulation to the hindpaw at different time points revealed that a large number of c-Fos-IR, but not p-ERK-IR, neuron profiles were distributed in the tibial territory after injury. Although administration of a MEK 1/2 inhibitor to the spinal cord suppressed noxious heat-induced c-Fos expression in the peroneal territory, this treatment did not alter c-Fos induction in the tibial territory after nerve injury. ERK phosphorylation may be involved in c-Fos induction in normal nociceptive responses, but not in exaggerated c-Fos induction after nerve injury.

  16. Identification of the Visceral Pain Pathway Activated by Noxious Colorectal Distension in Mice

    PubMed Central

    Kyloh, Melinda; Nicholas, Sarah; Zagorodnyuk, Vladimir P.; Brookes, Simon J.; Spencer, Nick J.

    2011-01-01

    In patients with irritable bowel syndrome, visceral pain is evoked more readily following distension of the colorectum. However, the identity of extrinsic afferent nerve pathway that detects and transmits visceral pain from the colorectum to the spinal cord is unclear. In this study, we identified which extrinsic nerve pathway(s) underlies nociception from the colorectum to the spinal cord of rodents. Electromyogram recordings were made from the transverse oblique abdominal muscles in anesthetized wild type (C57BL/6) mice and acute noxious intraluminal distension stimuli (100–120 mmHg) were applied to the terminal 15 mm of colorectum to activate visceromotor responses (VMRs). Lesioning the lumbar colonic nerves in vivo had no detectable effect on the VMRs evoked by colorectal distension. Also, lesions applied to the right or left hypogastric nerves failed to reduce VMRs. However, lesions applied to both left and right branches of the rectal nerves abolished VMRs, regardless of whether the lumbar colonic or hypogastric nerves were severed. Electrical stimulation applied to either the lumbar colonic or hypogastric nerves in vivo, failed to elicit a VMR. In contrast, electrical stimulation (2–5 Hz, 0.4 ms, 60 V) applied to the rectum reliably elicited VMRs, which were abolished by selective lesioning of the rectal nerves. DiI retrograde labeling from the colorectum (injection sites 9–15 mm from the anus, measured in unstretched preparations) labeled sensory neurons primarily in dorsal root ganglia (DRG) of the lumbosacral region of the spinal cord (L6-S1). In contrast, injection of DiI into the mid to proximal colon (injection sites 30–75 mm from the anus, measured in unstretched preparations) labeled sensory neurons in DRG primarily of the lower thoracic level (T6-L2) of the spinal cord. The visceral pain pathway activated by acute noxious distension of the terminal 15 mm of mouse colorectum is transmitted predominantly, if not solely, through

  17. Noxious Colorectal Distention in Spinalized Rats Reduces Pseudorabies Virus Labeling of Sympathetic Neurons

    PubMed Central

    Duale, Hanad; Lyttle, Travis S.; Smith, Bret N.

    2010-01-01

    Abstract The retrograde transsynaptic tracer pseudorabies virus (PRV) has been widely used as a marker for synaptic connectivity in the spinal cord. Notably, the PRV-152 construct expresses enhanced green fluorescent protein (EGFP). We recently reported a significant attenuation of PRV-152 labeling of the intermediolateral cell column (IML) and celiac ganglia after complete T4 spinal cord transection versus sham injury in rats at 96 h after PRV-152 inoculation of the left kidney. Here we found a significant increase in noxious colorectal distention (CRD)-evoked c-Fos expression in spinal cords of injured versus sham rats without PRV infection. In order to assess whether enhancing neuronal activity in spinalized rats might increase PRV-152 labeling, we subjected awake spinalized rats to 1.5 h of intermittent noxious CRD either: (1) just prior to inoculation, or (2) 96 h after inoculation (n = 3/group). Equal numbers of spinalized rats in both groups received PRV-152 inoculations without CRD (non-stimulated; n = 3/group). At 96 h post-inoculation fixed spinal cords and left celiac ganglionic tissues were assessed for the distribution and quantification of EGFP-labeled cells. The injured cohort that received CRD just prior to PRV injection showed a significant reduction in EGFP-labeled cells in both the IML and left celiac ganglion compared to non-stimulated injured rats. In contrast, the injured cohort that received CRD 96 h after PRV-152 inoculation showed no differences in EGFP-labeled cell numbers in the IML or celiac ganglia versus non-stimulated injured rats. Interestingly, microglia near c-Fos-positive cells after acute CRD appeared more reactive compared to non-stimulated spinalized rats, and activated microglial cells markedly reduce viral transduction and progression following PRV inoculation of the CNS. Hence our results imply that increased CRD-induced c-Fos expression in the injured paradigm, prior to but not after PRV injection, further

  18. [Effect of noxious stimulation on regional distribution of propofol in canine spinal cord].

    PubMed

    Lin, Chun-shui; Xu, Jin-dong; Gu, Miao-ning; Chen, Ying; Zhou, Feng-zhi

    2010-05-01

    To observe the regional distribution of propofol in canine spinal cord under noxious stimulation. Twelve healthy hybrid dogs (12-18 months old, weighing 10-12 kg) were randomly divided into control group (n=6) and stimulation group (n=6). All the dogs were anesthetized with a single bolus dose of propofol (7 mg/kg) in 15 seconds followed by propofol infusion at a constant rate of 70 mg/kg/h via the great saphenous vein of the right posterior limb. In the stimulation group, the tails of the dogs were clamped for 5 min after 45 min of propofol infusion. Blood samples were taken from the internal carotid artery and internal jugular vein at 50 min after propofol infusion to detect plasma propofol concentrations by high-pressure liquid chromatography (HPLC). The dogs were then immediately sacrificed by decapitation and the frontal horn, posterior horn, intermediate zone, frontal funiculus, posterior funiculus and lateral funiculus of the spinal cord were dissected for determination of propol content by HPLC. The plasma concentrations of propofol in the internal carotid artery and internal jugular vein were 5.07-/+0.23 and 5.03-/+0.10 microg/ml in the stimulation group, respectively showing no significant differences from those in the control group (5.09-/+0.03 and 5.08-/+0.03 microg/ml, P>0.05). In the control group, the propofol concentration was 5.09-/+0.08 microg/g in the frontal horm, 5.10-/+0.08 microg/g in the posterior horn, 5.05-/+0.19 microg/g in the intermediate zone, 5.06-/+0.14 microg/g in the frontal funiculus, 5.06-/+0.15 microg/g in the posterior funiculus and 5.06-/+0.41 microg/g in the lateral funiculus, showing no significant differences (P>0.05). The propofol concentrations in the frontal horn (7.65-/+0.47 microg/g) and posterior funiculus (7.06-/+0.82 microg/g) in the stimulation group were significantly higher than those in the other spinal cord tissues (P<0.05) and those in the control group (P<0.05). At 50 min after intravenous injection of

  19. Noxious compounds activate TRPA1 ion channels through covalent modification of cysteines.

    PubMed

    Macpherson, Lindsey J; Dubin, Adrienne E; Evans, Michael J; Marr, Felix; Schultz, Peter G; Cravatt, Benjamin F; Patapoutian, Ardem

    2007-02-01

    The nervous system senses peripheral damage through nociceptive neurons that transmit a pain signal. TRPA1 is a member of the Transient Receptor Potential (TRP) family of ion channels and is expressed in nociceptive neurons. TRPA1 is activated by a variety of noxious stimuli, including cold temperatures, pungent natural compounds, and environmental irritants. How such diverse stimuli activate TRPA1 is not known. We observed that most compounds known to activate TRPA1 are able to covalently bind cysteine residues. Here we use click chemistry to show that derivatives of two such compounds, mustard oil and cinnamaldehyde, covalently bind mouse TRPA1. Structurally unrelated cysteine-modifying agents such as iodoacetamide (IA) and (2-aminoethyl)methanethiosulphonate (MTSEA) also bind and activate TRPA1. We identified by mass spectrometry fourteen cytosolic TRPA1 cysteines labelled by IA, three of which are required for normal channel function. In excised patches, reactive compounds activated TRPA1 currents that were maintained at least 10 min after washout of the compound in calcium-free solutions. Finally, activation of TRPA1 by disulphide-bond-forming MTSEA is blocked by the reducing agent dithiothreitol (DTT). Collectively, our data indicate that covalent modification of reactive cysteines within TRPA1 can cause channel activation, rapidly signalling potential tissue damage through the pain pathway.

  20. Greenhouse Gas and Noxious Emissions from Dual Fuel Diesel and Natural Gas Heavy Goods Vehicles.

    PubMed

    Stettler, Marc E J; Midgley, William J B; Swanson, Jacob J; Cebon, David; Boies, Adam M

    2016-02-16

    Dual fuel diesel and natural gas heavy goods vehicles (HGVs) operate on a combination of the two fuels simultaneously. By substituting diesel for natural gas, vehicle operators can benefit from reduced fuel costs and as natural gas has a lower CO2 intensity compared to diesel, dual fuel HGVs have the potential to reduce greenhouse gas (GHG) emissions from the freight sector. In this study, energy consumption, greenhouse gas and noxious emissions for five after-market dual fuel configurations of two vehicle platforms are compared relative to their diesel-only baseline values over transient and steady state testing. Over a transient cycle, CO2 emissions are reduced by up to 9%; however, methane (CH4) emissions due to incomplete combustion lead to CO2e emissions that are 50-127% higher than the equivalent diesel vehicle. Oxidation catalysts evaluated on the vehicles at steady state reduced CH4 emissions by at most 15% at exhaust gas temperatures representative of transient conditions. This study highlights that control of CH4 emissions and improved control of in-cylinder CH4 combustion are required to reduce total GHG emissions of dual fuel HGVs relative to diesel vehicles.

  1. The capsaicin receptor TRPV1 is a crucial mediator of the noxious effects of mustard oil.

    PubMed

    Everaerts, Wouter; Gees, Maarten; Alpizar, Yeranddy A; Farre, Ricard; Leten, Cindy; Apetrei, Aurelia; Dewachter, Ilse; van Leuven, Fred; Vennekens, Rudi; De Ridder, Dirk; Nilius, Bernd; Voets, Thomas; Talavera, Karel

    2011-02-22

    Mustard oil (MO) is a plant-derived irritant that has been extensively used in experimental models to induce pain and inflammation. The noxious effects of MO are currently ascribed to specific activation of the cation channel TRPA1 in nociceptive neurons. In contrast to this view, we show here that the capsaicin receptor TRPV1 has a surprisingly large contribution to aversive and pain responses and visceral irritation induced by MO. Furthermore, we found that this can be explained by previously unknown properties of this compound. First, MO has a bimodal effect on TRPA1, producing current inhibition at millimolar concentrations. Second, it directly and stably activates mouse and human recombinant TRPV1, as well as TRPV1 channels in mouse sensory neurons. Finally, physiological temperatures enhance MO-induced TRPV1 stimulation. Our results refute the dogma that TRPA1 is the sole nocisensor for MO and motivate a revision of the putative roles of these channels in models of MO-induced pain and inflammation. We propose that TRPV1 has a generalized role in the detection of irritant botanical defensive traits and in the coevolution of multiple mammalian and plant species.

  2. The Scalp Confounds Near-Infrared Signal from Rat Brain Following Innocuous and Noxious Stimulation

    PubMed Central

    He, Ji-Wei; Liu, Hanli; Peng, Yuan Bo

    2015-01-01

    Functional near-infrared imaging (fNIRI) is a non-invasive, low-cost and highly portable technique for assessing brain activity and functions. Both clinical and experimental evidence suggest that fNIRI is able to assess brain activity at associated regions during pain processing, indicating a strong possibility of using fNIRI-derived brain activity pattern as a biomarker for pain. However, it remains unclear how, especially in small animals, the scalp influences fNIRI signal in pain processing. Previously, we have shown that the use of a multi-channel system improves the spatial resolution of fNIRI in rats (without the scalp) during pain processing. Our current work is to investigate a scalp effect by comparing with new data from rats with the scalp during innocuous or noxious stimulation (n = 6). Results showed remarkable stimulus-dependent differences between the no-scalp and intact-scalp groups. In conclusion, the scalp confounded the fNIRI signal in pain processing likely via an autonomic mechanism; the scalp effect should be a critical factor in image reconstruction and data interpretation. PMID:26426058

  3. Optimal echo time for functional MRI of the infant brain identified in response to noxious stimulation

    PubMed Central

    Goksan, Sezgi; Hartley, Caroline; Hurley, Samuel A.; Winkler, Anderson M.; Duff, Eugene P.; Jenkinson, Mark; Rogers, Richard; Clare, Stuart

    2016-01-01

    Purpose Blood oxygen level dependent (BOLD) brain activity, measured using functional MRI (fMRI), is dependent on the echo time (TE) and the reversible spin–spin relaxation time constant ( T2*) that describes the decay of transverse magnetization. Use of the optimal TE during fMRI experiments allows maximal sensitivity to BOLD to be achieved. Reports that T2* values are longer in infants (due to higher water concentrations and lower lipid content) have led to the use of longer TEs during infant fMRI experiments; however, the optimal TE has not been established. Methods In this study, acute experimental mildly noxious stimuli were applied to the heel in 12 term infants (mean gestational age = 40 weeks, mean postnatal age = 3 days); and the percentage change in BOLD activity was calculated across a range of TEs, from 30 to 70 ms, at 3 Tesla. In addition, T2* maps of the whole brain were collected in seven infants. Results The maximal change in BOLD occurred at a TE of 52 ms, and the average T2* across the whole brain was 99 ms. Conclusion A TE of approximately 50 ms is recommended for use in 3T fMRI investigations in term infants. Magn Reson Med 78:625–631, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. PMID:27654315

  4. Review on hazardous and noxious substances (HNS) involved in marine spill incidents—an online database.

    PubMed

    Cunha, Isabel; Moreira, Susana; Santos, Miguel M

    2015-03-21

    In this review, we have collected information on the behavior, fate, weathering, and impact of hazardous and noxious substances (HNS) accidentally spilled at sea on the marine biota. The information was compiled on a datasheet and converted into a database that can be accessed by the general public (www.ciimar.up.pt/hns). Systematization of data is important to assist stakeholders involved in HNS spill preparedness and response, facilitating the incorporation of lessons from past incidents in the decision process. The database contains 184 entries of HNS spilled in 119 incidents in marine waters around the world. Data were analyzed in terms of HNS physical behavior in water according to SEBC (Standard European Behavior Classification) codes. The most common products involved in accidental spills in the marine environment were identified and major lessons highlighted. From the analysis, it was determined that most HNS spills were poorly documented and information was mistreated. In most cases, no monitoring programs were implemented following the incident. This conduct has occurred in 24 out of 119 incidents analyzed and has consequently limited the information on fate, behavior, and weathering of HNS spilled that could have been recovered. Major gaps were identified, and priorities and recommendations were drawn as a step toward improving preparedness and response to HNS spills.

  5. Preprotachykinin A is expressed by a distinct population of excitatory neurons in the mouse superficial spinal dorsal horn including cells that respond to noxious and pruritic stimuli

    PubMed Central

    Gutierrez-Mecinas, Maria; Bell, Andrew M.; Marin, Alina; Taylor, Rebecca; Boyle, Kieran A.; Furuta, Takahiro; Watanabe, Masahiko; Polgár, Erika; Todd, Andrew J.

    2016-01-01

    Abstract The superficial dorsal horn, which is the main target for nociceptive and pruritoceptive primary afferents, contains a high density of excitatory interneurons. Our understanding of their roles in somatosensory processing has been restricted by the difficulty of distinguishing functional populations among these cells. We recently defined 3 nonoverlapping populations among the excitatory neurons, based on the expression of neurotensin, neurokinin B, and gastrin-releasing peptide. Here we identify and characterise another population: neurons that express the tachykinin peptide substance P. We show with immunocytochemistry that its precursor protein (preprotachykinin A, PPTA) can be detected in ∼14% of lamina I-II neurons, and these are concentrated in the outer part of lamina II. Over 80% of the PPTA-positive cells lack the transcription factor Pax2 (which determines an inhibitory phenotype), and these account for ∼15% of the excitatory neurons in this region. They are different from the neurotensin, neurokinin B, or gastrin-releasing peptide neurons, although many of them contain somatostatin, which is widely expressed among superficial dorsal horn excitatory interneurons. We show that many of these cells respond to noxious thermal and mechanical stimuli and to intradermal injection of pruritogens. Finally, we demonstrate that these cells can also be identified in a knock-in Cre mouse line (Tac1Cre), although our findings suggest that there is an additional population of neurons that transiently express PPTA. This population of substance P–expressing excitatory neurons is likely to play an important role in the transmission of signals that are perceived as pain and itch. PMID:27902570

  6. Predicting value of pain and analgesia: nucleus accumbens response to noxious stimuli changes in the presence of chronic pain

    PubMed Central

    Baliki, M.N.; Geha, P.Y.; Fields, H.L.; Apkarian, A.V.

    2010-01-01

    We compared brain activations in response to acute noxious thermal stimuli in controls and chronic back pain (CBP) patients. Pain perception and related cortical activation patterns were similar in the two groups. However, nucleus accumbens (NAc) activity differentiated the groups at a very high accuracy, exhibiting phasic and tonic responses with distinct properties. Positive phasic NAc activations at stimulus onset and offset tracked stimulus salience and, in normal subjects predicted reward (pain relief) magnitude at stimulus offset. In CBP, NAc activity correlated with different cortical circuitry than normals and phasic activity at stimulus offset was negative in polarity, suggesting that the acute pain relieves the ongoing back pain. The relieving effect was confirmed in a separate psychophysical study in CBP. Therefore, in contrast to somatosensory pathways, which reflect sensory properties of acute noxious stimuli, NAc activity in humans encodes its predicted value and predicts its analgesic potential on chronic pain. PMID:20399736

  7. Encoding noxious heat by spike bursts of antennal bimodal hygroreceptor (dry) neurons in the carabid Pterostichus oblongopunctatus.

    PubMed

    Must, Anne; Merivee, Enno; Nurme, Karin; Sibul, Ivar; Muzzi, Maurizio; Di Giulio, Andrea; Williams, Ingrid; Tooming, Ene

    2016-12-28

    Despite thermosensation being crucial in effective thermoregulation behaviour, it is poorly studied in insects. Very little is known about encoding of noxious high temperatures by peripheral thermoreceptor neurons. In carabids, thermo- and hygrosensitive neurons innervate antennal dome-shaped sensilla (DSS). In this study, we demonstrate that several essential fine structural features of dendritic outer segments of the sensory neurons in the DSS and the classical model of insect thermo- and hygrosensitive sensilla differ fundamentally. Here, we show that spike bursts produced by the bimodal dry neurons in the antennal DSS may contribute to the sensation of noxious heat in P. oblongopunctatus. Our electrophysiological experiments showed that, at temperatures above 25 °C, these neurons switch from humidity-dependent regular spiking to temperature-dependent spike bursting. Five out of seven measured parameters of the bursty spike trains, the percentage of bursty dry neurons, the CV of ISIs in a spike train, the percentage of bursty spikes, the number of spikes in a burst and the ISIs in a burst, are unambiguously dependent on temperature and thus may precisely encode both noxious high steady temperatures up to 45 °C as well as rapid step-changes in it. The cold neuron starts to produce temperature-dependent spike bursts at temperatures above 30-35 °C. Thus, the two neurons encode different but largely overlapping ranges in noxious heat. The extent of dendritic branching and lamellation of the neurons largely varies in different DSS, which might be the structural basis for their variation in threshold temperatures for spike bursting.

  8. Transient receptor potential ankyrin 1 antagonists block the noxious effects of toxic industrial isocyanates and tear gases

    PubMed Central

    Bessac, Bret F.; Sivula, Michael; von Hehn, Christian A.; Caceres, Ana I.; Escalera, Jasmine; Jordt, Sven-Eric

    2009-01-01

    The release of methyl isocyanate in Bhopal, India, caused the worst industrial accident in history. Exposures to industrial isocyanates induce lacrimation, pain, airway irritation, and edema. Similar responses are elicited by chemicals used as tear gases. Despite frequent exposures, the biological targets of isocyanates and tear gases in vivo have not been identified, precluding the development of effective countermeasures. We use Ca2+ imaging and electrophysiology to show that the noxious effects of isocyanates and those of all major tear gas agents are caused by activation of Ca2+ influx and membrane currents in mustard oil-sensitive sensory neurons. These responses are mediated by transient receptor potential ankyrin 1 (TRPA1), an ion channel serving as a detector for reactive chemicals. In mice, genetic ablation or pharmacological inhibition of TRPA1 dramatically reduces isocyanate- and tear gas-induced nocifensive behavior after both ocular and cutaneous exposures. We conclude that isocyanates and tear gas agents target the same neuronal receptor, TRPA1. Treatment with TRPA1 antagonists may prevent and alleviate chemical irritation of the eyes, skin, and airways and reduce the adverse health effects of exposures to a wide range of toxic noxious chemicals.—Bessac, B. F., Sivula, M., von Hehn, C. A., Caceres, A. I., Escalera, J., Jordt, S.-E. Transient receptor potential ankyrin 1 antagonists block the noxious effects of toxic industrial isocyanates and tear gases. PMID:19036859

  9. Developmental changes in the electroencephalogram and responses to a noxious stimulus in anaesthetized tammar wallaby joeys (Macropus eugenii eugenii).

    PubMed

    Diesch, T J; Mellor, D J; Johnson, C B; Lentle, R G

    2010-04-01

    The tammar wallaby joey is born extremely immature and most of its neurological development occurs in the maternal pouch. It is not known at what in-pouch age functions such as conscious sensory perception commence. We determined the electroencephalographic (EEG) responses to noxious stimulation in lightly anaesthetized tammar wallaby joeys. Baseline median (F50) and spectral edge (F95) frequencies, total power (Ptot) and frequency spectra between 1 and 30 Hz of the EEG power spectrum were determined. Joeys aged less than 127 days showed little or no EEG activity. Prolonged periods of spontaneous EEG activity were present by 142 days. This activity increased, as did the power in all frequencies, while the duration of any intervening isoelectric periods decreased with increasing in-pouch age. EEG responses to a noxious stimulus (toe clamping) changed with increasing in-pouch age as there was no response from joeys aged 94-127 days (no EEG), a minimal decrease in the F50 in those aged between 142 and 181 days (P = 0.052) and a greater decrease in the F50 in those aged between 187 and 261 days (P < 0.001). The pattern of these changes, which presumably reflects anatomical and functional maturation of the cerebral cortex, is similar to, but develops more slowly than, that reported in the rat. The opening of the eyes and development of the pelage are discussed as markers of when brain development may be sufficient for joeys to consciously perceive noxious sensations including pain.

  10. Neonatal capsaicin treatment in rats affects TRPV1-related noxious heat sensation and circadian body temperature rhythm.

    PubMed

    Jeong, Keun-Yeong; Seong, Jinsil

    2014-06-15

    The transient receptor potential vanilloid 1 (TRPV1) is a cation channel that serves as a polymodal detector of noxious stimuli such as capsaicin. Therefore, capsaicin treatment has been used to investigate the physiological function of TRPV1. Here, we report physiological changes induced by treating neonatal rats with capsaicin. Capsaicin (50mg/kg) (cap-treated) or vehicle (vehicle-treated) was systemically administered to newborn SD rat pups within 48 h after birth. TRPV1 expression, intake volume of capsaicin water, and noxious heat sensation were measured 6 weeks after capsaicin treatment. Circadian body temperature and locomotion were recorded by biotelemetry. Expression of Per1, Per2, Bmal1 and Hsf1 (clock genes) was also investigated. Neonatal capsaicin treatment not only decreased TRPV1 expression but also induced desensitization to noxious heat stimuli. Circadian body temperature of cap-treated rats increased significantly compared with that of vehicle-treated rats. Additionally, the amplitude of the circadian body temperature was reversed in cap-treated rats. Expression of the hypothalamic Hsf1 and liver Per2 clock genes followed a similar trend. Therefore, we suggest that these findings will be useful in studying various physiological mechanisms related to TRPV1. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Effects of heterotopic noxious stimuli on activity of neurones in subnucleus reticularis dorsalis in the rat medulla.

    PubMed Central

    Villanueva, L; Bing, Z; Le Bars, D

    1994-01-01

    1. In anaesthetized rats, recordings were made in the medullary subnucleus reticularis dorsalis. Neurones with total nociceptive convergence (TNC) responded to percutaneous electrical stimuli with early and late peaks due to the activation of A delta and C fibres respectively, no matter which part of the body was stimulated. Neurones with partial nociceptive convergence (PNC) responded with an A delta peak regardless of which part of the body was stimulated, and with a C peak of activation from some, mainly contralateral, parts of the body. 2. All TNC neurones responded to noxious thermal stimulation of the limbs with a phasic discharge followed by tonic activity that lasted throughout the stimulation. Discharges elicited by applying stimuli simultaneously to both forepaws or to a hindpaw and a forepaw were lower than the individual responses to stimulation of a single limb. Similar negative interactions were observed in the responses of PNC neurones following noxious thermal stimulation of two paws. 3. In both neuronal populations, the simultaneous application of noxious thermal stimuli and microelectrophoretic application of D,L-homocysteic acid (DLH) induced responses of greater magnitude than those evoked by each stimulus alone. 4. TNC neurones responded to electrical stimulation of the contralateral hindpaw with A delta and C fibre responses. Noxious thermal stimuli applied to different areas of the body induced an excitatory response during the period that preceded the electrical stimulation, but an inhibition of both A delta and C fibre responses. By contrast, using a similar protocol, application of DLH induced a steady discharge in the period preceding the electrical stimulation and also in between the A delta and C fibre responses, which were not themselves inhibited. 5. The negative heterotopic influences in normal rats during simultaneous immersion of the ipsi- and contralateral hindpaws was strongly reduced in rats with bilateral lesions of the

  12. Activated platelets release sphingosine 1-phosphate and induce hypersensitivity to noxious heat stimuli in vivo

    PubMed Central

    Weth, Daniela; Benetti, Camilla; Rauch, Caroline; Gstraunthaler, Gerhard; Schmidt, Helmut; Geisslinger, Gerd; Sabbadini, Roger; Proia, Richard L.; Kress, Michaela

    2015-01-01

    At the site of injury activated platelets release various mediators, one of which is sphingosine 1-phosphate (S1P). It was the aim of this study to explore whether activated human platelets had a pronociceptive effect in an in vivo mouse model and whether this effect was based on the release of S1P and subsequent activation of neuronal S1P receptors 1 or 3. Human platelets were prepared in different concentrations (105/μl, 106/μl, 107/μl) and assessed in mice with different genetic backgrounds (WT, S1P1fl/fl, SNS-S1P1−/−, S1P3−/−). Intracutaneous injections of activated human platelets induced a significant, dose-dependent hypersensitivity to noxious thermal stimulation. The degree of heat hypersensitivity correlated with the platelet concentration as well as the platelet S1P content and the amount of S1P released upon platelet activation as measured with LC MS/MS. Despite the significant correlations between S1P and platelet count, no difference in paw withdrawal latency (PWL) was observed in mice with a global null mutation of the S1P3 receptor or a conditional deletion of the S1P1 receptor in nociceptive primary afferents. Furthermore, neutralization of S1P with a selective anti-S1P antibody did not abolish platelet induced heat hypersensitivity. Our results suggest that activated platelets release S1P and induce heat hypersensitivity in vivo. However, the platelet induced heat hypersensitivity was caused by mediators other than S1P. PMID:25954148

  13. NMDA receptor mediates chronic visceral pain induced by neonatal noxious somatic stimulation.

    PubMed

    Miranda, Adrian; Mickle, Aaron; Bruckert, Mitchell; Kannampalli, Pradeep; Banerjee, Banani; Sengupta, Jyoti N

    2014-12-05

    NMDA receptors (NMDAR) are important in the development and maintenance of central sensitization. Our objective was to investigate the role of spinal neurons and NMDAR in the maintenance of chronic visceral pain. Neonatal rats were injected with acidic saline adjusted to pH 4.0 in the gastrocnemius muscle every other day for 12 days. In adult rats, NR1 and NR2B subunits were examined in the lumbo-sacral (LS) spinal cord. A baseline, visceromotor response (VMR) to graded colorectal distension (CRD) was recorded before and after administration of the NMDA antagonist, CGS-19755. Extracellular recordings were performed from CRD-sensitive LS spinal neurons and pelvic nerve afferents (PNA) before and after CGS-19755. Rats that received pH 4.0 saline injections demonstrated a significant increase in the expression NR2B subunits and VMR response to CRD>20 mmHg. CGS-19755 (i.v. or i.t.) had no effect in naïve rats, but significantly decreased the response to CRD in pH 4.0 saline injected rats. CGS-19755 had no effect on the spontaneous firing of SL-A, but decreased that of SL-S. Similarly, CGS-19755 attenuates the responses of SL-S neurons to CRD, but had no effect on SL-A neurons or on the response characteristics of PNA fibers. Neonatal noxious somatic stimulation results in chronic visceral hyperalgesia and sensitizes a specific subpopulation of CRD-sensitive spinal neurons. The sensitization of these SL-S spinal neurons is attenuated by the NMDAR antagonist. The results of this study suggest that spinal NMDARs play an important role in the development of hyperalgesia early in life. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Light spectrum regulates cell accumulation during daytime in the raphidophyte Chattonella antiqua causing noxious red tides.

    PubMed

    Shikata, Tomoyuki; Matsunaga, Shigeru; Kuwahara, Yusuke; Iwahori, Sho; Nishiyama, Yoshitaka

    2016-07-01

    Most marine raphidophyte species cause noxious red tides in temperate coastal areas around the world. It is known that swimming abilities enable raphidophytes to accumulation of cells and to actively acquire light at surface layers and nutrients over a wide depth range. However, it remains unclear how the swimming behavior is affected by environmental conditions, especially light condition. In the present study, we observed the accumulation of the harmful red-tide raphidophyte Chattonella antiqua under various light conditions during the daytime in the laboratory. When exposed to ultraviolet-A/blue light (320-480nm) or red light (640-680nm) from above, cells moved downward. In the case of blue light (455nm), cells started to swim downward after 5-15min of irradiation at a photon flux density≥10μmolm(-2)s(-1). When exposed to monochromatic lights (400-680nm) from the side, cells moved away from the blue light source and then descended, but just moved downward under red light. However, mixing of green/orange light (520-630nm) diminished the effects of blue light. When exposed to a mixture of 30μmolm(-2)s(-1) of blue light (440nm) and ≥6μmolm(-2)s(-1) of yellow light (560nm) from above, cells did not move downward. These results indicate that blue light induces negative phototaxis and ultraviolet-A/blue and red lights induce descending, and green/orange light cancels out their effects in C. antiqua.

  15. NMDA receptor mediates chronic visceral pain induced by neonatal noxious somatic stimulation

    PubMed Central

    Miranda, Adrian; Mickle, Aaron; Bruckert, Mitchell; Kannampalli, Pradeep; Banerjee, Banani; Sengupta, Jyoti N.

    2014-01-01

    NMDA receptors (NMDAR) are important in the development and maintenance of central sensitization. Our objective was to investigate the role of spinal neurons and NMDAR in the maintenance of chronic visceral pain. Neonatal rats were injected with acidic saline adjusted to pH4.0 in the gastrocnemius muscle every other day for 12 days. In adult rats, NR1 and NR2B subunits were examined in the lumbo-sacral (LS) spinal cord. A baseline, visceromotor response (VMR) to graded colorectal distension (CRD) was recorded before and after administration of the NMDA antagonist, CGS-19755. Extracellular recordings were performed from CRD-sensitive LS spinal neurons and pelvic nerve afferents (PNA) before and after CGS-19755. Rats that received pH 4.0 saline injections demonstrated a significant increase in the expression NR2B subunits and VMR response to CRD >20mmHg. CGS-19755 (i.v. or i.t.) had no effect in naïve rats, but significantly decreased the response to CRD in pH4.0 saline injected rats. CGS-19755 had no effect on the spontaneous firing of SL-A, but decreased that of SL-S. Similarly, CGS-19755 attenuates the responses of SL-S neurons to CRD, but had no effect on SL-A neurons or on the response characteristics of PNA fibers. Neonatal noxious somatic stimulation results in chronic visceral hyperalgesia and sensitizes a specific subpopulation of CRD-sensitive spinal neurons. The sensitization of these SL-S spinal neurons is attenuated by the NMDAR antagonist. The results of this study suggest that spinal NMDARs play an important role in the development of hyperalgesia early in life. PMID:25281204

  16. Astaxanthin Protects Primary Hippocampal Neurons against Noxious Effects of Aβ-Oligomers

    PubMed Central

    Lobos, Pedro; Bruna, Barbara; Cordova, Alex; Barattini, Pablo; Galáz, Jose Luis; Adasme, Tatiana; Hidalgo, Cecilia; Muñoz, Pablo

    2016-01-01

    Increased reactive oxygen species (ROS) generation and the ensuing oxidative stress contribute to Alzheimer's disease pathology. We reported previously that amyloid-β peptide oligomers (AβOs) produce aberrant Ca2+ signals at sublethal concentrations and decrease the expression of type-2 ryanodine receptors (RyR2), which are crucial for hippocampal synaptic plasticity and memory. Here, we investigated whether the antioxidant agent astaxanthin (ATX) protects neurons from AβOs-induced excessive mitochondrial ROS generation, NFATc4 activation, and RyR2 mRNA downregulation. To determine mitochondrial H2O2 production or NFATc4 nuclear translocation, neurons were transfected with plasmids coding for HyperMito or NFATc4-eGFP, respectively. Primary hippocampal cultures were incubated with 0.1 μM ATX for 1.5 h prior to AβOs addition (500 nM). We found that incubation with ATX (≤10 μM) for ≤24 h was nontoxic to neurons, evaluated by the live/dead assay. Preincubation with 0.1 μM ATX also prevented the neuronal mitochondrial H2O2 generation induced within minutes of AβOs addition. Longer exposures to AβOs (6 h) promoted NFATc4-eGFP nuclear translocation and decreased RyR2 mRNA levels, evaluated by detection of the eGFP-tagged fluorescent plasmid and qPCR, respectively. Preincubation with 0.1 μM ATX prevented both effects. These results indicate that ATX protects neurons from the noxious effects of AβOs on mitochondrial ROS production, NFATc4 activation, and RyR2 gene expression downregulation. PMID:27034843

  17. Thalamic Kv7 channels: pharmacological properties and activity control during noxious signal processing

    PubMed Central

    Cerina, Manuela; Szkudlarek, Hanna J; Coulon, Philippe; Meuth, Patrick; Kanyshkova, Tatyana; Nguyen, Xuan Vinh; Göbel, Kerstin; Seidenbecher, Thomas; Meuth, Sven G; Pape, Hans-Christian; Budde, Thomas

    2015-01-01

    Background and Purpose The existence of functional Kv7 channels in thalamocortical (TC) relay neurons and the effects of the K+-current termed M-current (IM) on thalamic signal processing have long been debated. Immunocytochemical evidence suggests their presence in this brain region. Therefore, we aimed to verify their existence, pharmacological properties and function in regulating activity in neurons of the ventrobasal thalamus (VB). Experimental Approach Characterization of Kv7 channels was performed by combining in vitro, in vivo and in silico techniques with a pharmacological approach. Retigabine (30 μM) and XE991 (20 μM), a specific Kv7 channel enhancer and blocker, respectively, were applied in acute brain slices during electrophysiological recordings. The effects of intrathalamic injection of retigabine (3 mM, 300 nL) and/or XE991 (2 mM, 300 nL) were investigated in freely moving animals during hot-plate tests by recording behaviour and neuronal activity. Key Results Kv7.2 and Kv7.3 subunits were found to be abundantly expressed in TC neurons of mouse VB. A slow K+-current with properties of IM was activated by retigabine and inhibited by XE991. Kv7 channel activation evoked membrane hyperpolarization, a reduction in tonic action potential firing, and increased burst firing in vitro and in computational models. Single-unit recordings and pharmacological intervention demonstrated a specific burst-firing increase upon IM activation in vivo. A Kv7 channel-mediated increase in pain threshold was associated with fewer VB units responding to noxious stimuli, and increased burst firing in responsive neurons. Conclusions and Implications Kv7 channel enhancement alters somatosensory activity and may reflect an anti-nociceptive mechanism during acute pain processing. PMID:25684311

  18. Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent

    USGS Publications Warehouse

    González, Eduardo; Sher, Anna A.; Anderson, Robert M.; Bay, Robin F.; Bean, Daniel W.; Bissonnete, Gabriel J.; Cooper, David J.; Dohrenwend, Kara; Eichhorst, Kim D.; El Waer, Hisham; Kennard, Deborah K.; Harms-Weissinger, Rebecca; Henry, Annie L.; Makarick, Lori J.; Ostoja, Steven M.; Reynolds, Lindsay V.; Robinson, W. Wright; Shafroth, Patrick B.; Tabacchi, Erich

    2017-01-01

    Control of invasive species within ecosystems may induce secondary invasions of non-target invaders replacing the first alien. We used four plant species listed as noxious by local authorities in riparian systems to discern whether 1) the severity of these secondary invasions was related to the control method applied to the first alien; and 2) which species that were secondary invaders persisted over time. In a collaborative study by 16 research institutions, we monitored plant species composition following control of non-native Tamarix trees along southwestern U.S. rivers using defoliation by an introduced biocontrol beetle, and three physical removal methods: mechanical using saws, heavy machinery, and burning in 244 treated and 79 untreated sites across six U.S. states. Physical removal favored secondary invasions immediately after Tamarix removal (0–3 yrs.), while in the biocontrol treatment, secondary invasions manifested later (> 5 yrs.). Within this general trend, the response of weeds to control was idiosyncratic; dependent on treatment type and invader. Two annual tumbleweeds that only reproduce by seed (Bassia scoparia and Salsola tragus) peaked immediately after physical Tamarix removal and persisted over time, even after herbicide application. Acroptilon repens, a perennial forb that vigorously reproduces by rhizomes, and Bromus tectorum, a very frequent annual grass before removal that only reproduces by seed, were most successful at biocontrol sites, and progressively spread as the canopy layer opened. These results demonstrate that strategies to control Tamarix affect secondary invasions differently among species and that time since disturbance is an important, generally overlooked, factor affecting response.

  19. Dissection of perceptual, motor and autonomic components of brain activity evoked by noxious stimulation.

    PubMed

    Piché, M; Arsenault, M; Rainville, P

    2010-06-01

    In the past two decades, functional brain imaging has considerably advanced our knowledge of cerebral pain processing. However, many important links are still missing in our understanding of brain activity in relation to the regulation of pain-related physiological responses. This fMRI study investigates the cerebral correlates of pain (rating), motor responses (RIII-reflex) and autonomic activity (skin conductance response; SCR) evoked by noxious electrical stimulation. Stimulus intensity was adjusted individually based on the RIII threshold to control for differences in peripheral processes and baseline spinal activation. Covariance analyses were used to reveal individual differences in brain activity uniquely associated with individual differences in pain, RIII and SCR. Shock-evoked activity in cingulate, medial orbitofrontal and parahippocampal regions predicted pain sensitivity. Moreover, lateral orbitofrontal and cingulate areas showed strong positive associations with individual differences in motor reactivity but negative associations with autonomic reactivity. Notably, individual differences in OFC activation was almost fully accounted by the combination of individual measures of autonomic and motor reactivity (R(2)=0.93). Additionally, trial-to-trial fluctuations of RIII-reflex and SCR (within-subjects) were proportional to shock-evoked responses in subgenual cingulate cortex (RIII), anterior insula (SCR) and midcingulate cortex (SCR and RIII). Together, these results confirm that individual differences in perceptual, motor, and autonomic components of pain reflect robust individual differences in brain activity. Furthermore, the brain correlates of trial-to-trial fluctuations in pain responses provide additional evidence for a partial segregation of sub-systems involved more specifically in the ongoing monitoring, and possibly the regulation, of pain-related motor and autonomic responses.

  20. Leukemia inhibitory factor (LIF).

    PubMed

    Nicola, Nicos A; Babon, Jeffrey J

    2015-10-01

    Leukemia inhibitory factor (LIF) is the most pleiotropic member of the interleukin-6 family of cytokines. It utilises a receptor that consists of the LIF receptor β and gp130 and this receptor complex is also used by ciliary neurotrophic growth factor (CNTF), oncostatin M, cardiotrophin1 (CT1) and cardiotrophin-like cytokine (CLC). Despite common signal transduction mechanisms (JAK/STAT, MAPK and PI3K) LIF can have paradoxically opposite effects in different cell types including stimulating or inhibiting each of cell proliferation, differentiation and survival. While LIF can act on a wide range of cell types, LIF knockout mice have revealed that many of these actions are not apparent during ordinary development and that they may be the result of induced LIF expression during tissue damage or injury. Nevertheless LIF does appear to have non-redundant actions in maternal receptivity to blastocyst implantation, placental formation and in the development of the nervous system. LIF has also found practical use in the maintenance of self-renewal and totipotency of embryonic stem cells and induced pluripotent stem cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Leukemia Inhibitory Factor (LIF)

    PubMed Central

    Nicola, Nicos A; Babon, Jeffrey J

    2015-01-01

    Leukemia inhibitory factor (LIF) is the most pleiotropic member of the interleukin-6 family of cytokines. It utilises a receptor that consists of the LIF receptor β and gp130 and this receptor complex is also used by ciliary neurotrophic growth factor (CNTF), oncostatin M, cardiotrophin1 (CT1) and cardiotrophin-like cytokine (CLC). Despite common signal transduction mechanisms (JAK/STAT, MAPK and PI3K) LIF can have paradoxically opposite effects in different cell types including stimulating or inhibiting each of cell proliferation, differentiation and survival. While LIF can act on a wide range of cell types, LIF knockout mice have revealed that many of these actions are not apparent during ordinary development and that they may be the result of induced LIF expression during tissue damage or injury. Nevertheless LIF does appear to have non-redundant actions in maternal receptivity to blastocyst implantation, placental formation and in the development of the nervous system. LIF has also found practical use in the maintenance of self-renewal and totipotency of embryonic stem cells and induced pluripotent stem cells. PMID:26187859

  2. Diffusion MRI

    NASA Astrophysics Data System (ADS)

    Fukuyama, Hidenao

    Recent advances of magnetic resonance imaging have been described, especially stressed on the diffusion sequences. We have recently applied the diffusion sequence to functional brain imaging, and found the appropriate results. In addition to the neurosciences fields, diffusion weighted images have improved the accuracies of clinical diagnosis depending upon magnetic resonance images in stroke as well as inflammations.

  3. Perceptual and cerebro-spinal responses to graded innocuous and noxious stimuli following aerobic exercise.

    PubMed

    Micalos, P S; Harris, J; Drinkwater, E J; Cannon, J; Marino, F E

    2015-11-01

    The aim of this study was to evaluate the effect of aerobic exercise on perceptual and cerebro-spinal responses to graded electrocutaneous stimuli. The design comprised 2 x 30 min of cycling exercise at 30% and 70% of peak oxygen consumption (VO2 peak) on separate occasions in a counter-balanced order in 10 healthy participants. Assessment of nociceptive withdrawal reflex threshold (NWR-T), pain threshold (PT), and somatosensory evoked potentials (SEPs) to graded electrocutaneous stimuli were performed before and after exercise. Perceptual magnitude ratings and SEPs were compared at 30%PT, 60%PT, 100%PT before (Pre), 5 min after (Post1), and 15 min after (Post2) aerobic exercise. There was no difference in the NWR-T and the PT following exercise at 30% and 70% of VO2 peak. ANOVA for the perceptual response within pooled electrocutaneous stimuli show a significant main effect for time (F2,18=5.41, P=0.01) but no difference for exercise intensity (F1,9=0.02, P=0.88). Within-subject contrasts reveal trend differences between 30%PT and 100%PT for Pre-Post1 (P=0.09) and Pre-Post2 (P=0.02). ANOVA for the SEPs peak-to-peak signal amplitude (N1-P1) show significant main effect for time (F2,18=4.04, P=0.04) but no difference for exercise intensity (F1,9=1.83, P=0.21). Pairwise comparisons for time reveal differences between Pre-Post1 (P=0.06) and Pre-Post2 (P=0.01). There was a significant interaction for SEPs N1-P1 between exercise intensity and stimulus intensity (F2,18=3.56, P=0.05). These results indicate that aerobic exercise did not increase the electrocutaneous threshold for pain and the NWR-T. Aerobic exercise attenuated perceptual responses to innocuous stimuli and SEPs N1-P1 response to noxious stimuli.

  4. Inhibitory functioning in Alzheimer's disease.

    PubMed

    Amieva, Hélène; Phillips, Louise H; Della Sala, Sergio; Henry, Julie D

    2004-05-01

    We present a comprehensive review of studies assessing inhibitory functioning in Alzheimer's disease. The objectives of this review are: (i) to establish whether Alzheimer's disease affects all inhibitory mechanisms equally, and (ii) where possible, to assess whether any effects of Alzheimer's disease on inhibition tasks might be caused by other cognitive deficits, such as slowed processing. We review inhibitory mechanisms considered to play a crucial role in various domains of cognition, such as inhibition involved in working memory, selective attention and shifting abilities, and the inhibition of motor and verbal responses. It was found that whilst most inhibitory mechanisms are affected by the disorder, some are relatively preserved, suggesting that inhibitory deficits in Alzheimer's disease may not be the result of a general inhibitory breakdown. In particular, the experimental results reviewed showed that Alzheimer's disease has a strong effect on tasks requiring controlled inhibition processes, such as the Stroop task. However, the presence of the disease appears to have relatively little effect on tasks requiring more automatic inhibition, such as the inhibition of return task. Thus, the distinction between automatic, reflexive inhibitory mechanisms and controlled inhibitory mechanisms may be critical when predicting the integrity of inhibitory mechanisms in Alzheimer's disease. Substantial effects of Alzheimer's disease on tasks such as negative priming, which are not cognitively complex but do require some degree of controlled inhibition, support this hypothesis. A meta-analytic review of seven studies on the Stroop paradigm revealed substantially larger effects of Alzheimer's disease on the inhibition condition relative to the baseline condition, suggesting that these deficits do not simply reflect general slowing.

  5. Plasmapause diffusion

    NASA Technical Reports Server (NTRS)

    Horwitz, J. L.

    1983-01-01

    The Bohm diffusion coefficient and observed electrostatic wave scattering are used as the bases of estimates of the smoothing effect that diffusion may have on steep plasmapause density gradients. The estimate for diffusion resulting from scattering by observed electrostatic waves is found to be much lower than that of the perpendicular Bohm diffusion coefficient for characteristic plasma temperatures and magnetic fields. This diffusion rate estimate may be too small, however, if the wave amplitudes are significantly higher for steep plasmapauses. The effects are therefore negligible for most considerations of macroscopic plasmapause dynamics, but may be significant in limiting drift wave instabilities and similar phenomena driven by the steepness of the plasmapause density gradient.

  6. Inhibitory power of kefir: the role of organic acids.

    PubMed

    Garrote, G L; Abraham, A G; De Antoni, G L

    2000-03-01

    Milk and MRS broth fermented with kefir grains from different households were examined for inhibitory activity toward gram-negative and gram-positive strains. Fermented milk obtained with 10 g per 100 ml of inoculum (final pH 3.32 to 4.25) and MRS broth fermented with 1 and 10 g per 100 ml of inocula (final pH 4.18 to 5.25) had inhibitory power demonstrated by spot test and agar well diffusion assay. This inhibitory effect could be assigned to the undissociated form of lactic and acetic acid produced during the fermentation process. Kefir supernatants inhibited the growth of Escherichia coli 3 in nutrient broth at 37 degrees C for 24 h. However, supernatants of yogurt or milk artificially acidified with lactic and acetic acids allowed the growth of E. coli 3 in the same conditions. A bacteriostatic effect of milk fermented with kefir grains over E. coli 3 was also demonstrated.

  7. Federal Interagency Coordination for Invasive Plant Issues -- The Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW)

    USGS Publications Warehouse

    Westbrooks, Randy G.

    2011-01-01

    The U.S. Federal Interagency Committee for the Management of Noxious and Exotic Weeds (FICMNEW) is a formal partnership between 16 federal agencies that have invasive plant management and regulatory responsibilities for the United States and its territories. Efforts to develop a national level federal interagency committee to coordinate federal activities were initiated by national weed program managers with the USDA Forest Service and the Bureau of Land Management in 1989. FICMNEW was formally established through a Memorandum of Understanding that was signed by agency administrators of member agencies in August, 1994.

  8. Griffith diffusers

    NASA Technical Reports Server (NTRS)

    Yang, T.-T.; Nelson, C. D.

    1979-01-01

    Contoured wall diffusers are designed by using an inverse method. The prescribed wall velocity distribution(s) was taken from the high lift airfoil designed by A. A. Griffith in 1938; therefore, such diffusers are named Griffith diffusers. First the formulation of the inverse problem and the method of solution are outlined. Then the typical contour of a two-dimensional diffuser and velocity distributions across the flow channel at various stations are presented. For a Griffith diffuser to operate as it is designed, boundary layer suction is necessary. Discussion of the percentage of through-flow required to be removed for the purpose of boundary layer control is given. Finally, reference is made to the latest version of a computer program for a two-dimensional diffuser requiring only area ratio, nondimensional length and suction percentage as inputs.

  9. Griffith diffusers

    NASA Technical Reports Server (NTRS)

    Yang, T.-T.; Nelson, C. D.

    1979-01-01

    Contoured wall diffusers are designed by using an inverse method. The prescribed wall velocity distribution(s) was taken from the high lift airfoil designed by A. A. Griffith in 1938; therefore, such diffusers are named Griffith diffusers. First the formulation of the inverse problem and the method of solution are outlined. Then the typical contour of a two-dimensional diffuser and velocity distributions across the flow channel at various stations are presented. For a Griffith diffuser to operate as it is designed, boundary layer suction is necessary. Discussion of the percentage of through-flow required to be removed for the purpose of boundary layer control is given. Finally, reference is made to the latest version of a computer program for a two-dimensional diffuser requiring only area ratio, nondimensional length and suction percentage as inputs.

  10. Effect of fermented medicinal plants on growth performance, nutrient digestibility, fecal noxious gas emissions, and diarrhea score in weanling pigs.

    PubMed

    Zhao, Pinyao; Li, Hanlin; Lei, Yan; Li, Tianshui; Kim, Sunki; Kim, Inho

    2016-03-15

    Antibiotics used as growth promoters in livestock have been banned in the European Union since 2006. Alternatives of antibiotics have focused on phytogenic plants, such as herbs and medicinal plants. No studies have evaluated the use of fermented medicinal plants (FMP) made up of Gynura procumbens, Rehmannia glutinosa and Scutellaria baicalensis in weanling pigs. Therefore, an experiment was conducted to determine the effects of FMP on growth performance, nutrient digestibility, fecal noxious gas emissions and diarrhea score in weanling pigs. FMP supplementation increased (P < 0.05) average daily gain, average daily feed intake, gain:feed, apparent total tract digestibility of dry matter, nitrogen and gross energy compared with NC treatment, while a linear effect (P < 0.05) was observed on those criteria. Ammonia, total mercaptans and hydrogen sulfide concentrations were decreased (P < 0.05) by the supplementation of FMP compared with NC. Additionally, diarrhea score was lower (P < 0.05) by FMP addition compared with NC during days 0-7 and days 8-14. These results suggested that FMP could be used as an alternative to antibiotics by enhancing growth performance and nutrient digestibility, and decreasing fecal noxious gas emission and early diarrhea score of weanling pigs. © 2015 Society of Chemical Industry.

  11. Intrathecal oxytocin inhibits visceromotor reflex and spinal neuronal responses to noxious distention of the rat urinary bladder.

    PubMed

    Engle, Mitchell P; Ness, Timothy J; Robbins, Meredith T

    2012-01-01

    Oxytocin (OXY) is a neuropeptide that has recently been recognized as an important component of descending analgesic systems. The present study sought to determine if OXY produces antinociception to noxious visceral stimulation. Urethane-anesthetized female rats had intrathecal catheters placed acutely, and the effect of intrathecal OXY on visceromotor reflexes (VMRs; abdominal muscular contractions quantified using electromyograms) to urinary bladder distension (UBD; 10-60 mm Hg, 20 seconds; transurethral intravesical catheter) was determined. The effect of OXY applied to the surface of exposed spinal cord was determined in lumbosacral dorsal horn neurons excited by UBD using extracellular recordings. Oxytocin doses of 0.15 or 1.5 μg inhibited VMRs to UBD by 37% ± 8% and 68% ± 10%, respectively. Peak inhibition occurred within 30 minutes and was sustained for at least 60 minutes. The effect of OXY was both reversed and prevented by the intrathecal administration of an OXY-receptor antagonist. Application of 0.5 mM OXY to the dorsum of the spinal cord inhibited UBD-evoked action potentials by 76% ± 12%. Consistent with the VMR studies, peak inhibition occurred within 30 minutes and was sustained for greater than 60 minutes. These results argue that intrathecal OXY produces an OXY receptor-specific antinociception to noxious UBD, with part of this effect due to inhibition of spinal dorsal horn neurons. To our knowledge, these studies provide the first evidence that intrathecal OXY may be an effective pharmacological treatment for visceral pain.

  12. Efficacy of probiotics from anaerobic microflora with prebiotics on growth performance and noxious gas emission in growing pigs.

    PubMed

    Chu, Gyo Moon; Lee, Shin Ja; Jeong, Ho Sik; Lee, Sung Sill

    2011-04-01

    We investigated the effect of probiotics from anaerobic microflora with prebiotics (synbiotics) on growth performance, noxious gas emission and fecal pathogenic bacteria populations in growing pigs. The basal diet, which contained approximately 25% corn, 24% whey, 12% wheat and 12% soybean meal, was supplemented alternatively with 0.15% antibiotics (US diet), prebiotics and 0.2% probiotics from anaerobic bacteria (BS diet), yeast (YS diet), mold (MS diet) or compounds (CS diet). One hundred and fifty pigs were fed an experimental diet for 15 days. Although the growth performance was not affected by supplemental synbiotics, the BS group showed higher dry matter and crude protein digestibility. The BS group decreased fecal ammonia and amine gas emissions, and increased fecal acetate gas emission compared with the US group. All synbiotics groups decreased in fecal propionate gas emission. Fecal Escherichia coli population was lower in the synbiotics groups than in the US group. Therefore, the results of the present study suggest that synbiotics exert similar effects with antibiotics on the nutrient digestibility and fecal microflora composition in growing pigs. Moreover, synbiotics can also decrease the fecal noxious gas emission in growing pigs.

  13. Transient receptor potential ankyrin 1 antagonists block the noxious effects of toxic industrial isocyanates and tear gases.

    PubMed

    Bessac, Bret F; Sivula, Michael; von Hehn, Christian A; Caceres, Ana I; Escalera, Jasmine; Jordt, Sven-Eric

    2009-04-01

    The release of methyl isocyanate in Bhopal, India, caused the worst industrial accident in history. Exposures to industrial isocyanates induce lacrimation, pain, airway irritation, and edema. Similar responses are elicited by chemicals used as tear gases. Despite frequent exposures, the biological targets of isocyanates and tear gases in vivo have not been identified, precluding the development of effective countermeasures. We use Ca(2+) imaging and electrophysiology to show that the noxious effects of isocyanates and those of all major tear gas agents are caused by activation of Ca(2+) influx and membrane currents in mustard oil-sensitive sensory neurons. These responses are mediated by transient receptor potential ankyrin 1 (TRPA1), an ion channel serving as a detector for reactive chemicals. In mice, genetic ablation or pharmacological inhibition of TRPA1 dramatically reduces isocyanate- and tear gas-induced nocifensive behavior after both ocular and cutaneous exposures. We conclude that isocyanates and tear gas agents target the same neuronal receptor, TRPA1. Treatment with TRPA1 antagonists may prevent and alleviate chemical irritation of the eyes, skin, and airways and reduce the adverse health effects of exposures to a wide range of toxic noxious chemicals.

  14. Serotonin release in the central nucleus of the amygdala in response to noxious and innocuous cutaneous stimulation in anesthetized rats.

    PubMed

    Tokunaga, Ryota; Shimoju, Rie; Takagi, Noriaki; Shibata, Hideshi; Kurosawa, Mieko

    2016-07-01

    We investigated the effect of noxious (pinching) and innocuous (stroking) stimulation of skin on serotonin (5-HT) release in the central nucleus of the amygdala (CeA) in anesthetized rats. 5-HT in the CeA was collected by microdialysis methods. Dialysate output from consecutive 10-min periods was injected into a high-performance liquid chromatograph and 5-HT was measured with an electrochemical detector. Bilateral pinching of the back for 10 min increased 5-HT release significantly; 5-HT release was also increased with stimulation of the forelimb or hindlimb. In contrast, stroking of these areas decreased 5-HT release significantly. Furthermore, simultaneous stroking and pinching produced no change in the 5-HT release. In conclusion, the present study demonstrates that 5-HT release in the CeA is regulated by somatic afferent stimulation in a modality-dependent manner, and that innocuous stimulation can dampen the change in 5-HT release that occurs in response to noxious stimulation.

  15. Diffuse optical tomography activation in the somatosensory cortex: specific activation by painful vs. non-painful thermal stimuli.

    PubMed

    Becerra, Lino; Harris, Will; Grant, Margaret; George, Edward; Boas, David; Borsook, David

    2009-11-24

    Pain is difficult to assess due to the subjective nature of self-reporting. The lack of objective measures of pain has hampered the development of new treatments as well as the evaluation of current ones. Functional MRI studies of pain have begun to delineate potential brain response signatures that could be used as objective read-outs of pain. Using Diffuse Optical Tomography (DOT), we have shown in the past a distinct DOT signal over the somatosensory cortex to a noxious heat stimulus that could be distinguished from the signal elicited by innocuous mechanical stimuli. Here we further our findings by studying the response to thermal innocuous and noxious stimuli. Innocuous and noxious thermal stimuli were applied to the skin of the face of the first division (ophthalmic) of the trigeminal nerve in healthy volunteers (N = 6). Stimuli temperatures were adjusted for each subject to evoke warm (equivalent to a 3/10) and painful hot (7/10) sensations in a verbal rating scale (0/10 = no/max pain). A set of 26 stimuli (5 sec each) was applied for each temperature with inter-stimulus intervals varied between 8 and 15 sec using a Peltier thermode. A DOT system was used to capture cortical responses on both sides of the head over the primary somatosensory cortical region (S1). For the innocuous stimuli, group results indicated mainly activation on the contralateral side with a weak ipsilateral response. For the noxious stimuli, bilateral activation was observed with comparable amplitudes on both sides. Furthermore, noxious stimuli produced a temporal biphasic response while innocuous stimuli produced a monophasic response. These results are in accordance with fMRI and our other DOT studies of innocuous mechanical and noxious heat stimuli. The data indicate the differentiation of DOT cortical responses for pain vs. innocuous stimuli that may be useful in assessing objectively acute pain.

  16. Effects of noxious stimulation and pain expectations on neuromuscular control of the spine in patients with chronic low back pain.

    PubMed

    Henchoz, Yves; Tétreau, Charles; Abboud, Jacques; Piché, Mathieu; Descarreaux, Martin

    2013-10-01

    Alterations of the neuromuscular control of the lumbar spine have been reported in patients with chronic low back pain (LBP). During trunk flexion and extension tasks, the reduced myoelectric activity of the low back extensor musculature observed during full trunk flexion is typically absent in patients with chronic LBP. To determine whether pain expectations could modulate neuromuscular responses to experimental LBP to a higher extent in patients with chronic LBP compared with controls. A cross-sectional, case-control study. Twenty-two patients with nonspecific chronic LBP and 22 age- and sex-matched control participants. Trunk flexion-extension tasks were performed under three experimental conditions: innocuous heat, noxious stimulation with low pain expectation, and noxious stimulation with high pain expectation. Noxious stimulations were delivered using a contact heat thermode applied on the skin of the lumbar region (L4-L5), whereas low or high pain expectations were induced by verbal and visual instructions. Surface electromyography of erector spinae at L2-L3 and L4-L5, as well as lumbopelvic kinematic variables were collected during the tasks. Pain was evaluated using a numerical rating scale. Pain catastrophizing, disability, anxiety, and fear-avoidance beliefs were measured using validated questionnaires. Two-way mixed analysis of variance revealed that pain was significantly different among the three experimental conditions (F2,84=317.5; p<.001). Increased myoelectric activity of the low back extensor musculature during full trunk flexion was observed in the high compared with low pain expectations condition at the L2-L3 level (F2,84=9.5; p<.001) and at the L4-L5 level (F2,84=3.7; p=.030). At the L4-L5 level, this effect was significantly more pronounced for the control participants compared with patients with chronic LBP (F2,84=3.4; p=.045). Pearson correlation analysis revealed that increased lumbar muscle activity in full flexion induced by

  17. Inhibitory Control Predicts Grammatical Ability

    PubMed Central

    Ibbotson, Paul; Kearvell-White, Jennifer

    2015-01-01

    We present evidence that individual variation in grammatical ability can be predicted by individual variation in inhibitory control. We tested 81 5-year-olds using two classic tests from linguistics and psychology (Past Tense and the Stroop). Inhibitory control was a better predicator of grammatical ability than either vocabulary or age. Our explanation is that giving the correct response in both tests requires using a common cognitive capacity to inhibit unwanted competition. The implications are that understanding the developmental trajectory of language acquisition can benefit from integrating the developmental trajectory of non-linguistic faculties, such as executive control. PMID:26659926

  18. A novel role of ethephon in controlling the noxious weed Ipomoea cairica (Linn.) Sweet

    PubMed Central

    Sun, Zhong-Yu; Zhang, Tai-Jie; Su, Jin-Quan; Soon Chow, Wah; Liu, Jia-Qin; Chen, Li-Ling; Li, Wei-Hua; Peng, Shao-Lin; Peng, Chang-Lian

    2015-01-01

    Several auxin herbicides, such as 2, 4-D and dicamba, have been used to eradicate an exotic invasive weed Ipomoea cairica in subtropical China, but restraining the re-explosion of this weed is still a challenge. Since ethylene is one of the major intermediate functioning products during the eradication process, we explored the possibility, mechanism and efficiency of using ethephon which can release ethylene to control Ipomoea cairica. The results of the pot experiment showed that 7.2 g /L ethephon could totally kill Ipomoea cairica including the stems and roots. The water culture experiment indicated that ethephon released an abundance of ethylene directly in leaves and caused increases in electrolyte leakage, 1-aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA) and H2O2 and decreases in chlorophyll content and photosynthetic activity, finally leading to the death of Ipomoea cairica. The field experiment showed that the theoretical effective concentration of ethephon for controlling Ipomoea cairica (weed control efficacy, WCE = 98%) was 4.06 g/L and the half inhibitory concentration (I50) was 0.56 g/L. More than 50% of the accompanying species were insensitive to the phytotoxicity of ethephon. Therefore, ethephon is an excellent alternative herbicide for controlling Ipomoea cairica. PMID:26087386

  19. A novel role of ethephon in controlling the noxious weed Ipomoea cairica (Linn.) Sweet.

    PubMed

    Sun, Zhong-Yu; Zhang, Tai-Jie; Su, Jin-Quan; Chow, Wah Soon; Liu, Jia-Qin; Chen, Li-Ling; Li, Wei-Hua; Peng, Shao-Lin; Peng, Chang-Lian

    2015-06-18

    Several auxin herbicides, such as 2, 4-D and dicamba, have been used to eradicate an exotic invasive weed Ipomoea cairica in subtropical China, but restraining the re-explosion of this weed is still a challenge. Since ethylene is one of the major intermediate functioning products during the eradication process, we explored the possibility, mechanism and efficiency of using ethephon which can release ethylene to control Ipomoea cairica. The results of the pot experiment showed that 7.2 g /L ethephon could totally kill Ipomoea cairica including the stems and roots. The water culture experiment indicated that ethephon released an abundance of ethylene directly in leaves and caused increases in electrolyte leakage, 1-aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA) and H2O2 and decreases in chlorophyll content and photosynthetic activity, finally leading to the death of Ipomoea cairica. The field experiment showed that the theoretical effective concentration of ethephon for controlling Ipomoea cairica (weed control efficacy, WCE = 98%) was 4.06 g/L and the half inhibitory concentration (I50) was 0.56 g/L. More than 50% of the accompanying species were insensitive to the phytotoxicity of ethephon. Therefore, ethephon is an excellent alternative herbicide for controlling Ipomoea cairica.

  20. Hazardous and Noxious Substances (HNS) in the marine environment: prioritizing HNS that pose major risk in a European context.

    PubMed

    Neuparth, T; Moreira, S; Santos, M M; Reis-Henriques, M A

    2011-01-01

    Increases in the maritime transportation of Hazardous and Noxious Substances (HNS), alongside the need for an effective response to HNS spills have led environmental managers and the scientific community to focus attention on HNS spill preparedness and responsiveness. In the context of the ARCOPOL project, a weight-of-evidence approach was developed aimed at prioritizing HNS that pose major environmental risks to European waters. This approach takes into consideration the occurrence probability of HNS spills in European Atlantic waters and the severity of exposure associated with their physico-chemical properties and toxicity to marine organisms. Additionally, a screening analysis of the toxicological information available for the prioritization of HNS was performed. Here we discuss the need for a prioritization methodology to select HNS that are likely to cause severe marine environmental effects as an essential step towards the establishment of a more effective preparedness and response to HNS incidents. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Occupational hazards in hospitals: accidents, radiation, exposure to noxious chemicals, drug addiction and psychic problems, and assault.

    PubMed Central

    Gestal, J J

    1987-01-01

    Except for infectious diseases all the main occupational hazards affecting health workers are reviewed: accidents (explosions, fires, electrical accidents, and other sources of injury); radiation (stochastic and non-stochastic effects, protective measures, and personnel most at risk); exposure to noxious chemicals, whose effects may be either local (allergic eczema) or generalised (cancer, mutations), particular attention being paid to the hazards presented by formol, ethylene oxide, cytostatics, and anaesthetic gases; drug addiction (which is more common among health workers than the general population) and psychic problems associated with promotion, shift work, and emotional stress; and assault (various types of assault suffered by health workers, its causes, and the characterisation of the most aggressive patients). PMID:3307896

  2. Heterogeneous Photocatalysis and Photoelectrocatalysis: From Unselective Abatement of Noxious Species to Selective Production of High-Value Chemicals.

    PubMed

    Augugliaro, Vincenzo; Camera-Roda, Giovanni; Loddo, Vittorio; Palmisano, Giovanni; Palmisano, Leonardo; Soria, Javier; Yurdakal, Sedat

    2015-05-21

    Heterogeneous photocatalysis and photoelectrocatalysis have been considered as oxidation technologies to abate unselectively noxious species. This article focuses instead on the utilization of these methods for selective syntheses of organic molecules. Some promising reactions have been reported in the presence of various TiO2 samples and the important role played by the amorphous phase has been discussed. The low solubility of most of the organic compounds in water limits the utilization of photocatalysis. Dimethyl carbonate has been proposed as an alternative green organic solvent. The recovery of the products by coupling photocatalysis with pervaporation membrane technology seems to be a solution for future industrial applications. As far as photoelectrocatalysis is concerned, a decrease in recombination of the photogenerated pairs occurs, enhancing the rate of the oxidation reactions and the quantum yield. Another benefit is to avoid reaction(s) between the intermediates and the substrate, as anodic and cathodic reactions take place in different places.

  3. Diverse Ensembles of Inhibitory Interneurons.

    PubMed

    Crandall, Shane R; Connors, Barry W

    2016-04-06

    In this issue of Neuron, Karnani et al. (2016) show that ensembles of specific types of inhibitory interneurons generate coordinated activity in mouse visual cortex. They also describe chemical and electrical synaptic mechanisms that may enable diverse interneuron ensembles to function as distinct operational units. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Inhibitory Control in Childhood Stuttering

    ERIC Educational Resources Information Center

    Eggers, Kurt; De Nil, Luc F.; Van den Bergh, Bea R. H.

    2013-01-01

    Purpose: The purpose of this study was to investigate whether previously reported parental questionnaire-based differences in inhibitory control (IC; Eggers, De Nil, & Van den Bergh, 2010) would be supported by direct measurement of IC using a computer task. Method: Participants were 30 children who stutter (CWS; mean age = 7;05 years) and 30…

  5. Inhibitory Control in Childhood Stuttering

    ERIC Educational Resources Information Center

    Eggers, Kurt; De Nil, Luc F.; Van den Bergh, Bea R. H.

    2013-01-01

    Purpose: The purpose of this study was to investigate whether previously reported parental questionnaire-based differences in inhibitory control (IC; Eggers, De Nil, & Van den Bergh, 2010) would be supported by direct measurement of IC using a computer task. Method: Participants were 30 children who stutter (CWS; mean age = 7;05 years) and 30…

  6. Effect of resiniferatoxin on the noxious heat threshold temperature in the rat: a novel heat allodynia model sensitive to analgesics

    PubMed Central

    Almási, Róbert; Pethö, Gábor; Bölcskei, Kata; Szolcsányi, János

    2003-01-01

    An increasing-temperature hot plate (ITHP) was introduced to measure the noxious heat threshold (45.3±0.3°C) of unrestrained rats, which was reproducible upon repeated determinations at intervals of 5 or 30 min or 1 day. Morphine, diclofenac and paracetamol caused an elevation of the noxious heat threshold following i.p. pretreatment, the minimum effective doses being 3, 10 and 200 mg kg−1, respectively. Unilateral intraplantar injection of the VR1 receptor agonist resiniferatoxin (RTX, 0.048 nmol) induced a profound drop of heat threshold to the innocuous range with a maximal effect (8–10°C drop) 5 min after RTX administration. This heat allodynia was inhibited by pretreatment with morphine, diclofenac and paracetamol, the minimum effective doses being 1, 1 and 100 mg kg−1 i.p., respectively. The long-term sensory desensitizing effect of RTX was examined by bilateral intraplantar injection (0.048 nmol per paw) which produced, after an initial threshold drop, an elevation (up to 2.9±0.5°C) of heat threshold lasting for 5 days. The VR1 receptor antagonist iodo-resiniferatoxin (I-RTX, 0.05 nmol intraplantarly) inhibited by 51% the heat threshold-lowering effect of intraplantar RTX but not α,β-methylene-ATP (0.3 μmol per paw). I-RTX (0.1 or 1 nmol per paw) failed to alter the heat threshold either acutely (5–60 min) or on the long-term (5 days). The heat threshold of VR1 receptor knockout mice was not different from that of wild-type animals (45.6±0.5 vs 45.2±0.4°C). In conclusion, the RTX-induced drop of heat threshold measured by the ITHP is a novel heat allodynia model exhibiting a high sensitivity to analgesics. PMID:12746222

  7. Cross-organ sensitization of thoracic spinal neurons receiving noxious cardiac input in rats with gastroesophageal reflux

    PubMed Central

    Malykhina, Anna P.; Thompson, Ann M.; Farber, Jay P.; Foreman, Robert D.

    2010-01-01

    Gastroesophageal reflux (GER) frequently triggers or worsens cardiac pain or symptoms in patients with coronary heart disease. This study aimed to determine whether GER enhances the activity of upper thoracic spinal neurons receiving noxious cardiac input. Gastric fundus and pyloric ligations as well as a longitudinal myelotomy at the gastroesophageal junction induced acute GER in pentobarbital-anesthetized, paralyzed, and ventilated male Sprague-Dawley rats. Manual manipulations of the stomach and lower esophagus were used as surgical controls in another group. At 4–9 h after GER surgery, extracellular potentials of single neurons were recorded from the T3 spinal segment. Intrapericardial bradykinin (IB) (10 μg/ml, 0.2 ml, 1 min) injections were used to activate cardiac nociceptors, and esophageal distensions were used to activate esophageal afferent fibers. Significantly more spinal neurons in the GER group responded to IB compared with the control group (69.1 vs. 38%, P < 0.01). The proportion of IB-responsive neurons in the superficial laminae of GER animals was significantly different from those in deeper layers (1/8 vs. 46/60, P < 0.01); no difference was found in control animals (7/25 vs. 20/46, P > 0.05). Excitatory responses of spinal neurons to IB in the GER group were greater than in the control group [32.4 ± 3.5 impulses (imp)/s vs. 13.3 ± 2.3 imp/s, P < 0.01]. Forty-five of 47 (95.7%) neurons responded to cardiac input and ED, which was higher than the control group (61.5%, P < 0.01). These results indicate that acute GER enhanced the excitatory responses of thoracic spinal neurons in deeper laminae of the dorsal horn to noxious cardiac stimulus. PMID:20378832

  8. Diffusion barriers

    NASA Technical Reports Server (NTRS)

    Nicolet, M. A.

    1983-01-01

    The choice of the metallic film for the contact to a semiconductor device is discussed. One way to try to stabilize a contact is by interposing a thin film of a material that has low diffusivity for the atoms in question. This thin film application is known as a diffusion barrier. Three types of barriers can be distinguished. The stuffed barrier derives its low atomic diffusivity to impurities that concentrate along the extended defects of a polycrystalline layer. Sacrificial barriers exploit the fact that some (elemental) thin films react in a laterally uniform and reproducible fashion. Sacrificial barriers have the advantage that the point of their failure is predictable. Passive barriers are those most closely approximating an ideal barrier. The most-studied case is that of sputtered TiN films. Stuffed barriers may be viewed as passive barriers whose low diffusivity material extends along the defects of the polycrystalline host.

  9. Diffuse radiation

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A diffuse celestial radiation which is isotropic at least on a course scale were measured from the soft X-ray region to about 150 MeV, at which energy the intensity falls below that of the galactic emission for most galactic latitudes. The spectral shape, the intensity, and the established degree of isotropy of this diffuse radiation already place severe constraints on the possible explanations for this radiation. Among the extragalactic theories, the more promising explanations of the isotropic diffuse emission appear to be radiation from exceptional galaxies from matter antimatter annihilation at the boundaries of superclusters of galaxies of matter and antimatter in baryon symmetric big bang models. Other possible sources for extragalactic diffuse gamma radiation are discussed and include normal galaxies, clusters of galaxies, primordial cosmic rays interacting with intergalactic matter, primordial black holes, and cosmic ray leakage from galaxies.

  10. Supplement Analysis for the Transmission System Vegetation Management Program FEIS (DOE/EIS-0285/SA-46) - Franklin County Noxious Weed Management

    SciTech Connect

    Hermeston, Mark W.

    2002-02-27

    Franklin County noxious weed management along BPA rights-of-ways, transmission structures, roads, and switches listed in Attachment 1. Attachment 1 identifies the ROW, ROW width, and ROW length of the proposed action. Includes all BPA 115kV, 230kV, and 500 kV ROWs in Franklin County, Washington. BPA proposes to clear noxious and/or unwanted low-growing vegetation in all BPA ROWs in Franklin County, Washington. In a cooperative effort, BPA, through landowners and the Franklin County Weed Control Board, plan to eradicate noxious plants and other unwanted, low-growing vegetation within the ROW width including all structures and access roads. BPA’s overall goal is to eradicate all noxious and unwanted vegetation through chemical treatment and reseeding. Selective and nonselective chemical treatment using spot, local and broadcast methods. All work will be executed in accordance with the National Electrical Safety Code and BPA standards. Work is to begin in March 2002.

  11. Distribution of extracellular signal-regulated kinase 1- and 2-activated neurons in the rat periaqueductal gray matter after noxious stimulation.

    PubMed

    Gioia, Magda; Moscheni, Claudia; Gagliano, Nicoletta

    2005-05-01

    The periaqueductal gray matter (PAG), the midbrain region made up of neuronal columns encircling the cerebral aqueduct, plays a key role in nociception. As the extracellular signal-regulated kinases (ERKs) 1 and 2 are activated after noxious stimulation, we analyzed the distribution of ERK-activated neurons in the PAG after visceral noxious stimulation. Ether- and urethane-anesthetized rats received an intraperitoneal injection of acetic acid or were left untreated and were perfused after 2 hr. Serial sections immunoreacted with an antibody selective for the activated ERKs. Significant ERK activation occurred only in the ether-anesthetized noxious stimulated rats. In these rats, we evaluated the number of ERK-activated neurons and their density as the ratio of the number of immunolabeled neurons to the extension of the region where they were located. ERK-activated neurons were more numerous in the lateral (LPAG) and ventrolateral (VLPAG) columns, but without significant differences. No ERK activation was seen in neurons of the most rostral PAG. The ERK-activated neurons were significantly denser at the intermediate level of the PAG. At the caudal level, they were denser in the LPAG and VLPAG columns, and in the DPAG column at the intermediate and rostral level. These findings suggest that noxious stimulation activates ERKs in neurons involved in the different functional activities related to nociception, overlapping in the PAG columns, and strengthens the role of PAG in integration.

  12. Supplement Analysis for the Transmission System Vegetation Management Program FEIS (DOE/EIS-0285/SA-45) - Benton County Noxious Weed Management

    SciTech Connect

    Hermeston, Mark W.

    2002-02-27

    Benton County noxious weed management along BPA rights-of-ways, transmission structures, roads, and switches listed in Attachment 1. Attachment 1 identifies the ROW, ROW width, and ROW length of the proposed action. Includes all BPA 115kV, 230kV, 345kV and 500 kV ROWs in Benton County, Washington. BPA proposes to clear noxious and/or unwanted low-growing vegetation in all BPA ROWs in Benton County, Washington. In a cooperative effort, BPA, through landowners and the Benton County Weed Control Board, plan to eradicate noxious plants and other unwanted, low-growing vegetation within the ROW width including all structures and access roads. BPA’s overall goal is to eradicate all noxious and unwanted vegetation through chemical treatment and reseeding. Selective and nonselective chemical treatment using spot, local and broadcast methods. All work will be executed in accordance with the National Electrical Safety Code and BPA standards. Work is to begin in March 2002.

  13. Sex Differences in Functional Brain Activation during Noxious Visceral Stimulation in Rats

    PubMed Central

    Bradesi, Sylvie; Labus, Jennifer S.; Maarek, Jean-Michel I.; Lee, Kevin; Winchester, Wendy J.; Mayer, Emeran A.; Holschneider, Daniel P.

    2009-01-01

    Studies in healthy human subjects and patients with irritable bowel syndrome suggest sex differences in cerebral nociceptive processing. Here we examine sex differences in functional brain activation in the rat during colorectal distention (CRD), a preclinical model of acute visceral pain. [14C]-iodoantipyrine was injected intravenously in awake, nonrestrained female rats during 60-mmHg or 0-mmHg CRD while electromyographic abdominal activity (EMG) and pain behavior were recorded. Regional cerebral blood flow related tissue radioactivity was analyzed by statistical parametric mapping from autoradiographic images of 3-dimensionally reconstructed brains. Sex differences were addressed by comparing current data with our previously published data collected from male rats. While sex differences in EMG and pain scores were modest, significant differences were noted in functional brain activation. Females showed widespread changes in limbic (amygdala, hypothalamus) and paralimbic structures (ventral striatum, nucleus accumbens, raphe), while males demonstrated broad cortical changes. Sex differences were apparent in the homeostatic afferent network (parabrachial nucleus, thalamus, insular and dorsal anterior cingulate cortices), in an emotional-arousal network (amygdala, locus coeruleus complex), and in cortical areas modulating these networks (prefrontal cortex). Greater activation of the ventromedial prefrontal cortex and broader limbic/paralimbic changes in females suggest greater engagement of affective mechanisms during visceral pain. Greater cortical activation in males is consistent with the concept of greater cortical inhibitory effects on limbic structures in males, which may relate to differences in attentional and cognitive attribution to visceral stimuli. These findings show remarkable similarities to reported sex differences in brain responses to visceral stimuli in humans. PMID:19560270

  14. Hemodynamic and Light-Scattering Changes of Rat Spinal Cord and Primary Somatosensory Cortex in Response to Innocuous and Noxious Stimuli

    PubMed Central

    He, Ji-Wei; Liu, Hanli; Peng, Yuan Bo

    2015-01-01

    Neuroimaging technologies with an exceptional spatial resolution and noninvasiveness have become a powerful tool for assessing neural activity in both animals and humans. However, the effectiveness of neuroimaging for pain remains unclear partly because the neurovascular coupling during pain processing is not completely characterized. Our current work aims to unravel patterns of neurovascular parameters in pain processing. A novel fiber-optic method was used to acquire absolute values of regional oxy- (HbO) and deoxy-hemoglobin concentrations, oxygen saturation rates (SO2), and the light-scattering coefficients from the spinal cord and primary somatosensory cortex (SI) in 10 rats. Brief mechanical and electrical stimuli (ranging from innocuous to noxious intensities) as well as a long-lasting noxious stimulus (formalin injection) were applied to the hindlimb under pentobarbital anesthesia. Interhemispheric comparisons in the spinal cord and SI were used to confirm functional activation during sensory processing. We found that all neurovascular parameters showed stimulation-induced changes; however, patterns of changes varied with regions and stimuli. Particularly, transient increases in HbO and SO2 were more reliably attributed to brief stimuli, whereas a sustained decrease in SO2 was more reliably attributed to formalin. Only the ipsilateral SI showed delayed responses to brief stimuli. In conclusion, innocuous and noxious stimuli induced significant neurovascular responses at critical centers (e.g., the spinal cord and SI) along the somatosensory pathway; however, there was no single response pattern (as measured by amplitude, duration, lateralization, decrease or increase) that was able to consistently differentiate noxious stimuli. Our results strongly suggested that the neurovascular response patterns differ between brief and long-lasting noxious stimuli, and can also differ between the spinal cord and SI. Therefore, a use of multiple-parameter strategy

  15. 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.

  16. TRPM8, but not TRPA1, is required for neural and behavioral responses to acute noxious cold temperatures and cold-mimetics in vivo.

    PubMed

    Knowlton, Wendy M; Bifolck-Fisher, Amber; Bautista, Diana M; McKemy, David D

    2010-08-01

    Somatosensory neurons detect environmental stimuli, converting external cues into neural activity that is relayed first to second-order neurons in the spinal cord. The detection of cold is proposed to be mediated by the ion channels TRPM8 and TRPA1. However, there is significant debate regarding the role of each channel in cold-evoked pain, complicating their potential as drug targets for conditions such as cold allodynia and hyperalgesia. To address this debate, we generated mice lacking functional copies of both channels and examined behaviors and neural activity in response to painful cold and noxious cooling compounds. Whereas normal mice display a robust preference for warmth over cold, both TRPM8-null (TRPM8(-/-)) and TRPM8/TRPA1 double-knockout mice (DKO) display no preference until temperatures reach the extreme noxious range. Additionally, in contrast to wildtype mice that avoid touching cold surfaces, mice lacking TRPM8 channels display no such avoidance and explore noxious cold surfaces, even at 5 degrees C. Furthermore, nocifensive behaviors to the cold-mimetic icilin are absent in TRPM8(-/-) and DKO mice, but are retained in TRPA1-nulls (TRPA1(-/-)). Finally, neural activity, measured by expression of the immediate-early gene c-fos, evoked by hindpaw stimulation with noxious cold, menthol, or icilin is reduced in TRPM8(-/-) and DKO mice, but not in TRPA1(-/-) animals. Thus our results show that noxious cold signaling is exclusive to TRPM8, mediating neural and behavioral responses to cold and cold-mimetics, and that TRPA1 is not required for acute cold pain in mammals.

  17. TRPM8, but not TRPA1, is required for neural and behavioral responses to acute noxious cold temperatures and cold-mimetics in vivo

    PubMed Central

    Knowlton, Wendy M.; Fisher, Amber; Bautista, Diana M.; McKemy, David D.

    2010-01-01

    Somatosensory neurons detect environmental stimuli, converting external cues into neural activity that is relayed first to second-order neurons in the spinal cord. The detection of cold is proposed to be mediated by the ion channels TRPM8 and TRPA1. However, there is significant debate regarding the role of each channel in cold-evoked pain, complicating their potential as drug targets for conditions such as cold allodynia and hyperalgesia. To address this debate, we generated mice lacking functional copies of both channels and examined behaviors and neural activity in response to painful cold and noxious cooling compounds. Whereas normal mice display a robust preference for warmth over cold, both TRPM8-null (TRPM8−/−) and TRPM8/TRPA1 double knockout mice (DKO) display no preference until temperatures reach the extreme noxious range. Additionally, in contrast to wildtype mice that avoid touching cold surfaces, mice lacking TRPM8 channels display no such avoidance and explore noxious cold surfaces, even at 5°C. Furthermore, nocifensive behaviors to the cold mimetic icilin are absent in TRPM8−/− and DKO mice, but are retained in TRPA1-nulls (TRPA1−/−). Lastly, neural activity, measured by expression of the immediate early gene c-fos, evoked by hindpaw stimulation with noxious cold, menthol, or icilin is reduced in TRPM8−/− and DKO mice, but not in TRPA1−/− animals. Thus our results show that noxious cold signaling is exclusive to TRPM8, mediating neural and behavioral responses to cold and cold mimetics, and that TRPA1 is not required for acute cold pain in mammals. PMID:20542379

  18. Diffuser Test

    NASA Image and Video Library

    2007-09-13

    Tests begun at Stennis Space Center's E Complex Sept. 13 evaluated a liquid oxygen lead for engine start performance, part of the A-3 Test Facility Subscale Diffuser Risk Mitigation Project at SSC's E-3 Test Facility. Phase 1 of the subscale diffuser project, completed Sept. 24, was a series of 18 hot-fire tests using a 1,000-pound liquid oxygen and gaseous hydrogen thruster to verify maximum duration and repeatability for steam generation supporting the A-3 Test Stand project. The thruster is a stand-in for NASA's developing J-2X engine, to validate a 6 percent scale version of A-3's exhaust diffuser. Testing the J-2X at altitude conditions requires an enormous diffuser. Engineers will generate nearly 4,600 pounds per second of steam to reduce pressure inside A-3's test cell to simulate altitude conditions. A-3's exhaust diffuser has to be able to withstand regulated pressure, temperatures and the safe discharge of the steam produced during those tests. Before the real thing is built, engineers hope to work out any issues on the miniature version. Phase 2 testing is scheduled to begin this month.

  19. Adrenoceptors and colocolonic inhibitory reflex.

    PubMed

    Hughes, S F; Scott, S M; Pilot, M A; Williams, N S

    1999-12-01

    The colocolonic inhibitory reflex is characterized by inhibition of proximal colonic motility induced by distal colonic distension. The aim of this study was to investigate the underlying neural mechanisms of this reflex, in vivo, using an isolated loop of canine colon. In five beagle dogs, motility was recorded from an exteriorized colonic loop via a serosal strain gauge connected to a digital data logger and chart recorder. Inflation of a balloon in the distal colon resulted in inhibition of motility in the isolated loop. Inhibition of motor activity persisted following injection of propranolol (100 microg/kg intravenously), a beta-adrenoceptor antagonist, but was abolished following administration of the alpha2-adrenoceptor antagonist yohimbine (200 microg/kg intravenously). This study confirms that the colocolonic inhibitory reflex is mediated via the extrinsic nerves to the colon. As the reflex was abolished by alpha2-, but not beta-adrenoceptor blockade, this indicates that the reflex pathway involves alpha2-adrenoceptors.

  20. Minimal inhibitory concentrations of antimicrobial agents against Actinobacillus pleuropneumoniae.

    PubMed Central

    Nadeau, M; Larivière, S; Higgins, R; Martineau, G P

    1988-01-01

    Forty-five isolates of Actinobacillus pleuropneumoniae were tested for susceptibility to 12 antimicrobial agents using a microdilution method for the minimal inhibitory concentration determinations. These results confirmed the high prevalence of A. pleuropneumoniae strains resistant to antibiotics as reported earlier using the disc diffusion method (Kirby-Bauer method). While 36% of the isolates were resistant to the penicillins, 47% were resistant to chloramphenicol and 68% were resistant to tetracycline. Minimal inhibitory concentrations for the resistant isolates were approximately 32 times higher than those for the susceptible isolates to the above antibacterial agents. The isolates were in general weakly susceptible or resistant to spectinomycin, lincomycin, tiamulin and spiramycin whereas most of them were susceptible to gentamicin, trimethoprim and erythromycin. The susceptibility pattern was similar throughout the 1980 to 1984 period. The 14 serotype 5 isolates were more resistant to tetracycline but less resistant to chloramphenicol and the penicillins than the 28 serotype 1 isolates. PMID:3167716

  1. Cortical neurodynamics of inhibitory control.

    PubMed

    Hwang, Kai; Ghuman, Avniel S; Manoach, Dara S; Jones, Stephanie R; Luna, Beatriz

    2014-07-16

    The ability to inhibit prepotent responses is critical for successful goal-directed behaviors. To investigate the neural basis of inhibitory control, we conducted a magnetoencephalography study where human participants performed the antisaccade task. Results indicated that neural oscillations in the prefrontal cortex (PFC) showed significant task modulations in preparation to suppress saccades. Before successfully inhibiting a saccade, beta-band power (18-38 Hz) in the lateral PFC and alpha-band power (10-18 Hz) in the frontal eye field (FEF) increased. Trial-by-trial prestimulus FEF alpha-band power predicted successful saccadic inhibition. Further, inhibitory control enhanced cross-frequency amplitude coupling between PFC beta-band (18-38 Hz) activity and FEF alpha-band activity, and the coupling appeared to be initiated by the PFC. Our results suggest a generalized mechanism for top-down inhibitory control: prefrontal beta-band activity initiates alpha-band activity for functional inhibition of the effector and/or sensory system.

  2. Cortical Neurodynamics of Inhibitory Control

    PubMed Central

    Ghuman, Avniel S.; Manoach, Dara S.; Jones, Stephanie R.; Luna, Beatriz

    2014-01-01

    The ability to inhibit prepotent responses is critical for successful goal-directed behaviors. To investigate the neural basis of inhibitory control, we conducted a magnetoencephalography study where human participants performed the antisaccade task. Results indicated that neural oscillations in the prefrontal cortex (PFC) showed significant task modulations in preparation to suppress saccades. Before successfully inhibiting a saccade, beta-band power (18–38 Hz) in the lateral PFC and alpha-band power (10–18 Hz) in the frontal eye field (FEF) increased. Trial-by-trial prestimulus FEF alpha-band power predicted successful saccadic inhibition. Further, inhibitory control enhanced cross-frequency amplitude coupling between PFC beta-band (18–38 Hz) activity and FEF alpha-band activity, and the coupling appeared to be initiated by the PFC. Our results suggest a generalized mechanism for top-down inhibitory control: prefrontal beta-band activity initiates alpha-band activity for functional inhibition of the effector and/or sensory system. PMID:25031398

  3. Inhibitory control of nociceptive responses of trigeminal spinal nucleus cells by somatosensory corticofugal projection in rat.

    PubMed

    Malmierca, E; Martin, Y B; Nuñez, A

    2012-09-27

    The caudal division of the trigeminal spinal nucleus (Sp5C) is an important brainstem relay station of orofacial pain transmission. The aim of the present study was to examine the effect of cortical electrical stimulation on nociceptive responses in Sp5C neurons. Extracellular recordings were performed in the Sp5C nucleus by tungsten microelectrodes in urethane-anesthetized Sprague-Dawley rats. Nociceptive stimulation was produced by application of capsaicin cream on the whisker pad or by constriction of the infraorbital nerve. Capsaicin application evoked a long-lasting increase in the spontaneous firing rate from 1.4±0.2 to 3.4±0.6 spikes/s. Non-noxious tactile responses from stimuli delivered to the receptive field (RF) center decreased 5 min. after capsaicin application (from 2.3±0.1 to 1.6±0.1 spikes/stimulus) while responses from the whisker located at the RF periphery increased (from 1.3±0.2 to 2.0±0.1 spikes/stimulus under capsaicin). Electrical train stimulation of the primary (S1) or secondary (S2) somatosensory cortical areas reduced the increase in the firing rate evoked by capsaicin. Also, S1, but not S2, cortical stimulation reduced the increase in non-noxious tactile responses from the RF periphery. Inhibitory cortical effects were mediated by the activation of GABAergic and glycinergic neurons because they were blocked by bicuculline or strychnine. The S1 and S2 cortical stimulation also inhibited Sp5C neurons in animals with constriction of the infraorbital nerve. Consequently, the corticofugal projection from S1 and S2 cortical areas modulates nociceptive responses of Sp5C neurons and may control the transmission of nociceptive sensory stimulus.

  4. Defusing Diffusion

    ERIC Educational Resources Information Center

    Dou, Remy; Hogan, DaNel; Kossover, Mark; Spuck, Timothy; Young, Sarah

    2013-01-01

    Diffusion has often been taught in science courses as one of the primary ways by which molecules travel, particularly within organisms. For years, classroom teachers have used the same common demonstrations to illustrate this concept (e.g., placing drops of food coloring in a beaker of water). Most of the time, the main contributor to the motion…

  5. Demonstrating Diffusion

    ERIC Educational Resources Information Center

    Foy, Barry G.

    1977-01-01

    Two demonstrations are described. Materials and instructions for demonstrating movement of molecules into cytoplasm using agar blocks, phenolphthalein, and sodium hydroxide are given. A simple method for demonstrating that the rate of diffusion of a gas is inversely proportional to its molecular weight is also presented. (AJ)

  6. Defusing Diffusion

    ERIC Educational Resources Information Center

    Dou, Remy; Hogan, DaNel; Kossover, Mark; Spuck, Timothy; Young, Sarah

    2013-01-01

    Diffusion has often been taught in science courses as one of the primary ways by which molecules travel, particularly within organisms. For years, classroom teachers have used the same common demonstrations to illustrate this concept (e.g., placing drops of food coloring in a beaker of water). Most of the time, the main contributor to the motion…

  7. Demonstrating Diffusion

    ERIC Educational Resources Information Center

    Foy, Barry G.

    1977-01-01

    Two demonstrations are described. Materials and instructions for demonstrating movement of molecules into cytoplasm using agar blocks, phenolphthalein, and sodium hydroxide are given. A simple method for demonstrating that the rate of diffusion of a gas is inversely proportional to its molecular weight is also presented. (AJ)

  8. 3-iodothyroacetic acid, a metabolite of thyroid hormone, induces itch and reduces threshold to noxious and to painful heat stimuli in mice

    PubMed Central

    Laurino, Annunziatina; De Siena, Gaetano; Resta, Francesco; Masi, Alessio; Musilli, Claudia; Zucchi, Riccardo; Raimondi, Laura

    2015-01-01

    Background and purpose Itch is associated with increased sensitization to nociceptive stimuli. We investigated whether 3-iodothyroacetic acid (TA1), by releasing histamine, induces itch and increases sensitization to noxious and painful heat stimuli. Experimental Approach Itch was evaluated after s.c. administration of TA1 (0.4, 1.32 and 4 μg·kg−1). Mice threshold to noxious (NHT) and to painful heat stimuli were evaluated by the increasing-temperature hot plate (from 45.5 to 49.5°C) or by the hot plate (51.5°C) test, respectively, 15 min after i.p. injection of TA1 (0.4, 1.32 and 4 μg·kg−1). Itch, NHT and pain threshold evaluation were repeated in mice pretreated with pyrilamine. Itch and NHT were also measured in HDC+/+ and HDC−/− following injection of saline or TA1 (1.32, 4 and 11 μg·kg−1; s.c. and i.p.). pERK1/2 levels were determined by Western blot in dorsal root ganglia (DRG) isolated from CD1 mice 15 min after they received (i.p.): saline, saline and noxious heat stimulus (46.5°C), TA1 (0.1, 0.4, 1.32, 4 μg·kg−1) or TA1 1.32 μg·kg−1 and noxious heat stimulus. Key Results TA1 0.4 and 1.32 μg·kg−1 induced itch and reduced NHT; pyrilamine pretreatment prevented both of these effects. TA1 4 μg·kg−1 (i.p.) reduced pain threshold without inducing itch or modifying NHT. In HDC−/− mice, TA1 failed to induce itch and to reduce NHT. In DRG, pERK1/2 levels were significantly increased by noxious heat stimuli and by TA1 0.1, 0.4 and 1.32 μg·kg−1; i.p. Conclusions and Implications Increased TA1 levels induce itch and an enhanced sensitivity to noxious heat stimuli suggesting that TA1 might represent a potential cause of itch in thyroid diseases. PMID:25439265

  9. Monetary rewards modulate inhibitory control.

    PubMed

    Herrera, Paula M; Speranza, Mario; Hampshire, Adam; Bekinschtein, Tristán A

    2014-01-01

    The ability to override a dominant response, often referred to as behavioral inhibition, is considered a key element of executive cognition. Poor behavioral inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioral inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/NoGo and Stop Signal Tasks (SSTs). Several studies have reported a positive modulatory effect of reward on performance in pathological conditions such as substance abuse, pathological gambling, and Attention Deficit Hyperactive Disorder (ADHD). However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory tasks are scarce and little is known about the finer grained relationship between motivation and inhibitory control. Here we probed the effect of reward magnitude and context on behavioral inhibition with three modified versions of the widely used SST. The pilot study compared inhibition performance during six blocks alternating neutral feedback, low, medium, and high monetary rewards. Study One compared increasing vs. decreasing rewards, with low, high rewards, and neutral feedback; whilst Study Two compared low and high reward magnitudes alone also in an increasing and decreasing reward design. The reward magnitude effect was not demonstrated in the pilot study, probably due to a learning effect induced by practice in this lengthy task. The reward effect per se was weak but the context (order of reward) was clearly suggested in Study One, and was particularly strongly confirmed in study two. In addition, these findings revealed a "kick start effect" over global performance measures. Specifically, there was a long lasting improvement in performance throughout the task when participants received the highest reward magnitudes at the beginning of the

  10. Monetary rewards modulate inhibitory control

    PubMed Central

    Herrera, Paula M.; Speranza, Mario; Hampshire, Adam; Bekinschtein, Tristán A.

    2014-01-01

    The ability to override a dominant response, often referred to as behavioral inhibition, is considered a key element of executive cognition. Poor behavioral inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioral inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/NoGo and Stop Signal Tasks (SSTs). Several studies have reported a positive modulatory effect of reward on performance in pathological conditions such as substance abuse, pathological gambling, and Attention Deficit Hyperactive Disorder (ADHD). However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory tasks are scarce and little is known about the finer grained relationship between motivation and inhibitory control. Here we probed the effect of reward magnitude and context on behavioral inhibition with three modified versions of the widely used SST. The pilot study compared inhibition performance during six blocks alternating neutral feedback, low, medium, and high monetary rewards. Study One compared increasing vs. decreasing rewards, with low, high rewards, and neutral feedback; whilst Study Two compared low and high reward magnitudes alone also in an increasing and decreasing reward design. The reward magnitude effect was not demonstrated in the pilot study, probably due to a learning effect induced by practice in this lengthy task. The reward effect per se was weak but the context (order of reward) was clearly suggested in Study One, and was particularly strongly confirmed in study two. In addition, these findings revealed a “kick start effect” over global performance measures. Specifically, there was a long lasting improvement in performance throughout the task when participants received the highest reward magnitudes at the beginning of the

  11. Selective blockade of TRPA1 channel attenuates pathological pain without altering noxious cold sensation or body temperature regulation.

    PubMed

    Chen, Jun; Joshi, Shailen K; DiDomenico, Stanley; Perner, Richard J; Mikusa, Joe P; Gauvin, Donna M; Segreti, Jason A; Han, Ping; Zhang, Xu-Feng; Niforatos, Wende; Bianchi, Bruce R; Baker, Scott J; Zhong, Chengmin; Simler, Gricelda H; McDonald, Heath A; Schmidt, Robert G; McGaraughty, Steve P; Chu, Katharine L; Faltynek, Connie R; Kort, Michael E; Reilly, Regina M; Kym, Philip R

    2011-05-01

    Despite the increasing interest in TRPA1 channel as a pain target, its role in cold sensation and body temperature regulation is not clear; the efficacy and particularly side effects resulting from channel blockade remain poorly understood. Here we use a potent, selective, and bioavailable antagonist to address these issues. A-967079 potently blocks human (IC(50): 51 nmol/L, electrophysiology, 67 nmol/L, Ca(2+) assay) and rat TRPA1 (IC(50): 101 nmol/L, electrophysiology, 289 nmol/L, Ca(2+) assay). It is >1000-fold selective over other TRP channels, and is >150-fold selective over 75 other ion channels, enzymes, and G-protein-coupled receptors. Oral dosing of A-967079 produces robust drug exposure in rodents, and exhibits analgesic efficacy in allyl isothiocyanate-induced nocifensive response and osteoarthritic pain in rats (ED(50): 23.2 mg/kg, p.o.). A-967079 attenuates cold allodynia produced by nerve injury but does not alter noxious cold sensation in naive animals, suggesting distinct roles of TRPA1 in physiological and pathological states. Unlike TRPV1 antagonists, A-967079 does not alter body temperature. It also does not produce locomotor or cardiovascular side effects. Collectively, these data provide novel insights into TRPA1 function and suggest that the selective TRPA1 blockade may present a viable strategy for alleviating pain without untoward side effects. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  12. Accumulation of ammonia and other potentially noxious gases on live export shipments from Australia to the Middle East.

    PubMed

    Pines, M K; Phillips, C J C

    2011-10-01

    Noxious gases on ships are irritant pollutants that have potential impacts on the comfort and health of both livestock and humans. Identification of environmental influences on the pollutants will assist live exporters to control them. Ammonia, hydrogen sulphide and carbon dioxide, as well as wet and dry bulb temperature, dew point, air speed and depth of faeces that the sheep stood in, were measured on two ship voyages in which sheep were transported from Australia to the Middle East. Daily measurements were made at 20 measurement locations over 12 days. At four sites, the mean ammonia concentration for the voyage was above the recommended maximum limit for the live export industry (25 ppm). The mean ammonia concentrations at the remaining 16 sites were below 18 ppm and considered safe. High ammonia concentrations were localised and occurred particularly on closed decks, as well as at the front of the vessel and near the engine block on open decks. Ammonia concentration on the open decks was correlated with cumulative wind during the voyage, air speed, dew point, wet bulb temperature and faecal pad depth, and on the closed decks with dew point, and wet and dry bulb temperature. Hydrogen sulphide (<1.8 ppm) and carbon dioxide (<1900 ppm) concentrations were low and did not pose a risk to animal or human welfare or health. The results suggest that high ammonia concentrations occur in those parts of the ship where there is insufficient ventilation and/or high temperatures and humidity.

  13. Emotion-focused coping and distraction: sex differences in the influence of anxiety sensitivity during noxious heat stimulation.

    PubMed

    Thompson, T; Keogh, E; Chen, M J-L; French, C C

    2012-03-01

    While previous research has indicated that the relative efficacy of attentional strategies on pain may be influenced by anxiety sensitivity (AS) and sex, no study appears to have examined this within the context of an emotion-focus versus distraction paradigm. The present study compared the effect of attentional emotion-focus and distraction instructions on pain response with noxious heat stimulation in 114 healthy adults (62 women and 52 men) varying in levels of AS. Results indicated that men reported a significantly higher mean tolerance time than women. Moderated regression analysis also revealed a significant strategy × anxiety sensitivity × sex interaction on pain tolerance. For those low in AS, relative efficacy was dependent upon sex, with distraction superior to emotion-focusing in women, but with strategies equivalent in men. For those high in AS, however, distraction resulted in uniformly greater pain tolerance than attentional emotion-focusing. These results indicate that AS and sex may be influential in determining the relative effectiveness of distraction and emotion-based attentional strategies for pain management.

  14. Responses of the antennal bimodal hygroreceptor neurons to innocuous and noxious high temperatures in the carabid beetle, Pterostichus oblongopunctatus.

    PubMed

    Nurme, Karin; Merivee, Enno; Must, Anne; Sibul, Ivar; Muzzi, Maurizio; Di Giulio, Andrea; Williams, Ingrid; Tooming, Ene

    2015-10-01

    Electrophysiological responses of thermo- and hygroreceptor neurons from antennal dome-shaped sensilla of the carabid beetle Pterostichus oblongopunctatus to different levels of steady temperature ranging from 20 to 35°C and rapid step-changes in it were measured and analysed at both constant relative and absolute ambient air humidity conditions. It appeared that both hygroreceptor neurons respond to temperature which means that they are bimodal. For the first time in arthropods, the ability of antennal dry and moist neurons to produce high temperature induced spike bursts is documented. Burstiness of the spike trains is temperature dependent and increases with temperature increase. Threshold temperatures at which the two neurons switch from regular spiking to spike bursting are lower compared to that of the cold neuron, differ and approximately coincide with the upper limit of preferred temperatures of the species. We emphasise that, in contrast to various sensory systems studied, the hygroreceptor neurons of P. oblongopunctatus have stable and continuous burst trains, no temporal information is encoded in the timing of the bursts. We hypothesise that temperature dependent spike bursts produced by the antennal thermo- and hygroreceptor neurons may be responsible for detection of noxious high temperatures important in behavioural thermoregulation of carabid beetles.

  15. Concurrent conditioned taste aversion: a learning mechanism based on rapid neural versus flexible humoral processing of visceral noxious substances.

    PubMed

    Mediavilla, Cristina; Molina, Filomena; Puerto, Amadeo

    2005-01-01

    Taste aversion learning (TAL) consists of the avoidance of a taste previously associated with a noxious visceral stimulus. Clinical and experimental studies suggest that this adaptive process can be established by different procedures that imply distinct forms of learning and memory, although the final result is analogous, i.e. avoidance of the gustatory stimulus associated with gastrointestinal discomfort. In fact, a double neurobiological system has been anatomically dissociated and, functionally, may be implicated in nausea and emesis, in food selection, and in neuroimmune interactions. Actually, a dual, parallel, and non-redundant gut-brain system has been proposed that sustain two different TAL modalities, concurrent and sequential. Concurrent TAL requires several trials and is inflexible, requiring simultaneity of the stimuli and the participation of the vagus nerve. In contrast, sequential TAL can be acquired in one trial and is flexible, permits long inter-stimulus delays, and is independent of vagal pathways. These two TAL modalities are analyzed in the light of the recent proposal that different acquisition processes are sustained by distinct cerebral systems.

  16. Amorpha fruticosa – A Noxious Invasive Alien Plant in Europe or a Medicinal Plant against Metabolic Disease?

    PubMed Central

    Kozuharova, Ekaterina; Matkowski, Adam; Woźniak, Dorota; Simeonova, Rumiana; Naychov, Zheko; Malainer, Clemens; Mocan, Andrei; Nabavi, Seyed M.; Atanasov, Atanas G.

    2017-01-01

    Amorpha fruticosa L. (Fabaceae) is a shrub native to North America which has been cultivated mainly for its ornamental features, honey plant value and protective properties against soil erosion. It is registered amongst the most noxious invasive species in Europe. However, a growing body of scientific literature also points to the therapeutic potential of its chemical constituents. Due to the fact that A. fruticosa is an aggressive invasive species, it can provide an abundant and cheap resource of plant chemical constituents which can be utilized for therapeutic purposes. Additionally, exploitation of the biomass for medicinal use might contribute to relieving the destructive impact of this species on natural habitats. The aim of this review is to provide a comprehensive summary and systematize the state-of-the-art in the knowledge of the phytochemical composition and the potential of A. fruticosa in disease treatment and prevention, with especial emphasis on diabetes and metabolic syndrome. Also reviewed are aspects related to potential toxicity of A. fruticosa which has not yet been systematically evaluated in human subjects. PMID:28642702

  17. The balance between cytoplasmic and nuclear CaM Kinase-1 signaling controls the operating range of noxious heat avoidance

    PubMed Central

    Schild, Lisa C.; Zbinden, Laurie; Bell, Harold W.; Yu, Yanxun V.; Sengupta, Piali; Goodman, Miriam B.; Glauser, Dominique A.

    2015-01-01

    SUMMARY Through encounters with predators, competitors, and noxious stimuli, animals have evolved defensive responses that minimize injury and are essential for survival. Physiological adaptation modulates the stimulus intensities that trigger such nocifensive behaviors, but the molecular networks that define their operating range are largely unknown. Here, we identify a novel, gain-of-function allele of the cmk-1 CaMKI gene in C. elegans and show that loss of the regulatory domain of the CaMKI enzyme produces thermal analgesia and shifts the operating range for nocifensive heat avoidance to higher temperatures. Such analgesia depends on nuclear CMK-1 signaling, while cytoplasmic CMK-1 signaling lowers the threshold for thermal avoidance. CMK-1 acts downstream of heat detection in thermal receptor neurons and controls neuropeptide release. Our results establish CaMKI as a key regulator of the operating range for nocifensive behaviors, and suggest strategies for producing thermal analgesia through the regulation of CaMKI-dependent signaling. PMID:25467982

  18. Effects of Lactobacillus acidophilus supplementation on growth performance, nutrient digestibility, fecal microbial and noxious gas emission in weaning pigs.

    PubMed

    Lan, Ruixia; Koo, Jinmo; Kim, Inho

    2017-03-01

    Antibiotics used as growth promoters in livestock have been banned in the European Union since 2006. Antibiotics alternatives have focused on probiotics, such as Lactobacillus acidophilus. The concentration of L. acidophilus is considered crucial for obtaining the desired effects. However, limited studies have been conducted to test the dose-dependent effects of L. acidophilus. Therefore, the present study aimed to test the dose-dependent effects of L. acidophilus on growth performance, nutrient digestibility, fecal microbial flora and fecal noxious gas emission in weaning pigs. Lactobacillus acidophilus supplementation increased (P < 0.05) average daily gain, average daily feed intake, apparent nutrient digestibility of dry matter, nitrogen and gross energy, and Lactobacillus counts compared to the basal diet treatment, and a linear effect (P < 0.05) was observed on those criteria. Escherichia coli counts and NH3 emission were decreased (P < 0.05) by L. acidophilus supplementation, and a linear effect (P < 0.05) was observed on E. coli counts. These results suggest that L. acidophilus could be used as an antibiotic alternative by improving growth performance, nutrient digestibility and gut balance (i.e. increased Lactobacillus counts and decreased E. coli counts), and decreasing NH3 emission, of weaning pigs. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. Diffusion bonding

    DOEpatents

    Anderson, Robert C.

    1976-06-22

    1. A method for joining beryllium to beryllium by diffusion bonding, comprising the steps of coating at least one surface portion of at least two beryllium pieces with nickel, positioning a coated surface portion in a contiguous relationship with an other surface portion, subjecting the contiguously disposed surface portions to an environment having an atmosphere at a pressure lower than ambient pressure, applying a force upon the beryllium pieces for causing the contiguous surface portions to abut against each other, heating the contiguous surface portions to a maximum temperature less than the melting temperature of the beryllium, substantially uniformly decreasing the applied force while increasing the temperature after attaining a temperature substantially above room temperature, and maintaining a portion of the applied force at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions.

  20. Peripheral noxious stimulation reduces withdrawal threshold to mechanical stimuli after spinal cord injury: Role of tumor necrosis factor alpha and apoptosis

    PubMed Central

    Woller, Sarah A.; Huie, J. Russell; Hartman, John J.; Hook, Michelle A.; Miranda, Rajesh C.; Huang, Yung-Jen; Ferguson, Adam R.; Grau, James W.

    2014-01-01

    We previously showed that peripheral noxious input after spinal cord injury (SCI) inhibits beneficial spinal plasticity and impairs recovery of locomotor and bladder functions. These observations suggest that noxious input may similarly affect the development and maintenance of chronic neuropathic pain, an important consequence of SCI. In adult rats with a moderate contusion SCI, we investigated the effect of noxious tail stimulation, administered one day after SCI, on mechanical withdrawal responses to von Frey stimuli from 1 to 28 days, post-treatment. In addition, because the pro-inflammatory cytokine tumor necrosis factor α (TNFα) is implicated in numerous injury-induced processes including pain hypersensitivity, we assessed the temporal and spatial expression of TNFα, TNF receptors, and several downstream signaling targets after stimulation. Our results showed that unlike sham surgery or SCI only, nociceptive stimulation following SCI induced mechanical sensitivity by 24 hours. These behavioral changes were accompanied by increased expression of TNFα. Cellular assessments of downstream targets of TNFα revealed that nociceptive stimulation increased the expression of caspase 8 and the active subunit (12 kDa) of caspase 3 at a time point consistent with the onset of mechanical allodynia, indicative of active apoptosis. In addition, immunohistochemical analysis revealed distinct morphological signs of apoptosis in neurons and microglia at 24 hours post-stimulation. Interestingly, expression of the inflammatory mediator NFκB was unaltered by nociceptive stimulation. These results suggest that noxious input caudal to the level of SCI can increase the onset and expression of behavioral responses indicative of pain, potentially involving TNFα signaling. PMID:25180012

  1. Peripheral noxious stimulation reduces withdrawal threshold to mechanical stimuli after spinal cord injury: role of tumor necrosis factor alpha and apoptosis.

    PubMed

    Garraway, Sandra M; Woller, Sarah A; Huie, J Russell; Hartman, John J; Hook, Michelle A; Miranda, Rajesh C; Huang, Yung-Jen; Ferguson, Adam R; Grau, James W

    2014-11-01

    We previously showed that peripheral noxious input after spinal cord injury (SCI) inhibits beneficial spinal plasticity and impairs recovery of locomotor and bladder functions. These observations suggest that noxious input may similarly affect the development and maintenance of chronic neuropathic pain, an important consequence of SCI. In adult rats with a moderate contusion SCI, we investigated the effect of noxious tail stimulation, administered 1 day after SCI on mechanical withdrawal responses to von Frey stimuli from 1 to 28 days after treatment. In addition, because the proinflammatory cytokine tumor necrosis factor alpha (TNFα) is implicated in numerous injury-induced processes including pain hypersensitivity, we assessed the temporal and spatial expression of TNFα, TNF receptors, and several downstream signaling targets after stimulation. Our results showed that unlike sham surgery or SCI only, nociceptive stimulation after SCI induced mechanical sensitivity by 24h. These behavioral changes were accompanied by increased expression of TNFα. Cellular assessments of downstream targets of TNFα revealed that nociceptive stimulation increased the expression of caspase 8 and the active subunit (12 kDa) of caspase 3, indicative of active apoptosis at a time point consistent with the onset of mechanical allodynia. In addition, immunohistochemical analysis revealed distinct morphological signs of apoptosis in neurons and microglia at 24h after stimulation. Interestingly, expression of the inflammatory mediator NFκB was unaltered by nociceptive stimulation. These results suggest that noxious input caudal to the level of SCI can increase the onset and expression of behavioral responses indicative of pain, potentially involving TNFα signaling. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  2. Cardiopulmonary effects of three concentrations of isoflurane with or without mechanical ventilation and supramaximal noxious stimulation in New Zealand white rabbits.

    PubMed

    Barter, Linda S; Epstein, Steven E

    2013-10-01

    To determine the cardiopulmonary effects of 3 doses of isoflurane, with and without controlled mechanical ventilation and noxious stimulation, in healthy adult New Zealand white rabbits. 6 adult female rabbits. Each rabbit was administered isoflurane in oxygen at each of 3 anesthetic doses (1.0, 1.5, or 2.0 times the published minimum alveolar concentration of 2.07%). At each anesthetic dose, blood gas and cardiopulmonary measurements were obtained before and during application of a supramaximal noxious stimulus. Effects of spontaneous and mechanical ventilation were assessed during separate anesthetic episodes. Mean ± SEM isoflurane concentrations used were 2.11 ± 0.04%, 3.14 ± 0.07%, and 4.15 ± 0.06%. During spontaneous ventilation, the rabbits' Paco2 and mixed venous Pco2 significantly increased with concomitant reductions in both arterial and mixed venous pH as isoflurane concentration increased. Cardiac output and vascular resistance did not change significantly. Noxious stimulation minimally affected measured cardiopulmonary variables. During mechanical ventilation, significant reductions in arterial blood pressures and cardiac output occurred with increasing isoflurane dose. Systemic vascular resistance index at the highest anesthetic dose was significantly lower than the value at the lowest anesthetic dose. During noxious stimulation, systolic arterial blood pressure and cardiac output significantly increased at the 2 lower isoflurane concentrations, but not at the highest concentration. In rabbits, isoflurane-induced dose-dependent cardiopulmonary depression was attributable to vasodilation and negative inotropy. At an isoflurane concentration of 4.15% with mechanical ventilation, cardiovascular depression was severe; use of unnecessarily high isoflurane concentrations in this species should be avoided.

  3. La3+ Alters the Response Properties of Neurons in the Mouse Primary Somatosensory Cortex to Low-Temperature Noxious Stimulation of the Dental Pulp

    PubMed Central

    Jin, Yanjiao

    2015-01-01

    Although dental pain is a serious health issue with high incidence among the human population, its cellular and molecular mechanisms are still unclear. Transient receptor potential (TRP) channels are assumed to be involved in the generation of dental pain. However, most of the studies were conducted with molecular biological or histological methods. In vivo functional studies on the role of TRP channels in the mechanisms of dental pain are lacking. This study uses in vivo cellular electrophysiological and neuropharmacological method to directly disclose the effect of LaCl3, a broad spectrum TRP channel blocker, on the response properties of neurons in the mouse primary somatosensory cortex to low-temperature noxious stimulation of the dental pulp. It was found that LaCl3 suppresses the high-firing-rate responses of all nociceptive neurons to noxious low-temperature stimulation and also inhibits the spontaneous activities in some nonnociceptive neurons. The effect of LaCl3 is reversible. Furthermore, this effect is persistent and stable unless LaCl3 is washed out. Washout of LaCl3 quickly revitalized the responsiveness of neurons to low-temperature noxious stimulation. This study adds direct evidence for the hypothesis that TRP channels are involved in the generation of dental pain and sensation. Blockade of TRP channels may provide a novel therapeutic treatment for dental pain. PMID:26604777

  4. Correlation of Netilmicin Agar Dilution and Disk Diffusion Susceptibilities

    PubMed Central

    Goldmann, Donald A.; Syriopoulou, Georgia Ph.; Semple, Anne Markley

    1977-01-01

    A study of 283 isolates of gram-negative bacilli revealed a good correlation (r = −0.74) between disk diffusion zones of inhibition and agar dilution minimal inhibitory concentrations. Regression analysis suggested that strains with zone sizes ⋜11 mm should be considered resistant, but 34 of 45 strains resistant by minimal inhibitory concentration (including 27 strains of Pseudomonas aeruginosa) would have been called susceptible using this break point. PMID:900923

  5. DIFFUSION PUMP

    DOEpatents

    Levenson, L.

    1963-09-01

    A high-vacuum diffusion pump is described, featuring a novel housing geometry for enhancing pumping speed. An upright, cylindrical lower housing portion is surmounted by a concentric, upright, cylindrical upper housing portion of substantially larger diameter; an uppermost nozzle, disposed concentrically within the upper portion, is adapted to eject downwardly a conical sheet of liquid outwardly to impinge upon the uppermost extremity of the interior wall of the lower portion. Preferably this nozzle is mounted upon a pedestal rising coaxially from within the lower portion and projecting up into said upper portion. (AEC)

  6. Sleep Deprivation and Recovery Sleep Prior to a Noxious Inflammatory Insult Influence Characteristics and Duration of Pain

    PubMed Central

    Vanini, Giancarlo

    2016-01-01

    Study Objectives: Insufficient sleep and chronic pain are public health epidemics. Sleep loss worsens pain and predicts the development of chronic pain. Whether previous, acute sleep loss and recovery sleep determine pain levels and duration remains poorly understood. This study tested whether acute sleep deprivation and recovery sleep prior to formalin injection alter post-injection pain levels and duration. Methods: Male Sprague-Dawley rats (n = 48) underwent sleep deprivation or ad libitum sleep for 9 hours. Thereafter, rats received a subcutaneous injection of formalin or saline into a hind paw. In the recovery sleep group, rats were allowed 24 h between sleep deprivation and the injection of formalin. Mechanical and thermal nociception were assessed using the von Frey test and Hargreaves' method. Nociceptive measures were performed at 1, 3, 7, 10, 14, 17 and 21 days post-injection. Results: Formalin caused bilateral mechanical hypersensitivity (allodynia) that persisted for up to 21 days post-injection. Sleep deprivation significantly enhanced bilateral allodynia. There was a synergistic interaction when sleep deprivation preceded a formalin injection. Rats allowed a recovery sleep period prior to formalin injection developed allodynia only in the injected limb, with higher mechanical thresholds (less allodynia) and a shorter recovery period. There were no persistent changes in thermal nociception. Conclusion: The data suggest that acute sleep loss preceding an inflammatory insult enhances pain and can contribute to chronic pain. The results encourage studies in a model of surgical pain to test whether enhancing sleep reduces pain levels and duration. Citation: Vanini G. Sleep deprivation and recovery sleep prior to a noxious inflammatory insult influence characteristics and duration of pain. SLEEP 2016;39(1):133–142. PMID:26237772

  7. Cerebrovascular responses of the rat brain to noxious stimuli as examined by functional near-infrared whole brain imaging

    PubMed Central

    He, Ji-Wei; Tian, Fenghua; Liu, Hanli

    2012-01-01

    While near-infrared (NIR) spectroscopy has been increasingly used to detect stimulated brain activities with an advantage of dissociating regional oxy- and deoxyhemoglobin concentrations simultaneously, it has not been utilized much in pain research. Here, we investigated and demonstrated the feasibility of using this technique to obtain whole brain hemodynamics in rats and speculated on the functional relevance of the NIR-based hemodynamic signals during pain processing. NIR signals were emitted and collected using a 26-optodes array on rat's dorsal skull surface after the removal of skin. Following the subcutaneous injection of formalin (50 μl, 3%) into a hindpaw, several isolable brain regions showed hemodynamic changes, including the anterior cingulate cortex, primary/secondary somatosensory cortexes, thalamus, and periaqueductal gray (n = 6). Time courses of hemodynamic changes in respective regions matched with the well-documented biphasic excitatory response. Surprisingly, an atypical pattern (i.e., a decrease in oxyhemoglobin concentration with a concomitant increase in deoxyhemoglobin concentration) was seen in phase II. In a separate group of rats with innocuous brush and noxious pinch of the same area (n = 11), results confirmed that the atypical pattern occurred more likely in the presence of nociception than nonpainful stimulation, suggesting it as a physiological substrate when the brain processes pain. In conclusion, the NIR whole brain imaging provides a useful alternative to study pain in vivo using small-animal models. Our results support the notion that neurovascular response patterns depend on stimuli, bringing attention to the interpretation of vascular-based neuroimaging data in studies of pain. PMID:22378174

  8. Investigation of human frontal cortex under noxious thermal stimulation of temporo-mandibular joint using functional near infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Yennu, Amarnath; Rawat, Rohit; Manry, Michael T.; Gatchel, Robert; Liu, Hanli

    2013-03-01

    According to American Academy of Orofacial Pain, 75% of the U.S. population experiences painful symptoms of temporo-mandibular joint and muscle disorder (TMJMD) during their lifetime. Thus, objective assessment of pain is crucial for efficient pain management. We used near infrared spectroscopy (NIRS) as a tool to explore hemodynamic responses in the frontal cortex to noxious thermal stimulation of temporomadibular joint (TMJ). NIRS experiments were performed on 9 healthy volunteers under both low pain stimulation (LPS) and high pain stimulation (HPS), using a temperature-controlled thermal stimulator. To induce thermal pain, a 16X16 mm2 thermode was strapped onto the right TMJ of each subject. Initially, subjects were asked to rate perceived pain on a scale of 0 to 10 for the temperatures from 41°C to 47°C. For the NIRS measurement, two magnitudes of temperatures, one rated as 3 and another rated as 7, were chosen as LPS and HPS, respectively. By analyzing the temporal profiles of changes in oxy-hemoglobin concentration (HbO) using cluster-based statistical tests, we were able to identify several regions of interest (ROI), (e.g., secondary somatosensory cortex and prefrontal cortex), where significant differences (p<0.05) between HbO responses to LPS and HPS are shown. In order to classify these two levels of pain, a neural-network-based classification algorithm was used. With leave-one-out cross validation from 9 subjects, the two levels of pain were identified with 100% mean sensitivity, 98% mean specificity and 99% mean accuracy to high pain. From the receiver operating characteristics curve, 0.99 mean area under curve was observed.

  9. A combined electrophysiological and morphological study of neuropeptide Y-expressing inhibitory interneurons in the spinal dorsal horn of the mouse.

    PubMed

    Iwagaki, Noboru; Ganley, Robert P; Dickie, Allen C; Polgár, Erika; Hughes, David I; Del Rio, Patricia; Revina, Yulia; Watanabe, Masahiko; Todd, Andrew J; Riddell, John S

    2016-03-01

    The spinal dorsal horn contains numerous inhibitory interneurons that control transmission of somatosensory information. Although these cells have important roles in modulating pain, we still have limited information about how they are incorporated into neuronal circuits, and this is partly due to difficulty in assigning them to functional populations. Around 15% of inhibitory interneurons in laminae I-III express neuropeptide Y (NPY), but little is known about this population. We therefore used a combined electrophysiological/morphological approach to investigate these cells in mice that express green fluorescent protein (GFP) under control of the NPY promoter. We show that GFP is largely restricted to NPY-immunoreactive cells, although it is only expressed by a third of those in lamina I-II. Reconstructions of recorded neurons revealed that they were morphologically heterogeneous, but never islet cells. Many NPY-GFP cells (including cells in lamina III) appeared to be innervated by C fibres that lack transient receptor potential vanilloid-1, and consistent with this, we found that some lamina III NPY-immunoreactive cells were activated by mechanical noxious stimuli. Projection neurons in lamina III are densely innervated by NPY-containing axons. Our results suggest that this input originates from a small subset of NPY-expressing interneurons, with the projection cells representing only a minority of their output. Taken together with results of previous studies, our findings indicate that somatodendritic morphology is of limited value in classifying functional populations among inhibitory interneurons in the dorsal horn. Because many NPY-expressing cells respond to noxious stimuli, these are likely to have a role in attenuating pain and limiting its spread.

  10. Inhibitory effects of some plant essential oils against Arcobacter butzleri and potential for rosemary oil as a natural food preservative.

    PubMed

    Irkin, Reyhan; Abay, Secil; Aydin, Fuat

    2011-03-01

    We investigated the inhibitory activity of commercially marketed essential oils of mint, rosemary, orange, sage, cinnamon, bay, clove, and cumin against Arcobacter butzleri and Arcobacter skirrowii and the effects of the essential oil of rosemary against A. butzleri in a cooked minced beef system. Using the disc diffusion method to determine the inhibitory activities of these plant essential oils against strains of Arcobacter, we found that those of rosemary, bay, cinnamon, and clove had strong inhibitory activity against these organisms, whereas the essential oils of cumin, mint, and sage failed to show inhibitory activity against most of the Arcobacter strains tested. The 0.5% (vol/wt) essential oil of rosemary was completely inhibitory against A. butzleri in the cooked minced beef system at 4°C. These essential oils may be further investigated as a natural solution to the food industry by creating an additional barrier (hurdle technology) to inhibit the growth of Arcobacter strains.

  11. Transient inhibitory seizures mimicking crescendo TIAs.

    PubMed

    Lee, H; Lerner, A

    1990-01-01

    Somatic inhibitory seizures are thought to occur rarely. We describe a patient with somatic inhibitory seizures who initially presented with a clinical picture of crescendo transient ischemic attacks. He did not improve with anticoagulation, but the episodes ceased promptly after the administration of an anticonvulsant.

  12. The Diversity of Cortical Inhibitory Synapses

    PubMed Central

    Kubota, Yoshiyuki; Karube, Fuyuki; Nomura, Masaki; Kawaguchi, Yasuo

    2016-01-01

    The most typical and well known inhibitory action in the cortical microcircuit is a strong inhibition on the target neuron by axo-somatic synapses. However, it has become clear that synaptic inhibition in the cortex is much more diverse and complicated. Firstly, at least ten or more inhibitory non-pyramidal cell subtypes engage in diverse inhibitory functions to produce the elaborate activity characteristic of the different cortical states. Each distinct non-pyramidal cell subtype has its own independent inhibitory function. Secondly, the inhibitory synapses innervate different neuronal domains, such as axons, spines, dendrites and soma, and their inhibitory postsynaptic potential (IPSP) size is not uniform. Thus, cortical inhibition is highly complex, with a wide variety of anatomical and physiological modes. Moreover, the functional significance of the various inhibitory synapse innervation styles and their unique structural dynamic behaviors differ from those of excitatory synapses. In this review, we summarize our current understanding of the inhibitory mechanisms of the cortical microcircuit. PMID:27199670

  13. Developmental broadening of inhibitory sensory maps.

    PubMed

    Quast, Kathleen B; Ung, Kevin; Froudarakis, Emmanouil; Huang, Longwen; Herman, Isabella; Addison, Angela P; Ortiz-Guzman, Joshua; Cordiner, Keith; Saggau, Peter; Tolias, Andreas S; Arenkiel, Benjamin R

    2017-02-01

    Sensory maps are created by networks of neuronal responses that vary with their anatomical position, such that representations of the external world are systematically and topographically organized in the brain. Current understanding from studying excitatory maps is that maps are sculpted and refined throughout development and/or through sensory experience. Investigating the mouse olfactory bulb, where ongoing neurogenesis continually supplies new inhibitory granule cells into existing circuitry, we isolated the development of sensory maps formed by inhibitory networks. Using in vivo calcium imaging of odor responses, we compared functional responses of both maturing and established granule cells. We found that, in contrast to the refinement observed for excitatory maps, inhibitory sensory maps became broader with maturation. However, like excitatory maps, inhibitory sensory maps are sensitive to experience. These data describe the development of an inhibitory sensory map as a network, highlighting the differences from previously described excitatory maps.

  14. Inhibitory effect of Zanthoxylum bungeanum essential oil (ZBEO) on Escherichia coli and intestinal dysfunction.

    PubMed

    Hong, Lei; Jing, Wu; Qing, Wang; Anxiang, Su; Mei, Xue; Qin, Liu; Qiuhui, Hu

    2017-03-10

    The inhibitory effects of Zanthoxylum bungeanum essential oil (ZBEO) on Escherichia coli (E. coli) in vitro and in vivo were investigated, as well as its function of improvement of intestinal health. The results of in vitro studies, such as minimal inhibitory concentration (MIC) analysis, agar disc diffusion test and growth curve analysis of E. coli, showed that ZBEO had an excellent inhibitory effect on the growth of E. coli, which may be related to the loss of the normal shape of the cell membranes and the leakage of intracellular constituents, on the basis of SEM observation and cell constituents' release assay. ZBEO also had an inhibitory effect on enteritis and intestinal dysfunction induced by infection of E. coli in vivo, and histopathological observation indicated that ZBEO could markedly ameliorate the structural destruction of intestinal tissues, which might be related to its inhibitory effect on the gene expression of inflammatory cytokines (TLR2, TLR4, TNFα and IL-8). In conclusion, ZBEO showed an excellent inhibitory effect on E. coli both in vitro and in vivo, suggesting the potential application of ZBEO as a kind of functional component having the effects of improving intestinal function and health.

  15. Using early life stages of marine animals to screen the toxicity of priority hazardous and noxious substances.

    PubMed

    Cunha, Isabel; Torres, Tiago; Oliveira, Helena; Martins, Rosário; McGowan, Thomas; Sheahan, David; Santos, Miguel Machado

    2017-04-01

    This study provides toxicity values for early life stages (ELS) of two phylogenetically distinct marine animal taxa, the sea urchin (Paracentrotus lividus), a deuterostome invertebrate, and the turbot (Scophthalmus maximus), a vertebrate (teleost), when challenged by six hazardous and noxious substances (HNS): aniline, butyl acrylate, m-cresol, cyclohexylbenzene, hexane and trichloroethylene. The aim of the study was to provide preliminary information on toxic effects of representative and relevant priority HNS to assess the risk posed by spills to marine habitats and therefore improve preparedness and the response at the operational level. Selection criteria to include each compound in the study were (1) inclusion in the HASREP (2005) list; (2) presence on the priority list established by Neuparth et al. (2011); (3) paucity of toxicological data (TOXnet and ECOTOX) for marine organisms; (4) behaviour in the water according to the categories defined by the European Behaviour classification system (GESAMP 2002), by selecting compounds with different behaviours in water; and (5) physicochemical and toxicological properties, where available, in order to anticipate the most toxic compounds. Aniline and m-cresol were the most toxic compounds with no observed apical effect concentration (NOAEC) values for sea urchin ranging between 0.01 and 0.1 mg/L, followed by butyl acrylate and cyclohexylbenzene with NOAECs ranging between 0.1 and 1.0 mg/L and trichloroethylene with NOAEC values that were in the range between 1 and 10 mg/L, reflecting their behaviour in water, mostly vapour pressure, but also solubility and log Kow. Hexane was toxic only for turbot embryos, due to its neurotoxic effects, and not for sea urchin larvae, at concentrations in the range between 1 and 10 mg/L. The concentrations tested were of the same order of magnitude for both species, and it was observed that sea urchin embryos (length of the longest arm) are more sensitive than turbot eggs larvae

  16. The "plantar test" apparatus (Ugo Basile Biological Apparatus), a controlled infrared noxious radiant heat stimulus for precise withdrawal latency measurement in the rat, as a tool for humans?

    PubMed

    Montagne-Clavel, J; Oliveras, J L

    1996-01-01

    In the present study, we precisely and automatically measured the withdrawal latency to noxious radiant heat application in unrestrained male rats and in human subjects of both sexes, by means of the "plantar test" apparatus (Ugo Basile Biological Apparatus). The infrared light stimulus of this tool was applied underneath the hindpaws of rats and the middle fingers of human subjects. With one right and one left stimulation every 10 min, we observed a decrease in latency over a 40-min testing period in rats; the latency reached a mean value of 5.08 +/- 0.25 sec after 40 min with a 36-W stimulus, which corresponded to 46.5 degrees C. In pilot experiments, also performed on rats, we showed that the opiate morphine (10 mg/kg, i.p.) produced remarkable increases of the withdrawal latency only in "naive" animals (i.e., ones that had never experienced the plantar test stimulus) and not in animals "habituated" to it. Among humans, we noted gender differences, such as less sensitivity to the infrared noxious radiant heat for women, particularly during the menstrual period. A difference from rats was that there was no significant latency modification along the 40-min testing period for either women or men, with a mean latency of 5.61 +/- 0.18 sec (47.5 degrees C) for the women and 4.39 +/- 0.10 sec (45.5 degrees C) for the men. These data confirm the reliability of the plantar test in rats, and demonstrate the possible use of an infrared source in human subjects as a noxious heat stimulus; the withdrawal reaction to this stimulus is emphasized as a good index of nociception in humans.

  17. Noxious mechanical stimulation evokes the segmental release of opioid peptides that induce μ-opioid receptor internalization in the presence of peptidase inhibitors

    PubMed Central

    Lao, Lijun; Song, Bingbing; Chen, Wenling; Marvizón, Juan Carlos G.

    2008-01-01

    The internalization of μ-opioid receptors (MORs) provides an ideal way to locate areas of opioid peptide release. We used this method to study opioid release in the spinal cord evoked by noxious stimuli in anesthetized rats. Previous studies have shown that opioids released in the spinal cord produce MOR internalization only when they are protected from peptidase degradation. Accordingly, rats were implanted with chronic intrathecal catheters that were used to inject a mixture of peptidase inhibitors (amastatin, captopril and phosphoramidon) onto the lumbar spinal cord. Five minutes later, a noxious stimulus was delivered to the paw. Lumbar spinal segments were double-stained with antibodies against MORs and neurokinin 1 receptors (NK1Rs) using immunofluorescence. Mechanical stimulation of the hindpaw consisted of repeated 10 sec clamps with a hemostat for 10 min. In the ipsilateral dorsal horn, the stimulus produced abundant NK1R internalization in segments L3–L6, and a more modest but significant MOR internalization in segments L5 and L6. In the contralateral dorsal horn, NK1R was substantially lower and MOR internalization was negligible. The same mechanical stimulus applied to a forepaw did not produce NK1R or MOR internalization in the lumbar spinal cord. Thermal stimulation consisted of immersing a hindpaw in water at 52 °C for 2 min. It produced substantial NK1R internalization ipsilaterally in segment L6, but no MOR internalization. These results show that mechanical stimulation induces segmental opioid release, i.e., in the dorsal horn receiving the noxious signals and not in other spinal segments. PMID:18207137

  18. Response of neurons in the thalamic nucleus submedius (Sm) to noxious stimulation and electrophysiological identification of on- and off-cells in rats.

    PubMed

    Fu, Jian-Jun; Tang, Jing-Shi; Yuan, Bin; Jia, Hong

    2002-09-01

    Previous studies have indicated that thalamic nucleus submedius (Sm) is involved in nociceptive modulation and plays an important role in an endogenous analgesic system (a feedback loop) consisting of spinal cord (Sc)-Sm-ventrolateral orbital cortex-periaqueductal gray-Sc. However, the function of different types of Sm neurons in nociceptive modulation is unclear. For this reason, on the basis of further studies of properties of the Sm neurons responding to noxious stimuli, the different effects of systemic morphine on the Sm neurons were examined and two classes of nociceptive modulatory neurons, named as off- and on-cells, in this region were identified in lightly anesthetized rats. The results showed that (1) most (84%, 132/157) of the Sm neurons responded to peripheral noxious stimuli. Of these neurons, 66% (n = 87) were inhibited, 34% (n = 45) excited. All neurons had very large and bilateral, even all body receptive fields. No neuron was found to be responsive to innocuous stimulation; (2) systemic morphine increased the firing rate of neurons inhibited by noxious stimulation, but decreased that of neurons excited by the same stimulation. Furthermore, the effects of morphine could be reversed by systemic naloxone; (3) 45 of Sm neurons examined could be divided into three different classes: off-cells that decreased the firing rate from tail heating just prior to occurrence of the tail-flick (TF) reflex (3140 +/- 167 ms, n = 27), on-cells that increased the firing rate just before the TF reflex (1720 +/- 240 ms, n = 8), and neutral-cells that did not respond to any stimuli and neuronal activities were not related to the TF reflex (n = 10). Findings of this study provided electrophysiological evidence for involvement of Sm neurons, as those in the rostral ventromedial medulla, in the opioid-receptor-mediated descending nociceptive modulation.

  19. Diffusion archeology for diffusion progression history reconstruction.

    PubMed

    Sefer, Emre; Kingsford, Carl

    2016-11-01

    Diffusion through graphs can be used to model many real-world processes, such as the spread of diseases, social network memes, computer viruses, or water contaminants. Often, a real-world diffusion cannot be directly observed while it is occurring - perhaps it is not noticed until some time has passed, continuous monitoring is too costly, or privacy concerns limit data access. This leads to the need to reconstruct how the present state of the diffusion came to be from partial diffusion data. Here, we tackle the problem of reconstructing a diffusion history from one or more snapshots of the diffusion state. This ability can be invaluable to learn when certain computer nodes are infected or which people are the initial disease spreaders to control future diffusions. We formulate this problem over discrete-time SEIRS-type diffusion models in terms of maximum likelihood. We design methods that are based on submodularity and a novel prize-collecting dominating-set vertex cover (PCDSVC) relaxation that can identify likely diffusion steps with some provable performance guarantees. Our methods are the first to be able to reconstruct complete diffusion histories accurately in real and simulated situations. As a special case, they can also identify the initial spreaders better than the existing methods for that problem. Our results for both meme and contaminant diffusion show that the partial diffusion data problem can be overcome with proper modeling and methods, and that hidden temporal characteristics of diffusion can be predicted from limited data.

  20. Excitatory and inhibitory learning with absent stimuli.

    PubMed

    Wheeler, Daniel S; Sherwood, Andrew; Holland, Peter C

    2008-04-01

    Three experiments showed that 2 associatively activated stimulus representations may engage in excitatory or inhibitory learning, depending on their temporal relationship. Experiment 1a suggested that simultaneously activated stimulus representations show evidence of inhibitory learning in an acquisition test. Experiment 1b showed similar evidence of inhibition in a summation test. Experiment 2 found that activation of 2 stimulus representations in a serial compound resulted in excitatory learning between the antecedent and the subsequent (forward) and inhibitory learning between the subsequent and the antecedent (backward). The results show the dynamic influence of temporal contiguity on mediated learning.

  1. NIST Diffusion Data Center

    National Institute of Standards and Technology Data Gateway

    NIST Diffusion Data Center (Web, free access)   The NIST Diffusion Data Center is a collection of over 14,100 international papers, theses, and government reports on diffusion published before 1980.

  2. Parallel flow diffusion battery

    DOEpatents

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  3. Parallel flow diffusion battery

    DOEpatents

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  4. FRACTIONAL PEARSON DIFFUSIONS.

    PubMed

    Leonenko, Nikolai N; Meerschaert, Mark M; Sikorskii, Alla

    2013-07-15

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change.

  5. FRACTIONAL PEARSON DIFFUSIONS

    PubMed Central

    Leonenko, Nikolai N.; Meerschaert, Mark M.

    2013-01-01

    Pearson diffusions are governed by diffusion equations with polynomial coefficients. Fractional Pearson diffusions are governed by the corresponding time-fractional diffusion equation. They are useful for modeling sub-diffusive phenomena, caused by particle sticking and trapping. This paper provides explicit strong solutions for fractional Pearson diffusions, using spectral methods. It also presents stochastic solutions, using a non-Markovian inverse stable time change. PMID:23626377

  6. Inhibitory Circuits in Cortical Layer 5

    PubMed Central

    Naka, Alexander; Adesnik, Hillel

    2016-01-01

    Inhibitory neurons play a fundamental role in cortical computation and behavior. Recent technological advances, such as two photon imaging, targeted in vivo recording, and molecular profiling, have improved our understanding of the function and diversity of cortical interneurons, but for technical reasons most work has been directed towards inhibitory neurons in the superficial cortical layers. Here we review current knowledge specifically on layer 5 (L5) inhibitory microcircuits, which play a critical role in controlling cortical output. We focus on recent work from the well-studied rodent barrel cortex, but also draw on evidence from studies in primary visual cortex and other cortical areas. The diversity of both deep inhibitory neurons and their pyramidal cell targets make this a challenging but essential area of study in cortical computation and sensory processing. PMID:27199675

  7. A quantification of the relationship between neuronal responses in the rat rostral ventromedial medulla and noxious stimulation-evoked withdrawal reflexes.

    PubMed

    Devonshire, I M; Kwok, C H T; Suvik, A; Haywood, A R; Cooper, A H; Hathway, G J

    2015-07-01

    The rostral ventromedial medulla (RVM) regulates a range of involuntary behaviours but is most often associated with nociception via the action of pronociceptive ON cells and antinociceptive OFF cells. The phasic responses of ON and OFF cells determine whether or not incoming noxious signals provoke a withdrawal reflex, and previous studies have suggested that reflex RVM activity patterns actively shape motor output. Here we challenged the model by using juvenile rats, which are known to exhibit markedly different reflex responses compared with adults. By recording single-cell activity in the RVM and the electromyography responses of hindlimb flexor muscles to noxious thermal stimulation we found that the juvenile reflex had a shorter onset latency, was larger in amplitude and exhibited a decreased rise time compared with the adult reflex. The responses of ON and OFF cells faithfully tracked the shorter onset latency of the reflex by also responding earlier and, thus, still preceded the reflex. However, neither the reflex amplitude nor the ongoing response profile was predicted by the firing rate of RVM cells in either age group. Instead we found a close correspondence between RVM activity and the reflex only during the initiation of the response. Furthermore, the short rise time of the juvenile reflex was reflected in higher rates of change of both ON and OFF cell firing. Our data suggest that the RVM is associated only with the initiation of reflexes and does not shape ongoing muscle activity, which is more likely to be subserved by downstream spinal processes.

  8. Prediction of movement following noxious stimulation during 1 minimum alveolar anesthetic concentration isoflurane/nitrous oxide anesthesia by means of middle latency auditory evoked responses.

    PubMed

    Leistritz, L; Kochs, E; Galicki, M; Witte, H

    2002-06-01

    This paper investigates the applicability of generalized dynamic neural networks for the design of a two-valued anesthetic depth indicator during isoflurane/nitrous oxide anesthesia. The indicator construction is based on the processing of middle latency auditory evoked responses (MLAER) in combination with the observation of the patient's movement reaction to skin incision. The framework of generalized dynamic neural networks does not require any data preprocessing, visual data inspection or subjective feature extraction. The study is based on a data set of 106 patients scheduled for elective surgery under isoflurane/nitrous oxide anesthesia. The processing of the measured MLAER is performed by a recurrent neural network that transforms the MLAER signals into signals having a very uncomplex structure. The evaluation of these signals is self-evident, and yields to a simple threshold classifier. Using only evoked potentials before the pain stimulus, the patient's reaction could be predicted with a probability of 81.5%. The MLAER is closely associated to the patient's reaction to skin incision following noxious stimulation during 1 minimum alveolar anesthetic concentration isoflurane/nitrous oxide anesthesia. In combination with other parameters, MLAER could contribute to an objective and trustworthy movement prediction to noxious stimulation.

  9. Diffusing diffusivity: Rotational diffusion in two and three dimensions

    NASA Astrophysics Data System (ADS)

    Jain, Rohit; Sebastian, K. L.

    2017-06-01

    We consider the problem of calculating the probability distribution function (pdf) of angular displacement for rotational diffusion in a crowded, rearranging medium. We use the diffusing diffusivity model and following our previous work on translational diffusion [R. Jain and K. L. Sebastian, J. Phys. Chem. B 120, 3988 (2016)], we show that the problem can be reduced to that of calculating the survival probability of a particle undergoing Brownian motion, in the presence of a sink. We use the approach to calculate the pdf for the rotational motion in two and three dimensions. We also propose new dimensionless, time dependent parameters, αr o t ,2 D and αr o t ,3 D, which can be used to analyze the experimental/simulation data to find the extent of deviation from the normal behavior, i.e., constant diffusivity, and obtain explicit analytical expressions for them, within our model.

  10. Spinothalamic and spinohypothalamic tract neurons in the cervical enlargement of rats. II. Responses to innocuous and noxious mechanical and thermal stimuli.

    PubMed

    Dado, R J; Katter, J T; Giesler, G J

    1994-03-01

    1. The goal of this study was to gather data that would increase our understanding of nociceptive processing by spinothalamic tract (STT) neurons that receive inputs from the hand and arm. Fifty neurons in the cervical enlargement of urethan-anesthetized rats were antidromically activated from the contralateral posterior thalamus. A stimulating electrode was moved systematically within an anterior-posterior plane in the thalamus until a point was located where the smallest amount of current antidromically activated the neuron. The antidromic thresholds at each of these lowest threshold points was < or = 30 microA; the mean antidromic threshold was 15.4 +/- 1.0 (SE) microA. Lowest threshold points were found primarily in the posterior thalamic group (Po), zona incerta, and in or near the supraoptic decussation. 2. The recording sites of 47 neurons were marked and recovered. Recording sites were located in the superficial dorsal horn (SDH, n = 15), deep dorsal horn (DDH, n = 31), and ventral horn (n = 1). Recording sites were located across the mediolateral extent of the SDH. Within the DDH, recording sites were concentrated laterally in nucleus proprius and dorsally in the lateral reticulated area. The locations of the recording points confirm previous anatomic descriptions of STT neurons in the cervical enlargement. 3. Cutaneous excitatory receptive fields were restricted to the ipsilateral forepaw or forelimb in 67% (10/15) of the neurons recorded in the SDH and 42% (13/31) of the neurons recorded in the DDH. Neurons having larger, more complex receptive fields were also commonly encountered. Thirty-three percent (5/15) of the neurons recorded in the SDH and 58% (18/31) recorded in the DDH had receptive fields that were often discontinuous and included areas of the ipsilateral shoulder, thorax, and head, including the face. 4. Innocuous and noxious mechanical stimuli were applied to the receptive field of each neuron. Fifty percent (25/50) responded to innocuous

  11. Novel thiourea-based sirtuin inhibitory warheads.

    PubMed

    Zang, Wenwen; Hao, Yujun; Wang, Zhenghe; Zheng, Weiping

    2015-08-15

    N(ε)-Thiocarbamoyl-lysine was recently demonstrated by our laboratory to be a potent catalytic mechanism-based SIRT1/2/3 inhibitory warhead, in the current study, among the prepared analogs of N(ε)-thiocarbamoyl-lysine with its terminal NH2 mono-substituted with alkyl and aryl groups, we found that N(ε)-methyl-thiocarbamoyl-lysine and N(ε)-carboxyethyl-thiocarbamoyl-lysine, respectively, also behaved as strong inhibitory warheads against SIRT1/2/3 and SIRT5, typical deacetylases and deacylase in the human sirtuin family, respectively. Moreover, N(ε)-methyl-thiocarbamoyl-lysine was found in the study to be a ∼ 2.5-18.4-fold stronger SIRT1/2/3 inhibitory warhead than its lead warhead N(ε)-thiocarbamoyl-lysine.

  12. Effects of non-steroidal anti-inflammatory drugs on the hyperalgesia to noxious mechanical stimulation induced by the application of a tourniquet to a forelimb of sheep.

    PubMed

    Welsh, E M; Nolan, A M

    1994-11-01

    A tourniquet was used in conjunction with a mechanical threshold testing device to investigate the suitability of the technique for the investigation of analgesic drugs in sheep. The changes to the mechanical thresholds to noxious stimulation during and after the inflation of a pneumatic tourniquet on a limb were recorded, and the influence of pre-treatment with two non-steroidal anti-inflammatory drugs was studied. Fentanyl, an opioid agonist with known analgesic properties in sheep, was used as a positive control. The tourniquet significantly reduced the mechanical thresholds on the ipsi- but not the contralateral limb. Pretreatment with either flunixin meglumine or carprofen attenuated the development of mechanical hyperalgesia, and fentanyl initially caused a significant anti-nociceptive effect. The time to aversion was not significantly different between the treatments. These results suggest that hyperalgesia induced by a tourniquet may be a useful technique for the investigation of the anti-nociceptive effects of analgesic drugs in sheep.

  13. Calcium/calmodulin dependent protein kinase II regulates the phosphorylation of cyclic AMP-responsive element-binding protein of spinal cord in rats following noxious stimulation.

    PubMed

    Fang, Li; Wu, Jing; Zhang, Xuan; Lin, Qing; Willis, William D

    2005-02-01

    We have previously reported that intradermal capsaicin injection causes the phosphorylation of cyclic adenosine monophosphate-responsive element-binding protein (CREB) in the spinal cord of rats. The present study was designed to investigate the role of calcium/camodulin protein dependent protein kinase II (CaM kinase II) in the regulation of phosphorylation of CREB after capsaicin injection. We found that capsaicin injection produces a significant upregulation of phosphorylated CREB in the spinal cord of rat. Intrathecal treatment with a CaM kinase II inhibitor, KN-93, significantly blocked the increased phosphorylation of CREB, but did not affect the CREB protein itself. These results suggest that increased phosphorylation of CREB protein may contribute to central sensitization following acute peripheral noxious stimuli, and the effect may be regulated through the activation of CaM kinase cascades.

  14. Effects of Repeated Morphine on Intracranial Self-Stimulation in Male Rats In the Absence or Presence of a Noxious Pain Stimulus

    PubMed Central

    Miller, Laurence L.; Altarifi, Ahmad A.; Negus, S. Stevens

    2015-01-01

    Research on opioid analgesics such as morphine suggests that expression of abuse-related effects increases with repeated exposure. Repeated exposure to opioids often occurs clinically in the context of pain management, and a major concern for clinicians is the risk of iatrogenic addiction and dependence in patients receiving opioids for treatment of pain. This study compared abuse-related morphine effects in male rats in an intracranial self-stimulation (ICSS) procedure after repeated treatment either with morphine alone or with morphine in combination with a repeated noxious stimulus (intraperitoneal administration of dilute acid). The study also permitted comparison of morphine potency and effectiveness to block acid-induced depression of ICSS (antinociception) and to produce enhanced facilitation of ICSS (abuse-related effect). There were three main findings. First, initial morphine exposure to drug naïve rats did not produce abuse-related ICSS facilitation. Second, repeated daily treatment with 3.2 mg/kg/day morphine for six days increased expression of ICSS facilitation. This occurred whether morphine was administered in the absence or presence of the noxious stimulus. Finally, a lower dose of 1.0 mg/kg/day morphine was sufficient to produce antinociception during repeated acid treatment, but this lower dose did not reliably increase abuse-related morphine effects. Taken together, these results suggest that prior morphine exposure can increase abuse liability of subsequent morphine treatments even when that morphine exposure occurs in the context of a pain state. However, it may be possible to relieve pain with relatively low morphine doses that do not produce increases in abuse-related morphine effects. PMID:26375515

  15. Hindlimb flexion withdrawal evoked by noxious heat in conscious rats: magnitude measurement of stimulus-response function, suppression by morphine and habituation.

    PubMed

    Carstens, E; Ansley, D

    1993-08-01

    1. The aim of this study was to develop a quantitative behavioral model of nociception. Electromyographic (EMG) recordings from a hamstring flexor muscle provided a measure of the magnitude of hindlimb withdrawals elicited by brief, graded noxious contact thermal stimuli applied to the hindpaw in conscious rats. 2. The magnitude of limb withdrawals showed a significant, usually linear, increase with stimulus temperature from a threshold of approximately 40 up to 52 degrees C. Stimulus-response functions of withdrawal magnitude versus temperature were reproducible within and across rats. Withdrawal magnitude was much more tightly correlated with stimulus temperature (r2 = 0.76, 0.73) than was withdrawal latency (r2 = 0.57, 0.55). 3. Systemic administration of the opiate analgesic morphine (3.5 mg/kg ip) suppressed withdrawals in a naloxone-reversible manner, such that the slope of the stimulus-response function was significantly reduced without an increase in threshold. 4. Successive withdrawals to repeated, identical noxious heat stimuli decreased in a manner consistent with habituation. The response recovered to the prehabituated level after a 15-min rest period, and subsequently decremented even more quickly. The decrement in withdrawal magnitude was greater at lower stimulus intensities and shorter interstimulus intervals, and transferred to a nearby (7.5 mm) but not distant (2.5 cm) site. Evidence for dishabituation was also obtained. 5. The advantages of this method as an animal model of nociception are presented and discussed in terms of the underlying neural circuitry and its modulation.

  16. Painful swelling after a noxious event and the development of complex regional pain syndrome 1: A one-year prospective study.

    PubMed

    Brunner, F; Bachmann, L M; Perez, R S G M; Marinus, J; Wertli, M M

    2017-10-01

    The timing of diagnosis of complex regional pain syndrome (CRPS) 1 remains a challenge due to the large heterogeneity of clinical presentations. We describe the distribution and differences in outcomes and clinical manifestations between time points and patient groups with and without CRPS 1 following an initiating event. Prospective cohort study with a consecutive registration of patients presenting with painful swelling of the affected extremity after an initiating event and follow-up visits after 3, 6 and 12 months. Forty-two patients were enrolled (37 females, mean age 55.1 years). At baseline, 35 participants (83%, females n = 30) fulfilled the diagnostic criteria for CRPS 1. At 3 months, 19 out of the initial 35 CRPS 1 patients (54%) did not meet the diagnostic criteria anymore. Besides our inclusion criteria of a painful swelling, early manifestations indicating a CRPS 1 primarily include an impaired quality of life (SF-35, EQ5-D), more pain (NRS, MPQ) and restricted range of motion. CRPS 1 develops within 8 weeks following a noxious event. Although many CRPS 1 patients reach partial remission within the first 3 months, signs and symptoms do not improve significantly at 1 year. In order to identify prognostic risk factors large prospective cohort studies are needed. This prospective cohort study follows patients with complaints most suspected for complex regional pain syndrome (CRPS) 1. CRPS 1 develops within 8 weeks following a noxious event. Although many CRPS 1 patients reach partial remission within the 3 months, symptoms do not improve significantly at 1 year. © 2017 European Pain Federation - EFIC®.

  17. The non-peptide neurokinin-1 antagonist, RPR 100893, decreases c-fos expression in trigeminal nucleus caudalis following noxious chemical meningeal stimulation.

    PubMed

    Cutrer, F M; Moussaoui, S; Garret, C; Moskowitz, M A

    1995-02-01

    The effect of RPR 100893, a selective and specific neurokinin-1 antagonist, or its enantiomer RPR 103253 was examined on c-fos antigen expression in brain stem and upper cervical cord 2 h after intracisternal capsaicin injection (30.5 micrograms/ml) in pentobarbital-anesthetized Hartley guinea-pigs. Positive cells were counted at three levels corresponding to obex, -2.25 mm and -6.75 mm in 18 sections (50 microns). Immunoreactivity was strongly expressed within laminae I and IIo of trigeminal nucleus caudalis, area postrema and the leptomeninges. Moderate labeling was present in the nucleus of the solitary tract and the medullary lateral reticular nucleus, whereas few positive cells were found in the ventral portion of the medullary reticular nucleus and Rexed laminae III-V and X. The distribution of labeled cells was consistent with previously reported results following subarachnoid placement of the noxious agents, blood or carrageenin. Pretreatment with RPR 100893 (1, 10 and 100 micrograms/kg, i.v.) but not its enantiomer (100 micrograms/kg, i.v.) 30 min prior to capsaicin injection significantly reduced the number of positive cells in the trigeminal nucleus caudalis (P < 0.01) in a dose-dependent manner, but not within area postrema or nucleus of the solitary tract. These results indicate that (i) the instillation of capsaicin into the subarachnoid space is an effective stimulus for the induction of c-fos antigen within trigeminal nucleus caudalis, presumably through activation of trigeminovascular afferents, and (ii) the neurokinin-1 antagonist RPR 100893 reduces the number of positive cells selectively within this nucleus. The findings are significant because drugs which alleviate vascular headaches decrease the number of c-fos-positive cells within trigeminal nucleus caudalis following noxious meningeal stimulation. Hence, strategies aimed at blocking the neurokinin-1 receptor may be useful for treating migraine and cluster headache.

  18. Heat and noxious chemical sensor, chicken TRPA1, as a target of bird repellents and identification of its structural determinants by multispecies functional comparison.

    PubMed

    Saito, Shigeru; Banzawa, Nagako; Fukuta, Naomi; Saito, Claire T; Takahashi, Kenji; Imagawa, Toshiaki; Ohta, Toshio; Tominaga, Makoto

    2014-03-01

    Nociceptive receptors enable animals to sense tissue-damaging stimuli, thus playing crucial roles in survival. Due to evolutionary diversification, responses of nociceptive receptors to specific stimuli can vary among species. Multispecies functional comparisons of nociceptive receptors help elucidate their evolutionary process and molecular basis for activation. The transient receptor potential ankyrin 1 (TRPA1) ion channel serves as a nociceptive receptor for chemical and thermal stimuli that is heat-activated in reptiles and frogs while potentially cold-activated in rodents. Here, we characterized channel properties of avian TRPA1 in chicken. Chicken TRPA1 was activated by noxious chemicals that also activate TRPA1 in other vertebrates. Regarding thermal sensitivity, chicken TRPA1 was activated by heat stimulation, but not cold, thus thermal sensitivity of avian TRPA1 does not coincide with rodent TRPA1, although both are homeotherms. Furthermore, in chicken sensory neurons, TRPA1 was highly coexpressed with TRPV1, another nociceptive heat and chemical receptor, similar to mammals and frogs. These results suggest that TRPA1 acted as a noxious chemical and heat receptor, and was coexpressed with TRPV1 in the ancestral terrestrial vertebrate. The acquisition of TRPV1 as a novel heat receptor in the ancestral terrestrial vertebrate is likely to have affected the functional evolution of TRPA1 regarding thermal sensitivity and led to the diversification among diverse vertebrate species. Additionally, we found for the first time that chicken TRPA1 is activated by methyl anthranilate (MA) and its structurally related chemicals used as nonlethal bird repellents. MA-induced responses were abolished by a TRPA1 antagonist in somatosensory neurons, indicating that TRPA1 acts as a MA receptor in chicken. Furthermore, TRPA1 responses to MA varied among five diverse vertebrate species. Utilizing species diversity and mutagenesis experiments, three amino acids were identified

  19. Effects of baclofen on mechanical noxious and innocuous transmission in the spinal dorsal horn of the adult rat: in vivo patch-clamp analysis.

    PubMed

    Fukuhara, Kaori; Katafuchi, Toshihiko; Yoshimura, Megumu

    2013-11-01

    The effects of a GABAB agonist, baclofen, on mechanical noxious and innocuous synaptic transmission in the substantia gelatinosa (SG) were investigated in adult rats with the in vivo patch-clamp technique. Under current-clamp conditions, perfusion with baclofen (10 μm) on the surface of the spinal cord caused hyperpolarisation of SG neurons and a decrease in the number of action potentials elicited by pinch and touch stimuli applied to the receptive field of the ipsilateral hindlimb. The suppression of action potentials was preserved under blockade of postsynaptic G-proteins, although baclofen-induced hyperpolarisation was completely blocked. These findings suggest presynaptic effects of baclofen on the induced action potentials. Under voltage-clamp conditions, application of baclofen reduced the frequency, but not the amplitude, of miniature excitatory postsynaptic currents (mEPSCs), whereas the GABAB receptor antagonist CGP55845 increased the frequency of mEPSCs without affecting the amplitude. Furthermore, application of a GABA uptake inhibitor, nipecotic acid, decreased the frequency of mEPSCs; this effect was blocked by CGP55845, but not by the GABAA antagonist bicuculline. Both the frequency and the amplitude of the pinch-evoked barrage of excitatory postsynaptic currents (EPSCs) were suppressed by baclofen in a dose-dependent manner. The frequency and amplitude of touch-evoked EPSCs was also suppressed by baclofen, but the suppression was significantly smaller than that of pinch-evoked EPSCs. We conclude that mechanical noxious transmission is presynaptically blocked through GABAB receptors in the SG, and is more effectively suppressed than innocuous transmission, which may account for a part of the mechanism of the efficient analgesic effects of baclofen.

  20. Microfabricated diffusion source

    DOEpatents

    Oborny, Michael C.; Frye-Mason, Gregory C.; Manginell, Ronald P.

    2008-07-15

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  1. Bilingualism Influences Inhibitory Control in Auditory Comprehension

    ERIC Educational Resources Information Center

    Blumenfeld, Henrike K.; Marian, Viorica

    2011-01-01

    Bilinguals have been shown to outperform monolinguals at suppressing task-irrelevant information. The present study aimed to identify how processing linguistic ambiguity during auditory comprehension may be associated with inhibitory control. Monolinguals and bilinguals listened to words in their native language (English) and identified them among…

  2. Neuraminidase inhibitory terpenes from endophytic Cochliobolus sp.

    PubMed

    Zhang, Gao-Fei; Guo, Zhi-Kai; Wang, Wei; Cui, Jiang-Tao; Tan, Ren-Xiang; Ge, Hui-Ming

    2011-08-01

    The chemical study of endophytic fungus of Cochliobolus led to the isolation of 10 terpenes (1-10), including one new compound named isocochlioquinone B (1). Their structures were elucidated on the basis of spectroscopic methods, including 2D NMR techniques. Compounds 5-7 showed significant neuraminidase inhibitory activity with IC(50) values of 0.79-1.75 μM.

  3. Inhibitory neurosteroids and the GABAA receptor.

    PubMed

    Seljeset, Sandra; Laverty, Duncan; Smart, Trevor G

    2015-01-01

    γ-Aminobutyric acid type A receptors (GABAARs) are vital proteins that are engaged in regulating neural circuit activity in the central nervous system. Their effectiveness in this task is dependent on the extent of receptor modulation by naturally occurring ligands that are released in the brain. One of the foremost examples of such ligands is the neurosteroids that can either potentiate GABAAR function or cause direct inhibition. To fully understand the underlying mechanisms by which neurosteroids modulate GABAARs, it is necessary to identify their binding sites on the receptors. For potentiating neurosteroids, recent work has made substantive progress in identifying a binding site located in the transmembrane domains of GABAAR α subunits. However, for the inhibitory neurosteroids, several possibilities exist including an ion channel site as well as potential sites in the transmembrane domain. This review systematically analyzes the evidence behind possible binding sites for the inhibitory neurosteroids. We consider the chemical structure-function properties of such inhibitory neurosteroids, their physiological effects on synaptic inhibition, and whether a binding site exists in the GABA ion channel or in other areas of the transmembrane domain. Finally, we discuss how structural homology modeling and Cys-loop receptor homologues may help to locate the inhibitory neurosteroid-binding site on GABAARs.

  4. Inhibitory ability of children with developmental dyscalculia.

    PubMed

    Zhang, Huaiying; Wu, Hanrong

    2011-02-01

    Inhibitory ability of children with developmental dyscalculia (DD) was investigated to explore the cognitive mechanism underlying DD. According to the definition of developmental dyscalculia, 19 children with DD-only and 10 children with DD&RD (DD combined with reading disability) were selected step by step, children in two control groups were matched with children in case groups by gender and age, and the match ratio was 1:1. Psychological testing software named DMDX was used to measure inhibitory ability of the subjects. The differences of reaction time in number Stroop tasks and differences of accuracy in incongruent condition of color-word Stroop tasks and object inhibition tasks between DD-only children and their controls reached significant levels (P<0.05), and the differences of reaction time in number Stroop tasks between dyscalculic and normal children did not disappear after controlling the non-executive components. The difference of accuracy in color-word incongruent tasks between children with DD&RD and normal children reached significant levels (P<0.05). Children with DD-only confronted with general inhibitory deficits, while children with DD&RD confronted with word inhibitory deficits only.

  5. Diffusion bonding aeroengine components

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, G. A.; Broughton, T.

    1988-10-01

    The use of diffusion bonding processes at Rolls-Royce for the manufacture of titanium-alloy aircraft engine components and structures is described. A liquid-phase diffusion bonding process called activated diffusion bonding has been developed for the manufacture of the hollow titanium wide chord fan blade. In addition, solid-state diffusion bonding is being used in the manufacture of hollow vane/blade airfoil constructions mainly in conjunction with superplastic forming and hot forming techniques.

  6. Inhibitory feedback required for network oscillatory responses to communication but not prey stimuli.

    PubMed

    Doiron, Brent; Chacron, Maurice J; Maler, Leonard; Longtin, André; Bastian, Joseph

    2003-01-30

    Stimulus-induced oscillations occur in visual, olfactory and somatosensory systems. Several experimental and theoretical studies have shown how such oscillations can be generated by inhibitory connections between neurons. But the effects of realistic spatiotemporal sensory input on oscillatory network dynamics and the overall functional roles of such oscillations in sensory processing are poorly understood. Weakly electric fish must detect electric field modulations produced by both prey (spatially localized) and communication (spatially diffuse) signals. Here we show, through in vivo recordings, that sensory pyramidal neurons in these animals produce an oscillatory response to communication-like stimuli, but not to prey-like stimuli. On the basis of well-characterized circuitry, we construct a network model of pyramidal neurons that predicts that diffuse delayed inhibitory feedback is required to achieve oscillatory behaviour only in response to communication-like stimuli. This prediction is experimentally verified by reversible blockade of feedback inhibition that removes oscillatory behaviour in the presence of communication-like stimuli. Our results show that a sensory system can use inhibitory feedback as a mechanism to 'toggle' between oscillatory and non-oscillatory firing states, each associated with a naturalistic stimulus.

  7. Acoustic diffusers III

    NASA Astrophysics Data System (ADS)

    Bidondo, Alejandro

    2002-11-01

    This acoustic diffusion research presents a pragmatic view, based more on effects than causes and 15 very useful in the project advance control process, where the sound field's diffusion coefficient, sound field diffusivity (SFD), for its evaluation. Further research suggestions are presented to obtain an octave frequency resolution of the SFD for precise design or acoustical corrections.

  8. Reduce Confusion about Diffusion.

    ERIC Educational Resources Information Center

    Hebrank, Mary R.

    1997-01-01

    Presents activities that allow students to explore the fundamental but poorly understood concept of diffusion by appealing to their kinesthetic senses first, then challenging their analytical skills as they try to deduce the mathematical principle involved. Presents a computer simulation of diffusion and discusses diffusion's limitations and…

  9. A Student Diffusion Activity

    ERIC Educational Resources Information Center

    Kutzner, Mickey; Pearson, Bryan

    2017-01-01

    Diffusion is a truly interdisciplinary topic bridging all areas of STEM education. When biomolecules are not being moved through the body by fluid flow through the circulatory system or by molecular motors, diffusion is the primary mode of transport over short distances. The direction of the diffusive flow of particles is from high concentration…

  10. Diffusion of tungsten hexafluoride

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of tungsten hexafluoride

  11. Reduce Confusion about Diffusion.

    ERIC Educational Resources Information Center

    Hebrank, Mary R.

    1997-01-01

    Presents activities that allow students to explore the fundamental but poorly understood concept of diffusion by appealing to their kinesthetic senses first, then challenging their analytical skills as they try to deduce the mathematical principle involved. Presents a computer simulation of diffusion and discusses diffusion's limitations and…

  12. Handbook on atmospheric diffusion

    SciTech Connect

    Hanna, S.R.; Briggs, G.A.; Hosker, R.P. Jr.

    1982-01-01

    Basic meteorological concepts are covered as well as plume rise, source effects, and diffusion models. Chapters are included on cooling tower plumes and urban diffusion. Suggestions are given for calculating diffusion in special situations, such as for instantaneous releases over complex terrain, over long distances, and during times when chemical reactions or dry or wet deposition are important. (PSB)

  13. Diffusion Strategy Guide.

    ERIC Educational Resources Information Center

    McCutcheon, James R.; Sanders, John R.

    A methodology is presented for planning and managing the spread of educational innovations. The first portion of the guide develops a theoretical framework for diffusion which summarizes and capitalizes on the latest marketing and on the latest marketing and diffusion research findings. Major stages in the diffusion paradigm discussed include…

  14. Diffusion of uranium hexafluoride

    NASA Astrophysics Data System (ADS)

    Winkelmann, J.

    This document is part of Subvolume A `Gases in Gases, Liquids and their Mixtures' of Volume 15 `Diffusion in Gases, Liquids and Electrolytes' of Landolt-Börnstein Group IV `Physical Chemistry'. It is part of the chapter of the chapter `Diffusion in Pure Gases' and contains data on diffusion of uranium hexafluoride

  15. A Student Diffusion Activity

    NASA Astrophysics Data System (ADS)

    Kutzner, Mickey; Pearson, Bryan

    2017-02-01

    Diffusion is a truly interdisciplinary topic bridging all areas of STEM education. When biomolecules are not being moved through the body by fluid flow through the circulatory system or by molecular motors, diffusion is the primary mode of transport over short distances. The direction of the diffusive flow of particles is from high concentration toward low concentration.

  16. Transient receptor potential ankyrin 1 is expressed by inhibitory motoneurons of the mouse intestine.

    PubMed

    Poole, Daniel P; Pelayo, Juan Carlos; Cattaruzza, Fiore; Kuo, Yien-Ming; Gai, Gregory; Chiu, Jonathon V; Bron, Romke; Furness, John B; Grady, Eileen F; Bunnett, Nigel W

    2011-08-01

    Transient receptor potential ankyrin (TRPA) 1, an excitatory ion channel expressed by sensory neurons, mediates somatic and visceral pain in response to direct activation or noxious mechanical stimulation. Although the intestine is routinely exposed to irritant alimentary compounds and inflammatory mediators that activate TRPA1, there is no direct evidence for functional TRPA1 receptors on enteric neurons, and the effects of TRPA1 activation on intestinal function have not been determined. We characterized expression of TRPA1 by enteric neurons and determined its involvement in the control of intestinal contractility and transit. TRPA1 expression was characterized by reverse-transcription polymerase chain reaction and immunofluorescence analyses. TRPA1 function was examined by Ca(2+) imaging and by assays of contractile activity and transit. We detected TRPA1 messenger RNA in the mouse intestine and TRPA1 immunoreactivity in enteric neurons. The cecum and colon had immunoreactivity for neuronal TRPA1, but the duodenum did not. TRPA1 immunoreactivity was also detected in inhibitory motoneurons and descending interneurons, cholinergic neurons, and intrinsic primary afferent neurons. TRPA1 activators, including cinnamaldehyde, allyl isothiocyanate (AITC), and 4-hydroxynonenal, increased [Ca(2+)](i) in myenteric neurons. These were reduced by a TRPA1 antagonist (HC-030031) or deletion of Trpa1. TRPA1 activation inhibited contractility of the segments of colon but not stomach or small intestine of Trpa1(+/+) but not Trpa1(-/-) mice; this effect was reduced by tetrodotoxin or N(G)-nitro-l-arginine methyl ester. Administration of AITC by gavage did not alter gastric emptying or small intestinal transit, but luminal AITC inhibited colonic transit via TRPA1. Functional TRPA1 is expressed by enteric neurons, and activation of neuronal TRPA1 inhibits spontaneous neurogenic contractions and transit of the colon. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All

  17. [Experimental study of the inhibitory effects of Chelidonium majus L. extractive on Streptococcus mutans in vitro].

    PubMed

    Cheng, Rui-bo; Chen, Xu; Liu, Shu-jie; Zhang, Xiao-fang; Zhang, Guang-he

    2006-06-01

    To study the inhibitory effects of Chelidonium majus L. extractive on the growth of Streptococcus mutans in vitro, and to explore its mechanism in caries prevention. Streptococcus mutans 25175 was chosen as the experimental bacterium. The Chelidonium majus L. extractives chelidonine and chelerythrine were double diluted to different concentrations by two-fold dilution. The inhibitory effect of Streptococcus mutans was measured by slip diffusion method. The minimal inhibitory concentration(MIC) was also determined. 0.16% liquor hibitane was used as positive control. Spearman correlation was used for statistical analysis. Inhibition zone of Streptococcus mutans appeared in some concentration of chelerythrine, but no inhibition zone in each concentration of chelidonine. The MIC of chelerythrine was 0.78 mg/ml which determined by liquid culture medium. The concentration of chelerythrine was highly related to the inhibitory zone of Streptococcus mutans (r=0.99, P<0.01). The antibacterial activity of Chelidonium majus L. extractive chelerythrine on Streptococcus mutans was significant,and the antibacterial activity of the concentration 100 mg/ml was higher than that of 0.16% liquor hibitane (19.4 mm), indicating that chelerythrine can be used as an agent for prevention of dental caries.

  18. Bi-functional peptides with both trypsin-inhibitory and antimicrobial activities are frequent defensive molecules in Ranidae amphibian skins.

    PubMed

    Yan, Xiuwen; Liu, Huan; Yang, Xuening; Che, Qiaolin; Liu, Rui; Yang, Hailong; Liu, Xiuhong; You, Dewen; Wang, Aili; Li, Jianxu; Lai, Ren

    2012-07-01

    Amphibian skins act as the first line against noxious aggression by microorganisms, parasites, and predators. Anti-microorganism activity is an important task of amphibian skins. A large amount of gene-encoded antimicrobial peptides (AMPs) has been identified from amphibian skins. Only a few of small protease inhibitors have been found in amphibian skins. From skin secretions of 5 species (Odorrana livida, Hylarana nigrovittata, Limnonectes kuhlii, Odorrana grahami, and Amolops loloensis) of Ranidae frogs, 16 small serine protease inhibitor peptides have been purified and characterized. They have lengths of 17-20 amino acid residues (aa). All of them are encoded by precursors with length of 65-70 aa. These small peptides show strong trypsin-inhibitory abilities. Some of them can exert antimicrobial activities. They share the conserved GCWTKSXXPKPC fragment in their primary structures, suggesting they belong to the same families of peptide. Signal peptides of precursors encoding these serine protease inhibitors share obvious sequence similarity with those of precursors encoding AMPs from Ranidae frogs. The current results suggest that these small serine protease inhibitors are the common defensive compounds in frog skin of Ranidae as amphibian skin AMPs.

  19. A unified framework for inhibitory control.

    PubMed

    Munakata, Yuko; Herd, Seth A; Chatham, Christopher H; Depue, Brendan E; Banich, Marie T; O'Reilly, Randall C

    2011-10-01

    Inhibiting unwanted thoughts, actions and emotions figures centrally in daily life, and the prefrontal cortex (PFC) is widely viewed as a source of this inhibitory control. We argue that the function of the PFC is best understood in terms of representing and actively maintaining abstract information, such as goals, which produces two types of inhibitory effects on other brain regions. Inhibition of some subcortical regions takes a directed global form, with prefrontal regions providing contextual information relevant to when to inhibit all processing in a region. Inhibition within neocortical (and some subcortical) regions takes an indirect competitive form, with prefrontal regions providing excitation of goal-relevant options. These distinctions are crucial for understanding the mechanisms of inhibition and how they can be impaired or improved. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. A unified framework for inhibitory control

    PubMed Central

    Munakata, Yuko; Herd, Seth A.; Chatham, Christopher H.; Depue, Brendan E.; Banich, Marie T.; O’Reilly, Randall C.

    2011-01-01

    Inhibiting unwanted thoughts, actions and emotions figures centrally in daily life, and the prefrontal cortex is widely viewed as a source of this inhibitory control. We argue that the function of the prefrontal cortex is best understood in terms of representing and actively maintaining abstract information such as goals, which produces two types of inhibitory effects on other brain regions. Inhibition of some subcortical regions takes a directed, global form, with prefrontal regions providing contextual information relevant to when to inhibit all processing in a region. Inhibition within neocortical (and some subcortical) regions takes an indirect, competitive form, with prefrontal regions providing excitation of goal-relevant options. These distinctions are critical for understanding the mechanisms of inhibition and how they can be impaired or improved. PMID:21889391

  1. Interactions between Autophagy and Inhibitory Cytokines

    PubMed Central

    Wu, Tian-tian; Li, Wei-Min; Yao, Yong-Ming

    2016-01-01

    Autophagy is a degradative pathway that plays an essential role in maintaining cellular homeostasis. Most early studies of autophagy focused on its involvement in age-associated degeneration and nutrient deprivation. However, the immunological functions of autophagy have become more widely studied in recent years. Autophagy has been shown to be an intrinsic cellular defense mechanism in the innate and adaptive immune responses. Cytokines belong to a broad and loose category of proteins and are crucial for innate and adaptive immunity. Inhibitory cytokines have evolved to permit tolerance to self while also contributing to the eradication of invading pathogens. Interactions between inhibitory cytokines and autophagy have recently been reported, revealing a novel mechanism by which autophagy controls the immune response. In this review, we discuss interactions between autophagy and the regulatory cytokines IL-10, transforming growth factor-β, and IL-27. We also mention possible interactions between two newly discovered cytokines, IL-35 and IL-37, and autophagy. PMID:27313501

  2. Circadian Plasticity of Mammalian Inhibitory Interneurons

    PubMed Central

    2017-01-01

    Inhibitory interneurons participate in all neuronal circuits in the mammalian brain, including the circadian clock system, and are indispensable for their effective function. Although the clock neurons have different molecular and electrical properties, their main function is the generation of circadian oscillations. Here we review the circadian plasticity of GABAergic interneurons in several areas of the mammalian brain, suprachiasmatic nucleus, neocortex, hippocampus, olfactory bulb, cerebellum, striatum, and in the retina. PMID:28367335

  3. Two networks of electrically coupled inhibitory neurons in neocortex

    NASA Astrophysics Data System (ADS)

    Gibson, Jay R.; Beierlein, Michael; Connors, Barry W.

    1999-11-01

    Inhibitory interneurons are critical to sensory transformations, plasticity and synchronous activity in the neocortex. There are many types of inhibitory neurons, but their synaptic organization is poorly understood. Here we describe two functionally distinct inhibitory networks comprising either fast-spiking (FS) or low-threshold spiking (LTS) neurons. Paired-cell recordings showed that inhibitory neurons of the same type were strongly interconnected by electrical synapses, but electrical synapses between different inhibitory cell types were rare. The electrical synapses were strong enough to synchronize spikes in coupled interneurons. Inhibitory chemical synapses were also common between FS cells, and between FS and LTS cells, but LTS cells rarely inhibited one another. Thalamocortical synapses, which convey sensory information to the cortex, specifically and strongly excited only the FS cell network. The electrical and chemical synaptic connections of different types of inhibitory neurons are specific, and may allow each inhibitory network to function independently.

  4. Context specificity of inhibitory control in dogs

    PubMed Central

    MacLean, Evan L.; Hare, Brian A.

    2014-01-01

    Across three experiments, we explored whether a dog's capacity for inhibitory control is stable or variable across decision-making contexts. In the social task, dogs were first exposed to the reputations of a stingy experimenter that never shared food and a generous experimenter who always shared food. In subsequent test trials, dogs were required to avoid approaching the stingy experimenter when this individual offered (but withheld) a higher-value reward than the generous experimenter did. In the A-not-B task, dogs were required to inhibit searching for food in a previously rewarded location after witnessing the food being moved from this location to a novel hiding place. In the cylinder task, dogs were required to resist approaching visible food directly (because it was behind a transparent barrier), in favor of a detour reaching response. Overall, dogs exhibited inhibitory control in all three tasks. However, individual scores were not correlated between tasks, suggesting that context has a large effect on dogs' behavior. This result mirrors studies of humans, which have highlighted intra-individual variation in inhibitory control as a function of the decision-making context. Lastly, we observed a correlation between a subject's age and performance on the cylinder task, corroborating previous observations of age-related decline in dogs' executive function. PMID:23584618

  5. Proactive inhibitory control: A general biasing account☆

    PubMed Central

    Elchlepp, Heike; Lavric, Aureliu; Chambers, Christopher D.; Verbruggen, Frederick

    2016-01-01

    Flexible behavior requires a control system that can inhibit actions in response to changes in the environment. Recent studies suggest that people proactively adjust response parameters in anticipation of a stop signal. In three experiments, we tested the hypothesis that proactive inhibitory control involves adjusting both attentional and response settings, and we explored the relationship with other forms of proactive and anticipatory control. Subjects responded to the color of a stimulus. On some trials, an extra signal occurred. The response to this signal depended on the task context subjects were in: in the ‘ignore’ context, they ignored it; in the ‘stop’ context, they had to withhold their response; and in the ‘double-response’ context, they had to execute a secondary response. An analysis of event-related brain potentials for no-signal trials in the stop context revealed that proactive inhibitory control works by biasing the settings of lower-level systems that are involved in stimulus detection, action selection, and action execution. Furthermore, subjects made similar adjustments in the double-response and stop-signal contexts, indicating an overlap between various forms of proactive action control. The results of Experiment 1 also suggest an overlap between proactive inhibitory control and preparatory control in task-switching studies: both require reconfiguration of task-set parameters to bias or alter subordinate processes. We conclude that much of the top-down control in response inhibition tasks takes place before the inhibition signal is presented. PMID:26859519

  6. Development of Inhibitory Timescales in Auditory Cortex

    PubMed Central

    Reyes, Alex D.

    2011-01-01

    The time course of inhibition plays an important role in cortical sensitivity, tuning, and temporal response properties. We investigated the development of L2/3 inhibitory circuitry between fast-spiking (FS) interneurons and pyramidal cells (PCs) in auditory thalamocortical slices from mice between postnatal day 10 (P10) and P29. We found that the maturation of the intrinsic and synaptic properties of both FS cells and their connected PCs influence the timescales of inhibition. FS cell firing rates increased with age owing to decreased membrane time constants, shorter afterhyperpolarizations, and narrower action potentials. Between FS–PC pairs, excitatory postsynaptic potentials (EPSPs) and inhibitory postsynaptic potentials (IPSPs) changed with age. The latencies, rise, and peak times of the IPSPs, as well as the decay constants of both EPSPs and IPSPs decreased between P10 and P29. In addition, decreases in short-term depression at excitatory PC–FS synapses resulted in more sustained synaptic responses during repetitive stimulation. Finally, we show that during early development, the temporal properties that influence the recruitment of inhibition lag those of excitation. Taken together, our results suggest that the changes in the timescales of inhibitory recruitment coincide with the development of the tuning and temporal response properties of auditory cortical networks. PMID:21068186

  7. Proactive inhibitory control: A general biasing account.

    PubMed

    Elchlepp, Heike; Lavric, Aureliu; Chambers, Christopher D; Verbruggen, Frederick

    2016-05-01

    Flexible behavior requires a control system that can inhibit actions in response to changes in the environment. Recent studies suggest that people proactively adjust response parameters in anticipation of a stop signal. In three experiments, we tested the hypothesis that proactive inhibitory control involves adjusting both attentional and response settings, and we explored the relationship with other forms of proactive and anticipatory control. Subjects responded to the color of a stimulus. On some trials, an extra signal occurred. The response to this signal depended on the task context subjects were in: in the 'ignore' context, they ignored it; in the 'stop' context, they had to withhold their response; and in the 'double-response' context, they had to execute a secondary response. An analysis of event-related brain potentials for no-signal trials in the stop context revealed that proactive inhibitory control works by biasing the settings of lower-level systems that are involved in stimulus detection, action selection, and action execution. Furthermore, subjects made similar adjustments in the double-response and stop-signal contexts, indicating an overlap between various forms of proactive action control. The results of Experiment 1 also suggest an overlap between proactive inhibitory control and preparatory control in task-switching studies: both require reconfiguration of task-set parameters to bias or alter subordinate processes. We conclude that much of the top-down control in response inhibition tasks takes place before the inhibition signal is presented.

  8. Proactive inhibitory control varies with task context.

    PubMed

    Wardak, Claire; Ramanoël, Stephen; Guipponi, Olivier; Boulinguez, Philippe; Ben Hamed, Suliann

    2012-12-01

    The goal of executive control is to adjust our behaviour to the environment. It involves not only the continuous planning and adaptation of actions but also the inhibition of inappropriate movements. Recently, a proactive form of inhibitory control has been shown, demonstrating that actions can be withheld, in an uncertain environment, thanks to the proactive locking of the mechanism by which motor commands are triggered (e.g. while waiting at traffic lights in a dense pedestrian zone, one will refrain in anticipation of a brisk acceleration when the green light comes on). However, little is known about this executive function and it remains unclear whether the overall amount of inhibitory control can be modulated as a function of the context. Here, we show that the level of this control varies parametrically as a function of the exogenous and endogenous factors setting the task context. We also show that the level of implemented proactive inhibitory control is dynamically readjusted to match the implicit temporal structure of the environment. These observations are discussed in relation to possible underlying functional substrates and related neurological and psychiatric pathologies.

  9. Context specificity of inhibitory control in dogs.

    PubMed

    Bray, Emily E; MacLean, Evan L; Hare, Brian A

    2014-01-01

    Across three experiments, we explored whether a dog's capacity for inhibitory control is stable or variable across decision-making contexts. In the social task, dogs were first exposed to the reputations of a stingy experimenter that never shared food and a generous experimenter who always shared food. In subsequent test trials, dogs were required to avoid approaching the stingy experimenter when this individual offered (but withheld) a higher-value reward than the generous experimenter did. In the A-not-B task, dogs were required to inhibit searching for food in a previously rewarded location after witnessing the food being moved from this location to a novel hiding place. In the cylinder task, dogs were required to resist approaching visible food directly (because it was behind a transparent barrier), in favor of a detour reaching response. Overall, dogs exhibited inhibitory control in all three tasks. However, individual scores were not correlated between tasks, suggesting that context has a large effect on dogs' behavior. This result mirrors studies of humans, which have highlighted intra-individual variation in inhibitory control as a function of the decision-making context. Lastly, we observed a correlation between a subject's age and performance on the cylinder task, corroborating previous observations of age-related decline in dogs' executive function.

  10. Inhibitory mechanisms of glabridin on tyrosinase

    NASA Astrophysics Data System (ADS)

    Chen, Jianmin; Yu, Xiaojing; Huang, Yufeng

    2016-11-01

    Tyrosinase is an oxidase that is the rate-limiting enzyme for controlling the production of melanin in the human body. Overproduction of melanin could lead to a variety of skin disorders. Glabridin, an isoflavan, isolated from the root of Glycyrrhiza glabra Linn, has exhibited several pharmacological activities, including excellent inhibitory effects on tyrosinase. In this paper, the inhibitory kinetics of glabridin on tyrosinase and their binding mechanisms were determined using spectroscopic, zebrafish model and molecular docking techniques. The results indicate that glabridin reversibly inhibits tyrosinase in a noncompetitive manner through a multiphase kinetic process with the IC50 of 0.43 μmol/L. It has been shown that glabridin had a strong ability to quench the intrinsic fluorescence of tyrosinase mainly through a static quenching procedure, suggesting a stable glabridin-tyrosinase complex may be generated. The results of molecular docking suggest that glabridin did not directly bind to the active site of tyrosinase. Moreover, according to the results of zebrafish model system, glabridin shows no effects on melanin synthesis in zebrafish but presents toxicity to zebrafish embryo. The possible inhibitory mechanisms, which will help to design and search for tyrosinase inhibitors especially for glabridin analogues, were proposed.

  11. Effects of probiotic supplementation in different energy and nutrient density diets on performance, egg quality, excreta microflora, excreta noxious gas emission, and serum cholesterol concentrations in laying hens.

    PubMed

    Zhang, Z F; Kim, I H

    2013-10-01

    This 6-wk study was conducted to determine the effects of probiotic (Enterococcus faecium DSM 7134) supplementation of different energy and nutrient density diets on performance, egg quality, excreta microflora, excreta noxious gas emission, and serum cholesterol concentrations in laying hens. A total of 432 Hy-Line brown layers (40 wk old) were allotted into 4 dietary treatments with 2 levels of probiotic supplementation (0 or 0.01%) and 2 levels of energy (2,700 or 2,800 kcal ME/kg) and nutrient density. Weekly feed intake, egg quality, and daily egg production were determined. Eighteen layers per treatment (2 layers/replication) were bled to determine serum cholesterol concentrations at wk 3 and 6. Excreta microbial shedding of Lactobacillus, Escherichia coli, and Salmonella and noxious gas emission were determined at the end of the experiment. Hens fed the high-energy and high-nutrient-density diets had less (P < 0.01) ADFI than those fed the low-energy and low-nutrient-density diets throughout the experimental period. During wk 4 to 6 and overall, hens fed the diets supplemented with the probiotic had greater (P < 0.01) egg production, egg weight, and eggshell thickness than hens fed the diets without the probiotic. Dietary supplementation of the probiotic increased (P = 0.01) excreta Lactobacillus counts and decreased (P = 0.02) Escherichia coli counts compared with hens fed the diets without the probiotic. The excreta ammonia emission was decreased (P = 0.02) in hens fed the probiotic diets compared with hens fed the diets without the probiotic. Serum total cholesterol concentration was decreased (P < 0.01) by feeding hens with the probiotic at wk 3 and 6. Layers fed the probiotic-incorporated diets had greater (P < 0.01) high-density lipoprotein (HDL) cholesterol and lower (P = 0.03) low-density lipoprotein (LDL) cholesterol concentrations than hens fed the nonsupplemented diets at wk 6. Interactive effects (P < 0.05) of energy and nutrient density and the

  12. Inhibitory Control and Emotion Regulation in Preschool Children

    ERIC Educational Resources Information Center

    Carlson, Stephanie M.; Wang, Tiffany S.

    2007-01-01

    This research investigated the relation between individual differences in inhibitory control and emotion regulation. Preschool children (N=53) ages 4-6 (M=5; 0) were assessed on brief batteries of inhibitory control of prepotent responses and emotion regulation. Individual differences in inhibitory control were significantly correlated with…

  13. Preparation and crystallization of the stimulatory and inhibitory complexes of GTP cyclohydrolase I and its feedback regulatory protein GFRP.

    PubMed

    Maita, N; Okada, K; Hirotsu, S; Hatakeyama, K; Hakoshima, T

    2001-08-01

    Mammalian GTP cyclohydrolase I is a decameric enzyme in the first and rate-limiting step in the biosynthesis of tetrahydrobiopterin, which is an essential cofactor for enzymes producing neurotransmitters such as catecholamines and for nitric oxide synthases. The enzyme is dually regulated by its feedback regulatory protein GFRP in the presence of its stimulatory effector phenylalanine and its inhibitory effector biopterin. Here, both the stimulatory and inhibitory complexes of rat GTP cyclohydrolase I bound to GFRP were crystallized by vapour diffusion. Diffraction data sets at resolutions of 3.0 and 2.64 A were collected for the stimulatory and inhibitory complexes, respectively. Each complex consists of two GTPCHI pentamer rings and two GFRP pentamer rings, with pseudo-52 point-group symmetry.

  14. Inhibitory activity of spices and essential oils on psychrotrophic bacteria.

    PubMed

    Fabio, A; Corona, A; Forte, E; Quaglio, P

    2003-01-01

    This study was designed to evaluate "in vitro" the inhibitory effects of spices and essential oils on the growth of psycrotrophic food-borne bacteria: Aeromonas hydrophila, Listeria monocytogenes and Yersinia enterocolitica. The sensitivity to nine spices and their oils (chilli, cinnamon, cloves, ginger, nutmeg, oregano, rosemary, sage, thyme) was studied. Antibacterial activity was evaluated on liquid and solid medium. Spices: 1% concentration of each spice was added separately to Triptic Soy Broth and then inoculated to contain 10(8)/ml organism and held to 4 degrees C for 7 days. Populations of test organism were determined on Triptic Soy Agar. Oils: Inhibition of growth was tested by using the paper disc agar diffusion method (at 35, 20 and 4 degrees C) and measuring their inhibition zone. MIC was determined by the broth microdilution method. Some culinary spices produce antibacterial activity: inhibition of growth ranged from complete (cinnamon and cloves against A. hydrophila) to no inhibition. Antibacterial inhibition zone ranged from 8 mm to 45 mm: thyme essential oil showed the greatest inhibition against A. hydrophila.

  15. Hereditary Diffuse Infiltrating Retinoblastoma.

    PubMed

    Schedler, Katharina J E; Traine, Peter G; Lohmann, Dietmar R; Haritoglou, Christos; Metz, Klaus A; Rodrigues, Eduardo B

    2016-01-01

    Retinoblastoma is one of the most common childhood cancers. The diffuse infiltrating retinoblastoma is a rare subtype of this neoplasm. The majority of cases of diffuse infiltrating retinoblastoma are unilateral and occur sporadically. Herein we report on a family with three children affected by retinoblastoma, among them one girl with diffuse infiltrating retinoblastoma. This girl was diagnosed at the age of 8 years with a unilateral diffuse infiltrating retinoblastoma. By contrast, the two brothers became clinically apparent in the first 2 years of life with bilateral retinoblastoma. The parents were clinically unremarkable. Genetic analysis of RB1 gene was performed. The girl with diffuse infiltrating RB was found to be heterozygous for an oncogenic mutation in the RB1 gene that was also carried by both brothers and the father of the family. These results show that diffuse infiltrating retinoblastoma can develop on the background of a hereditary predisposition to retinoblastoma.

  16. Correlated diffusion imaging

    PubMed Central

    2013-01-01

    Background Prostate cancer is one of the leading causes of cancer death in the male population. Fortunately, the prognosis is excellent if detected at an early stage. Hence, the detection and localization of prostate cancer is crucial for diagnosis, as well as treatment via targeted focal therapy. New imaging techniques can potentially be invaluable tools for improving prostate cancer detection and localization. Methods In this study, we introduce a new form of diffusion magnetic resonance imaging called correlated diffusion imaging, where the tissue being imaged is characterized by the joint correlation of diffusion signal attenuation across multiple gradient pulse strengths and timings. By taking into account signal attenuation at different water diffusion motion sensitivities, correlated diffusion imaging can provide improved delineation between cancerous tissue and healthy tissue when compared to existing diffusion imaging modalities. Results Quantitative evaluation using receiver operating characteristic (ROC) curve analysis, tissue class separability analysis, and visual assessment by an expert radiologist were performed to study correlated diffusion imaging for the task of prostate cancer diagnosis. These results are compared with that obtained using T2-weighted imaging and standard diffusion imaging (via the apparent diffusion coefficient (ADC)). Experimental results suggest that correlated diffusion imaging provide improved delineation between healthy and cancerous tissue and may have potential as a diagnostic tool for cancer detection and localization in the prostate gland. Conclusions A new form of diffusion magnetic resonance imaging called correlated diffusion imaging (CDI) was developed for the purpose of aiding radiologists in cancer detection and localization in the prostate gland. Preliminary results show CDI shows considerable promise as a diagnostic aid for radiologists in the detection and localization of prostate cancer. PMID:23924150

  17. Gaseous diffusion system

    DOEpatents

    Garrett, George A.; Shacter, John

    1978-01-01

    1. A gaseous diffusion system comprising a plurality of diffusers connected in cascade to form a series of stages, each of said diffusers having a porous partition dividing it into a high pressure chamber and a low pressure chamber, and means for combining a portion of the enriched gas from a succeeding stage with a portion of the enriched gas from the low pressure chamber of each stage and feeding it into one extremity of the high pressure chamber thereof.

  18. Prenatal Hypoxia–Ischemia Induces Abnormalities in CA3 Microstructure, Potassium Chloride Co-Transporter 2 Expression and Inhibitory Tone

    PubMed Central

    Jantzie, Lauren L.; Getsy, Paulina M.; Denson, Jesse L.; Firl, Daniel J.; Maxwell, Jessie R.; Rogers, Danny A.; Wilson, Christopher G.; Robinson, Shenandoah

    2015-01-01

    Infants who suffer perinatal brain injury, including those with encephalopathy of prematurity, are prone to chronic neurological deficits, including epilepsy, cognitive impairment, and behavioral problems, such as anxiety, inattention, and poor social interaction. These deficits, especially in combination, pose the greatest hindrance to these children becoming independent adults. Cerebral function depends on adequate development of essential inhibitory neural circuits and the appropriate amount of excitation and inhibition at specific stages of maturation. Early neuronal synaptic responses to γ-amino butyric acid (GABA) are initially excitatory. During the early postnatal period, GABAAR responses switch to inhibitory with the upregulation of potassium-chloride co-transporter KCC2. With extrusion of chloride by KCC2, the Cl− reversal potential shifts and GABA and glycine responses become inhibitory. We hypothesized that prenatal hypoxic–ischemic brain injury chronically impairs the developmental upregulation of KCC2 that is essential for cerebral circuit formation. Following late gestation hypoxia–ischemia (HI), diffusion tensor imaging in juvenile rats shows poor microstructural integrity in the hippocampal CA3 subfield, with reduced fractional anisotropy and elevated radial diffusivity. The loss of microstructure correlates with early reduced KCC2 expression on NeuN-positive pyramidal neurons, and decreased monomeric and oligomeric KCC2 protein expression in the CA3 subfield. Together with decreased inhibitory post-synaptic currents during a critical window of development, we document for the first time that prenatal transient systemic HI in rats impairs hippocampal CA3 inhibitory tone. Failure of timely development of inhibitory tone likely contributes to a lower seizure threshold and impaired cognitive function in children who suffer perinatal brain injury. PMID:26388734

  19. Phase singularity diffusion.

    PubMed

    Cheng, Xiaojun; Lockerman, Yitzchak; Genack, Azriel Z

    2014-06-01

    We follow the trajectories of phase singularities at nulls of intensity in the speckle pattern of waves transmitted through random media as the frequency of the incident radiation is scanned in microwave experiments and numerical simulations. Phase singularities are observed to diffuse with a linear increase of the square displacement 〈R2〉 with frequency shift. The product of the diffusion coefficient of phase singularities in the transmitted speckle pattern and the photon diffusion coefficient through the random medium is proportional to the square of the effective sample length. This provides the photon diffusion coefficient and a method for characterizing the motion of dynamic material systems.

  20. Inpainting using airy diffusion

    NASA Astrophysics Data System (ADS)

    Lorduy Hernandez, Sara

    2015-09-01

    One inpainting procedure based on Airy diffusion is proposed, implemented via Maple and applied to some digital images. Airy diffusion is a partial differential equation with spatial derivatives of third order in contrast with the usual diffusion with spatial derivatives of second order. Airy diffusion generates the Airy semigroup in terms of the Airy functions which can be rewritten in terms of Bessel functions. The Airy diffusion can be used to smooth an image with the corresponding noise elimination via convolution. Also the Airy diffusion can be used to erase objects from an image. We build an algorithm using the Maple package ImageTools and such algorithm is tested using some images. Our results using Airy diffusion are compared with the similar results using standard diffusion. We observe that Airy diffusion generates powerful filters for image processing which could be incorporated in the usual packages for image processing such as ImageJ and Photoshop. Also is interesting to consider the possibility to incorporate the Airy filters as applications for smartphones and smart-glasses.

  1. Experimental study of vortex diffusers

    SciTech Connect

    Shakerin, S.; Miller, P.L.

    1995-11-01

    This report documents experimental research performed on vortex diffusers used in ventilation and air-conditioning systems. The main objectives of the research were (1) to study the flow characteristics of isothermal jets issuing from vortex diffusers, (2) to compare the vortex diffuser`s performance with that of a conventional diffuser, and (3) to prepare a report that disseminates the results to the designers of ventilation and air-conditioning systems. The researchers considered three diffusers: a conventional round ceiling diffuser and two different styles of vortex diffusers. Overall, the vortex diffusers create slightly more induction of ambient air in comparison to the conventional diffuser.

  2. Effect of eugenol and cinnamaldehyde on the growth performance, nutrient digestibility, blood characteristics, fecal microbial shedding and fecal noxious gas content in growing pigs.

    PubMed

    Yan, L; Kim, I H

    2012-08-01

    A 5-wk trial with 96 ((Landrace× Yorkshire)×Duroc) pigs (BW = 26.56±0.42 kg) was conducted to investigate the effect of eugenol and cinnamaldehyde as feed additive in growing pigs. Pigs were assigned to 1 of 3 treatments in a randomized complete block design according to their sex and BW. Each treatment contained 8 replications with 4 pigs (2 gilts and 2 barrows) per pen. Treatments included: control (basal diet; CON); (basal diet+1,000 mg eugenol/kg; ET); (basal diet+1,000 mg cinnamaldehyde/kg; CT). Administration of eugenol and cinnamaldehyde did not did not affect (p>0.05) the growth performance and apparent total tract digestibility. Dietary CT and ET led to a higher (p<0.05) lymphocyte concentration compared with CON. The inclusion of CT and ET decreased (p<0.05) the fecal E. coli concentration (p>0.05). Pigs fed the diets supplemented with eugenol and cinnamaldehyde had reduced (p<0.05) NH3 and H2S concentration throughout the experiment. In conclusion, results obtained in the present study indicated that supplementation of eugenol and cinamaldehyde had no effect on growth performance of pigs but exhibited lymphocyte-enhancing activity and decreased the fecal E. coli concentration and fecal noxious gas content (NH3 and H2S).

  3. Effect of Eugenol and Cinnamaldehyde on the Growth Performance, Nutrient Digestibility, Blood Characteristics, Fecal Microbial Shedding and Fecal Noxious Gas Content in Growing Pigs

    PubMed Central

    Yan, L.; Kim, I. H.

    2012-01-01

    A 5-wk trial with 96 ((Landrace× Yorkshire)×Duroc) pigs (BW = 26.56±0.42 kg) was conducted to investigate the effect of eugenol and cinnamaldehyde as feed additive in growing pigs. Pigs were assigned to 1 of 3 treatments in a randomized complete block design according to their sex and BW. Each treatment contained 8 replications with 4 pigs (2 gilts and 2 barrows) per pen. Treatments included: control (basal diet; CON); (basal diet+1,000 mg eugenol/kg; ET); (basal diet+1,000 mg cinnamaldehyde/kg; CT). Administration of eugenol and cinnamaldehyde did not did not affect (p>0.05) the growth performance and apparent total tract digestibility. Dietary CT and ET led to a higher (p<0.05) lymphocyte concentration compared with CON. The inclusion of CT and ET decreased (p<0.05) the fecal E. coli concentration (p>0.05). Pigs fed the diets supplemented with eugenol and cinnamaldehyde had reduced (p<0.05) NH3 and H2S concentration throughout the experiment. In conclusion, results obtained in the present study indicated that supplementation of eugenol and cinamaldehyde had no effect on growth performance of pigs but exhibited lymphocyte-enhancing activity and decreased the fecal E. coli concentration and fecal noxious gas content (NH3 and H2S). PMID:25049678

  4. Toxicity effects of hazardous and noxious substances (HNS) to marine organisms: acute and chronic toxicity of p-xylene to the amphipod Gammarus locusta.

    PubMed

    Neuparth, T; Capela, R; Pereira, S P P; Moreira, S M; Santos, M M; Reis-Henriques, M A

    2014-01-01

    Despite the recent focus on hazardous and noxious substances (HNS) spills preparedness and responses, much remains to be done regarding the threat posed by HNS spills on marine biota. Among the identified priority HNS, p-xylene was selected to conduct ecotoxicological assays. The aim of this study was to assess the performance of the amphipod Gammarus locusta under acute and chronic exposure to p-xylene simulating conditions of a spill incident. In the acute exposure (96 h) the p-xylene LC50 was estimated. In the chronic bioassay (36 d), an integration of organism-level endpoints (survival, growth rate, and sex ratio) with biochemical markers indicative of oxidative stress including catalase (CAT), glutathione S-transferase (GST), and superoxide dismutase (SOD) activities and lipid peroxidation (LPO) levels was determined. The aim was to increase the xylene ecotoxicological database and better predict its impact in aquatic environments. p-Xylene induced several chronic toxicity effects in G. locusta. Significant alterations in antioxidant enzymes and lipid peroxidation levels as well as growth rate and biased sex-ratio were observed. p-Xylene significantly affected the activities of CAT, SOD, and GST in G. locusta and produced oxidative damage by increasing levels of LPO in males. Further, impacts in key ecological endpoints, that is, growth and sex ratio, were noted that might be indicative of potential effects at the population level in a spill scenario. The present data may be useful to assist relevant bodies in preparedness and response to HNS spills.

  5. [Monitoring of contamination of foodstuffs with elements noxious to human health. Part II. Mineral waters, soft drinks, fruits, nuts, rice, soybeans, fish and seafood].

    PubMed

    Wojciechowska-Mazurek, Maria; Starska, Krystyna; Mania, Monika; Brulińska-Ostrowska, Elzbieta; Biernat, Urszula; Karłowski, Kazimierz

    2010-01-01

    Results of the 5-years cycle (2004-2008) monitoring investigations on food contamination with elements noxious to human health, involving testing of mineral waters and soft drinks (226 samples), fruits (467 samples), rice (234 samples), soybeans (236 samples), nuts and peanuts (237 samples), fish and seafood (237 samples) are discussed. The parties involved in testing were: laboratories of State Sanitary Inspection and the national reference laboratory of the Department of Food and Consumer Articles Research of National Institute of Public Health - National Institute of Hygiene. The reported metals contents did not give rise to health concerns, remaining generally below the levels set forth in food legislation and being comparable with contamination levels reported in other European countries; and for cadmium--often lower. Health hazard assessment was performed taking into account the mean contamination levels obtained and average domestic consumption of these food products groups in Poland. The highest intake expressed as the percentage of provisional tolerable weekly intake (PTWI) was obtained for mercury in fish, which has reached mean 3.2% PTWI. Controlled fish consumption recommendations should be adhered to by prospective mothers, pregnant women, breast-feeding women and young children. Lead and arsenic intake with mineral waters and soft drinks comprises approx. 15% of total intake of these elements with food.

  6. Clonidine as adjuvant for oxybuprocaine, bupivacaine or dextrorphan has a significant peripheral action in intensifying and prolonging analgesia in response to local dorsal cutaneous noxious pinprick in rats.

    PubMed

    Chen, Yu-Wen; Chu, Chin-Chen; Chen, Yu-Chung; Hung, Ching-Hsia; Hsueh, Meng-I; Wang, Jhi-Joung

    2011-06-08

    The aim of the study was to evaluate co-administration of clonidine with oxybuprocaine (ester type), bupivacaine (amide type) or dextrorphan (non-ester or non-amide type) and to see whether it could have a peripheral action in enhancing local anesthesia on infiltrative cutaneous analgesia in rats. Cutaneous analgesia was evaluated by a block of the cutaneous trunci muscle reflex (CTMR) in response to local dorsal cutaneous noxious pinprick in rats. The analgesic effect of the addition of clonidine with oxybuprocaine, bupivacaine or dextrorphan by subcutaneous injection was evaluated. On an ED(50) basis, the rank of drug potency was oxybuprocaine>bupivacaine>dextrorphan (P<0.01). Mixtures of clonidine (0.12μmol) with oxybuprocaine, bupivacaine or dextrorphan (ED(50) or ED(95)) extended the duration of action and increased the potency on infiltrative cutaneous analgesia. Among these drugs, the addition of clonidine to bupivacaine (amide type) elicits the most effective cutaneous analgesia. Clonidine at the dose of 0.12 and 0.24μmol did not produce cutaneous analgesia. Oxybuprocaine showed more potent cutaneous analgesia than bupivacaine or dextrorphan in rats. Co-administration of oxybuprocaine, bupivacaine or dextrorphan with clonidine increased the potency and duration on infiltrative cutaneous analgesia. The addition of clonidine to bupivacaine (amide type) elicits more effective cutaneous analgesia than oxybuprocaine (ester type) or dextrorphan (non-ester or non-amide type). Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  7. Effects of probiotic supplementation in different nutrient density diets on growth performance, nutrient digestibility, blood profiles, fecal microflora and noxious gas emission in weaning pig.

    PubMed

    Lan, Ruixia; Tran, Hoainam; Kim, Inho

    2017-03-01

    Probiotics can serve as alternatives to antibiotics to increase the performance of weaning pigs, and the intake of probiotics is affected by dietary nutrient density. The objective of this study was to evaluate the effects of a probiotic complex in different nutrient density diets on growth performance, digestibility, blood profiles, fecal microflora and noxious gas emission in weaning pigs. From day 22 to day 42, both high-nutrient-density and probiotic complex supplementation diets increased (P < 0.05) the average daily gain. On day 42, the apparent total tract digestibility (ATTD) of dry matter, nitrogen and gross energy (GE), blood urea nitrogen concentration and NH3 and H2 S emissions were increased (P < 0.05) in pigs fed high-nutrient-density diets. Pigs fed probiotic complex supplementation diets had higher (P < 0.05) ATTD of GE than pigs fed non-supplemented diets. Fecal Lactobacillus counts were increased whereas Escherichia coli counts and NH3 and H2 S emissions were decreased (P < 0.05) in pigs fed probiotic complex supplementation diets. Interactive effects on average daily feed intake (ADFI) were observed from day 22 to day 42 and overall, where probiotic complex improved ADFI more dramatically in low-nutrient-density diets. The beneficial effects of probiotic complex (Bacillus coagulans, Bacillus licheniformis, Bacillus subtilis and Clostridium butyricum) supplementation on ADFI is more dramatic with low-nutrient-density diets. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  8. Basal μ-opioid receptor availability in the amygdala predicts the inhibition of pain-related brain activity during heterotopic noxious counter-stimulation.

    PubMed

    Piché, Mathieu; Watanabe, Nobuhiro; Sakata, Muneyuki; Oda, Keiichi; Toyohara, Jun; Ishii, Kenji; Ishiwata, Kiichi; Hotta, Harumi

    2014-01-01

    The aim of this study was to investigate the association between the magnitude of anti-nociceptive effects induced by heterotopic noxious counter-stimulation (HNCS) and the basal μ-opioid receptor availability in the amygdala. In 8 healthy volunteers (4 females and 4 males), transcutaneous electrical stimulation was applied to the right sural nerve to produce the nociceptive flexion reflex (RIII-reflex), moderate pain, and scalp somatosensory evoked potentials (SEPs). Immersion of the left hand in cold water for 20min was used as HNCS. In a separate session, basal μ-opioid receptor availability was measured using positron emission tomography with the radiotracer [(11)C]carfentanil. HNCS produced a reduction of the P260 amplitude (p<0.05), a late component of SEP that reflects activity in the anterior cingulate cortex. This reduction was associated with higher basal μ-opioid receptor availability in the amygdala on the right (R(2)=0.55, p=0.03) with a similar trend on the left (R(2)=0.24, p=0.22). Besides, HNCS did not induce significant changes in pain and RIII-reflex amplitude (p>0.05). These results suggest that activation of μ-opioid receptors in the amygdala may contribute to the anti-nociceptive effects of HNCS. The lack of RIII-reflex modulation further suggests that μ-opioid receptor activation in the amygdala contributes to decrease pain-related brain activity through a cerebral mechanism independent of descending modulation.

  9. Trade-offs between predator avoidance and electric shock avoidance in hermit crabs demonstrate a non-reflexive response to noxious stimuli consistent with prediction of pain.

    PubMed

    Magee, Barry; Elwood, Robert W

    2016-09-01

    Arthropods have long been thought to respond to noxious stimuli by reflex reaction. One way of testing if this is true is to provide the animal with a way to avoid the stimulus but to vary the potential cost of avoidance. If avoidance varies with potential cost then a decision making process is evident and the behaviour is not a mere reflex. Here we examine the responses of hermit crabs to electric shock within their shell when also exposed to predator or non-predator odours or to no odour. The electric shocks start with low voltage but increase in voltage with each repetition to determine how odour affects the voltage at which the shell is abandoned. There was no treatment effect on the voltage at which hermit crabs left their shells, however, those exposed to predator odours were less likely to evacuate their shells compared with no odour or low concentrations of non-predator odour. However, highly concentrated non-predator also inhibited evacuation. The data show that these crabs trade-off avoidance of electric shock with predator avoidance. They are thus not responding purely by reflex and the data are thus consistent with predictions of pain but do not prove pain. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Electroacupuncture Reduces the Effects of Acute Noxious Stimulation on the Electrical Activity of Pain-Related Neurons in the Hippocampus of Control and Neuropathic Pain Rats

    PubMed Central

    Wang, Jun-Ying; Chen, Renbo; Feng, Xiu-Mei; Yan, Yaxia; Lippe, Irmgard Th.

    2016-01-01

    To study the effects of acupuncture analgesia on the hippocampus, we observed the effects of electroacupuncture (EA) and mitogen-activated protein kinase (MEK) inhibitor on pain-excited neurons (PENs) and pain-inhibited neurons (PINs) in the hippocampal area CA1 of sham or chronic constrictive injury (CCI) rats. The animals were randomly divided into a control, a CCI, and a U0126 (MEK1/2 inhibitor) group. In all experiments, we briefly (10-second duration) stimulated the sciatic nerve electrically and recorded the firing rates of PENs and PINs. The results showed that in both sham and CCI rats brief sciatic nerve stimulation significantly increased the electrical activity of PENs and markedly decreased the electrical activity of PINs. These effects were significantly greater in CCI rats compared to sham rats. EA treatment reduced the effects of the noxious stimulus on PENs and PINs in both sham and CCI rats. The effects of EA treatment could be inhibited by U0126 in sham-operated rats. The results suggest that EA reduces effects of acute sciatic nerve stimulation on PENs and PINs in the CA1 region of the hippocampus of both sham and CCI rats and that the ERK (extracellular regulated kinase) signaling pathway is involved in the modulation of EA analgesia. PMID:27833763

  11. Prenatal stress and inhibitory neuron systems: implications for neuropsychiatric disorders

    PubMed Central

    Fine, Rebecca; Zhang, Jie; Stevens, Hanna E.

    2014-01-01

    Prenatal stress is a risk factor for several psychiatric disorders in which inhibitory neuron pathology is implicated. A growing body of research demonstrates that inhibitory circuitry in the brain is directly and persistently affected by prenatal stress. This review synthesizes research that elucidates how this early, developmental risk factor impacts inhibitory neurons and how these findings intersect with research on risk factors and inhibitory neuron pathophysiology in schizophrenia, anxiety, autism and Tourette syndrome. The specific impact of prenatal stress on inhibitory neurons, particularly developmental mechanisms, may elucidate further the pathophysiology of these disorders. PMID:24751963

  12. Migration Inhibitory Factor and Macrophage Bactericidal Function

    PubMed Central

    Simon, Harvey B.; Sheagren, John N.

    1972-01-01

    A homogeneous population of immunologically active lymphocytes was obtained from peritoneal exudates of guinea pigs with delayed hypersensitivity to bovine gamma globulin (BGG). The lymphocytes were cultured with and without BGG for 24 hr, and cell-free supernatant fluids were then assayed simultaneously for their ability to influence two in vitro parameters of macrophage function: migration from capillary tubes and bactericidal capacity. In four consecutive experiments, supernatants from antigenically stimulated lymphocytes exhibited substantial migration-inhibitory-factor activity without enhancing the ability of macrophages to kill Listeria monocytogenes. Lymphocyte lysates were inactive in both assays. Possible mechanisms of lymphocyte-macrophage interactions are discussed. PMID:4120244

  13. Anatomy of Particle Diffusion

    ERIC Educational Resources Information Center

    Bringuier, E.

    2009-01-01

    The paper analyses particle diffusion from a thermodynamic standpoint. The main goal of the paper is to highlight the conceptual connection between particle diffusion, which belongs to non-equilibrium statistical physics, and mechanics, which deals with particle motion, at the level of third-year university courses. We start out from the fact…

  14. Anatomy of Particle Diffusion

    ERIC Educational Resources Information Center

    Bringuier, E.

    2009-01-01

    The paper analyses particle diffusion from a thermodynamic standpoint. The main goal of the paper is to highlight the conceptual connection between particle diffusion, which belongs to non-equilibrium statistical physics, and mechanics, which deals with particle motion, at the level of third-year university courses. We start out from the fact…

  15. Investigating Diffusion with Technology

    ERIC Educational Resources Information Center

    Miller, Jon S.; Windelborn, Augden F.

    2013-01-01

    The activities described here allow students to explore the concept of diffusion with the use of common equipment such as computers, webcams and analysis software. The procedure includes taking a series of digital pictures of a container of water with a webcam as a dye slowly diffuses. At known time points, measurements of the pixel densities…

  16. Adaptation and Cultural Diffusion.

    ERIC Educational Resources Information Center

    Ormrod, Richard K.

    1992-01-01

    Explores the role of adaptation in cultural diffusion. Explains that adaptation theory recognizes the lack of independence between innovations and their environmental settings. Discusses testing and selection, modification, motivation, and cognition. Suggests that adaptation effects are pervasive in cultural diffusion but require a broader, more…

  17. Diffusion of Botulinum Toxins

    PubMed Central

    Brodsky, Matthew A.; Swope, David M.; Grimes, David

    2012-01-01

    Background It is generally agreed that diffusion of botulinum toxin occurs, but the extent of the spread and its clinical importance are disputed. Many factors have been suggested to play a role but which have the most clinical relevance is a subject of much discussion. Methods This review discusses the variables affecting diffusion, including protein composition and molecular size as well as injection factors (e.g., volume, dose, injection method). It also discusses data on diffusion from comparative studies in animal models and human clinical trials that illustrate differences between the available botulinum toxin products (onabotulinumtoxinA, abobotulinumtoxinA, incobotulinumtoxinA, and rimabotulinumtoxinB). Results Neither molecular weight nor the presence of complexing proteins appears to affect diffusion; however, injection volume, concentration, and dose all play roles and are modifiable. Both animal and human studies show that botulinum toxin products are not interchangeable, and that some products are associated with greater diffusion and higher rates of diffusion-related adverse events than others. Discussion Each of the botulinum toxins is a unique pharmacologic entity. A working knowledge of the different serotypes is essential to avoid unwanted diffusion-related adverse events. In addition, clinicians should be aware that the factors influencing diffusion may range from properties intrinsic to the drug to accurate muscle selection as well as dilution, volume, and dose injected. PMID:23440162

  18. Galactic Diffuse Emissions

    SciTech Connect

    Digel, Seth W.; /SLAC

    2007-10-25

    Interactions of cosmic rays with interstellar nucleons and photons make the Milky Way a bright, diffuse source of high-energy {gamma}-rays. Observationally, the results from EGRET, COMPTEL, and OSSE have now been extended to higher energies by ground-based experiments, with detections of diffuse emission in the Galactic center reported by H.E.S.S. in the range above 100 GeV and of diffuse emission in Cygnus by MILAGRO in the TeV range. In the range above 100 keV, INTEGRAL SPI has found that diffuse emission remains after point sources are accounted for. I will summarize current knowledge of diffuse {gamma}-ray emission from the Milky Way and review some open issues related to the diffuse emission -- some old, like the distribution of cosmic-ray sources and the origin of the 'excess' of GeV emission observed by EGRET, and some recently recognized, like the amount and distribution of molecular hydrogen not traced by CO emission -- and anticipate some of the advances that will be possible with the Large Area Telescope on GLAST. We plan to develop an accurate physical model for the diffuse emission, which will be useful for detecting and accurately characterizing emission from Galactic point sources as well as any Galactic diffuse emission from exotic processes, and for studying the unresolved extragalactic emission.

  19. The Diffusion of Innovation

    NASA Technical Reports Server (NTRS)

    Earabino, Gerard J.; Heyl, G. Christopher; Percorini, Thomas J.

    1987-01-01

    New ideas encounter obstacles on way to becoming products. Report examines process by which new ideas become products, processes, or accepted standards. Sequence of events called "the diffusion of innovation." Focuses on development of material processing in low gravity as case study in diffusion of innovation.

  20. Investigating Diffusion with Technology

    ERIC Educational Resources Information Center

    Miller, Jon S.; Windelborn, Augden F.

    2013-01-01

    The activities described here allow students to explore the concept of diffusion with the use of common equipment such as computers, webcams and analysis software. The procedure includes taking a series of digital pictures of a container of water with a webcam as a dye slowly diffuses. At known time points, measurements of the pixel densities…

  1. Cosmology with matter diffusion

    SciTech Connect

    Calogero, Simone; Velten, Hermano E-mail: velten@cce.ufes.br

    2013-11-01

    We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field φ which we identify with the dark energy component of the universe. The model is characterized by only one new degree of freedom, the diffusion parameter σ. The standard ΛCDM model can be recovered by setting σ = 0. If diffusion takes place (σ > 0) the dynamics of the matter and of the dark energy fields are coupled. We argue that the existence of a diffusion mechanism in the universe may serve as a theoretical motivation for interacting models. We constrain the background dynamics of the diffusion model with Supernovae, H(z) and BAO data. We also perform a perturbative analysis of this model in order to understand structure formation in the universe. We calculate the impact of diffusion both on the CMB spectrum, with particular attention to the integrated Sachs-Wolfe signal, and on the matter power spectrum P(k). The latter analysis places strong constraints on the magnitude of the diffusion mechanism but does not rule out the model.

  2. Glutamatergic inputs and glutamate-releasing immature inhibitory inputs activate a shared postsynaptic receptor population in lateral superior olive

    PubMed Central

    Alamilla, Javier; Gillespie, Deda C

    2013-01-01

    Principal cells of the lateral superior olive (LSO) compute interaural intensity differences by comparing converging excitatory and inhibitory inputs. The excitatory input carries information from the ipsilateral ear and the inhibitory input carries information from the contralateral ear. Throughout life, the excitatory input pathway releases glutamate. In adulthood, the inhibitory input pathway releases glycine. During a period of major developmental refinement in the LSO, however, synaptic terminals of the immature inhibitory input pathway release not only glycine, but also GABA and glutamate. To determine whether glutamate released by terminals in either pathway could spill over to activate postsynaptic NMDA receptors under the other pathway, we made whole-cell recordings from LSO principal cells in acute slices of neonatal rat brainstem bathed in the use-dependent NMDA receptor antagonist MK-801, and stimulated in the two opposing pathways. We found that during the first postnatal week glutamate spillover occurs bidirectionally from both immature excitatory terminals and immature inhibitory terminals. We further found that a population of postsynaptic NMDA receptors is shared: glutamate released from either pathway can diffuse to and activate these receptors. We suggest that these shared receptors contain the GluN2B subunit and are located extrasynaptically. PMID:21907763

  3. Intraosseous concentration and inhibitory effect of different intravenous cefazolin doses used in preoperative prophylaxis of total knee arthroplasty.

    PubMed

    Angthong, Chayanin; Krajubngern, Pongpaibool; Tiyapongpattana, Warawut; Pongcharoen, Boonchana; Pinsornsak, Piya; Tammachote, Nattapol; Kittisupaluck, Wanna

    2015-12-01

    The aim of this study was to compare the intraosseous concentrations and the inhibitory effects on the growth of Staphylococcus aureus of 1 g versus 2 g of intravenous (IV) prophylactic cefazolin in total knee arthroplasty (TKA). Eighteen patients (21 knees) with primary knee osteoarthritis were divided into two groups receiving 1 g (12 patients: 14 knees) versus 2 g (six patients: seven knees) IV prophylactic cefazolin prior to the incision in TKA. Subchondral bone samples (proximal tibia, distal femur) were taken during the operation. These samples were analyzed for intraosseous concentration of cefazolin and their inhibitory effects on the growth of S. aureus, using high-performance liquid chromatography (HPLC) and agar disc diffusion bioassays. The mean intraosseous concentration in the 2 g dose group was significantly higher than in the 1 g dose group in the proximal tibia (p = 0.007) and distal femur (p = 0.016). There were no significant differences between the two groups in terms of mean inhibitory effects in the proximal tibia or distal femur (p > 0.05). No significant correlations were found between the intraosseous concentrations and inhibitory effects in the proximal tibia (r = 0.18, p = 0.52) and distal femur (r = -0.29, p = 0.30). IV cefazolin at a dose of 2 g produced greater intraosseous concentrations overall than a dose of 1 g. However, the higher intraosseous concentrations did not correlate with higher inhibitory effects.

  4. Changes in levels of the tripeptide Tyr-Gly-Gly as an index of enkephalin release in the spinal cord: effects of noxious stimuli and parenterally-active peptidase inhibitors.

    PubMed

    Llorens-Cortes, C; Gros, C; Schwartz, J C; Clot, A M; Le Bars, D

    1989-01-01

    The tripeptide Tyr-Gly-Gly (YGG), representing the product of enkephalin hydrolysis by enkephalinase (EC 3.4.24.11), was characterized and its levels measured in spinal cord perfusates of halothane-anaesthetized rats. During noxious pinching of the muzzle, which is known to trigger enkephalin release, YGG levels were enhanced more markedly and for longer than were those of [Met5]enkephalin (YGGFM), in the same samples. By contrast, neither YGG nor YGGFM levels were affected by pinching the tail. Treatment with carbaphethiol, a parenterally-active aminopeptidase inhibitor, markedly increased YGG levels and lengthened the duration of the increase produced by pinching the muzzle. Treatment with acetorphan, a parenterally-active enkephalinase inhibitor, given alone or in combination with carbaphethiol, completely prevented the rise in YGG triggered by noxious stimulation. By contrast, [Met5]enkephalin levels in the perfusates were increased by the combined administration of the two peptidase inhibitors but these levels were not further enhanced by noxious stimulation. Thus, spinal cord YGG appears to be formed under the influence of enkephalinase and to constitute a sensitive index of enkephalin release.

  5. Diffusion in Coulomb crystals.

    PubMed

    Hughto, J; Schneider, A S; Horowitz, C J; Berry, D K

    2011-07-01

    Diffusion in Coulomb crystals can be important for the structure of neutron star crusts. We determine diffusion constants D from molecular dynamics simulations. We find that D for Coulomb crystals with relatively soft-core 1/r interactions may be larger than D for Lennard-Jones or other solids with harder-core interactions. Diffusion, for simulations of nearly perfect body-centered-cubic lattices, involves the exchange of ions in ringlike configurations. Here ions "hop" in unison without the formation of long lived vacancies. Diffusion, for imperfect crystals, involves the motion of defects. Finally, we find that diffusion, for an amorphous system rapidly quenched from Coulomb parameter Γ=175 to Coulomb parameters up to Γ=1750, is fast enough that the system starts to crystalize during long simulation runs. These results strongly suggest that Coulomb solids in cold white dwarf stars, and the crust of neutron stars, will be crystalline and not amorphous.

  6. Combustor diffuser interaction program

    NASA Technical Reports Server (NTRS)

    Srinivasan, Ram; Thorp, Daniel

    1986-01-01

    Advances in gas turbine engine performance are achieved by using compressor systems with high stage loading and low part count, which result in high exit Mach numbers. The diffuser and combustor systems in such engines should be optimized to reduce system pressure loss and to maximize the engine thrust-to-weight ratio and minimize length. The state-of-the-art combustor-diffuser systems do not meet these requirements. Detailed understanding of the combustor-diffuser flow field interaction is required for designing advanced gas turbine engines. An experimental study of the combustor-diffuser interaction (CDI) is being conducted to obtain data for the evaluation and improvement of analytical models applicable to a wide variety of diffuser designs. The CDI program consists of four technical phases: Literature Search; Baseline Configuration; Parametric Configurations; and Performance Configurations. Phase 2 of the program is in progress.

  7. Diffusion in Coulomb crystals

    SciTech Connect

    Hughto, J.; Schneider, A. S.; Horowitz, C. J.; Berry, D. K.

    2011-07-15

    Diffusion in Coulomb crystals can be important for the structure of neutron star crusts. We determine diffusion constants D from molecular dynamics simulations. We find that D for Coulomb crystals with relatively soft-core 1/r interactions may be larger than D for Lennard-Jones or other solids with harder-core interactions. Diffusion, for simulations of nearly perfect body-centered-cubic lattices, involves the exchange of ions in ringlike configurations. Here ions ''hop'' in unison without the formation of long lived vacancies. Diffusion, for imperfect crystals, involves the motion of defects. Finally, we find that diffusion, for an amorphous system rapidly quenched from Coulomb parameter {Gamma}=175 to Coulomb parameters up to {Gamma}=1750, is fast enough that the system starts to crystalize during long simulation runs. These results strongly suggest that Coulomb solids in cold white dwarf stars, and the crust of neutron stars, will be crystalline and not amorphous.

  8. Maximizing exposure therapy: an inhibitory learning approach.

    PubMed

    Craske, Michelle G; Treanor, Michael; Conway, Christopher C; Zbozinek, Tomislav; Vervliet, Bram

    2014-07-01

    Exposure therapy is an effective approach for treating anxiety disorders, although a substantial number of individuals fail to benefit or experience a return of fear after treatment. Research suggests that anxious individuals show deficits in the mechanisms believed to underlie exposure therapy, such as inhibitory learning. Targeting these processes may help improve the efficacy of exposure-based procedures. Although evidence supports an inhibitory learning model of extinction, there has been little discussion of how to implement this model in clinical practice. The primary aim of this paper is to provide examples to clinicians for how to apply this model to optimize exposure therapy with anxious clients, in ways that distinguish it from a 'fear habituation' approach and 'belief disconfirmation' approach within standard cognitive-behavior therapy. Exposure optimization strategies include (1) expectancy violation, (2) deepened extinction, (3) occasional reinforced extinction, (4) removal of safety signals, (5) variability, (6) retrieval cues, (7) multiple contexts, and (8) affect labeling. Case studies illustrate methods of applying these techniques with a variety of anxiety disorders, including obsessive-compulsive disorder, posttraumatic stress disorder, social phobia, specific phobia, and panic disorder.

  9. When is an inhibitory synapse effective?

    PubMed

    Qian, N; Sejnowski, T J

    1990-10-01

    Interactions between excitatory and inhibitory synaptic inputs on dendrites determine the level of activity in neurons. Models based on the cable equation predict that silent shunting inhibition can strongly veto the effect of an excitatory input. The cable model assumes that ionic concentrations do not change during the electrical activity, which may not be a valid assumption, especially for small structures such as dendritic spines. We present here an analysis and computer simulations to show that for large Cl- conductance changes, the more general Nernst-Planck electrodiffusion model predicts that shunting inhibition on spines should be much less effective than that predicted by the cable model. This is a consequence of the large changes in the intracellular ionic concentration of Cl- that can occur in small structures, which would alter the reversal potential and reduce the driving force for Cl-. Shunting inhibition should therefore not be effective on spines, but it could be significantly more effective on the dendritic shaft at the base of the spine. In contrast to shunting inhibition, hyperpolarizing synaptic inhibition mediated by K+ currents can be very effective in reducing the excitatory synaptic potentials on the same spine if the excitatory conductance change is less than 10 nS. We predict that if the inhibitory synapses found on cortical spines are to be effective, then they should be mediated by K+ through GABAB receptors.

  10. When is an Inhibitory Synapse Effective?

    NASA Astrophysics Data System (ADS)

    Qian, Ning; Sejnowski, Terrence J.

    1990-10-01

    Interactions between excitatory and inhibitory synaptic inputs on dendrites determine the level of activity in neurons. Models based on the cable equation predict that silent shunting inhibition can strongly veto the effect of an excitatory input. The cable model assumes that ionic concentrations do not change during the electrical activity, which may not be a valid assumption, especially for small structures such as dendritic spines. We present here an analysis and computer simulations to show that for large Cl^- conductance changes, the more general Nernst-Planck electrodiffusion model predicts that shunting inhibition on spines should be much less effective than that predicted by the cable model. This is a consequence of the large changes in the intracellular ionic concentration of Cl^- that can occur in small structures, which would alter the reversal potential and reduce the driving force for Cl^-. Shunting inhibition should therefore not be effective on spines, but it could be significantly more effective on the dendritic shaft at the base of the spine. In contrast to shunting inhibition, hyperpolarizing synaptic inhibition mediated by K^+ currents can be very effective in reducing the excitatory synaptic potentials on the same spine if the excitatory conductance change is less than 10 nS. We predict that if the inhibitory synapses found on cortical spines are to be effective, then they should be mediated by K^+ through GABA_B receptors.

  11. New cholinesterase inhibitory constituents from Lonicera quinquelocularis.

    PubMed

    Khan, Dilfaraz; Khan, Hidayat Ullah; Khan, Farmanullah; Khan, Shafiullah; Badshah, Syed; Khan, Abdul Samad; Samad, Abdul; Ali, Farman; Khan, Ihsanullah; Muhammad, Nawshad

    2014-01-01

    A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1-5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile.

  12. New Cholinesterase Inhibitory Constituents from Lonicera quinquelocularis

    PubMed Central

    Khan, Dilfaraz; Khan, Hidayat Ullah; Khan, Farmanullah; Khan, Shafiullah; Badshah, Syed; Khan, Abdul Samad; Samad, Abdul; Ali, Farman; Khan, Ihsanullah; Muhammad, Nawshad

    2014-01-01

    A phytochemical investigation on the ethyl acetate soluble fraction of Lonicera quinquelocularis (whole plant) led to the first time isolation of one new phthalate; bis(7-acetoxy-2-ethyl-5-methylheptyl) phthalate (3) and two new benzoates; neopentyl-4-ethoxy-3, 5-bis (3-methyl-2-butenyl benzoate (4) and neopentyl-4-hydroxy-3, 5-bis (3-methyl-2-butenyl benzoate (5) along with two known compounds bis (2-ethylhexyl phthalate (1) and dioctyl phthalate (2). Their structures were established on the basis of spectroscopic analysis and by comparison with available data in the literature. All the compounds (1–5) were tested for their acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities in dose dependent manner. The IC50 (50% inhibitory effect) values of compounds 3 and 5 against AChE were 1.65 and 3.43 µM while the values obtained against BChE were 5.98 and 9.84 µM respectively. Compounds 2 and 4 showed weak inhibition profile. PMID:24733024

  13. Rational Decision-Making in Inhibitory Control

    PubMed Central

    Shenoy, Pradeep; Yu, Angela J.

    2011-01-01

    An important aspect of cognitive flexibility is inhibitory control, the ability to dynamically modify or cancel planned actions in response to changes in the sensory environment or task demands. We formulate a probabilistic, rational decision-making framework for inhibitory control in the stop signal paradigm. Our model posits that subjects maintain a Bayes-optimal, continually updated representation of sensory inputs, and repeatedly assess the relative value of stopping and going on a fine temporal scale, in order to make an optimal decision on when and whether to go on each trial. We further posit that they implement this continual evaluation with respect to a global objective function capturing the various reward and penalties associated with different behavioral outcomes, such as speed and accuracy, or the relative costs of stop errors and go errors. We demonstrate that our rational decision-making model naturally gives rise to basic behavioral characteristics consistently observed for this paradigm, as well as more subtle effects due to contextual factors such as reward contingencies or motivational factors. Furthermore, we show that the classical race model can be seen as a computationally simpler, perhaps neurally plausible, approximation to optimal decision-making. This conceptual link allows us to predict how the parameters of the race model, such as the stopping latency, should change with task parameters and individual experiences/ability. PMID:21647306

  14. Social inhibitory control in five lemur species.

    PubMed

    Reddy, Rachna B; MacLean, Evan L; Sandel, Aaron A; Hare, Brian

    2015-07-01

    We tested five lemur species-ring-tailed lemurs, ruffed lemurs, mongoose lemurs, black lemurs, and Coquerel's sifakas-(N = 52) in an experiment that evaluated skills for inhibitory control in a social context. First, two human experimenters presented identical food rewards; the "generous" experimenter allowed the subject to eat from her hand, whereas the "competitive" experimenter always withheld the reward. Lemurs quickly learned to approach the generous experimenter and avoid the competitive one. In the inhibition test phase, we endowed the competitive experimenter with a more valuable food reward but the competitive experimenter continued to withhold food from the subject. Thus, lemurs were required to inhibit approaching the more desirable reward in favor of the lesser but obtainable reward presented by the generous experimenter. In test trials, lemurs' tendency to approach the competitive experimenter increased from the reputation phase, demonstrating sensitivity to the experimental manipulation. However, subjects approached the larger reward less frequently in test trials compared with pretest food-preference trials, evidencing some capacity for inhibitory control in this context. Despite differences in sociality and ecology, the five lemur species did not differ in this ability. Although the study did not uncover species differences, this experimental task may provide a useful measure of social inhibition in broader comparative studies.

  15. Maximizing Exposure Therapy: An Inhibitory Learning Approach

    PubMed Central

    Craske, Michelle G.; Treanor, Michael; Conway, Chris; Zbozinek, Tomislav; Vervliet, Bram

    2014-01-01

    Exposure therapy is an effective approach for treating anxiety disorders, although a substantial number of individuals fail to benefit or experience a return of fear after treatment. Research suggests that anxious individuals show deficits in the mechanisms believed to underlie exposure therapy, such as inhibitory learning. Targeting these processes may help improve the efficacy of exposure-based procedures. Although evidence supports an inhibitory learning model of extinction, there has been little discussion of how to implement this model in clinical practice. The primary aim of this paper is to provide examples to clinicians for how to apply this model to optimize exposure therapy with anxious clients, in ways that distinguish it from a ‘fear habituation’ approach and ‘belief disconfirmation’ approach within standard cognitive-behavior therapy. Exposure optimization strategies include 1) expectancy violation, 2) deepened extinction, 3) occasional reinforced extinction, 4) removal of safety signals, 5) variability, 6) retrieval cues, 7) multiple contexts, and 8) affect labeling. Case studies illustrate methods of applying these techniques with a variety of anxiety disorders, including obsessive-compulsive disorder, posttraumatic stress disorder, social phobia, specific phobia, and panic disorder. PMID:24864005

  16. Mechanisms underlying electrical and mechanical responses of the bovine retractor penis to inhibitory nerve stimulation and to an inhibitory extract.

    PubMed Central

    Byrne, N. G.; Muir, T. C.

    1985-01-01

    The response of the bovine retractor penis (BRP) to stimulation of non-adrenergic, non-cholinergic (NANC) inhibitory nerves and to an inhibitory extract prepared from this muscle have been studied using intracellular microelectrode, sucrose gap and conventional mechanical recording techniques. Both inhibitory nerve stimulation and inhibitory extract hyperpolarized the membrane potential and relaxed spontaneous or guanethidine (3 X 10(-5) M)-induced tone. These effects were accompanied by an increase in membrane resistance. Following membrane potential displacement from an average value of -53 +/- 7 mV (n = 184; Byrne & Muir, 1984) inhibitory potentials to nerve stimulation were abolished at approximately -30 mV; there was no evidence of reversal. Displacement by inward hyperpolarizing current over the range -45 to -60 mV increased the inhibitory response to nerve stimulation and to inhibitory extract; at more negative potential values (above approximately -60 mV) the inhibitory potential decreased and was abolished (approximately -103 mV). There was no evidence of reversal. Removal of [K+]o reversibly reduced hyperpolarization to nerve stimulation and inhibitory extract. No enhancement was observed. Increasing the [K+]o to 20 mM reduced the inhibitory potential to nerve stimulation but this was restored by passive membrane hyperpolarization. Inhibitory potentials were obtained at membrane potential values exceeding that of the estimated EK (-49 mV). [Cl-]o-free or [Cl-]o-deficient solutions reduced and abolished (after some 20-25 min) the hyperpolarization produced by inhibitory nerve stimulation or inhibitory extract. The inhibitory potential amplitude following nerve stimulation was not restored by passive displacement of the membrane potential from -26 to -104 mV approximately. Ouabain (1-5 X 10(-5) M) reduced then (45-60 min later) abolished the inhibitory potential to nerve stimulation. The effects of this drug on the extract were not investigated. It is

  17. Helium Diffusion in Olivine

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.; Watson, E. B.

    2011-12-01

    Diffusion of helium has been characterized in natural Fe-bearing olivine (~Fo90) and synthetic forsterite. Polished, oriented slabs of olivine were implanted with 3He, at 100 keV at a dose of 5x1015/cm2 or at 3.0 MeV at a dose of 1x1016/cm2. A set of experiments on the implanted olivine were run in 1-atm furnaces. In addition to the one-atm experiments, experiments on implanted samples were also run at higher pressures (2.6 and 2.7 GPa) to assess the potential effects of pressure on He diffusion and the applicability of the measured diffusivities in describing He transport in the mantle. The high-pressure experiments were conducted in a piston-cylinder apparatus using an "ultra-soft" pressure cell, with the diffusion sample directly surrounded by AgCl. 3He distributions following experiments were measured with Nuclear Reaction Analysis using the reaction 3He(d,p)4He. This direct profiling method permits us to evaluate anisotropy of diffusion, which cannot be easily assessed using bulk-release methods. For diffusion in forsterite parallel to c we obtain the following Arrhenius relation over the temperatures 250-950°C: D = 3.91x10-6exp(-159 ± 4 kJ mol-1/RT) m2/sec. The data define a single Arrhenius line spanning more than 7 orders of magnitude in D and 700°C in temperature. Diffusion parallel to a appears slightly slower, yielding an activation energy for diffusion of 135 kJ/mol and a pre-exponential factor of 3.73x10-8 m2/sec. Diffusion parallel to b is slower than diffusion parallel to a (by about two-thirds of a log unit); for this orientation an activation energy of 138 kJ/mol and a pre-exponential factor of 1.34x10-8 m2/sec are obtained. This anisotropy is broadly consistent with observations for diffusion of Ni and Fe-Mg in olivine. Diffusion in Fe-bearing olivine (transport parallel to b) agrees within uncertainty with findings for He diffusion in forsterite. The higher-pressure experiments yield diffusivities in agreement with those from the 1-atm

  18. Helium diffusion in carbonates

    NASA Astrophysics Data System (ADS)

    Amidon, W. H.; Cherniak, D. J.; Watson, E. B.; Hobbs, D.

    2013-12-01

    The abundance and large grain size of carbonate minerals make them a potentially attractive target for 4He thermochronology and 3He cosmogenic dating, although the diffusive properties of helium in carbonates remain poorly understood. This work characterizes helium diffusion in calcite and dolomite to better understand the crystal-chemical factors controlling He transport and retentivity. Slabs of cleaved natural calcite and dolomite, and polished sections of calcite cut parallel or normal to c, were implanted with 3He at 3 MeV with a dose of 5x1015/cm2. Implanted carbonates were heated in 1-atm furnaces, and 3He distributions following diffusion anneals were profiled with Nuclear Reaction Analysis using the reaction 3He(d,p)4He. For 3He transport normal to cleavage surfaces in calcite, we obtain the following Arrhenius relation over the temperature range 78-300°C: Dcalcite = 9.0x10-9exp(-55 × 6 kJ mol-1/RT) m2sec-1. Diffusion in calcite exhibits marked anisotropy, with diffusion parallel to c about two orders of magnitude slower than diffusion normal to cleavage faces. He diffusivities for transport normal to the c-axis are similar in value to those normal to cleavage surfaces. Our findings are broadly consistent with helium diffusivities from step-heating measurements of calcite by Copeland et al. (2007); these bulk degassing data may reflect varying effects of diffusional anisotropy. Helium diffusion normal to cleavage surfaces in dolomite is significantly slower than diffusion in calcite, and has a much higher activation energy for diffusion. For dolomite, we obtain the following Arrhenius relation for He diffusion over the temperature range 150-400°C: Ddolomite = 9.0x10-8exp(-92 × 9 kJ mol-1/RT) m2sec-1. The role of crystallographic structure in influencing these differences among diffusivities was evaluated using the maximum aperture approach of Cherniak and Watson (2011), in which crystallographic structures are sectioned along possible diffusion

  19. Thorium Diffusion in Monazite

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.

    2006-05-01

    Diffusion of thorium has been characterized in synthetic monazite under dry conditions. The synthetic monazites (either pure CePO4, NdPO4, or a mixed LREE phosphate containing Ce, Nd, and Sm) were grown via a Na2CO3-MoO3 flux method. The source of diffusant for the experiments were either synthesized ThSiO4 or CaTh(PO4)2 powders. Experiments were performed by placing source and monazite in Pt capsules and annealing capsules in 1 atm furnaces for times ranging from 10 days to a few hours, at temperatures from 1400 to 1550C. The Th distributions in the monazite were profiled by Rutherford Backscattering Spectrometry (RBS). The following Arrhenius relation was obtained for diffusion in monazite: DSm = 7.2x103 exp(-814 kJ mol-1/RT) m2sec-1 The diffusivity of Th was similar for monazites containing a single REE and the mixed LREE phosphates. Th diffusion was also similar for experiments run using the Th silicate and Ca-Th phosphate sources, suggesting that the substitutional mechanism for Th in monazite, i.e, Th+4 + Si+4 for REE+3 + P+5 with the ThSiO4 source, and Th+4 + Ca+2 for 2REE+3 with the CaTh(PO4)2 source, does not significantly affect Th diffusivities, and that Th is likely the rate-limiting species. Th diffusion in monazite is about 4 orders of magnitude slower than Pb diffusion (Cherniak et al., 2004). This contrasts with findings of Gardes et al. (2005) who determined that Pb, Th and REE diffusivities in monazite are similar. Th diffusion in zircon (Cherniak et al., 1997) is about an order of magnitude slower than in monazite, but with similar activation energy for diffusion. The smaller diffusivities in zircon may be a consequence of the larger disparity in size between Th and the Zr site in zircon as compared with Th and the REE site in monazite. Nonetheless, Th is essentially immobile in monazite with respect to exchange by volume diffusion under most geologic conditions; these findings may have implications for containment of high- level actinide

  20. Inhibitory ryanodine prevents ryanodine receptor-mediated Ca²⁺ release without affecting endoplasmic reticulum Ca²⁺ content in primary hippocampal neurons.

    PubMed

    Adasme, Tatiana; Paula-Lima, Andrea; Hidalgo, Cecilia

    2015-02-27

    Ryanodine is a cell permeant plant alkaloid that binds selectively and with high affinity to ryanodine receptor (RyR) Ca(2+) release channels. Sub-micromolar ryanodine concentrations activate RyR channels while micromolar concentrations are inhibitory. Several reports indicate that neuronal synaptic plasticity, learning and memory require RyR-mediated Ca(2+)-release, which is essential for muscle contraction. The use of micromolar (inhibitory) ryanodine represents a common strategy to suppress RyR activity in neuronal cells: however, micromolar ryanodine promotes RyR-mediated Ca(2+) release and endoplasmic reticulum Ca(2+) depletion in muscle cells. Information is lacking in this regard in neuronal cells; hence, we examined here if addition of inhibitory ryanodine elicited Ca(2+) release in primary hippocampal neurons, and if prolonged incubation of primary hippocampal cultures with inhibitory ryanodine affected neuronal ER calcium content. Our results indicate that inhibitory ryanodine does not cause Ca(2+) release from the ER in primary hippocampal neurons, even though ryanodine diffusion should produce initially low intracellular concentrations, within the RyR activation range. Moreover, neurons treated for 1 h with inhibitory ryanodine had comparable Ca(2+) levels as control neurons. These combined findings imply that prolonged incubation with inhibitory ryanodine, which effectively abolishes RyR-mediated Ca(2+) release, preserves ER Ca(2+) levels and thus constitutes a sound strategy to suppress neuronal RyR function. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Tungsten diffusion in silicon

    SciTech Connect

    De Luca, A.; Texier, M.; Burle, N.; Oison, V.; Pichaud, B.; Portavoce, A.; Grosjean, C.

    2014-01-07

    Two doses (10{sup 13} and 10{sup 15} cm{sup −2}) of tungsten (W) atoms were implanted in different Si(001) wafers in order to study W diffusion in Si. The samples were annealed or oxidized at temperatures between 776 and 960 °C. The diffusion profiles were measured by secondary ion mass spectrometry, and defect formation was studied by transmission electron microscopy and atom probe tomography. W is shown to reduce Si recrystallization after implantation and to exhibit, in the temperature range investigated, a solubility limit close to 0.15%–0.2%, which is higher than the solubility limit of usual metallic impurities in Si. W diffusion exhibits unusual linear diffusion profiles with a maximum concentration always located at the Si surface, slower kinetics than other metals in Si, and promotes vacancy accumulation close to the Si surface, with the formation of hollow cavities in the case of the higher W dose. In addition, Si self-interstitial injection during oxidation is shown to promote W-Si clustering. Taking into account these observations, a diffusion model based on the simultaneous diffusion of interstitial W atoms and W-Si atomic pairs is proposed since usual models used to model diffusion of metallic impurities and dopants in Si cannot reproduce experimental observations.

  2. Inhibitory effect against pathogenic and spoilage bacteria of Pseudomonas strains isolated from spoiled and fresh fish.

    PubMed Central

    Gram, L

    1993-01-01

    The antibacterial effects of 209 Pseudomonas strains isolated from spoiled iced fish and newly caught fish were assessed by screening target organisms in agar diffusion assays. One-third (67 strains) inhibited the growth of one or several of six target organisms (Escherichia coli, Shewanella putrefaciens, Aeromonas sobria, Pseudomonas fluorescens, Listeria monocytogenes, and Staphylococcus aureus), of which S. aureus and A. sobria were the most sensitive. The inhibitory action was most pronounced among the strains producing siderophores, and the presence of iron eliminated the antibacterial effect of two-thirds of the inhibitory strains. Siderophore-mediated competition for iron may explain the inhibitory activity of these strains. All but nine of the inhibiting strains were found to inhibit the growth of 38 psychrotrophic S. putrefaciens strains isolated from spoiling fish and fish products. Siderophore-containing Pseudomonas culture supernatants inhibited growth of S. putrefaciens, as did the addition of iron chelators (ethylenediamine dihydroxyphenylacetic acid [EDDHA]). In particular, Pseudomonas strains isolated from newly caught and spoiled Nile perch (Lates niloticus) inhibited S. putrefaciens. This suggests that microbial interaction (e.g., competition or antagonism) may influence the selection of a microflora for some chilled food products. PMID:8357253

  3. Diffusion Flame Stabilization

    NASA Technical Reports Server (NTRS)

    Takahashi, Fumiaki; Katta, Viswanath R.

    2007-01-01

    Diffusion flames are commonly used for industrial burners in furnaces and flares. Oxygen/fuel burners are usually diffusion burners, primarily for safety reasons, to prevent flashback and explosion in a potentially dangerous system. Furthermore, in most fires, condensed materials pyrolyze, vaporize, and burn in air as diffusion flames. As a result of the interaction of a diffusion flame with burner or condensed-fuel surfaces, a quenched space is formed, thus leaving a diffusion flame edge, which plays an important role in flame holding in combustion systems and fire spread through condensed fuels. Despite a long history of jet diffusion flame studies, lifting/blowoff mechanisms have not yet been fully understood, compared to those of premixed flames. In this study, the structure and stability of diffusion flames of gaseous hydrocarbon fuels in coflowing air at normal earth gravity have been investigated experimentally and computationally. Measurements of the critical mean jet velocity (U(sub jc)) of methane, ethane, or propane at lifting or blowoff were made as a function of the coflowing air velocity (U(sub a)) using a tube burner (i.d.: 2.87 mm) (Fig. 1, left). By using a computational fluid dynamics code with 33 species and 112 elementary reaction steps, the internal chemical-kinetic structures of the stabilizing region of methane and propane flames were investigated (Fig. 1, right). A peak reactivity spot, i.e., reaction kernel, is formed in the flame stabilizing region due to back-diffusion of heat and radical species against an oxygen-rich incoming flow, thus holding the trailing diffusion flame. The simulated flame base moved downstream under flow conditions close to the measured stability limit.

  4. Diffusion Flame Stabilization

    NASA Technical Reports Server (NTRS)

    Takahashi, Fumiaki; Katta, V. R.

    2006-01-01

    Diffusion flames are commonly used for industrial burners in furnaces and flares. Oxygen/fuel burners are usually diffusion burners, primarily for safety reasons, to prevent flashback and explosion in a potentially dangerous system. Furthermore, in most fires, condensed materials pyrolyze, vaporize, and burn in air as diffusion flames. As a result of the interaction of a diffusion flame with burner or condensed-fuel surfaces, a quenched space is formed, thus leaving a diffusion flame edge, which plays an important role in flame holding in combustion systems and fire spread through condensed fuels. Despite a long history of jet diffusion flame studies, lifting/blowoff mechanisms have not yet been fully understood, compared to those of premixed flames. In this study, the structure and stability of diffusion flames of gaseous hydrocarbon fuels in coflowing air at normal earth gravity have been investigated experimentally and computationally. Measurements of the critical mean jet velocity (U(sub jc)) of methane, ethane, or propane at lifting or blowoff were made as a function of the coflowing air velocity (U(sub a)) using a tube burner (i.d.: 2.87 mm). By using a computational fluid dynamics code with 33 species and 112 elementary reaction steps, the internal chemical-kinetic structures of the stabilizing region of methane and propane flames were investigated. A peak reactivity spot, i.e., reaction kernel, is formed in the flame stabilizing region due to back-diffusion of heat and radical species against an oxygen-rich incoming flow, thus holding the trailing diffusion flame. The simulated flame base moved downstream under flow conditions close to the measured stability limit.

  5. Toxicity of seven priority hazardous and noxious substances (HNSs) to marine organisms: Current status, knowledge gaps and recommendations for future research.

    PubMed

    Rocha, A Cristina S; Reis-Henriques, Maria Armanda; Galhano, Victor; Ferreira, Marta; Guimarães, Laura

    2016-01-15

    Shipping industry and seaborne trade have rapidly increased over the last fifty years, mainly due to the continuous increasing demand for chemicals and fuels. Consequently, despite current regulations, the occurrence of accidental spills poses an important risk. Hazardous and noxious substances (HNSs) have been raising major concern among environmental managers and scientific community for their heterogeneity, hazardous potential towards aquatic organisms and associated social-economic impacts. A literature review on ecotoxicological hazards to aquatic organisms was conducted for seven HNSs: acrylonitrile, n-butyl acrylate, cyclohexylbenzene, hexane, isononanol, trichloroethylene and xylene. Information on the mechanisms of action of the selected HNS was also reviewed. The main purpose was to identify: i) knowledge gaps in need of being addressed in future research; and ii) a set of possible biomarkers suitable for ecotoxicological assessment and monitoring in both estuarine and marine systems. Main gaps found concern the scarcity of information available on ecotoxicological effects of HNS towards marine species and their poorly understood mode of action in wildlife. Differences were found between the sensitivity of freshwater and seawater organisms, so endpoints produced in the former may not be straightforwardly employed in evaluations for the marine environment. The relationship between sub-individual effects and higher level detrimental alterations (e.g. behavioural, morphological, reproductive effects and mortality) are not fully understood. In this context, a set of biomarkers associated to neurotoxicity, detoxification and anti-oxidant defences is suggested as potential indicators of toxic exposure/effects of HNS in marine organisms. Overall, to support the development of contingency plans and the establishment of environmental safety thresholds, it will be necessary to undertake targeted research on HNS ecotoxicity in the marine environment. Research should

  6. New perspectives on taste and primate evolution: the dichotomy in gustatory coding for perception of beneficent versus noxious substances as supported by correlations among human thresholds.

    PubMed

    Hladik, Claude-Marcel; Pasquet, P; Simmen, B

    2002-04-01

    In various environments where primates are presently observed, as well as in forests and savannas which have been inhabited by australopithecines and early hominids, there are (or there have been presumably) categories of substances eliciting taste signals associated with stereotyped responses. Such is the case for various soluble sugars of fruits and nectars, attracting consumers, and for several plant compounds in which bitter or strongly astringent properties have a repulsive effect. The occurrence of such classes of tasty substances among natural products appears to be related to the evolutionary trends that shaped primate sensory perception (for detecting either beneficent or potentially noxious substances) in the context of a long history of coevolution between animals and plants. Here, we present original psychophysical data on humans (412 individuals aged 17-59 years) as an analogy with which to test recent evidence from electrophysiology in nonhuman primates (Hellekant et al. [1997] J. Neurophysiol. 77:978-993; Danilova et al. [1998] Ann. N.Y. Acad. Sci. 855:160-164) that taste fibers can be grouped into clusters of "best-responding fibers" with two more specific clusters, one for sugars and one for quinine and tannins. The collinearity found between human taste responses (recognition thresholds) for fructose and sucrose, as well as for quinine and tannins, is presented and discussed as another evidence of the two-direction evolutionary trend determining taste sensitivity. Salt perception appears to be totally independent of these trends. Accordingly, the appreciation of a salty taste seems to be a recent culturally learned response, and not a primary taste perception. The very existence of primary tastes is discussed in the context of evolutionary trends, past and present.

  7. [Monitoring of contamination of foodstuffs with elements noxious to human health. Part I. Wheat cereal products, vegetable products, confectionery and products for infants and children (2004 year)].

    PubMed

    Wojciechowska-Mazurek, Maria; Starska, Krystyna; Brulińska-Ostrowska, Elzbieta; Plewa, Monika; Biernat, Urszula; Karłowski, Kazimierz

    2008-01-01

    The testing of products of wheat cereal (310 samples), vegetable (418 samples), confectionery (439 samples) and 952 samples of products for infants and children has initiated the 5-years cycle of monitoring investigations on food contamination with elements noxious to human health planned to perform in 2004-2008. The parties involved in testing were: laboratories of State Sanitary Inspection collecting samples on all over the territory of Poland, both from retail market (of domestic origin as well as imported) and directly from producers; the national reference laboratory of the Department of Food and Consumer Articles Research of National Institute of Public Health - National Institute of Hygiene responsible for elaboration of official food control and monitoring plans to be approved by Chief Sanitary Inspectorate and for the substantive supervising of tests performance. The reported metals contents were not of health concern and generally below the levels set forth in food legislation. The health hazard assessment was performed taking into account the mean contamination obtained and average domestic consumption of these food products groups in Poland. The highest intake expressed as the percentage of provisional tolerable weekly intake (PTWI) was obtained for cadmium, which has reached 9.4% PTWI for cereal based products and 4.7% PTWI for vegetables. The cadmium content in chocolate and derived products due to contamination of cocoa beans and the levels of this element in products for infants and children originated from contamination of cereal and soybeans row materials should not be ignored. The decrease of lead contamination comparing to those reported in 1990 studies was observed.

  8. Simulation of a Hazardous and Noxious Substances (HNS) spill in the marine environment: lethal and sublethal effects of acrylonitrile to the European seabass.

    PubMed

    Neuparth, T; Capela, R; Rey-Salgueiro, L; Moreira, S M; Santos, M M; Reis-Henriques, M A

    2013-10-01

    Despite the extensive maritime transportation of Hazardous and Noxious Substances (HNS), there is a current lack of knowledge on the effects posed by HNS spills on the marine biota. Among the HNS identified as priority, acrylonitrile was selected to conduct ecotoxicological assays. We assessed the acute and subletal effects of acrylonitrile in seabass, followed by a recovery phase to simulate the conditions of a spill incident. The work aimed at testing a broad range of biological responses induced by acrylonitrile. Sublethal exposure to the highest two doses increased the fish mortality rate (8.3% and 25% mortality in 0.75 and 2 mg L(-1) acrylonitrile concentrations), whereas no mortality were observed in control and 0.15 mg L(-1) treatments. Additionally, important alterations at sub-individual level were observed. Acrylonitrile significantly induced the activities of Catalase- CAT and Glutathione S-Transferase - GST; and the levels of DNA damage were significantly increased. Conversely, Superoxide Dismutase- SOD - activity was found to be significantly inhibited and no effects were found on Lipid Peroxidation- LPO and ethoxyresorufin O-deethylase - EROD - activity. Following a 7d recovery period, the levels of CAT, GST and EROD fell to levels at or below those in the control. In the 2 mg L(-1) group, SOD remained at the levels found during exposure phase. This study has gathered essential information on the acute and subletal toxicity of acrylonitrile to seabass. It also demonstrated that 7d recovery allowed a return of most endpoints to background levels. These data will be useful to assist relevant bodies in preparedness and response to HNS spills. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Light-Emitting Diode Phototherapy Reduces Nocifensive Behavior Induced by Thermal and Chemical Noxious Stimuli in Mice: Evidence for the Involvement of Capsaicin-Sensitive Central Afferent Fibers.

    PubMed

    Pigatto, Glauce Regina; Coelho, Igor Santos; Aquino, Rosane Schenkel; Bauermann, Liliane Freitas; Santos, Adair Roberto Soares

    2016-04-07

    Low-intensity phototherapy using light fonts, like light-emitting diode (LED), in the red to infrared spectrum is a promising alternative for the treatment of pain. However, the underlying mechanisms by which LED phototherapy reduces acute pain are not yet well understood. This study investigated the analgesic effect of multisource LED phototherapy on the acute nocifensive behavior of mice induced by thermal and chemical noxious stimuli. The involvement of central afferent C fibers sensitive to capsaicin in this effect was also investigated. Mice exposed to multisource LED (output power 234, 390, or 780 mW and power density 10.4, 17.3, and 34.6 mW/cm(2), respectively, from 10 to 30 min of stimulation with a wavelength of 890 nm) showed rapid and significant reductions in formalin- and acetic acid-induced nocifensive behavior. This effect gradually reduced but remained significant for up to 7 h after LED treatment in the last model used. Moreover, LED (390 mW, 17.3 mW/cm(2)/20 min) irradiation also reduced nocifensive behavior in mice due to chemical [endogenous (i.e., glutamate, prostaglandins, and bradykinin) or exogenous (i.e., formalin, acetic acid, TRPs and ASIC agonist, and protein kinase A and C activators)] and thermal (hot plate test) stimuli. Finally, ablating central afferent C fibers abolished LED analgesia. These experimental results indicate that LED phototherapy reduces the acute painful behavior of animals caused by chemical and thermal stimuli and that LED analgesia depends on the integrity of central afferent C fibers sensitive to capsaicin. These findings provide new information regarding the underlying mechanism by which LED phototherapy reduces acute pain. Thus, LED phototherapy may be an important tool for the management of acute pain.

  10. Effect of phytogenics on growth performance, fecal score, blood profiles, fecal noxious gas emission, digestibility, and intestinal morphology of weanling pigs challenged with Escherichia coli K88.

    PubMed

    Devi, S Mohana; Lee, S I; Kim, I H

    2015-01-01

    Phytogenic feed additives have become attractive alternatives for use in animal diets. The objective of the present study was to evaluate the effect of a phytogenic-based feed additive on growth performance, nutrient digestibility, blood profiles, fecal noxious gas emission, and intestinal morphology of weaning pigs after dietary challenge with E. coli K88. A total of 120 crossbred pigs [(Yorkshire×Landrace)×Duroc)] with an initial body weight (BW) of 6.09±0.96 kg (21 d of age) were assigned randomly to 1 of the 4 dietary treatments. Each pen housed 5 pigs, and there were 6 pens/treatment. Treatments included: T1, negative control (without antibiotics); T2, T1+antibiotic; T3, T1+0.05% phytogenics; and T4, T1+0.2% commercial mix of organic acids. Overall, the average daily gain (ADG) with the T3 treatment was higher (P<0.05). At wk 1, the apparent total tract digestibility (ATTD) of dry matter (DM) was increased (P<0.05) with T4 treatment. The ATTD of ash with T3 and T4 treatments was greater (P<0.05). At wk 3, pigs fed with the T4 diet had a significantly higher (P<0.05) ATTD of DM. The ATTD of ash and calcium (Ca) was significantly increased (P<0.05) with the T4 treatment. Pigs fed with the T3 diet had a higher (P<0.05) ATTD of phosphorus (P). At wk 6, the ATTD of ash was significantly increased (P<0.05) with the T1 and T3 treatments. The data indicate that phytogenics positively affect growth performance of weaning pigs, indicating that their use as an alternative in the diets of weaning pigs can significantly improve ADG, under challenge with E.coli K88.

  11. Regulatory effects of intermittent noxious stimulation on spinal cord injury-sensitive microRNAs and their presumptive targets following spinal cord contusion.

    PubMed

    Strickland, Eric R; Woller, Sarah A; Garraway, Sandra M; Hook, Michelle A; Grau, James W; Miranda, Rajesh C

    2014-01-01

    Uncontrollable nociceptive stimulation adversely affects recovery in spinally contused rats. Spinal cord injury (SCI) results in altered microRNA (miRNA) expression both at, and distal to the lesion site. We hypothesized that uncontrollable nociception further influences SCI-sensitive miRNAs and associated gene targets, potentially explaining the progression of maladaptive plasticity. Our data validated previously described sensitivity of miRNAs to SCI alone. Moreover, following SCI, intermittent noxious stimulation decreased expression of miR124 in dorsal spinal cord 24 h after stimulation and increased expression of miR129-2 in dorsal, and miR1 in ventral spinal cord at 7 days. We also found that brain-derived neurotrophic factor (BDNF) mRNA expression was significantly down-regulated 1 day after SCI alone, and significantly more so, after SCI followed by tailshock. Insulin-like growth factor-1 (IGF-1) mRNA expression was significantly increased at both 1 and 7 days post-SCI, and significantly more so, 7 days post-SCI with shock. MiR1 expression was positively and significantly correlated with IGF-1, but not BDNF mRNA expression. Further, stepwise linear regression analysis indicated that a significant proportion of the changes in BDNF and IGF-1 mRNA expression were explained by variance in two groups of miRNAs, implying co-regulation. Collectively, these data show that uncontrollable nociception which activates sensorimotor circuits distal to the injury site, influences SCI-miRNAs and target mRNAs within the lesion site. SCI-sensitive miRNAs may well mediate adverse consequences of uncontrolled sensorimotor activation on functional recovery. However, their sensitivity to distal sensory input also implicates these miRNAs as candidate targets for the management of SCI and neuropathic pain.

  12. Identification of different types of spinal afferent nerve endings that encode noxious and innocuous stimuli in the large intestine using a novel anterograde tracing technique.

    PubMed

    Spencer, Nick J; Kyloh, Melinda; Duffield, Michael

    2014-01-01

    must underlie the transduction of noxious and/or innocuous stimuli from the large intestine.

  13. Ginsenosides Have a Suppressive Effect on c-Fos Expression in Brain and Reduce Cardiovascular Responses Increased by Noxious Stimulation to the Rat Tooth

    PubMed Central

    Jung, Ji-Yeon; Seong, Kyung-Joo; Moon, In-Ohk; Cho, Jin-Hyoung; Kim, Sun-Hun

    2013-01-01

    The purpose of this study is to investigate the antinociceptive effects of ginsenosides on toothache. c-Fos immunoreactive (IR) neurons were examined after noxious intrapulpal stimulation (NS) by intrapulpal injection of 2 M KCl into upper and lower incisor pulps exposed by bone cutter in Sprague Dawley rats. The number of Fos-IR neurons was increased in the trigeminal subnucleus caudalis (Vc) and the transitional region between Vc and subnucleus interpolaris (Vi) by NS to tooth. The intradental NS raised arterial blood pressure (BP) and heart rate (HR). The number of Fos-IR neurons was also enhanced in thalamic ventral posteromedial nucleus (VPMN) and centrolateral nucleus (CLN) by NS to tooth. The intradental NS increased the number of Fos-IR neurons in the nucleus tractus solitarius (NTS) and rostral ventrolateral medulla (RVLM), hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN), central cardiovascular regulation centers. Ginsenosides reduced the number of c-Fos-IR increased by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Naloxone, an opioid antagonist, did not block the effect of ginsenoside on the number of Fos-IR neurons enhanced by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Ginsenosides ameliorated arterial BP and HR raised by NS to tooth and reduced the number of Fos-IR neurons increased by NS to tooth in the NTS, RVLM, hypothalamic SON, and PVN. These results suggest that ginsenosides have an antinociceptive effect on toothache through non-opioid system and attenuates BP and HR increased by NS to tooth. PMID:23626473

  14. Sucrose and naltrexone prevent increased pain sensitivity and impaired long-term memory induced by repetitive neonatal noxious stimulation: Role of BDNF and β-endorphin.

    PubMed

    Nuseir, Khawla Q; Alzoubi, Karem H; Alhusban, Ahmed; Bawaane, Areej; Al-Azzani, Mohammed; Khabour, Omar F

    2017-10-01

    Pain in neonates is associated with short and long-term adverse outcomes. Data demonstrated that long-term consequences of untreated pain are linked to the plasticity of the neonate's brain. Sucrose is effective and safe for reducing painful procedures from single events. However, the mechanism of sucrose-induced analgesia is not fully understood. The role of the opioid system in this analgesia using the opioid receptor antagonist Naltrexone was investigated, plus the long-term effects on learning and memory formation during adulthood. Pain was induced in rat pups via needle pricks of the paws. Sucrose solution and/or naltrexone were administered before the pricks. All treatments started on day one of birth and continued for two weeks. At the end of 8weeks, behavioral studies were conducted to test spatial learning and memory using radial arm water maze (RAWM), and pain threshold via foot-withdrawal response to a hot plate. The hippocampus was dissected; levels of brain derived neurotrophic factor (BDNF) and endorphins were assessed using ELISA. Acute repetitive neonatal pain increased pain sensitivity later in life, while naltrexone with sucrose decreased pain sensitivity. Naltrexone and/or sucrose prevented neonatal pain induced impairment of long-term memory, while neonatal pain decreased levels of BDNF in the hippocampus; this decrease was averted by sucrose and naltrexone. Sucrose with naltrexone significantly increased β-endorphin levels in noxiously stimulated rats. In conclusion, naltrexone and sucrose can reverse increased pain sensitivity and impaired long-term memory induced by acute repetitive neonatal pain probably by normalizing BDNF expression and increasing β-endorphin levels. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Simultaneous multisite recordings of neural ensemble responses in the motor cortex of behaving rats to peripheral noxious heat and chemical stimuli.

    PubMed

    Wang, Chang-Ming; Yang, Lei; Lu, Dan; Lu, Yun-Fei; Chen, Xue-Feng; Yu, Yao-Qing; Li, Zhen; Zhang, Fu-Kang; Li, Hua; Chen, Jun

    2011-09-30

    Chronic motor cortex (MCx) stimulation (MCS) is an effective approach for patients with chronic, intractable neuropathic pain. However, the underlying neural mechanisms are less known. Combining an in vivo simultaneous multisite recording technique with a video-based behavioral tracker, simultaneous neuronal ensemble activities of the MCx and behavioral responses to noxious heat stimuli applied to bilateral hindpaw pads under naïve and inflammatory pain state were studied in freely behaving rats receiving prior implantation of microwire multielectrode array (2 × 4). Totally, 81 active units were sorted and separated from 40 microwire electrodes pre-implanted in the MCx of 5 rats. Under naïve state, 41% (33/81) units were responsive to contralateral, while 27% (22/81) were responsive to ipsilateral heat stimuli. However, the proportion of heat-responsive units under inflammatory pain state induced by subcutaneous bee venom (BV) injection was significantly increased when compared with saline control (BV vs. saline: 60% vs. 48% for contralateral and 51% vs. 37% for ipsilateral, P < 0.05, n = 81 units) as a consequence of recruitment of some previously heat non-responsive to heat sensitive units. Moreover, under the BV-inflamed condition, the discharge rate of the MCx neurons was significantly increased. The time course of increased spontaneous neuronal ensemble activities (n = 81) was in parallel with that of pain-related behaviors following BV injection. It is concluded that there are pain-related neurons in the MCx that can be functionally changed by peripheral inflammatory pain condition.

  16. Infrared diffuse interstellar bands

    NASA Astrophysics Data System (ADS)

    Galazutdinov, G. A.; Lee, Jae-Joon; Han, Inwoo; Lee, Byeong-Cheol; Valyavin, G.; Krełowski, J.

    2017-05-01

    We present high-resolution (R ˜ 45 000) profiles of 14 diffuse interstellar bands in the ˜1.45 to ˜2.45 μm range based on spectra obtained with the Immersion Grating INfrared Spectrograph at the McDonald Observatory. The revised list of diffuse bands with accurately estimated rest wavelengths includes six new features. The diffuse band at 15 268.2 Å demonstrates a very symmetric profile shape and thus can serve as a reference for finding the 'interstellar correction' to the rest wavelength frame in the H range, which suffers from a lack of known atomic/molecular lines.

  17. Diffusion in monodisperse ferrofluids

    NASA Astrophysics Data System (ADS)

    Peredo-Ortíz, R.; Hernández-Contreras, M.; Hernández Gómez, R.

    2017-01-01

    The diffusion coefficients characterizing the translational and rotational Brownian motion of a particle in a concentrated suspension were determined in the long time diffusive regime for a ferrofluid suspension with the use of a Langevin equation approach. These dynamical properties depend on the equilibrium micro-structural information of the suspension and take into account the effect of direct anisotropic inter-particle's interactions on self-diffusion. The comparison of this theory with Brownian dynamic simulations results is made in terms of colloid density and dipole interaction strength.

  18. Asymmetry between excitatory and inhibitory learning.

    PubMed

    Harris, Justin A; Patterson, Angela E; Andrew, Benjamin J; Kwok, Dorothy W S; Loy, Ignacio

    2016-10-01

    Five experiments investigated how learning about the added feature in a feature-positive discrimination or feature-negative discrimination is related to the change in reinforcement rate that the feature signals. Rats were trained in a magazine-approach paradigm with 2 concurrent discriminations between A versus AX and B versus BY. In 2 experiments (1 and 3), X and Y signaled an increase of 0.3 in the probability of reinforcement, from 0.1 to 0.4 (A vs. AX), or from 0.6 to 0.9 (B vs. BY). After extended training, each session included probe test trials in which X and Y were presented alone (Experiment 1) or in compound with another excitatory conditional stimulus (CS), C (Experiment 3). There was no difference in response rate between the 2 types of test trial (X vs. Y; XC vs. YC), consistent with the fact that X and Y signaled the same absolute change in reinforcement. In Experiments 2 and 4, X and Y signaled a decrease of 0.3 in the probability of reinforcement, from 0.4 to 0.1 (A vs. AX) or from 0.9 to 0.6 (B vs. BY). Test trials in which X or Y was presented with C showed that X had greater inhibitory strength than Y, consistent with the fact that X signaled a larger relative change in reinforcement. This was confirmed in Experiment 5, in which X and Y had the same inhibitory strength on test after training in which they signaled the same relative change in reinforcement but different absolute changes (0.3 to 0.1 for A vs. AX; 0.9 to 0.3 for B vs. BY). The results show that excitatory conditioning is linearly related to the increase in reinforcement rate, whereas inhibitory learning is not linearly related to the decrease in reinforcement rate. Implications of this for theories of associative learning are discussed. (PsycINFO Database Record

  19. Extrasynaptic glutamate and inhibitory neurotransmission modulate ganglion cell participation during glutamatergic retinal waves.

    PubMed

    Firl, Alana; Sack, Georgeann S; Newman, Zachary L; Tani, Hiroaki; Feller, Marla B

    2013-04-01

    During the first 2 wk of mouse postnatal development, transient retinal circuits give rise to the spontaneous initiation and lateral propagation of depolarizations across the ganglion cell layer (GCL). Glutamatergic retinal waves occur during the second postnatal week, when GCL depolarizations are mediated by ionotropic glutamate receptors. Bipolar cells are the primary source of glutamate in the inner retina, indicating that the propagation of waves depends on their activation. Using the fluorescence resonance energy transfer-based optical sensor of glutamate FLII81E-1μ, we found that retinal waves are accompanied by a large transient increase in extrasynaptic glutamate throughout the inner plexiform layer. Using two-photon Ca(2+) imaging to record spontaneous Ca(2+) transients in large populations of cells, we found that despite this spatially diffuse source of depolarization, only a subset of neurons in the GCL and inner nuclear layer (INL) are robustly depolarized during retinal waves. Application of the glutamate transporter blocker dl-threo-β-benzyloxyaspartate (25 μM) led to a significant increase in cell participation in both layers, indicating that the concentration of extrasynaptic glutamate affects cell participation in both the INL and GCL. In contrast, blocking inhibitory transmission with the GABAA receptor antagonist gabazine and the glycine receptor antagonist strychnine increased cell participation in the GCL without significantly affecting the INL. These data indicate that during development, glutamate spillover provides a spatially diffuse source of depolarization, but that inhibitory circuits dictate which neurons within the GCL participate in retinal waves.

  20. Anion channelrhodopsins for inhibitory cardiac optogenetics

    PubMed Central

    Govorunova, Elena G.; Cunha, Shane R.; Sineshchekov, Oleg A.; Spudich, John L.

    2016-01-01

    Optical control of the heart muscle is a promising strategy for cardiology because it is more specific than traditional electrical stimulation, and allows a higher temporal resolution than pharmacological interventions. Anion channelrhodopsins (ACRs) from cryptophyte algae expressed in cultured neonatal rat ventricular cardiomyocytes produced inhibitory currents at less than one-thousandth of the light intensity required by previously available optogenetic tools, such as the proton pump archaerhodopsin-3 (Arch). Because of their greater photocurrents, ACRs permitted complete inhibition of cardiomyocyte electrical activity under conditions in which Arch was inefficient. Most importantly, ACR expression allowed precisely controlled shortening of the action potential duration by switching on the light during its repolarization phase, which was not possible with previously used optogenetic tools. Optical shortening of cardiac action potentials may benefit pathophysiology research and the development of optogenetic treatments for cardiac disorders such as the long QT syndrome. PMID:27628215

  1. Melanogenesis inhibitory compounds from Saussureae Radix.

    PubMed

    Choi, Ji Young; Choi, Eun Hyang; Jung, Hee Wook; Oh, Joon Seok; Lee, Won-Hee; Lee, Jong Gu; Son, Jong-Keun; Kim, Youngsoo; Lee, Seung Ho

    2008-03-01

    Ten compounds were isolated from the EtOAc soluble part of the MeOH extract of Saussureae Radix, with their effects on melanin production also evaluated in B-16 mouse melanoma cell lines stimulated with 3-isobutyl-1-methylxanthine (IBMX), an elevator of cellular cAMP. The compounds were identified as aplotaxene (1), 1 beta-hydroxy arbusculin A (2), costunolide (3), dehydrocostuslactone (4), 11 beta,13-dihydrocostunolide (5), reynosin (6), heptadec-(9Z)-enoic acid (7), beta-sitosterol (8), linoleic acid methyl ester (9) and betulinic acid methyl ester (10). Compounds 2, 9 and 10 were identified from Saussureae Radix for the first time. Furthermore, compounds 2, 3 and 6 showed potent inhibitory effects on the IBMX-induced melanogenesis, in dose-dependent manners, with IC50 values of 11, 3 and 2.5 microg/mL, respectively. As a positive control, arbutin exhibited an IC50 value of 29 microg/mL.

  2. Timing control by redundant inhibitory neuronal circuits

    NASA Astrophysics Data System (ADS)

    Tristan, I.; Rulkov, N. F.; Huerta, R.; Rabinovich, M.

    2014-03-01

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.

  3. Timing control by redundant inhibitory neuronal circuits

    SciTech Connect

    Tristan, I. Rulkov, N. F.; Huerta, R.; Rabinovich, M.

    2014-03-15

    Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.

  4. Nootropic dipeptide noopept enhances inhibitory synaptic transmission in the hippocampus.

    PubMed

    Povarov, I S; Kondratenko, R V; Derevyagin, V I; Ostrovskaya, R U; Skrebitskii, V G

    2015-01-01

    Application of nootropic agent Noopept on hippocampal slices from Wistar rats enhanced the inhibitory component of total current induced by stimulation of Shaffer collaterals in CA1 pyramidal neurons, but did not affect the excitatory component. A direct correlation between the increase in the amplitude of inhibitory current and agent concentration was found. The substance did not affect the release of inhibitory transmitters from terminals in the pyramidal neurons, which indicated changes in GABAergic interneurons.

  5. Melatonin, an inhibitory agent in breast cancer.

    PubMed

    Nooshinfar, Elaheh; Safaroghli-Azar, Ava; Bashash, Davood; Akbari, Mohammad Esmaeil

    2017-01-01

    The heterogeneous nature of breast cancer makes it one of the most challenging cancers to treat. Due to the stimulatory effect of estrogen in mammary cancer progression, anti-estrogenic agents like melatonin have found their way into breast cancer treatment. Further studies confirmed a reverse correlation between nocturnal melatonin levels and the development of mammary cancer. In this study we reviewed the molecular inhibitory effects of melatonin in breast cancer therapy. To open access the articles, Google scholar and science direct were used as a motor search. We used from valid external and internal databases. To reach the search formula, we determined mean key words like breast cancer, melatonin, cell proliferation and death. To retrieval the related articles, we continuously search the articles from 1984 to 2015. The relevance and the quality of the 480 articles were screened; at least we selected 80 eligible articles about melatonin molecular mechanism in breast cancer. The results showed that melatonin not only inhibits breast cancer cell growth, but also is capable of inhibiting angiogenesis, cancer cell invasion, and telomerase activity. Interestingly this hormone is able to induce apoptosis through the suppression or induction of a wide range of signaling pathways. Moreover, it seems that the concomitant administration of melatonin with other conventional chemotherapy agents had beneficial effects for patients with breast cancer, by alleviating unfavorable effects of those agents and enhancing their efficacy. The broad inhibitory effects of melatonin in breast cancer make it a promising agent and may add it to the list of potential drugs in treatment of this cancer.

  6. Inhibitory control of reaching movements in humans.

    PubMed

    Mirabella, Giovanni; Pani, Pierpaolo; Paré, Martin; Ferraina, Stefano

    2006-09-01

    Behavioral flexibility provides a very large repertoire of actions and strategies, however, it carries a cost: a potential interference between different options. The voluntary control of behavior starts exactly with the ability of deciding between alternatives. Certainly inhibition plays a key role in this process. Here we examined the inhibitory control of reaching arm movements with the countermanding paradigm. Right-handed human subjects were asked to perform speeded reaching movements toward a visual target appearing either on the same or opposite side of the reaching arm (no-stop trials), but to withhold the commanded movement whenever an infrequent stop signal was presented (stop trials). As the delay between go and stop signals increased, subjects increasingly failed to inhibit the movement. From this inhibitory function and the reaction times of movements in no-stop trials, we estimated the otherwise unobservable duration of the stopping process, the stop signal reaction time (SSRT). We found that the SSRT for reaching movements was, on average, 206 ms and that it varied with the reaching arm and the target position even though the stop signal was a central stimulus. In fact, subjects were always faster to withhold reaching movements toward visual targets appearing on the same side of the reaching arm. This behavior strictly parallels the course of the reaction times of no-stop trials. These data show that the stop and go processes interacting in this countermanding task are independent, but most likely influenced by a common factor when under the control of the same hemisphere. In addition, we show that the point beyond which the response cannot be inhibited, the so-called point-of-no-return that divides controlled and ballistic phases of movement processing, lies after the inter-hemispheric transfer.

  7. Monoamine oxidase inhibitory components from Cayratia japonica.

    PubMed

    Han, Xiang Hua; Hong, Seong Su; Hwang, Ji Sang; Lee, Myung Koo; Hwang, Bang Yeon; Ro, Jai Seup

    2007-01-01

    Seven flavonoids were isolated from the whole plants and fruits of Cayratia japonica through the activity-guided isolation of a methanol extract using a monoamine oxidase (MAO) inhibition assay as a monitor. The chemical structures of the isolates were assigned as apigenin-7-O-beta-D-glucuronopyranoside (1), apigenin (2), luteolin (3), luteolin-7-O-beta-D-glucopyranoside (4), (+)-dihydroquercetin (taxifolin) (5), (+)-dihydrokaempferol (aromadendrin) (6) and quercetin (7). Among the isolated compounds, flavones such as apigenin (2) and luteolin (3), as well as the flavonol, quercetin (7) showed potent inhibitory effects against the MAO activity with IC50 values of 6.5, 22.6, and 31.6 microM, respectively. However, the flavone glycosides, apigenin-7-O-beta-D-glucuronopyranoside (1) and luteolin-7-O-beta-D-glucopyranoside (4), showed mild MAO inhibition (IC50 values: 81.7 and 118.6 microM, respectively). The flavanonol derivatives, taxifolin (5) and aromadendrin (6), also showed weak inhibition (IC50 values: 154.7 and 153.1 microM, respectively). Furthermore, quercetin (7) had a more potent inhibitory effect on MAO-A (IC50 value: 2.8 microM) than MAO-B (IC50 value: 90.0 microM). Apigenin (2) and luteolin (3) also preferentially inhibited MAO-A (IC50 values: 1.7 and 4.9 microM, respectively) compared with MAO-B (IC50 values: 12.8 and 59.7 microM, respectively).

  8. Diffusion of eccentric microswimmers.

    PubMed

    Debnath, Debajyoti; Ghosh, Pulak K; Li, Yunyun; Marchesoni, Fabio; Li, Baowen

    2016-02-21

    We model the two-dimensional diffusive dynamics of an eccentric artificial microswimmer in a highly viscous medium. We assume that the swimmer's propulsion results from an effective force applied to a center distinct from its center of mass, both centers resting on a body's axis parallel to its average self-propulsion velocity. Moreover, we allow for angular fluctuations of the velocity about the body's axis. We prove, both analytically and numerically, that the ensuing active diffusion of the swimmer is suppressed to an extent that strongly depends on the model parameters. In particular, the active diffusion constant undergoes a transition from a quadratic to a linear dependence on the self-propulsion speed, with practical consequences on the interpretation of the experimental data. Finally, we extend our model to describe the diffusion of chiral eccentric swimmers.

  9. Novel Diffusivity Measurement Technique

    NASA Technical Reports Server (NTRS)

    Rashidnia, Nasser

    2001-01-01

    A common-path interferometer (CPI) system was developed to measure the diffusivity of liquid pairs. The CPI is an optical technique that can be used to measure changes in the gradient of the refraction index of transparent materials. This system uses a shearing interferometer that shares the same optical path from a laser light source to the final imaging plane. Hence, the molecular diffusion coefficient of liquids can be determined using the physical relations between changes in the optical path length and the liquid phase properties. The data obtained with this interferometer were compared with similar results from other techniques and demonstrated that the instrument is superior in measuring the diffusivity of miscible liquids while keeping the system very compact and robust. CPI can also be used for studies in interface dynamics and other diffusion-dominated-process applications.

  10. Factorized Diffusion Map Approximation

    PubMed Central

    Amizadeh, Saeed; Valizadegan, Hamed; Hauskrecht, Milos

    2013-01-01

    Diffusion maps are among the most powerful Machine Learning tools to analyze and work with complex high-dimensional datasets. Unfortunately, the estimation of these maps from a finite sample is known to suffer from the curse of dimensionality. Motivated by other machine learning models for which the existence of structure in the underlying distribution of data can reduce the complexity of estimation, we study and show how the factorization of the underlying distribution into independent subspaces can help us to estimate diffusion maps more accurately. Building upon this result, we propose and develop an algorithm that can automatically factorize a high dimensional data space in order to minimize the error of estimation of its diffusion map, even in the case when the underlying distribution is not decomposable. Experiments on both the synthetic and real-world datasets demonstrate improved estimation performance of our method over the standard diffusion-map framework. PMID:25309676

  11. Hydrogen Diffusion in Forsterite

    NASA Astrophysics Data System (ADS)

    Demouchy, S.; Mackwell, S.

    2002-12-01

    Physical and chemical properties of Earth's mantle are readily modified by interaction with volatiles, such as water. Thus, characterization of solubility and kinetics of incorporation for water in nominally anhydrous minerals is important in order to understand the behavior of Earth's interior under hydrous conditions. Experimental studies on the olivine-water system indicate that significant amounts of OH can dissolve within olivine as point defects (Bell and Rossman, 1992; Kohlstedt et al. 1996). Extending Kohlstedt and Mackwell's (1998) work, our study concerns the kinetics of hydrogen transport in the iron-free olivine-water system. This study is based on hydrogenation of forsterite samples during piston-cylinder and TZM cold-seal vessel experiments. We use infrared analyses in order to constrain the speciation of the mobile water-derived defects in forsterite single-crystal sample, and the rates of diffusion of such species under uppermost mantle conditions (0.2 to 1.5 GPa, 900 to 1100° C). Hydrogen defect transport in single crystals of forsterite is investigated for diffusion parallel to each crystallographic axis. Defect diffusivities are obtained by fitting a diffusion law to the OH content as a function of position in the sample. Our current results indicate that incorporation of hydroxyl species into iron-free olivine is a one-stage process with hydrogen diffusion linked to magnesium vacancy self-diffusion DV, such that DV = D~/3 = 10-12 m2/s at 1000° C parallel to [001], where D~ represents the chemical diffusivity. Those diffusion rates are slightly lower than in iron-bearing olivine for the same incorporation mechanism. The different concentration profiles show a clear anisotropy of diffusion, with fastest diffusion parallel to [001] as in iron-bearing olivine. Thus, while hydrogen solubilities are dependent on iron content, the rate of incorporation of water-derived species in olivine is not strongly coupled to the concentration of iron. This

  12. Melanoma inhibitory activity in Brazilian patients with cutaneous melanoma*

    PubMed Central

    Odashiro, Macanori; Hans Filho, Gunter; Pereira, Patricia Rusa; Castro, Ana Rita Coimbra Motta; Stief, Alcione Cavalheiro; Pontes, Elenir Rose Jardim Cury; Odashiro, Alexandre Nakao

    2015-01-01

    BACKGROUND: Melanoma inhibitory activity is a protein secreted by melanoma cells and has been used as a tumor marker. Increased Melanoma inhibitory activity serum levels are related to metastatic disease or tumor recurrence. Currently there are no studies on Melanoma inhibitory activity and cutaneous melanoma involving Brazilian patients. OBJECTIVE: To evaluate the performance and feasibility of measuring Melanoma inhibitory activity levels in Brazilian patients with cutaneous melanoma. METHODS: Blood was obtained from ten patients with proved metastatic cutaneous melanoma (Group 1), 15 patients resected for cutaneous melanoma without metastasis (Group 2) and 5 healthy donors (Group 3). Melanoma inhibitory activity was measured using a commercially available ELISA kit. RESULTS: There was a statistically significant difference of Melanoma inhibitory activity levels between patients with and without metastasis (p=0.002), and between patients with metastasis and healthy donors (p=0.002). There was no difference between patients without metastasis and healthy donors (p=0.443). CONCLUSION: Melanoma inhibitory activity is a tumor marker for cutaneous melanoma and the Melanoma inhibitory activity-ELISA test can be easily performed. Patients with metastasis have increased Melanoma inhibitory activity serum levels when compared to patients without metastasis and healthy donors. PMID:26131861

  13. Guide tube flow diffuser

    SciTech Connect

    Berringer, R.T.; Myron, D.L.

    1980-11-04

    A nuclear reactor upper internal guide tube has a flow diffuser integral with its bottom end. The guide tube provides guidance for control rods during their ascent or descent from the reactor core. The flow diffuser serves to divert the upward flow of reactor coolant around the outside of the guide tube thereby limiting the amount of coolant flow and turbulence within the guide tube, thus enhancing the ease of movement of the control rods.

  14. Advanced manufacturing: Technology diffusion

    SciTech Connect

    Tesar, A.

    1995-12-01

    In this paper we examine how manufacturing technology diffuses rom the developers of technology across national borders to those who do not have the capability or resources to develop advanced technology on their own. None of the wide variety of technology diffusion mechanisms discussed in this paper are new, yet the opportunities to apply these mechanisms are growing. A dramatic increase in technology diffusion occurred over the last decade. The two major trends which probably drive this increase are a worldwide inclination towards ``freer`` markets and diminishing isolation. Technology is most rapidly diffusing from the US In fact, the US is supplying technology for the rest of the world. The value of the technology supplied by the US more than doubled from 1985 to 1992 (see the Introduction for details). History shows us that technology diffusion is inevitable. It is the rates at which technologies diffuse to other countries which can vary considerably. Manufacturers in these countries are increasingly able to absorb technology. Their manufacturing efficiency is expected to progress as technology becomes increasingly available and utilized.

  15. Brownian yet Non-Gaussian Diffusion: From Superstatistics to Subordination of Diffusing Diffusivities

    NASA Astrophysics Data System (ADS)

    Chechkin, Aleksei V.; Seno, Flavio; Metzler, Ralf; Sokolov, Igor M.

    2017-04-01

    A growing number of biological, soft, and active matter systems are observed to exhibit normal diffusive dynamics with a linear growth of the mean-squared displacement, yet with a non-Gaussian distribution of increments. Based on the Chubinsky-Slater idea of a diffusing diffusivity, we here establish and analyze a minimal model framework of diffusion processes with fluctuating diffusivity. In particular, we demonstrate the equivalence of the diffusing diffusivity process with a superstatistical approach with a distribution of diffusivities, at times shorter than the diffusivity correlation time. At longer times, a crossover to a Gaussian distribution with an effective diffusivity emerges. Specifically, we establish a subordination picture of Brownian but non-Gaussian diffusion processes, which can be used for a wide class of diffusivity fluctuation statistics. Our results are shown to be in excellent agreement with simulations and numerical evaluations.

  16. Diffusion in natural ilmenite

    NASA Astrophysics Data System (ADS)

    Stenhouse, Iona; O'Neill, Hugh; Lister, Gordon

    2010-05-01

    Diffusion rates in natural ilmenite of composition Fe0.842+ Fe0.163+Mn0.07Mg0.01Ti 0.92O3 from the Vishnevye Mountains (Urals, Russia) have been measured at 1000° C. Experiments were carried out in a one atmosphere furnace with oxygen fugacity controlled by flow of a CO-CO2 gas mixture, over a period of four hours. The diffusant source was a synthetic ilmenite (FeTiO3) powder doped with trace amounts of Mg, Co, Ni, Zr, Hf, V, Nb, Ta, Al, Cr, Ga and Y. Since, the natural ilmenite crystal contained Mn it was also possible to study diffusion of Mn from the ilmenite crystal. The experiments were analysed using the electron microprobe and scanning laser ablation ICP-MS. Diffusion profiles were measured for Al, Mg, Mn, Co, Ni, Ga, and Y. Diffusion of Cr, Hf, Zr, V, Nb and Ta was too slow to allow diffusion profiles to be accurately measured for the times and temperatures studied so far. The preliminary results show that diffusion in ilmenite is fast, with the diffusivity determined in this study on the order of 10-13 to 10-16 m2s-1. For comparison, Chakraborty (1997) found interdiffusion of Fe and Mg in olivine at 1000° C on the order of 10-17 to 10-18m2s-1 and Dieckmann (1998) found diffusivity of Fe, Mg, Co in magnetite at 1200° C to be on the order of 10-13 to 10-14 m2s-1. The order in which the diffusivity of the elements decreases is Mn > Co > Mg ≥ Ni > Al ≥ Y ≥ Ga, that is to say that Mn diffuses the fastest and Ga the slowest. Overall, this study intends to determine diffusion parameters such as frequency factor, activation energy and activation volume as a function of temperature and oxygen fugacity. This research is taking place in the context of a larger study focusing on the use of the garnet-ilmenite system as a geospeedometer. Examination of the consequences of simultaneous diffusion of multiple elements is a necessity if we are to develop an understanding of the crystal-chemical controls on diffusion (cf Spandler & O'Neill, in press). Chakraborty

  17. Multispecies diffusion models: A study of uranyl species diffusion

    SciTech Connect

    Liu, Chongxuan; Shang, Jianying; Zachara, John M.

    2011-12-14

    Rigorous numerical description of multi-species diffusion requires coupling of species, charge, and aqueous and surface complexation reactions that collectively affect diffusive fluxes. The applicability of a fully coupled diffusion model is, however, often constrained by the availability of species self-diffusion coefficients, as well as by computational complication for imposing charge conservation. In this study, several diffusion models with variable complexity in charge and species coupling were formulated and compared to describe reactive multi-species diffusion in groundwater. Diffusion of uranyl [U(VI)] species was used as an example in demonstrating the effectiveness of the models in describing multi-species diffusion. Numerical simulations found that a diffusion model with a single, common diffusion coefficient for all species was sufficient to describe multi-species U(VI) diffusion under steady-state condition of major chemical composition, but not under transient chemical conditions. Simulations revealed that a fully coupled diffusion model can be well approximated by a component-based diffusion model, which considers difference in diffusion coefficients between chemical components, but not between the species within each chemical component. This treatment significantly enhanced computational efficiency at the expense of minor charge conservation. The charge balance in the component-based diffusion model can be rigorously enforced, if necessary, by adding an artificial kinetic reaction term induced by the charge separation. The diffusion models were applied to describe U(VI) diffusive mass transfer in intragranular domains in two sediments collected from US Department of Energy's Hanford 300A where intragrain diffusion is a rate-limiting process controlling U(VI) adsorption and desorption. The grain-scale reactive diffusion model was able to describe U(VI) adsorption/desorption kinetics that has been described using a semi-empirical, multi-rate model

  18. Behavioral Interactions under Noxious Environments.

    DTIC Science & Technology

    1980-06-30

    Journal of the Experimental Analysis of Behavior , 1978...L. D.: Responding in the cat maintained under response-independent electric shock and response-produced electric shock. Journal of the Experimental Analysis of Behavior , 1969...1975, 27, 325-340. Kelleher, R. T.: Conditioned reinforcement in second-order schedules. Journal of the Experimental Analysis of

  19. Fire effects on noxious weeds

    Treesearch

    Robin Innes

    2012-01-01

    The Fire Effects Information System (FEIS, www.fs.fed.us/database/feis/) has been providing reviews of scientific knowledge about fire effects since 1986. FEIS is an online collection of literature reviews on more than 1,100 species and their relationships with fire. Reviews cover plants and animals throughout the United States, providing a wealth of information for...

  20. Bacterial maximum non-inhibitory and minimum inhibitory concentrations of different water activity depressing solutes.

    PubMed

    Cebrián, G; Arroyo, C; Mañas, P; Condón, S

    2014-10-01

    The NaCl MNICs (maximum non-inhibitory concentrations) and MICs (minimum inhibitory concentrations) for growth of various strains of six bacterial species were determined and then compared with those obtained for seven other solutes. The influence of prior growth conditions on the MNICs and MICs was also evaluated. No significant changes on the MNICs and MICs were found among the strains studied within each species. Among all factors investigated, only growth phase -for Gram-negatives- and growth at high NaCl concentrations led to a change in the NaCl MNICs. Species could be classified depending on its NaCl MNICs and MICs (in decreasing order) as follows: Staphylococcus aureus, Listeria monocytogenes, Cronobacter sakazakii, Enterococcus faecium, Escherichia coli and Salmonella Typhimurium. Similar results were obtained for KCl, LiCl, and sodium acetate, but not for the remaining solutes investigated (sucrose, glycerol, MgCl2 and CaCl2). Results obtained indicate that, in general, Gram-negatives showed lower MNICs and MICs than Gram-positives for all the solutes, S. aureus being the most solute tolerant microorganism. When compared on a molar basis, glycerol showed the highest MNICs and MICs for all the microorganisms -except for S. aureus- and LiCl the lowest ones. NaCl MNICs and MICs were not significantly different from those of KCl when compared on a molar basis. Therefore, the inhibitory action of NaCl could not be linked to the specific action of Na(+). Results also showed that the Na(+) tolerance of some species was Cl(-) dependent whereas for others it was not, and that factors others than aw-decrease contribute to the inhibitory action of LiCl, CaCl2 and MgCl2.

  1. Adolescents' inhibitory control: keep it cool or lose control.

    PubMed

    Aïte, Ania; Cassotti, Mathieu; Linzarini, Adriano; Osmont, Anaïs; Houdé, Olivier; Borst, Grégoire

    2016-11-23

    Inhibitory control (i.e., the ability to resist automatisms, temptations, distractions, or interference and to adapt to conflicting situations) is a determinant of cognitive and socio-emotional development. In light of the discrepancies of previous findings on the development of inhibitory control in affectively charged contexts, two important issues need to be addressed. We need to determine (a) whether cool inhibitory control (in affectively neutral contexts) and hot inhibitory control (in affectively charged contexts) follow the same developmental pattern and (b) the degree of specificity of these two types of inhibitory control at different ages. Thus, in the present study, we investigated the developmental patterns of cool and hot inhibitory control and the degree of specificity of these abilities in children, adolescents and adults. Typically developing children, adolescents, and adults performed two Stroop-like tasks: an affectively neutral one (Cool Stroop task) and an affectively charged one (Hot Stroop task). In the Cool Stroop task, the participants were asked to identify the ink color of the words independent of color that the words named; in the Hot Stroop task, the participants were asked to identify the emotional expression of a face independent of the emotion named by a simultaneously displayed written word. We found that cool inhibitory control abilities develop linearly with age, whereas hot inhibitory control abilities follow a quadratic developmental pattern, with adolescents displaying worse hot inhibitory control abilities than children and adults. In addition, cool and hot inhibitory control abilities were correlated in children but not in adolescents and adults. The present study suggests (a) that cool and hot inhibitory control abilities develop differently from childhood to adulthood - i.e., that cool inhibition follows a linear developmental pattern and hot inhibition follows an adolescent-specific pattern - and (b) that they become

  2. Chronic morphine increases Fos-positive neurons after concurrent cornea and tail stimulation.

    PubMed

    Robbins, Ashlee; Schmitt, David; Winterson, Barbara J; Meng, Ian D

    2012-02-01

    The aim of the present study was to examine the effect of chronic morphine exposure on diffuse noxious inhibitory controls in a large population of neurons throughout the medullary dorsal horn, as assessed using immunocytochemistry for c-Fos protein. Overuse of medications, including the opioids, to treat migraine headache can lead to progressively more frequent headaches. In addition, chronic daily headache sufferers and chronic opioid users both lack the inhibition of pain produced by noxious stimulation of a distal body region, often referred to as diffuse noxious inhibitory controls. In urethane anesthetized rats, Fos-positive neurons were quantified in chronic morphine and vehicle-treated animals following 52°C noxious thermal stimulation of the cornea with and without the application of a spatially remote noxious stimulus (placement of the tail in 55°C water). When compared to chronic morphine-treated animals that did not receive the spatially remote noxious stimulus, chronic morphine-treated animals given corneal stimulation along with the spatially remote noxious stimulus demonstrated a 163% increase (P < .05) in the number of Fos-positive neurons in the superficial laminae of the medullary dorsal horn and a 682% increase (P < .01) in deep laminae that was restricted to the side ipsilateral to the applied stimulus. In contrast, no significant difference was found in Fos-like immunoreactivity in vehicle-treated animals given concurrent cornea and tail stimulation or only cornea stimulation in either superficial or deep laminae. It is proposed that an increase in descending facilitation and subsequent loss of diffuse noxious inhibitory controls contributes to the development of medication overuse headache. © 2011 American Headache Society.

  3. New Chorus Diffusion Matrix

    NASA Astrophysics Data System (ADS)

    Horne, Richard B.; Kersten, Tobias; Glauert, Sarah A.; Meredith, Nigel P.; Boscher, Daniel; Sicard, Angelica; Maget, Vincent

    2013-04-01

    Whistler mode chorus waves play a major role in the loss and acceleration of electrons in the Earth's radiation belts. While high time resolution satellite data show that these waves are highly structured in frequency and time, at present their effects on the electron distribution can only be assessed on a global scale by using quasi-linear diffusion theory. Here we present new quasi-linear diffusion coefficients for upper and lower band chorus waves for use in global radiation belt models. Using data from DE 1 CRRES, Cluster 1, Double Star TC1 and THEMIS, we have constructed a database of wave properties and used this to construct new diffusion coefficients for L* = 1.5 to 10 in steps of 0.5, 10 latitude bins between 0o and 60o ,8 bins in MLT and 5 levels of geomagnetic activity as measured by Kp. We find that the peak frequency of lower band chorus is close to 0.2 fce, which is lower than that used in previous models. The combined upper and lower band chorus diffusion shows structure that should result in an energy dependent pitch angle anisotropy, particularly between 1 keV and 100 keV. The diffusion rates suggest that wave-particle interactions should still be very important outside geostationary orbit, out to at least L* = 8. We find significant energy diffusion near 1 keV near the loss cone, consistent with wave growth. By including the new chorus diffusion matrix into the BAS radiation belt (BRB) model we compare the effects on the evolution of the radiation belts against previous models.

  4. Effects of renal function on the intraosseous concentration and inhibitory effect of prophylactic cefazolin in knee arthroplasty.

    PubMed

    Angthong, C; Krajubngern, P; Tiyapongpattana, W; Pongcharoen, B; Pinsornsak, P; Tammachote, N; Kittisupaluck, W

    2016-12-01

    To compare intraosseous concentrations and inhibitory effects on the growth of Staphylococcus aureus following intravenous administration of 1 or 2 g of the prophylactic cefazolin between patients with decreased renal function vs. intact renal function undergoing total knee arthroplasty. Ten patients (13 knees) with primary knee osteoarthritis were divided into two groups by creatinine clearance (CrCl) level (intact renal function: CrCl ≥75 mg/mL (four knees); decreased renal function: CrCl <75 mg/mL (nine knees)). Subchondral bone samples (proximal tibia and distal femur) were obtained during the procedure and were analyzed for the intraosseous concentration of cefazolin and the inhibitory effects on the growth of S. aureus using high-performance liquid chromatography and agar disc diffusion bioassays. Different levels of renal function showed no significant associations with mean intraosseous concentration and mean inhibitory effects at the proximal tibia and distal femur in patients administered 1 g cefazolin (p>0.05). For patients administered 2 g cefazolin, mean intraosseous concentration in the decreased renal function group was significantly higher at the proximal tibia (p=0.049) and also higher (but not reaching statistical significance) at the distal femur (p=0.073) compared with the intact renal function group. Mean inhibitory effects in the decreased renal function group were significantly lower than the intact renal function group at the proximal tibia (p=0.003) and distal femur (p=0.003). Deceased renal function played a role in the increased intraosseous concentration and decreased inhibitory effects in the groups receiving 2 g cefazolin. An excessive intraosseous concentration showed a negative influence on inhibitory effects on the growth of Staphylococcus aureus.

  5. Diffuser for wellhead isolation tool

    SciTech Connect

    Surjaatmadja, J.B.

    1981-04-21

    An improved diffuser for a wellhead isolation tool which employs a combination of angles in its bore. This improvement reduces the incidence of erosion caused by the flow of fluids through the diffuser, in both the well production tubing adjacent the end of the diffuser and in the diffuser itself.

  6. Effects of lactulose supplementation on performance, blood profiles, excreta microbial shedding of Lactobacillus and Escherichia coli, relative organ weight and excreta noxious gas contents in broilers.

    PubMed

    Cho, J H; Kim, I H

    2014-06-01

    This study was to evaluate the effects of lactulose supplementation on performance, blood profiles, excreta microbial shedding of Lactobacillus and Escherichia coli, relative organ weight and excreta noxious gas contents in broilers. A total of 720 ROSS 308 broilers with a body weight of 46 ± 0.1 g (1 day of age) were used in a 28-d experiment. Broilers were randomly allotted to 4 experiment diets with 12 replicate pens and 15 birds per pen. Dietary treatments were as follows: NC, negative control (without antibiotic); PC, NC + 0.1% tiamulin; L1, NC + 0.1% lactulose; and L2, NC + 0.2% lactulose. Broilers were fed with phase 1 (1-8 day), phase 2 (9-18 day) and phase 3 (19-28 day) diets in the form of mash. During day 1-8, broilers fed the PC and L2 diets had higher (p < 0.05) body weight gain than those fed the NC diet. During day 19-28, broilers fed the L1 and L2 diets had lower (p < 0.05) feed intake than those fed the NC diet. The feed conversion ratio (FCR) was decreased (p < 0.05) in L1 treatment compared with NC treatment. Overall, the FCR was improved (p < 0.05) in all supplementation treatments compared with NC treatment. The apparently metabolizable nitrogen in L1 treatment was higher (p < 0.05) than that in NC treatment at day 28. The excreta Lactobacillus was increased and E. coli was decreased in PC and L2 treatments compared with NC treatment at day 28 (p < 0.05). The excreta NH3, H2S and acetic acid contents were decreased (p < 0.05) in L1 and L2 treatments compared with NC treatment. The relative weight of abdominal fat of broilers fed the PC diet was lowest (p < 0.05) compared with other treatments. In conclusion, this study indicated that dietary supplementation of 0.1% or 0.2% lactulose could improve growth performance, decrease excreta E. coli and excreta NH3 and H2S contents.

  7. Determination of the minimum infusion rate of propofol required to prevent purposeful movement of the extremities in response to a standardized noxious stimulus in goats.

    PubMed

    Ferreira, Jacques P; Ndawana, Patience S; Dzikiti, Loveness N; Dzikiti, Brighton T

    2016-09-01

    To determine the minimum infusion rate (MIR) of propofol required to prevent purposeful movement in response to a standardized stimulus in goats. Prospective, experimental study. Eight healthy goats (four does, four wethers). Anaesthesia was induced with 4 mg kg(-1) propofol intravenously (IV). A continuous IV infusion of propofol at 0.6 mg kg(-1)  minute(-1) was initiated immediately to maintain anaesthesia. Following endotracheal intubation, goats breathed spontaneously via a circle breathing system delivering supplementary oxygen. The initial propofol infusion rate was maintained for 30 minutes before responses to noxious stimulation provided by clamping the proximal part of the claw with a Vulsellum forceps for 60 seconds were tested. In the presence or absence of purposeful movements of the extremities, the infusion rate was increased or reduced by 0.1 mg kg(-1)  minute(-1) and held constant for 30 minutes before claw clamping was repeated. The propofol MIR for each goat was calculated as the mean of the infusion rates that allowed and abolished movement. Basic cardiopulmonary parameters were monitored, recorded and tested for statistical significance using Wilcoxon's signed rank test with Bonferroni adjustment for multiple testing. The quality of recovery from anaesthesia was assessed and scored. The median MIR of propofol was 0.45 mg kg(-1)  minute(-1) (range: 0.45-0.55 mg kg(-1)  minute(-1) ). Induction and recovery were free of adverse behaviour. No statistically significant cardiopulmonary changes in comparison with baseline were observed, but clinically relevant hypoxaemia at 2 minutes after induction of anaesthesia was consistently observed. Chewing during anaesthesia was observed in three goats. Median times to extubation and standing were 3 minutes (range: 2-6 minutes) and 10 minutes (range: 7-21 minutes), respectively. Propofol induction and maintenance of general anaesthesia minimally compromise cardiopulmonary function when

  8. Effect of Bacillus subtilis C-3102 spores as a probiotic feed supplement on growth performance, noxious gas emission, and intestinal microflora in broilers.

    PubMed

    Jeong, J S; Kim, I H

    2014-12-01

    Bacillus subtilis C-3102 has been used as a direct-fed microbial or probiotic product since 1986 to improve production performance in broilers worldwide. This study was conducted to determine and confirm the effect of B. subtilis C-3102 spore supplementation to feed on growth performance, nutrient digestibility, carcass quality, blood profiles, noxious gas emission, and intestinal and excreta microflora in broilers. A total of 816 one-day-old male Ross 308 broilers (46.06 ± 0.67 g) were used in a 5-wk study with Calsporin, B. subtilis final product (1.0 × 10(9) cfu/g of B. subtilis). Broilers were randomly allotted to 1 of 3 dietary treatments consisting of 16 replicate cages with 17 broilers each: I) CON (control, basal diet), II) BS300 (CON + 300 mg of B. subtilis/kg of feed), and III) BS600 (CON + 600 mg of B. subtilis/kg of feed). Regarding probiotic effect, B. subtilis significantly increased Lactobacillus counts in the cecum, ileal, and excreta, and reduced Escherichia coli counts in the cecum and excreta, compared with CON. In addition, supplementation also tended to reduce Clostridium perfringens counts in the large intestine and excreta, while linearly reducing Salmonella counts in the cecum, ileal, large intestine, and excreta, compared with CON. Regarding growth performance, B. subtilis enhanced ADG in the starter and overall experimental periods, without any effects on feed intake compared with CON. Consequently, feed conversion ratio in the grower-finisher and overall experimental periods decreased significantly. The inclusion of B. subtilis improved the digestibility of DM and gross energy, as well as reducing ammonia emission, compared with CON. No significant difference in breast muscle color, water holding capacity, and drip loss, and relative organ weights, as well as in white blood cells, red blood cells, lymphocyte counts, and IgG amount, were observed. Overall, B. subtilis C-1302 is capable of providing a probiotic effect leading to improved

  9. Residential Mobility, Inhibitory Control, and Academic Achievement in Preschool

    ERIC Educational Resources Information Center

    Schmitt, Sara A.; Finders, Jennifer K.; McClelland, Megan M.

    2015-01-01

    Research Findings: The present study investigated the direct effects of residential mobility on children's inhibitory control and academic achievement during the preschool year. It also explored fall inhibitory control and academic skills as mediators linking residential mobility and spring achievement. Participants included 359 preschool children…

  10. Residential Mobility, Inhibitory Control, and Academic Achievement in Preschool

    ERIC Educational Resources Information Center

    Schmitt, Sara A.; Finders, Jennifer K.; McClelland, Megan M.

    2015-01-01

    The present study investigated the direct effects of residential mobility on children's inhibitory control and academic achievement during the preschool year. It also explored fall inhibitory control and academic skills as mediators linking residential mobility and spring achievement. Participants included 359 preschool children (49% female)…

  11. Residential Mobility, Inhibitory Control, and Academic Achievement in Preschool

    ERIC Educational Resources Information Center

    Schmitt, Sara A.; Finders, Jennifer K.; McClelland, Megan M.

    2015-01-01

    Research Findings: The present study investigated the direct effects of residential mobility on children's inhibitory control and academic achievement during the preschool year. It also explored fall inhibitory control and academic skills as mediators linking residential mobility and spring achievement. Participants included 359 preschool children…

  12. Inhibitory Control Predicts Language Switching Performance in Trilingual Speech Production

    ERIC Educational Resources Information Center

    Linck, Jared A.; Schwieter, John W.; Sunderman, Gretchen

    2012-01-01

    This study investigated the role of domain-general inhibitory control in trilingual speech production. Taking an individual differences approach, we examined the relationship between performance on a non-linguistic measure of inhibitory control (the Simon task) and a multilingual language switching task for a group of fifty-six native English (L1)…

  13. Predictors of Longitudinal Growth in Inhibitory Control in Early Childhood

    ERIC Educational Resources Information Center

    Moilanen, Kristin L.; Shaw, Daniel S.; Dishion, Thomas J.; Gardner, Frances; Wilson, Melvin

    2010-01-01

    In the current study, we examined latent growth in 731 young children's inhibitory control from the ages of two to four years, and whether demographic characteristics or parenting behaviors were related to initial levels and growth in inhibitory control. As part of an ongoing longitudinal evaluation of the family check-up, children's inhibitory…

  14. Multidimensional diffusion MRI

    NASA Astrophysics Data System (ADS)

    Topgaard, Daniel

    2017-02-01

    Principles from multidimensional NMR spectroscopy, and in particular solid-state NMR, have recently been transferred to the field of diffusion MRI, offering non-invasive characterization of heterogeneous anisotropic materials, such as the human brain, at an unprecedented level of detail. Here we revisit the basic physics of solid-state NMR and diffusion MRI to pinpoint the origin of the somewhat unexpected analogy between the two fields, and provide an overview of current diffusion MRI acquisition protocols and data analysis methods to quantify the composition of heterogeneous materials in terms of diffusion tensor distributions with size, shape, and orientation dimensions. While the most advanced methods allow estimation of the complete multidimensional distributions, simpler methods focus on various projections onto lower-dimensional spaces as well as determination of means and variances rather than actual distributions. Even the less advanced methods provide simple and intuitive scalar parameters that are directly related to microstructural features that can be observed in optical microscopy images, e.g. average cell eccentricity, variance of cell density, and orientational order - properties that are inextricably entangled in conventional diffusion MRI. Key to disentangling all these microstructural features is MRI signal acquisition combining isotropic and directional dimensions, just as in the field of multidimensional solid-state NMR from which most of the ideas for the new methods are derived.

  15. Bicarbonate diffusion through mucus.

    PubMed

    Livingston, E H; Miller, J; Engel, E

    1995-09-01

    The mucus layer overlying duodenal epithelium maintains a pH gradient against high luminal acid concentrations. Despite these adverse conditions, epithelial surface pH remains close to neutrality. The exact nature of the gradient-forming barrier remains unknown. The barrier consists of mucus into which HCO3- is secreted. Quantification of the ability of HCO3- to establish and maintain the gradient depends on accurate measurement of this ion's diffusion coefficient through mucus. We describe new experimental and mathematical methods for diffusion measurement and report diffusion coefficients for HCO3- diffusion through saline, 5% mucin solutions, and rat duodenal mucus. The diffusion coefficients were 20.2 +/- 0.10, 3.02 +/- 0.31, and 1.81 +/- 0.12 x 10(-6) cm2/s, respectively. Modeling of the mucobicarbonate layer with this latter value suggests that for conditions of high luminal acid strength the neutralization of acid by HCO3- occurs just above the epithelial surface. Under these conditions the model predicts that fluid convection toward the lumen could be important in maintaining the pH gradient. In support of this hypothesis we were able to demonstrate a net luminal fluid flux of 5 microliters.min-1.cm-2 after perfusion of 0.15 N HCl in the rat duodenum.

  16. Diffusion Influenced Adsorption Kinetics.

    PubMed

    Miura, Toshiaki; Seki, Kazuhiko

    2015-08-27

    When the kinetics of adsorption is influenced by the diffusive flow of solutes, the solute concentration at the surface is influenced by the surface coverage of solutes, which is given by the Langmuir-Hinshelwood adsorption equation. The diffusion equation with the boundary condition given by the Langmuir-Hinshelwood adsorption equation leads to the nonlinear integro-differential equation for the surface coverage. In this paper, we solved the nonlinear integro-differential equation using the Grünwald-Letnikov formula developed to solve fractional kinetics. Guided by the numerical results, analytical expressions for the upper and lower bounds of the exact numerical results were obtained. The upper and lower bounds were close to the exact numerical results in the diffusion- and reaction-controlled limits, respectively. We examined the validity of the two simple analytical expressions obtained in the diffusion-controlled limit. The results were generalized to include the effect of dispersive diffusion. We also investigated the effect of molecular rearrangement of anisotropic molecules on surface coverage.

  17. Predictors of Longitudinal Growth in Inhibitory Control in Early Childhood.

    PubMed

    Moilanen, Kristin L; Shaw, Daniel S; Dishion, Thomas J; Gardner, Frances; Wilson, Melvin

    2009-02-18

    In the current study, we examined latent growth in 731 young children's inhibitory control from ages 2 to 4, and whether demographic characteristics or parenting behaviors were related to initial levels and growth in inhibitory control. As part of an ongoing longitudinal evaluation of the Family Check-Up (FCU), children's inhibitory control was assessed yearly at ages 2, 3, and 4. Inhibitory control was initially low and increased linearly to age 4. High levels of harsh parenting and male gender were associated with low initial status in inhibitory control. High levels of supportive parenting were associated with faster growth. Extreme family poverty and African American ethnicity were also associated with slower growth. The results highlight parenting as a target for early interventions in contexts of high socioeconomic risk.

  18. Molecular inhibitory mechanism of tricin on tyrosinase

    NASA Astrophysics Data System (ADS)

    Mu, Yan; Li, Lin; Hu, Song-Qing

    2013-04-01

    Tricin was evaluated as a type of tyrosinase inhibitor with good efficacy compared to arbutin. Tricin functioned as a non-competitive inhibitor of tyrosinase, with an equilibrium constant of 2.30 mmol/L. The molecular mechanisms underlying the inhibition of tyrosinase by tricin were investigated by means of circular dichroism spectra, fluorescence quenching and molecular docking. These assays demonstrated that the interactions between tricin and tyrosinase did not change the secondary structure. The interaction of tricin with residues in the hydrophobic pocket of tyrosinase was revealed by fluorescence quenching; the complex was stabilized by hydrophobic associations and hydrogen bonding (with residues Asn80 and Arg267). Docking results implied that the possible inhibitory mechanisms may be attributed to the stereospecific blockade effects of tricin on substrates or products and flexible conformation alterations in the tyrosinase active center caused by weak interactions between tyrosinase and tricin. The application of this type of flavonoid as a tyrosinase inhibitor will lead to significant advances in the field of depigmentation.

  19. Angiogenesis is inhibitory for mammalian digit regeneration

    PubMed Central

    Yu, Ling; Yan, Mingquan; Simkin, Jennifer; Ketcham, Paulina D.; Leininger, Eric; Han, Manjong

    2014-01-01

    Abstract The regenerating mouse digit tip is a unique model for investigating blastema formation and epimorphic regeneration in mammals. The blastema is characteristically avascular and we previously reported that blastema expression of a known anti‐angiogenic factor gene, Pedf, correlated with a successful regenerative response (Yu, L., Han, M., Yan, M., Lee, E. C., Lee, J. & Muneoka, K. (2010). BMP signaling induces digit regeneration in neonatal mice. Development, 137, 551–559). Here we show that during regeneration Vegfa transcripts are not detected in the blastema but are expressed at the onset of differentiation. Treating the amputation wound with vascular endothelial growth factor enhances angiogenesis but inhibits regeneration. We next tested bone morphogenetic protein 9 (BMP9), another known mediator of angiogenesis, and found that BMP9 is also a potent inhibitor of digit tip regeneration. BMP9 induces Vegfa expression in the digit stump suggesting that regenerative failure is mediated by enhanced angiogenesis. Finally, we show that BMP9 inhibition of regeneration is completely rescued by treatment with pigment epithelium‐derived factor. These studies show that precocious angiogenesis is inhibitory for regeneration, and provide compelling evidence that the regulation of angiogenesis is a critical factor in designing therapies aimed at stimulating mammalian regeneration. PMID:27499862

  20. Inhibitory effect of 5-iodotubercidin on pigmentation.

    PubMed

    Kim, Kyung-Il; Jeong, Hae Bong; Ro, Hyunju; Lee, Jeung-Hoon; Kim, Chang Deok; Yoon, Tae-Jin

    2017-09-02

    Melanin pigments are the primary contributors for the skin color. They are produced in melanocytes and then transferred to keratinocytes, eventually giving various colors on skin surface. Although many depigmenting and/or skin-lightening agents have been developed, there is still a growing demand on materials for reducing pigmentation. We attempted to find materials for depigmentation and/or skin-lightening using the small molecule compounds commercially available, and found that 5-iodotubercidin had inhibitory potential on pigmentation. When HM3KO melanoma cells were treated with 5-iodotubercidin, pigmentation was dramatically reduced. The 5-iodotubercidin decreased the protein level for pigmentation-related molecules such as MITF, tyrosinase, and TRP1. In addition, 5-iodotubercidin decreased the phosphorylation of CREB, while increased the phosphorylation of AKT and ERK. These data suggest that 5-iodotubercidin inhibits melanogenesis via the regulation of intracellular signaling related with pigmentation. Finally, 5-iodotubercidin markedly inhibited the melanogenesis of zebrafish embryos, an in vivo evaluation model for pigmentation. Together, these data suggest that 5-iodotubercidin can be developed as a depigmenting and/or skin-lightening agent. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Acetylcholinesterase inhibitory activity of Haplophyton cimicidum.

    PubMed

    Llanos-Romero, R E; Cárdenas, R; Zúñiga, B; Herrera-Santoyo, J; Guevara-Fefer, P

    2014-01-01

    In Oaxaca, México, Haplophyton cimicidum is used in combination with other plants as part of a folk strategy against arthropod pests of crops and cattle. Methanolic and crude alkaloid (acid-base extraction) extracts of H. cimicidum leaves were analysed by thin-layer chromatography (TLC) and assayed in vitro for acetylcholinesterase (AChE) inhibitory activity using Spodoptera frugiperda homogenates as source of enzyme. Derivatised chromatographic plates indicated the presence of indoles and alkaloids in the extracts. The crude alkaloid extract exhibited a higher number of compounds than the methanolic extract as judged by the number of spots on TLC plates. The crude alkaloid extract had a weak inhibition potential of AChE with a lower IC50 (93 μg mL(-1)) than the methanolic extract (159 μg mL(-1)). Indole alkaloids may be responsible for the activity, though a subsequent analysis of the extract components is necessary to determine the active alkaloid(s).

  2. Action Potential Initiation in Neocortical Inhibitory Interneurons

    PubMed Central

    Li, Tun; Tian, Cuiping; Scalmani, Paolo; Frassoni, Carolina; Mantegazza, Massimo; Wang, Yonghong; Yang, Mingpo; Wu, Si; Shu, Yousheng

    2014-01-01

    Action potential (AP) generation in inhibitory interneurons is critical for cortical excitation-inhibition balance and information processing. However, it remains unclear what determines AP initiation in different interneurons. We focused on two predominant interneuron types in neocortex: parvalbumin (PV)- and somatostatin (SST)-expressing neurons. Patch-clamp recording from mouse prefrontal cortical slices showed that axonal but not somatic Na+ channels exhibit different voltage-dependent properties. The minimal activation voltage of axonal channels in SST was substantially higher (∼7 mV) than in PV cells, consistent with differences in AP thresholds. A more mixed distribution of high- and low-threshold channel subtypes at the axon initial segment (AIS) of SST cells may lead to these differences. Surprisingly, NaV1.2 was found accumulated at AIS of SST but not PV cells; reducing NaV1.2-mediated currents in interneurons promoted recurrent network activity. Together, our results reveal the molecular identity of axonal Na+ channels in interneurons and their contribution to AP generation and regulation of network activity. PMID:25203314

  3. Hippocampal CA1 Ripples as Inhibitory Transients

    PubMed Central

    Krishnan, Giri P; Fellous, Jean-Marc; Bazhenov, Maxim

    2016-01-01

    Memories are stored and consolidated as a result of a dialogue between the hippocampus and cortex during sleep. Neurons active during behavior reactivate in both structures during sleep, in conjunction with characteristic brain oscillations that may form the neural substrate of memory consolidation. In the hippocampus, replay occurs within sharp wave-ripples: short bouts of high-frequency activity in area CA1 caused by excitatory activation from area CA3. In this work, we develop a computational model of ripple generation, motivated by in vivo rat data showing that ripples have a broad frequency distribution, exponential inter-arrival times and yet highly non-variable durations. Our study predicts that ripples are not persistent oscillations but result from a transient network behavior, induced by input from CA3, in which the high frequency synchronous firing of perisomatic interneurons does not depend on the time scale of synaptic inhibition. We found that noise-induced loss of synchrony among CA1 interneurons dynamically constrains individual ripple duration. Our study proposes a novel mechanism of hippocampal ripple generation consistent with a broad range of experimental data, and highlights the role of noise in regulating the duration of input-driven oscillatory spiking in an inhibitory network. PMID:27093059

  4. Caffeine does not modulate inhibitory control.

    PubMed

    Tieges, Zoë; Snel, Jan; Kok, Albert; Richard Ridderinkhof, K

    2009-03-01

    The effects of a 3mg/kg body weight (BW) dose of caffeine were assessed on behavioral indices of response inhibition. To meet these aims, we selected a modified AX version of the Continuous Performance Test (CPT), the stop task, and the flanker task. In three double-blind, placebo-controlled, within-subjects experiments, these tasks were administered to healthy participants. While the results for the AX-CPT were indicative of improved response inhibition after caffeine, they might also reflect caffeine-induced changes in mechanisms other than response inhibition (e.g., attentional processes). The results for the stop task and flanker task were more straightforward. That is, the effects of caffeine on overall flanker performance and selective response suppression as revealed by distribution-analytical techniques were negligible. In the stop task a global effect of caffeine on processing speed was seen, rather than specific effects on response inhibition. Taken together, these experiments showed that both active and reactive inhibition were not significantly modulated by caffeine. The present results are linked to neural circuits that underlie inhibitory control and the role of caffeine-induced strategic changes.

  5. Urease inhibitory constituents from Daphne retusa.

    PubMed

    Mansoor, Farrukh; Anis, Itrat; Khan, Ajmal; Marasini, Bishnu P; Choudhary, Muhammad Iqbal; Shah, Muhammad Raza

    2014-01-01

    The bioassay-guided fractionation of Daphne retusa Hemsl. has led to the isolation of a new aryl tetrahydronaphthalene lignan derivative named as daphnretusic acid (1), along with six new source compounds such as 5,7-dihydroxyflavone (2), 7-hydroxyflavone (3), 6-methoxyflavone (4), (+) pinoresinol (5), (+) sesamin (6), and β-sitosterol-3-O-β-D-glucopyranoside (7). Their structures were elucidated by (1)H NMR, (13)C NMR, 1D, 2D NMR, UV, IR, and EIMS analyses. All the fractions (n-hexane, CHCl3, AcOEt, CH3OH, and water) and pure compounds (1-7) were subjected to the assay of urease and α-chymotrypsin inhibitory activities. Chloroform and methanol soluble fractions showed moderate urease inhibition. Compound 2 exhibited significant urease inhibition with IC50 value 60.4 ± 0.72 μM, whereas compounds 1 and 3-7 remained inactive during urease inhibition and α-chymotrypsin bioassays.

  6. Angiogenesis is inhibitory for mammalian digit regeneration.

    PubMed

    Yu, Ling; Yan, Mingquan; Simkin, Jennifer; Ketcham, Paulina D; Leininger, Eric; Han, Manjong; Muneoka, Ken

    2014-06-01

    The regenerating mouse digit tip is a unique model for investigating blastema formation and epimorphic regeneration in mammals. The blastema is characteristically avascular and we previously reported that blastema expression of a known anti-angiogenic factor gene, Pedf, correlated with a successful regenerative response (Yu, L., Han, M., Yan, M., Lee, E. C., Lee, J. & Muneoka, K. (2010). BMP signaling induces digit regeneration in neonatal mice. Development, 137, 551-559). Here we show that during regeneration Vegfa transcripts are not detected in the blastema but are expressed at the onset of differentiation. Treating the amputation wound with vascular endothelial growth factor enhances angiogenesis but inhibits regeneration. We next tested bone morphogenetic protein 9 (BMP9), another known mediator of angiogenesis, and found that BMP9 is also a potent inhibitor of digit tip regeneration. BMP9 induces Vegfa expression in the digit stump suggesting that regenerative failure is mediated by enhanced angiogenesis. Finally, we show that BMP9 inhibition of regeneration is completely rescued by treatment with pigment epithelium-derived factor. These studies show that precocious angiogenesis is inhibitory for regeneration, and provide compelling evidence that the regulation of angiogenesis is a critical factor in designing therapies aimed at stimulating mammalian regeneration.

  7. Inhibitory effect of cyanide on wastewater nitrification ...

    EPA Pesticide Factsheets

    The effect of CN- (CN-) on nitrification was examined with samples from nitrifying wastewater enrichments using two different approaches: by measuring substrate (ammonia) specific oxygen uptake rates (SOUR), and by using RT-qPCR to quantify the transcripts of functional genes involved in nitrification. The nitrifying bioreactor was operated as a continuous reactor with a 24 h hydraulic retention time. The samples were exposed in batch vessels to cyanide for a period of 12 h. The concentrations of CN- used in the batch assays were 0.03, 0.06, 0.1 and 1.0 mg/L. There was considerable decrease in SOUR with increasing dosages of CN-. A decrease of more than 50% in nitrification activity was observed at 0.1 mg/L CN-. Based on the RT-qPCR data, there was notable reduction in the transcript levels of amoA and hao for increasing CN- dosage, which corresponded well with the ammonia oxidation activity measured via SOUR. The inhibitory effect of cyanide may be attributed to the affinity of cyanide to bind ferric heme proteins, which disrupt protein structure and function. The correspondence between the relative expression of functional genes and SOUR shown in this study demonstrates the efficacy of RNA based function-specific assays for better understanding of the effect of toxic compounds on nitrification activity in wastewater. Nitrification is the first step of nitrogen removal is wastewater, and it is susceptible to inhibition by many industrial chemical. We looked at

  8. Gastric inhibitory polypeptide secretion after radical pancreatoduodenectomy.

    PubMed Central

    Miyata, M; Nakao, K; Tanaka, Y; Sakamoto, T; Hamaji, M; Taketani, H; Kawashima, Y

    1984-01-01

    To elucidate the role of gastric inhibitory polypeptide (GIP) in the alteration of insulin secretion following pancreatoduodenal resection, in which the main sources of GIP are removed, plasma levels of GIP were measured for 180 minutes after oral glucose administration, both before and after radical pancreatoduodenectomy in nine patients with periampullary cancer. Fasting plasma levels of GIP remained much the same before and after surgery, and were not different from those in normal controls. The levels of GIP after glucose ingestion were significantly greater in the preoperative patients than in normal controls throughout 180 minutes. After pancreatoduodenectomy, the postglucose levels significantly diminished but remained within normal limits. Changes in plasma levels of insulin early after glucose ingestion in these patients, however, were significantly less both before and after surgery than in normal controls, and were not concomitant with the initial increase in plasma GIP. On the other hand, plasma levels of insulin greatly increased immediately after glucose ingestion in accordance with a rapid elevation of plasma GIP in 11 gastrectomized patients in whom the duodenum and the pancreas were preserved intact and who served as the control group. Thus, the diminution in GIP secretion following pancreatoduodenectomy may relate to the lack of main sources of this gut hormone and not to factors involved in the reconstruction of the alimentary tract. We conclude that the impaired insulin secretion following oral glucose ingestion in patients before and after pancreatoduodenectomy does not relate to the secretion of GIP. PMID:6367676

  9. Tyrosinase inhibitory flavonoid from Juniperus communis fruits.

    PubMed

    Jegal, Jonghwan; Park, Sang-A; Chung, KiWung; Chung, Hae Young; Lee, Jaewon; Jeong, Eun Ju; Kim, Ki Hyun; Yang, Min Hye

    2016-12-01

    The fruits of Juniperus communis have been traditionally used in the treatment of skin diseases. In our preliminary experiment, the MeOH extract of J. communis effectively suppressed mushroom tyrosinase activity. Three monoflavonoids and five biflavonoids were isolated from J. communis by bioassay-guided isolation and their inhibitory effect against tyrosinase was evaluated. According to the results of all isolates, hypolaetin 7-O-β-xylopyranoside isolated from J. communis exhibited most potent effect of decreasing mushroom tyrosinase activity with an IC50 value of 45.15 μM. Further study provided direct experimental evidence for hypolaetin 7-O-β-D-xylopyranoside-attenuated tyrosinase activity in α-MSH-stimulated B16F10 murine melanoma cell. Hypolaetin 7-O-β-D-xylopyranoside from the EtOAc fraction of J. communis was also effective at suppressing α-MSH-induced melanin synthesis. This is the first report of the enzyme tyrosinase inhibition by J. communis and its constituent. Therapeutic attempts with J. communis and its active component, hypolaetin 7-O-β-D-xylopyranoside, might be useful in treating melanin pigmentary disorders.

  10. Hippocampal CA1 Ripples as Inhibitory Transients.

    PubMed

    Malerba, Paola; Krishnan, Giri P; Fellous, Jean-Marc; Bazhenov, Maxim

    2016-04-01

    Memories are stored and consolidated as a result of a dialogue between the hippocampus and cortex during sleep. Neurons active during behavior reactivate in both structures during sleep, in conjunction with characteristic brain oscillations that may form the neural substrate of memory consolidation. In the hippocampus, replay occurs within sharp wave-ripples: short bouts of high-frequency activity in area CA1 caused by excitatory activation from area CA3. In this work, we develop a computational model of ripple generation, motivated by in vivo rat data showing that ripples have a broad frequency distribution, exponential inter-arrival times and yet highly non-variable durations. Our study predicts that ripples are not persistent oscillations but result from a transient network behavior, induced by input from CA3, in which the high frequency synchronous firing of perisomatic interneurons does not depend on the time scale of synaptic inhibition. We found that noise-induced loss of synchrony among CA1 interneurons dynamically constrains individual ripple duration. Our study proposes a novel mechanism of hippocampal ripple generation consistent with a broad range of experimental data, and highlights the role of noise in regulating the duration of input-driven oscillatory spiking in an inhibitory network.

  11. Lipoxygenase inhibitory sphingolipids from Launaea nudicaulis.

    PubMed

    Riaz, Naheed; Parveen, Shehla; Saleem, Muhammad; Ali, Muhammad Shaiq; Malik, Abdul; Ashraf, Muhammad; Afzal, Iftikhar; Jabbar, Abdul

    2012-01-01

    Four new sphingolipids: nudicaulin A [(2S,3S,4R,14E)-2-{[octadecanoyl]amino}tetraeicos-14-ene-1,3,4-triol; 1], nudicaulin B [(2S,3S,4R,14E)-2-{[(2R)-2-hydroxyoctadecanoyl]amino}tetraeicos-14-ene-1,3,4-triol; 2], nudicaulin C [(2S,3S,4R,14E)-2-{[(2R)-2-hydroxyoctadecanoyl]amino}tetraeicos-14-ene-1,3,4-triol-1-O-β-D-glucopyranoside; 3], and nudicaulin D [(2S,3S,4R)-2-{[(2R,3S,12E)-2,3-dihydroxyeicos-12-enoyl]amino}octadecane-1,3,4-triol; 4] together with 1-hexatriacontanol, β-sitosterol, octadecyl 4-hydroxycinnamate, elaidic acid, cholesta-5,22-diene-3,7-diol, oleanolic acid, apigenin, and β-sitosterol 3-O-β-D-glucopyranoside were isolated from the methanolic extract of the whole plant of Launaea nudicaulis. Their structures were elucidated using ¹H and ¹³C NMR spectra and 2D NMR analyses (HMQC, HMBC, and COSY) in combination with mass spectrometry (EI-MS, HR-EI-MS, FAB-MS, and HR-FAB-MS) experiments and comparison with literature data of related compounds. Compounds 1-4 displayed moderate inhibitory potential against enzyme lipoxygenase in concentration-dependent manner with IC₅₀ value ranges 103-193 μM.

  12. Structural studies on leukaemia inhibitory factor

    SciTech Connect

    Norton, R.S.; Maurer, T.; Smith, D.K.; Nicola, N.A.

    1994-12-01

    Leukaemia Inhibitory Factor (LIF) is a pleiotropic cytokine that acts on a wide range of target cells, including mega-karyocytes, osteoblasts, hepatocytes, adipocytes, neurons, embryonic stem cells, and primordial germ cells. Many of its activities are shared with other cytokines, particularly interleukin-6, oncostatin-M, ciliary neurotrophic factor, and granulocyte colony-stimulating factor (G-CSF). Although secreted in vivo as a glycoprotein, nonglycosylated recombinant protein expressed in E. coli is fully active and has been used in our nuclear magnetic resonance (NMR) studies of the three-dimensional structure and structure-function relationships of LIF. With 180 amino acids and a molecular mass of about 20 kDa, OF is too large for direct structure determination by two-dimensional and three-dimensional {sup 1}HNMR. It is necessary to label the protein with the stable isotopes {sup 15}N and {sup 13}C and employ heteronuclear three-dimensional NMR in order to resolve and interpret the spectral information required for three-dimensional structure determination. This work has been undertaken with both human LIF and a mouse-human chimaera that binds to the human LIF receptor with the same affinity as the human protein and yet expresses in E. coli at much higher levels. Sequence-specific resonance assignments and secondary structure elements for these proteins will be presented and progress towards determination of their three-dimensional structures described.

  13. Apparatus for diffusion separation

    DOEpatents

    Nierenberg, William A.; Pontius, Rex B.

    1976-08-10

    1. The method of testing the separation efficiency of porous permeable membranes which comprises causing a stream of a gaseous mixture to flow into contact with one face of a finely porous permeable membrane under such conditions that a major fraction of the mixture diffuses through the membrane, maintaining a rectangular cross section of the gaseous stream so flowing past said membrane, continuously recirculating the gas that diffuses through said membrane and continuously withdrawing the gas that does not diffuse through said membrane and maintaining the volume of said recirculating gas constant by continuously introducing into said continuously recirculating gas stream a mass of gas equivalent to that which is continuously withdrawn from said gas stream and comparing the concentrations of the light component in the entering gas, the withdrawn gas and the recirculated gas in order to determine the efficiency of said membrane.

  14. Memory-controlled diffusion

    NASA Astrophysics Data System (ADS)

    Trimper, Steffen; Zabrocki, Knud; Schulz, Michael

    2004-11-01

    Memory effects require for their incorporation into random-walk models an extension of the conventional equations. The linear Fokker-Planck equation for the probability density p(r⃗,t) is generalized by including nonlinear and nonlocal spatial-temporal memory effects. The realization of the memory kernel is restricted due the conservation of the basic quantity p . A general criteria is given for the existence of stationary solutions. In case the memory kernel depends on p polynomially, transport may be prevented. Owing to the delay effects a finite amount of particles remains localized and the further transport is terminated. For diffusion with nonlinear memory effects we find an exact solution in the long-time limit. Although the mean square displacement exhibits diffusive behavior, higher order cumulants offer differences to diffusion and they depend on the memory strength.

  15. Cesium diffusion in graphite

    SciTech Connect

    Evans, R.B. III; Davis, W. Jr.; Sutton, A.L. Jr.

    1980-05-01

    Experiments on diffusion of /sup 137/Cs in five types of graphite were performed. The document provides a completion of the report that was started and includes a presentation of all of the diffusion data, previously unpublished. Except for data on mass transfer of /sup 137/Cs in the Hawker-Siddeley graphite, analyses of experimental results were initiated but not completed. The mass transfer process of cesium in HS-1-1 graphite at 600 to 1000/sup 0/C in a helium atmosphere is essentially pure diffusion wherein values of (E/epsilon) and ..delta..E of the equation D/epsilon = (D/epsilon)/sub 0/ exp (-..delta..E/RT) are about 4 x 10/sup -2/ cm/sup 2//s and 30 kcal/mole, respectively.

  16. Positron diffusion in Si

    SciTech Connect

    Nielsen, B.; Lynn, K.G.; Vehanen, A.; Schultz, P.J.

    1985-06-01

    Positron diffusion in Si(100) and Si(111) has been studied using a variable energy positron beam. The positron diffusion coefficient is found to be D/sub +/ = 2.7 +- 0.3 cm/sup 2//sec using a Makhov-type positron implantation profile, which is demonstrated to fit the data more reliably than the more commonly applied exponential profile. The diffusion related parameter, E/sub 0/, which results from the exponential profile, is found to be 4.2 +- 0.2 keV, significantly longer than previously reported values. A drastic reduction in E/sub 0/ is found after annealing the sample at 1300 K, showing that previously reported low values of E/sub 0/ are probably associated with the thermal history of the sample.

  17. Effects of μ-opioid receptor agonists in assays of acute pain-stimulated and pain-depressed behavior in male rats: role of μ-agonist efficacy and noxious stimulus intensity.

    PubMed

    Altarifi, Ahmad A; Rice, Kenner C; Negus, S Stevens

    2015-02-01

    Pain is associated with stimulation of some behaviors and depression of others, and μ-opioid receptor agonists are among the most widely used analgesics. This study used parallel assays of pain-stimulated and pain-depressed behavior in male Sprague-Dawley rats to compare antinociception profiles for six μ-agonists that varied in efficacy at μ-opioid receptors (from highest to lowest: methadone, fentanyl, morphine, hydrocodone, buprenorphine, and nalbuphine). Intraperitoneal injection of diluted lactic acid served as an acute noxious stimulus to either stimulate stretching or depress operant responding maintained by electrical stimulation in an intracranial self-stimulation (ICSS). All μ-agonists blocked both stimulation of stretching and depression of ICSS produced by 1.8% lactic acid. The high-efficacy agonists methadone and fentanyl were more potent at blocking acid-induced depression of ICSS than acid-stimulated stretching, whereas lower-efficacy agonists displayed similar potency across assays. All μ-agonists except morphine also facilitated ICSS in the absence of the noxious stimulus at doses similar to those that blocked acid-induced depression of ICSS. The potency of the low-efficacy μ-agonist nalbuphine, but not the high-efficacy μ-agonist methadone, to block acid-induced depression of ICSS was significantly reduced by increasing the intensity of the noxious stimulus to 5.6% acid. These results demonstrate sensitivity of acid-induced depression of ICSS to a range of clinically effective μ-opioid analgesics and reveal distinctions between opioids based on efficacy at the μ-receptor. These results also support the use of parallel assays of pain-stimulated and -depressed behaviors to evaluate analgesic efficacy of candidate drugs.

  18. Characterization of Bacteriocin like inhibitory substance produced by a new Strain Brevibacillus borstelensis AG1 Isolated from 'Marcha'.

    PubMed

    Sharma, Nivedita; Gupta, Anupama; Gautam, Neha

    2014-01-01

    In the present study, a bacterium isolated from Marcha- a herbal cake used as traditional starter culture to ferment local wine in North East India, was evaluated for bacteriocin like inhibitory substance production and was tested against six food borne/spoilage causing pathogens viz. Listeria monocytogenes MTCC 839, Bacillus subtilis MTCC 121, Clostridium perfringens MTCC 450, Staphylococcus aureus, Lactobacillus plantarum and Leuconostoc mesenteroides MTCC 107 by using bit/disc method followed by well diffusion method. The bacterial isolate was identified as Brevibacillus borstelensis on the basis of phenotypic, biochemical and molecular characteristics using 16Sr RNA gene technique. Bacteriocin like inhibitory substance produced by Brevibacillus borstelensis AG1 was purified by gel exclusion chromatography. The molecular mass of the Brevibacillus borstelensis AG1 was found to be 12 kDa. Purified bacteriocin like inhibitory substance of Brevibacillus borstelensis was further characterized by studying the effect of temperature, pH, proteolytic enzyme and stability. Bacteriocin like inhibitory substance was found to be thermostable upto 100 °C, active at neutral pH, sensitive to trypsin, and partially stable till third week of storage thus showing a bright prospective to be used as a potential food biopreservative.

  19. Characterization of Bacteriocin like inhibitory substance produced by a new Strain Brevibacillus borstelensis AG1 Isolated from ‘Marcha’

    PubMed Central

    Sharma, Nivedita; Gupta, Anupama; Gautam, Neha

    2014-01-01

    In the present study, a bacterium isolated from Marcha- a herbal cake used as traditional starter culture to ferment local wine in North East India, was evaluated for bacteriocin like inhibitory substance production and was tested against six food borne/spoilage causing pathogens viz. Listeria monocytogenes MTCC 839, Bacillus subtilis MTCC 121, Clostridium perfringens MTCC 450, Staphylococcus aureus, Lactobacillus plantarum and Leuconostoc mesenteroides MTCC 107 by using bit/disc method followed by well diffusion method. The bacterial isolate was identified as Brevibacillus borstelensis on the basis of phenotypic, biochemical and molecular characteristics using 16Sr RNA gene technique. Bacteriocin like inhibitory substance produced by Brevibacillus borstelensis AG1 was purified by gel exclusion chromatography. The molecular mass of the Brevibacillus borstelensis AG1 was found to be 12 kDa. Purified bacteriocin like inhibitory substance of Brevibacillus borstelensis was further characterized by studying the effect of temperature, pH, proteolytic enzyme and stability. Bacteriocin like inhibitory substance was found to be thermostable upto 100 °C, active at neutral pH, sensitive to trypsin, and partially stable till third week of storage thus showing a bright prospective to be used as a potential food biopreservative. PMID:25477937

  20. Transverse Spin Diffusion

    NASA Astrophysics Data System (ADS)

    Mullin, William

    2014-05-01

    Transverse spin diffusion is a relatively new transport coefficient and a review of its history and physical basis will be presented. In NMR spin diffusion is often measured by spin echo techniques, which involve spin currents perpendicular to the direction of the magnetization, in contrast with the usual longitudinal case where the current is parallel to the magnetization. The first indication that this involved new physics was the Leggett-Rice effect (1970) in which spin waves, new spin-echo behavior, and an altered spin diffusion coefficient were predicted in liquid 3He. This effect gave the possibility of the first measurement of F1a, the parameter of the Landau Fermi-liquid theory mean-field responsible for the effect. In 1982 Lhuillier and Laloe found a transport equation very similar to the Leggett equation, but valid for highly-polarized dilute Boltzmann Bose and Fermi gases, and describing the ``identical spin rotation effect'' (ISRE), the analog of a Landau mean field. Coincidentally Bashkin and Meyerovich had also given equivalent descriptions of transport in polarized Boltzmann gases. That a mean-field effect could exists in dilute Boltzmann gases was theoretically surprising, but was confirmed experimentally. At low polarization the basic transverse diffusion constant D⊥ coincides with the longitudinal value D∥ however Meyerovich first pointed out that they could differ in highly polarized degenerate gases. Indeed detailed calculations (Jeon and Mullin) showed that, while D∥ is proportional to T-2, D⊥ approaches a constant (depending on polarization) at low T. Considerable controversy existed until experimental verification was achieved in 2004. The importance of ISRE again arose in 2008 as the basis of ``anomalous spin-state segregation'' in Duke and JILA experiments. More recently application of the ideas of transverse spin diffusion to strongly interacting Fermi gases has resulted in the observation of the diffusion constants at the quantum

  1. Lead diffusion in monazite

    NASA Astrophysics Data System (ADS)

    Smith, Harold A.; Giletti, Bruno J.

    1997-03-01

    We have measured the tracer diffusion rate of Pb in natural, annealed, gem-quality monazite from Alexander Co., NC, USA, and Riverside Co., CA, USA. Observations from the literature concerning low T annealing in monazite suggest the possibility that Pb diffusion at geologic conditions occurs, in effect, within a similarly annealed lattice. Our experiments were performed by evaporating an aqueous solution containing 204Pb onto a crystal face and then heating the charge to 1000-1200°C for 4 to 36 days. To the extent that the compositions of the two samples differed, we observed no effect of composition upon the rate of Pb diffusion. We do find that transport parallel to the c-axis is ˜2-5 times slower than that measured perpendicular to c. For Pb diffusion perpendicular to c, the Arrhenius parameters are Q = 180 ± 48 kJ/mol and log D0 = -14.18 ± 1.54 (for D0 in m 2/s). While these parameters now allow for a direct calculation of closure temperatures for monazite, we believe a more useful form of our data for geochronologists is the fraction of Pb lost from crystals, expressed as a function of T, time, and crystal size. We have applied this formalism to discordant monazite UPb ages from the recent literature and find that Pb diffusion at rates extrapolated from our experiments can account for the observed degree of discordancy. We suggest that, rather than employing the concept of closure temperature to evaluate possible Pb loss in monazite, the diffusion data presented here be used in Pb loss models based upon T and duration conditions appropriate for a given geological setting.

  2. Carbon Diffusion in Zircon

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.; Watson, E. B.; Boehnke, P.; Harrison, T. M.

    2016-12-01

    With the recent discovery of potentially biogenic carbon in 4.1 billion-year-old zircon (Bell et al., 2015), it is important to understand diffusion of C in zircon in order to assess the potential of these carbonaceous inclusions to preserve isotopic evidence of Earth's early history. In this study, we have characterized carbon diffusion in natural zircon at 1-atm and under high-pressure conditions in the presence of hydrous species. The 1-atm experiments were conducted by implanting 13C into polished, oriented slabs of zircon, with implanted samples heated in air or under buffered conditions in silica glass ampoules sealed under vacuum. High-pressure experiments (1 GPa) were conducted in a piston-cylinder apparatus, using 13C labeled glycine as the starting source (this breaks down at run conditions). In all cases, 13C distributions in zircon were measured by Nuclear Reaction Analysis (NRA) using the reaction 13C(p,γ)14N. In addition to the NRA measurements, we have also conducted analyses of carbon in zircon by ion microprobe. For diffusion parallel to c we obtain a well-constrained Arrhenius relation over the temperature range 600-1100°C. Diffusion normal to c is similar. Data from the high-pressure experiments and those run under buffered conditions also yield similar diffusivities, suggesting that carbon diffusion is not significantly affected by these parameters over the range of conditions studied. Carbon diffuses more rapidly than most cations in zircon, with the exception of lithium, but several orders of magnitude more slowly than helium. Zircon will therefore be moderately retentive of carbon. For example, diffusion distances on Gyr timescales would be on order of nm at 200°C, μm at 350°C and mm at 650°C, suggesting that carbon isotopic signatures contained within carbonaceous inclusions in zircon may be retained over long timeframes if zircons experience only moderate heating. E.A. Bell, P. Boehnke, T. M. Harrison, W.L. Mao (2015) PNAS 47, 14518-14521

  3. [Microbial diffusion and antibiotherapy].

    PubMed

    Vilain, R

    1982-01-01

    Cleaning leg ulcers depends on tissular and microbial enzymes, the production of which depends on good vascularization. When an aetiological treatment is started, the microbes ensure sufficient cleaning, leading to granulation and epidermization. Antibiotherapy is pointless. Sometimes it can be detrimental, replacing a natural growth with alien strains which cause diffusion. Very exceptionally, a short course of antibiotherapy may be necessary to cope with signs of diffusion, usually signifying a Group A streptococcal infection, with seasonal recrudescence. The Blue Pus Microbe has no special pathological significance. It merely indicates that the case has become chronic.

  4. Hydrogen diffusion in Zircon

    NASA Astrophysics Data System (ADS)

    Ingrin, Jannick; Zhang, Peipei

    2016-04-01

    Hydrogen mobility in gem quality zircon single crystals from Madagascar was investigated through H-D exchange experiments. Thin slices were annealed in a horizontal furnace flushed with a gas mixture of Ar/D2(10%) under ambient pressure between 900 ° C to 1150 ° C. FTIR analyses were performed on oriented slices before and after each annealing run. H diffusion along [100] and [010] follow the same diffusion law D = D0exp[-E /RT], with log D0 = 2.24 ± 1.57 (in m2/s) and E = 374 ± 39 kJ/mol. H diffusion along [001] follows a slightly more rapid diffusion law, with log D0 = 1.11 ± 0.22 (in m2/s) and E = 334 ± 49 kJ/mol. H diffusion in zircon has much higher activation energy and slower diffusivity than other NAMs below 1150 ° C even iron-poor garnets which are known to be among the slowest (Blanchard and Ingrin, 2004; Kurka et al. 2005). During H-D exchange zircon incorporates also deuterium. This hydration reaction involves uranium reduction as it is shown from the exchange of U5+ and U4+ characteristic bands in the near infrared region during annealing. It is the first time that a hydration reaction U5+ + OH- = U4+ + O2- + 1/2H2, is experimentally reported. The kinetics of deuterium incorporation is slightly slower than hydrogen diffusion, suggesting that the reaction is limited by hydrogen mobility. Hydrogen isotopic memory of zircon is higher than other NAMs. Zircons will be moderately retentive of H signatures at mid-crustal metamorphic temperatures. At 500 ° C, a zircon with a radius of 300 μm would retain its H isotopic signature over more than a million years. However, a zircon is unable to retain this information for geologically significant times under high-grade metamorphism unless the grain size is large enough. Refrences Blanchard, M. and Ingrin, J. (2004) Hydrogen diffusion in Dora Maira pyrope. Physics and Chemistry of Minerals, 31, 593-605. Kurka, A., Blanchard, M. and Ingrin, J. (2005) Kinetics of hydrogen extraction and deuteration in

  5. Multispecies diffusion models: A study of uranyl species diffusion

    NASA Astrophysics Data System (ADS)

    Liu, Chongxuan; Shang, Jianying; Zachara, John M.

    2011-12-01

    Rigorous numerical description of multispecies diffusion requires coupling of species, charge, and aqueous and surface complexation reactions that collectively affect diffusive fluxes. The applicability of a fully coupled diffusion model is, however, often constrained by the availability of species self-diffusion coefficients, as well as by computational complication in imposing charge conservation. In this study, several diffusion models with variable complexity in charge and species coupling were formulated and compared to describe reactive multispecies diffusion in groundwater. Diffusion of uranyl [U(VI)] species was used as an example in demonstrating the effectiveness of the models in describing multispecies diffusion. Numerical simulations found that a diffusion model with a single, common diffusion coefficient for all species was sufficient to describe multispecies U(VI) diffusion under a steady state condition of major chemical composition, but not under transient chemical conditions. Simulations revealed that for multispecies U(VI) diffusion under transient chemical conditions, a fully coupled diffusion model could be well approximated by a component-based diffusion model when the diffusion coefficient for each chemical component was properly selected. The component-based diffusion model considers the difference in diffusion coefficients between chemical components, but not between the species within each chemical component. This treatment significantly enhanced computational efficiency at the expense of minor charge conservation. The charge balance in the component-based diffusion model can be enforced, if necessary, by adding a secondary migration term resulting from model simplification. The effect of ion activity coefficient gradients on multispecies diffusion is also discussed. The diffusion models were applied to describe U(VI) diffusive mass transfer in intragranular domains in two sediments collected from U.S. Department of Energy's Hanford 300A

  6. Reduction of noxious substance emissions at the pulverized fuel combustion in the combustor of the BKZ-160 boiler of the Almaty heat electropower station using the "Overfire Air" technology

    NASA Astrophysics Data System (ADS)

    Askarova, A. S.; Messerle, V. E.; Ustimenko, A. B.; Bolegenova, S. A.; Bolegenova, S. A.; Maximov, V. Yu.; Yergalieva, A. B.

    2016-01-01

    The computational experiments using the "Overfire Air" (OFA) technology at the coal dust torch combustion in the combustor of the BKZ-160 boiler of the heat power plant No. 2 in Almaty have been conducted. The results show a possibility of reaching a reduction of the emission of noxious nitrogen oxides NO x and minimizing the energy losses. The results of numerical experiments on the influence of the additional air supply on the main characteristics of heat and mass transfer are presented. A comparison with the base regime of the solid fuel combustion when there is no supply of the additional air (OFA = 0 %) has been made.

  7. Brain imaging reveals that engagement of descending inhibitory pain pathways in healthy women in a low endogenous estradiol state varies with testosterone.

    PubMed

    Vincent, Katy; Warnaby, Catherine; Stagg, Charlotte J; Moore, Jane; Kennedy, Stephen; Tracey, Irene

    2013-04-01

    The combined oral contraceptive pill (COCP) has been implicated in the development of a number of chronic pain conditions. Modern COCP formulations produce a low endogenous estradiol, low progesterone environment similar to the early follicular phase of the natural menstrual cycle, with a variable effect on serum androgen levels. We used behavioural measures and functional magnetic resonance imaging to investigate the response to experimental thermal stimuli in healthy women, in both a natural and COCP-induced low endogenous estradiol state, to investigate whether alterations in central pain processing may underlie these observations in COCP users. Although COCP users overall did not require lower temperatures to obtain a fixed pain intensity, alterations in the brain response to these stimuli were observed. In a subgroup of COCP users with significantly reduced serum testosterone, however, lower temperatures were required. Region-of-interest analysis revealed that within key regions of the descending pain inhibitory system, activity in response to noxious stimulation varied with serum testosterone levels in both groups of women. Of particular interest, in COCP users, activity in the rostral ventromedial medulla increased with increasing testosterone and in those women with low testosterone, was significantly reduced compared to controls. These findings suggest that, in a low endogenous estradiol state, testosterone may be a key factor in modulating pain sensitivity via descending pathways. Specifically, failure to engage descending inhibition at the level of the rostral ventromedial medulla may be responsible for the reduction in temperature required by COCP users with low circulating testosterone.

  8. Mixed-mode synchronization between two inhibitory neurons with post-inhibitory rebound

    NASA Astrophysics Data System (ADS)

    Nagornov, Roman; Osipov, Grigory; Komarov, Maxim; Pikovsky, Arkady; Shilnikov, Andrey

    2016-07-01

    We study an array of activity rhythms generated by a half-center oscillator (HCO), represented by a pair of reciprocally coupled neurons with post-inhibitory rebounds (PIR). Such coupling-induced bursting possesses two time scales, one for fast spiking and another for slow quiescent periods, is shown to exhibit an array of synchronization properties. We discuss several HCO configurations constituted by two endogenous bursters, by tonic-spiking and quiescent neurons, as well as mixed-mode configurations composed of neurons of different type. We demonstrate that burst synchronization can be accompanied by complex, often chaotic, interactions of fast spikes within synchronized bursts.

  9. Birth control vaccine targeting leukemia inhibitory factor.

    PubMed

    Lemons, Angela R; Naz, Rajesh K

    2012-02-01

    The population explosion and unintended pregnancies resulting in elective abortions continue to impose major public health issues. This calls for a better method of contraception. Immunocontraception has been proposed as a valuable alternative that can fulfill most, if not all, of the properties of an ideal contraceptive. There are several targets that are being explored for contraceptive vaccine development. Leukemia inhibitory factor (LIF), a member of interleukin-6 family, is required for embryo development and successful blastocyst implantation in several mammalian species. The present study was conducted to examine if LIF can be a target for the development of a birth control vaccine. Three sequences from LIF and two sequences from LIF-receptor (LIF-R) that span the regions involved in ligand-receptor binding were delineated, and peptides were synthesized based upon these sequences. Antibodies raised against these five peptides reduced LIF bioactivity in an in vitro culture assay using BA/F3 mLIF-R-mpg130 cells. Vaccines were prepared by conjugating these peptides to various carrier proteins. Immunization of female mice with these peptide vaccines induced a long-lasting, circulating as well as local antibody response in various parts of the genital tract, and resulted in a significant (P ≤ 0.05) inhibition in fertility in all the three trials; the LIF-R peptide vaccines proved to be a better vaccine target. The data indicate that LIF/LIF-R is an excellent target for the development of a birth control vaccine. This is the first study, to our knowledge, that examined LIF/LIF-R as a target for immunocontraception. The findings of this study can be easily translated to humans since LIF/LIF-R is also important for implantation and pregnancy in women.

  10. DEVELOPMENT, DIFFUSION, AND EVALUATION.

    ERIC Educational Resources Information Center

    GUBA, EGON G.

    THE KNOWLEDGE GAP BETWEEN INITIAL RESEARCH AND FINAL USE IS DISCUSSED IN TERMS OF THE FOUR STATES OF THE THEORY-PRACTICE CONTINUUM (RESEARCH, DEVELOPMENT, DIFFUSION, AND ADOPTION). THE TWO MIDDLE STAGES ARE EMPHASIZED. RESEARCH AND DEVELOPMENT CENTERS, REGIONAL EDUCATIONAL LABORATORIES, AND TITLE III PROJECTS ARE SUGGESTED AS AGENCIES RESPONSIBLE…

  11. Diffusion in random networks

    DOE PAGES

    Zhang, Duan Z.; Padrino, Juan C.

    2017-06-01

    The ensemble averaging technique is applied to model mass transport by diffusion in random networks. The system consists of an ensemble of random networks, where each network is made of pockets connected by tortuous channels. Inside a channel, fluid transport is assumed to be governed by the one-dimensional diffusion equation. Mass balance leads to an integro-differential equation for the pocket mass density. The so-called dual-porosity model is found to be equivalent to the leading order approximation of the integration kernel when the diffusion time scale inside the channels is small compared to the macroscopic time scale. As a test problem,more » we consider the one-dimensional mass diffusion in a semi-infinite domain. Because of the required time to establish the linear concentration profile inside a channel, for early times the similarity variable is xt$-$1/4 rather than xt$-$1/2 as in the traditional theory. We found this early time similarity can be explained by random walk theory through the network.« less

  12. Lung diffusion testing

    MedlinePlus

    ... the blood from the lungs, and to allow carbon dioxide to "diffuse" from the blood into the lungs. How the Test is Performed You breathe in (inhale) air containing a very small amount of carbon monoxide and a tracer gas, such as methane ...

  13. Water vapor diffusion membranes

    NASA Technical Reports Server (NTRS)

    Holland, F. F., Jr.; Smith, J. K.

    1974-01-01

    The program is reported, which was designed to define the membrane technology of the vapor diffusion water recovery process and to test this technology using commercially available or experimental membranes. One membrane was selected, on the basis of the defined technology, and was subjected to a 30-day demonstration trial.

  14. Osmosis and Diffusion

    ERIC Educational Resources Information Center

    Sack, Jeff

    2005-01-01

    OsmoBeaker is a CD-ROM designed to enhance the learning of diffusion and osmosis by presenting interactive experimentation to the student. The software provides several computer simulations that take the student through different scenarios with cells, having different concentrations of solutes in them.

  15. Osmosis and Diffusion

    ERIC Educational Resources Information Center

    Sack, Jeff

    2005-01-01

    OsmoBeaker is a CD-ROM designed to enhance the learning of diffusion and osmosis by presenting interactive experimentation to the student. The software provides several computer simulations that take the student through different scenarios with cells, having different concentrations of solutes in them.

  16. Nanocrystal diffusion doping.

    PubMed

    Vlaskin, Vladimir A; Barrows, Charles J; Erickson, Christian S; Gamelin, Daniel R

    2013-09-25

    A diffusion-based synthesis of doped colloidal semiconductor nanocrystals is demonstrated. This approach involves thermodynamically controlled addition of both impurity cations and host anions to preformed seed nanocrystals under equilibrium conditions, rather than kinetically controlled doping during growth. This chemistry allows thermodynamic crystal compositions to be prepared without sacrificing other kinetically trapped properties such as shape, size, or crystallographic phase. This doping chemistry thus shares some similarities with cation-exchange reactions, but proceeds without the loss of host cations and excels at the introduction of relatively unreactive impurity ions that have not been previously accessible using cation exchange. Specifically, we demonstrate the preparation of Cd(1-x)Mn(x)Se (0 ≤ x ≤ ∼0.2) nanocrystals with narrow size distribution, unprecedentedly high Mn(2+) content, and very large magneto-optical effects by diffusion of Mn(2+) into seed CdSe nanocrystals grown by hot injection. Controlling the solution and lattice chemical potentials of Cd(2+) and Mn(2+) allows Mn(2+) diffusion into the internal volumes of the CdSe nanocrystals with negligible Ostwald ripening, while retaining the crystallographic phase (wurtzite or zinc blende), shape anisotropy, and ensemble size uniformity of the seed nanocrystals. Experimental results for diffusion doping of other nanocrystals with other cations are also presented that indicate this method may be generalized, providing access to a variety of new doped semiconductor nanostructures not previously attainable by kinetic routes or cation exchange.

  17. Activity-dependent inhibitory synapse remodeling through gephyrin phosphorylation.

    PubMed

    Flores, Carmen E; Nikonenko, Irina; Mendez, Pablo; Fritschy, Jean-Marc; Tyagarajan, Shiva K; Muller, Dominique

    2015-01-06

    Maintaining a proper balance between excitation and inhibition is essential for the functioning of neuronal networks. However, little is known about the mechanisms through which excitatory activity can affect inhibitory synapse plasticity. Here we used tagged gephyrin, one of the main scaffolding proteins of the postsynaptic density at GABAergic synapses, to monitor the activity-dependent adaptation of perisomatic inhibitory synapses over prolonged periods of time in hippocampal slice cultures. We find that learning-related activity patterns known to induce N-methyl-D-aspartate (NMDA) receptor-dependent long-term potentiation and transient optogenetic activation of single neurons induce within hours a robust increase in the formation and size of gephyrin-tagged clusters at inhibitory synapses identified by correlated confocal electron microscopy. This inhibitory morphological plasticity was associated with an increase in spontaneous inhibitory activity but did not require activation of GABAA receptors. Importantly, this activity-dependent inhibitory plasticity was prevented by pharmacological blockade of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), it was associated with an increased phosphorylation of gephyrin on a site targeted by CaMKII, and could be prevented or mimicked by gephyrin phospho-mutants for this site. These results reveal a homeostatic mechanism through which activity regulates the dynamics and function of perisomatic inhibitory synapses, and they identify a CaMKII-dependent phosphorylation site on gephyrin as critically important for this process.

  18. Delayed plasticity of inhibitory neurons in developing visual cortex.

    PubMed

    Gandhi, Sunil P; Yanagawa, Yuchio; Stryker, Michael P

    2008-10-28

    During postnatal development, altered sensory experience triggers the rapid reorganization of neuronal responses and connections in sensory neocortex. This experience-dependent plasticity is disrupted by reductions of intracortical inhibition. Little is known about how the responses of inhibitory cells themselves change during plasticity. We investigated the time course of inhibitory cell plasticity in mouse primary visual cortex by using functional two-photon microscopy with single-cell resolution and genetic identification of cell type. Initially, local inhibitory and excitatory cells had similar binocular visual response properties, both favoring the contralateral eye. After 2 days of monocular visual deprivation, excitatory cell responses shifted to favor the open eye, whereas inhibitory cells continued to respond more strongly to the deprived eye. By 4 days of deprivation, inhibitory cell responses shifted to match the faster changes in their excitatory counterparts. These findings reveal a dramatic delay in inhibitory cell plasticity. A minimal linear model reveals that the delay in inhibitory cell plasticity potently accelerates Hebbian plasticity in neighboring excitatory neurons. These findings offer a network-level explanation as to how inhibition regulates the experience-dependent plasticity of neocortex.

  19. THE FINE STRUCTURE OF INHIBITORY SYNAPSES IN THE CRAYFISH

    PubMed Central

    Peterson, R. Price; Pepe, Frank A.

    1961-01-01

    Physiological investigations have shown that the synaptic input to the sensory neuron of the stretch receptor in the abdominal muscles of the crayfish is purely inhibitory. This neuron was chosen, therefore, as a site in which to study the fine structure of inhibitory synaptic endings. It was hoped that this fine structure might (a) provide a morphological prototype for the study of more complex synaptic systems and (b) reflect the inhibitory mechanisms. Stretch receptors were fixed in situ in buffered OsO4, dehydrated, and embedded in Araldite. Both cross and longitudinal sections were examined after staining with phosphotungstic acid. The inhibitory endings were easily identified by their great similarity to previously described excitatory endings. Small circular profiles (synaptic vesicles) about 460 A in diameter and an accumulation of mitochondria were consistently observed within the presynaptic endings. An increased osmiophilia of pre- and postsynaptic membranes, where they were in apposition, was also seen. The only observed difference between these inhibitory endings and excitatory endings, described by other authors, was the variable presence of a latticework of 230 A tubules in the connective tissue immediately adjacent to the inhibitory endings. Inhibitory endings were observed on all parts of the sensory neuron except the axon. PMID:14485811

  20. Peripherally driven low-threshold inhibitory inputs to lamina I local-circuit and projection neurones: a new circuit for gating pain responses

    PubMed Central

    Luz, Liliana L; Szucs, Peter; Safronov, Boris V

    2014-01-01

    Spinal lamina I is a key element of the pain processing system which relays primary afferent input to supraspinal areas. However, little is known about how the signal is modulated by its intrinsic network including local-circuit neurones (LCNs) and much less numerous anterolateral tract projection neurones (PNs). Here, we used whole-cell patch clamp recordings in an isolated spinal cord preparation to examine properties of identified LCNs (n = 85) and PNs (n = 73) in their functionally preserved local networks. Forty LCNs showed spontaneous rhythmic firing (2–7 Hz) at zero current injection, which persisted in the presence of blockers of fast synaptic transmission. In the remaining cases, most LCNs and PNs fired tonically in response to depolarizing current injections. We identified LCNs and PNs receiving low-threshold primary afferent-driven inhibitory inputs, which in many cases were disynaptic and temporally preceded classical high-threshold excitatory inputs. This direct inhibitory link between low-threshold afferents and PNs can function as a postsynaptic gate controlling the nociceptive information flow in the spinal cord. The LCNs were found to be integrated into the superficial dorsal horn network by their receipt of monosynaptic and disynaptic inputs from other lamina I and II neurones. One-third of LCNs and two-thirds of PNs tested responded to substance P application. Thus, substance P released by a noxious afferent stimulation may excite PNs in two ways: directly, and via the activation of presynaptic LCN circuitries. In conclusion, we have described important properties of identified lamina I neurones and their roles in a new circuit for gating pain responses. PMID:24421354