Acid and stretch, but not capsaicin, are effective stimuli for ATP release in the porcine bladder mucosa: Are ASIC and TRPV1 receptors involved?

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Sadananda, Prajni; Kao, Felicity C L; Liu, Lu; Mansfield, Kylie J; Burcher, Elizabeth

2012-05-15

Stretch-evoked ATP release from the bladder mucosa is a key event in signaling bladder fullness. Our aim was to examine whether acid and capsaicin can also release ATP and to determine the receptors involved, using agonists and antagonists at TRPV1 and acid-sensing ion channels (ASICs). Strips of porcine bladder mucosa were exposed to acid, capsaicin or stretch. Strip tension was monitored. Bath fluid was collected for ATP measurement. Gene expression of ASICs and TRPV1 in porcine bladders was quantified using quantitative real-time PCR (qRT-PCR). Stretch stimulus (150% of original length) repeatedly and significantly increased ATP release to approximately 45 times basal release. Acid (pH 6.5, 6.0, 5.6) contracted mucosal strips and also increased ATP release up to 30-fold, without evidence of desensitization. Amiloride (0.3 μM) reduced the acid-evoked ATP release by approximately 70%, while capsazepine (10 μM) reduced acid-evoked ATP release at pH 6.0 and pH 5.6 (by 68% and 61%, respectively). Capsaicin (0.1-10 μM) was ineffective in causing ATP release, and also failed to contract porcine mucosal or detrusor strips. Gene expression for ASIC1, ASIC2, ASIC3 and TRPV1 was seen in the lateral wall, dome, trigone and neck of both detrusor and mucosa. In conclusion, stretch and acid induce ATP release in the porcine bladder mucosa, but capsaicin is ineffective. The pig bladder is a well-known model for the human bladder, however these data suggest that it should be used with caution, particularly for TRPV1 related studies. Copyright © 2012 Elsevier B.V. All rights reserved.

Behavioral analyses of wind-evoked escape of the cricket, Gryllodes sigillatus.

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Kanou, Masamichi; Konishi, Atsuko; Suenaga, Rie

2006-04-01

The wind-evoked escape behavior of the cricket Gryllodes sigillatus was investigated using an air puff stimulus. A high velocity air puff elicited the escape behavior in many crickets. The crickets tended to escape away from the stimulus source, but the direction was not accurately oriented 180 degrees from the stimulus. After bilateral cercal ablation, only a few crickets showed wind-evoked escape behavior, and their response rates did not increase even 19 days after ablation. Therefore, information on air motion detected by cercal filiform hairs is essential for triggering wind-evoked behavior. After unilateral cercal ablation, the 81.3% response rate of intact crickets decreased to 16.5%, that is, it decreased to almost 20% that of intact crickets. One week after unilateral cercal ablation, the response rate recovered to more than 60% that of intact crickets. However, the accuracy rate of the escape direction of G. sigillatus showed no change even immediately after the unilateral cercal ablation. Therefore, both cerci are not necessarily required to determine the escape direction. The behavioral characteristics of wind-evoked escape of G. sigillatus are compared with those of another species of cricket, Gryllus bimaculatus. The two species of cricket employ different strategies for wind-evoked escape.

Bioconversion of Capsaicin by Aspergillus oryzae.

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Lee, Minji; Cho, Jeong-Yong; Lee, Yu Geon; Lee, Hyoung Jae; Lim, Seong-Il; Park, So-Lim; Moon, Jae-Hak

2015-07-08

This study identified metabolites of capsaicin bioconverted by Aspergillus oryzae, which is generally used for mass production of gochujang prepared by fermenting red pepper powder in Korea. A. oryzae was incubated with capsaicin in potato dextrose broth. Capsaicin decreased depending on the incubation period, but new metabolites increased. Five capsaicin metabolites purified from the ethyl acetate fraction of the capsaicin culture were identified as N-vanillylcarbamoylbutyric acid, N-vanillyl-9-hydroxy-8-methyloctanamide, ω-hydroxycapsaicin, 8-methyl-N-vanillylcarbamoyl-6(E)-octenoic acid, and 2-methyl-N-vanillylcarbamoyl-6(Z)-octenoic acid by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The capsaicin metabolites in gochujang were confirmed and quantitated by selective multiple reaction monitoring detection after liquid chromatography electrospray ionization MS using the isolated compounds as external standards. On the basis of the structures of the capsaicin metabolites, it is proposed that capsaicin metabolites were converted by A. oryzae by ω-hydroxylation, alcohol oxidation, hydrogenation, isomerization, and α- and/or β-oxidation.

Modulation of TRP channels by resveratrol and other stilbenoids

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Yu Lina

2013-02-01

Full Text Available Abstract Background Resveratrol (3,5,4’ - trihydroxy-trans-stilbene, a widely distributed natural stilbenoid, was proposed to account for the unique effects of red wine on life span and health. It has been reported to possess various biological and pharmacological activities, such as anti-oxidant, anti-inflammatory, and anti-carcinogenic effects. Here, using whole-cell patch-clamp techniques and behavioral analyses, we investigated whether resveratrol and other stilbenoids can modulate TRP channels in sensory neurons in vitro, and have analgesic effects in vivo. Results We found that resveratrol dose-dependently suppressed the allyl isothiocyanate (AITC-induced currents (IAITC in HEK293 cells that express TRPA1, as well as in rat dorsal root ganglion (DRG neurons. Instead, pinosylvin methyl ether (PME, another derivate of stilbene which has a similar structure to resveratrol, dose-dependently blocked the capsaicin-induced currents (ICAP in HEK293 cells that express TRPV1 as well as in DRG neurons. Interestingly, resveratrol had no inhibitory effect on the ICAP, and PME had no effect on the IAITC. Otherwise, trans-stilbene showed no any effect on IAITC or ICAP. The concentration response curve of AITC showed that resveratrol inhibited the action of TRPA1 not by changing the EC50, but by suppressing the AITC-induced maximum response. By contrast, the inhibition of TRPV1 by PME did not change the capsaicin-induced maximum response but did cause a right shift of the EC50. Moreover, pre-administration of resveratrol suppressed intraplantar injections of AITC-evoked nocifensive behaviors, as well as that PME suppressed capsaicin-evoked one. Conclusions These data suggest that resveratrol and other stilbenoids may have an inhibitory effect on TRP channels. In addition, these stilbenoids modulate TRP channel activity in different ways.

Mass-spectrometric identification of T-kininogen I/thiostatin as an acute-phase inflammatory protein suppressed by curcumin and capsaicin.

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Joe, Bina; Nagaraju, Anitha; Gowda, Lalitha R; Basrur, Venkatesha; Lokesh, Belur R

2014-01-01

Curcumin and capsaicin are dietary xenobiotics with well-documented anti-inflammatory properties. Previously, the beneficial effect of these spice principles in lowering chronic inflammation was demonstrated using a rat experimental model for arthritis. The extent of lowering of arthritic index by the spice principles was associated with a significant shift in macrophage function favoring the reduction of pro-inflammatory molecules such as reactive oxygen species and production and release of anti-inflammatory metabolites of arachidonic acid. Beyond the cellular effects on macrophage function, oral administration of curcumin and capsaicin caused alterations in serum protein profiles of rats injected with adjuvant to develop arthritis. Specifically, a 72 kDa acidic glycoprotein, GpA72, which was elevated in pre-arthritic rats, was significantly lowered by feeding either curcumin or capsaicin to the rats. Employing the tandem mass spectrometric approach for direct sequencing of peptides, here we report the identification of GpA72 as T-kininogen I also known as Thiostatin. Since T-kininogen I is an early acute-phase protein, we additionally tested the efficiency of curcumin and capsaicin to mediate the inflammatory response in an acute phase model. The results demonstrate that curcumin and capsaicin lower the acute-phase inflammatory response, the molecular mechanism for which is, in part, mediated by pathways associated with the lowering of T-kininogen I.

Mass-spectrometric identification of T-kininogen I/thiostatin as an acute-phase inflammatory protein suppressed by curcumin and capsaicin.

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Bina Joe

Full Text Available Curcumin and capsaicin are dietary xenobiotics with well-documented anti-inflammatory properties. Previously, the beneficial effect of these spice principles in lowering chronic inflammation was demonstrated using a rat experimental model for arthritis. The extent of lowering of arthritic index by the spice principles was associated with a significant shift in macrophage function favoring the reduction of pro-inflammatory molecules such as reactive oxygen species and production and release of anti-inflammatory metabolites of arachidonic acid. Beyond the cellular effects on macrophage function, oral administration of curcumin and capsaicin caused alterations in serum protein profiles of rats injected with adjuvant to develop arthritis. Specifically, a 72 kDa acidic glycoprotein, GpA72, which was elevated in pre-arthritic rats, was significantly lowered by feeding either curcumin or capsaicin to the rats. Employing the tandem mass spectrometric approach for direct sequencing of peptides, here we report the identification of GpA72 as T-kininogen I also known as Thiostatin. Since T-kininogen I is an early acute-phase protein, we additionally tested the efficiency of curcumin and capsaicin to mediate the inflammatory response in an acute phase model. The results demonstrate that curcumin and capsaicin lower the acute-phase inflammatory response, the molecular mechanism for which is, in part, mediated by pathways associated with the lowering of T-kininogen I.

Effects of capsaicin, green tea and CH-19 sweet pepper on appetite and energy intake in humans in negative and positive energy balance

DEFF Research Database (Denmark)

Reinbach, Helene Christine; Smeets, A.; Martinussen, Torben

2009-01-01

Summary Background & aims Bioactive ingredients have been shown to reduce appetite and energy intake. The magnitude of these effects might depend on energy balance why it was investigated how capsaicin, green tea, CH-19 sweet pepper as well as green tea and capsaicin affect appetite and energy...... intake during respectively negative and positive energy balance. Methods 27 subjects were randomized to three weeks of negative and three weeks of positive energy balance during which capsaicin, green tea, CH-19 sweet pepper, capsaicin + green tea or placebo was ingested on ten separate test days while...... the effects on appetite, energy intake, body weight and heart rate were assessed. Results CH-19 sweet pepper and a combination of capsaicin and green tea reduced energy intake during positive energy balance. Capsaicin and green tea suppressed hunger and increased satiety more during negative than during...

Characterization of capsaicin synthase and identification of its gene (csy1) for pungency factor capsaicin in pepper (Capsicum sp.)

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Prasad, B. C. Narasimha; Kumar, Vinod; Gururaj, H. B.; Parimalan, R.; Giridhar, P.; Ravishankar, G. A.

2006-01-01

Capsaicin is a unique alkaloid of the plant kingdom restricted to the genus Capsicum. Capsaicin is the pungency factor, a bioactive molecule of food and of medicinal importance. Capsaicin is useful as a counterirritant, antiarthritic, analgesic, antioxidant, and anticancer agent. Capsaicin biosynthesis involves condensation of vanillylamine and 8-methyl nonenoic acid, brought about by capsaicin synthase (CS). We found that CS activity correlated with genotype-specific capsaicin levels. We purified and characterized CS (≈35 kDa). Immunolocalization studies confirmed that CS is specifically localized to the placental tissues of Capsicum fruits. Western blot analysis revealed concomitant enhancement of CS levels and capsaicin accumulation during fruit development. We determined the N-terminal amino acid sequence of purified CS, cloned the CS gene (csy1) and sequenced full-length cDNA (981 bp). The deduced amino acid sequence of CS from full-length cDNA was 38 kDa. Functionality of csy1 through heterologous expression in recombinant Escherichia coli was also demonstrated. Here we report the gene responsible for capsaicin biosynthesis, which is unique to Capsicum spp. With this information on the CS gene, speculation on the gene for pungency is unequivocally resolved. Our findings have implications in the regulation of capsaicin levels in Capsicum genotypes. PMID:16938870

Anticancer Properties of Capsaicin Against Human Cancer.

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Clark, Ruth; Lee, Seong-Ho

2016-03-01

There is persuasive epidemiological and experimental evidence that dietary phytochemicals have anticancer activity. Capsaicin is a bioactive phytochemical abundant in red and chili peppers. While the preponderance of the data strongly indicates significant anticancer benefits of capsaicin, more information to highlight molecular mechanisms of its action is required to improve our knowledge to be able to propose a potential therapeutic strategy for use of capsaicin against cancer. Capsaicin has been shown to alter the expression of several genes involved in cancer cell survival, growth arrest, angiogenesis and metastasis. Recently, many research groups, including ours, found that capsaicin targets multiple signaling pathways, oncogenes and tumor-suppressor genes in various types of cancer models. In this review article, we highlight multiple molecular targets responsible for the anticancer mechanism of capsaicin. In addition, we deal with the benefits of combinational use of capsaicin with other dietary or chemotherapeutic compounds, focusing on synergistic anticancer activities. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

The μ opioid agonist morphine modulates potentiation of capsaicin-evoked TRPV1 responses through a cyclic AMP-dependent protein kinase A pathway

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Roberts-Thomson Sarah J

2006-07-01

Full Text Available Abstract Background The vanilloid receptor 1 (TRPV1 is critical in the development of inflammatory hyperalgesia. Several receptors including G-protein coupled prostaglandin receptors have been reported to functionally interact with the TRPV1 through a cAMP-dependent protein kinase A (PKA pathway to potentiate TRPV1-mediated capsaicin responses. Such regulation may have significance in inflammatory pain. However, few functional receptor interactions that inhibit PKA-mediated potentiation of TRPV1 responses have been described. Results In the present studies we investigated the hypothesis that the μ opioid receptor (MOP agonist morphine can modulate forskolin-potentiated capsaicin responses through a cAMP-dependent PKA pathway. HEK293 cells were stably transfected with TRPV1 and MOP, and calcium (Ca2+ responses to injection of the TRPV1 agonist capsaicin were monitored in Fluo-3-loaded cells. Pre-treatment with morphine did not inhibit unpotentiated capsaicin-induced Ca2+ responses but significantly altered capsaicin responses potentiated by forskolin. TRPV1-mediated Ca2+ responses potentiated by the direct PKA activator 8-Br-cAMP and the PKC activator Phorbol-12-myristate-13-acetatewere not modulated by morphine. Immunohistochemical studies confirmed that the TRPV1 and MOP are co-expressed on cultured Dorsal Root Ganglion neurones, pointing towards the existence of a functional relationship between the G-protein coupled MOP and nociceptive TRPV1. Conclusion The results presented here indicate that the opioid receptor agonist morphine acts via inhibition of adenylate cyclase to inhibit PKA-potentiated TRPV1 responses. Targeting of peripheral opioid receptors may therefore have therapeutic potential as an intervention to prevent potentiation of TRPV1 responses through the PKA pathway in inflammation.

Distinct BOLD fMRI Responses of Capsaicin-Induced Thermal Sensation Reveal Pain-Related Brain Activation in Nonhuman Primates.

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Abu Bakar Ali Asad

Full Text Available Approximately 20% of the adult population suffer from chronic pain that is not adequately treated by current therapies, highlighting a great need for improved treatment options. To develop effective analgesics, experimental human and animal models of pain are critical. Topically/intra-dermally applied capsaicin induces hyperalgesia and allodynia to thermal and tactile stimuli that mimics chronic pain and is a useful translation from preclinical research to clinical investigation. Many behavioral and self-report studies of pain have exploited the use of the capsaicin pain model, but objective biomarker correlates of the capsaicin augmented nociceptive response in nonhuman primates remains to be explored.Here we establish an aversive capsaicin-induced fMRI model using non-noxious heat stimuli in Cynomolgus monkeys (n = 8. BOLD fMRI data were collected during thermal challenge (ON:20 s/42°C; OFF:40 s/35°C, 4-cycle at baseline and 30 min post-capsaicin (0.1 mg, topical, forearm application. Tail withdrawal behavioral studies were also conducted in the same animals using 42°C or 48°C water bath pre- and post- capsaicin application (0.1 mg, subcutaneous, tail.Group comparisons between pre- and post-capsaicin application revealed significant BOLD signal increases in brain regions associated with the 'pain matrix', including somatosensory, frontal, and cingulate cortices, as well as the cerebellum (paired t-test, p<0.02, n = 8, while no significant change was found after the vehicle application. The tail withdrawal behavioral study demonstrated a significant main effect of temperature and a trend towards capsaicin induced reduction of latency at both temperatures.These findings provide insights into the specific brain regions involved with aversive, 'pain-like', responses in a nonhuman primate model. Future studies may employ both behavioral and fMRI measures as translational biomarkers to gain deeper understanding of pain processing and evaluate

Psychophysics, flare, and neurosecretory function in human pain models: capsaicin versus electrically evoked pain.

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Geber, Christian; Fondel, Ricarda; Krämer, Heidrun H; Rolke, Roman; Treede, Rolfe-Detlef; Sommer, Claudia; Birklein, Frank

2007-06-01

Intradermal capsaicin injection (CAP) and electrical current stimulation (ES) are analyzed in respect to patterns and test-retest reliability of pain as well as sensory and neurosecretory changes. In 10 healthy subjects, 2x CAP (50 microg) and 2x ES (5 to 30 mA) were applied to the volar forearm. The time period between 2 identical stimulations was about 4 months. Pain ratings, areas of mechanical hyperalgesia, and allodynia were assessed. The intensity of sensory changes was quantified by using quantitative sensory testing. Neurogenic flare was assessed by using laser Doppler imaging. Calcitonin gene-related peptide (CGRP) release was quantified by dermal microdialysis in combination with an enzyme immunoassay. Time course and peak pain ratings were different between CAP and ES. Test-retest correlation was high (r > or = 0.73). Both models induced primary heat hyperalgesia and primary plus secondary pin-prick hyperalgesia. Allodynia occurred in about half of the subjects. Maximum flare sizes did not differ between CAP and ES, but flare intensities were higher for ES. Test-retest correlation was higher for flare sizes than for flare intensity. A significant CGRP release could only be measured after CAP. The different time courses of pain stimulation (CAP: rapidly decaying pain versus ES: pain plateau) led to different peripheral neurosecretory effects but induced similar central plasticity and hyperalgesia. The present study gives a detailed overview of psychophysical and neurosecretory characteristics induced by noxious stimulation with capsaicin and electrical current. We describe differences, similarities, and reproducibility of these human pain models. These data might help to interpret past and future results of human pain studies using experimental pain.

Neonatal capsaicin causes compensatory adjustments to energy homeostasis in rats

NARCIS (Netherlands)

van de Wall, E. H. E. M.; Wielinga, P. Y.; Strubbe, J. H.; van Dijk, G.

2006-01-01

Several mechanisms involved in ingestive behavior and neuroendocrine activity rely on vagal afferent neuronal signaling. Seemingly contradictory to this idea are observations that vagal afferent neuronal ablation by neonatal capsaicin (CAP) treatment has relatively small effects on glucose

CAPSAICIN: ITS BIOLOGICAL ACTIVITIES AND IN SILICO TARGET FISHING.

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Akhtar, Fahad; Muhammad Sharif, Hajra; Arshad Mallick, Muhammad; Zahoor, Fareeha; Abdulmalik, Attiya; Baig, Warda; Shujaat, Nodia; Gul, Sundas; Bibi, Gulfam; Ramzan, Rahdia; Murtaza, Ghulam

2017-03-01

Capsicum annuum L. is a rich source of capsaicin, an alkaloid, which is a very pungent compound. Due to ever growing need of capsaicin, an extensive research on its efficient cultivation as well as chemical synthesis is underway. Owing to the pungent nature of capsaicin, its analogous molecules without pungent effect are being explored. The objective of this descriptive review is to comprehensively present the updates on the bioactivities of capsaicin. Additionally, the in silico target fishing approach has been used to identify the possible protein targets of capsaicin. This article will definitely provide future perspectives of research on capsaicin.

Integrating TRPV1 Receptor Function with Capsaicin Psychophysics

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Gregory Smutzer

2016-01-01

Full Text Available Capsaicin is a naturally occurring vanilloid that causes a hot, pungent sensation in the human oral cavity. This trigeminal stimulus activates TRPV1 receptors and stimulates an influx of cations into sensory cells. TRPV1 receptors function as homotetramers that also respond to heat, proinflammatory substances, lipoxygenase products, resiniferatoxin, endocannabinoids, protons, and peptide toxins. Kinase-mediated phosphorylation of TRPV1 leads to increased sensitivity to both chemical and thermal stimuli. In contrast, desensitization occurs via a calcium-dependent mechanism that results in receptor dephosphorylation. Human psychophysical studies have shown that capsaicin is detected at nanomole amounts and causes desensitization in the oral cavity. Psychophysical studies further indicate that desensitization can be temporarily reversed in the oral cavity if stimulation with capsaicin is resumed at short interstimulus intervals. Pretreatment of lingual epithelium with capsaicin modulates the perception of several primary taste qualities. Also, sweet taste stimuli may decrease the intensity of capsaicin perception in the oral cavity. In addition, capsaicin perception and hedonic responses may be modified by diet. Psychophysical studies with capsaicin are consistent with recent findings that have identified TRPV1 channel modulation by phosphorylation and interactions with membrane inositol phospholipids. Future studies will further clarify the importance of capsaicin and its receptor in human health and nutrition.

Inattentional Deafness: Visual Load Leads to Time-Specific Suppression of Auditory Evoked Responses.

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Molloy, Katharine; Griffiths, Timothy D; Chait, Maria; Lavie, Nilli

2015-12-09

Due to capacity limits on perception, conditions of high perceptual load lead to reduced processing of unattended stimuli (Lavie et al., 2014). Accumulating work demonstrates the effects of visual perceptual load on visual cortex responses, but the effects on auditory processing remain poorly understood. Here we establish the neural mechanisms underlying "inattentional deafness"--the failure to perceive auditory stimuli under high visual perceptual load. Participants performed a visual search task of low (target dissimilar to nontarget items) or high (target similar to nontarget items) load. On a random subset (50%) of trials, irrelevant tones were presented concurrently with the visual stimuli. Brain activity was recorded with magnetoencephalography, and time-locked responses to the visual search array and to the incidental presence of unattended tones were assessed. High, compared to low, perceptual load led to increased early visual evoked responses (within 100 ms from onset). This was accompanied by reduced early (∼ 100 ms from tone onset) auditory evoked activity in superior temporal sulcus and posterior middle temporal gyrus. A later suppression of the P3 "awareness" response to the tones was also observed under high load. A behavioral experiment revealed reduced tone detection sensitivity under high visual load, indicating that the reduction in neural responses was indeed associated with reduced awareness of the sounds. These findings support a neural account of shared audiovisual resources, which, when depleted under load, leads to failures of sensory perception and awareness. The present work clarifies the neural underpinning of inattentional deafness under high visual load. The findings of near-simultaneous load effects on both visual and auditory evoked responses suggest shared audiovisual processing capacity. Temporary depletion of shared capacity in perceptually demanding visual tasks leads to a momentary reduction in sensory processing of auditory

Late sensory function after intraoperative capsaicin wound instillation

DEFF Research Database (Denmark)

Aasvang, E K; Hansen, J B; Kehlet, H

2010-01-01

is partly re-established after skin injection of capsaicin. However, no study has evaluated the long-term effects of wound instillation of purified capsaicin on sensory functions. METHODS: Patients included in a double-blind placebo-controlled randomized study of the analgesic effect of capsaicin after....... placebo group at the 1-week follow-up (Pfunction on the operated side between groups at the pre-operative, 1-week or 2 1/2 year post-operative follow-up (P>0.05). The sensory function......BACKGROUND: Intense capsaicin-induced C-fiber stimulation results in reversible lysis of the nerve soma, thereby making capsaicin wound instillation of potential interest for the treatment of post-operative pain. Clinical histological and short-term sensory studies suggest that the C-fiber function...

Capsaicin-sensitive intestinal mucosal afferent mechanism and body fat distribution.

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Leung, Felix W

2008-07-04

This report summarizes clinical and experimental data in support of the hypothesis that capsaicin-sensitive intestinal mucosal afferent mechanism plays a role in regulating body fat distribution. Epidemiological data have revealed that the consumption of foods containing capsaicin is associated with a lower prevalence of obesity. Rural Thai people consume diets containing 0.014% capsaicin. Rodents fed a diet containing 0.014% capsaicin showed no change in caloric intake but a significant 24% and 29% reduction in the visceral (peri-renal) fat weight. Increase in intestinal blood flow facilitates nutrient energy absorption and decrease in adipose tissue blood flow facilitates storage of nutrient energy in adipose tissue. Stimulation of intestinal mucosal afferent nerves increases intestinal blood flow, but decreases visceral (mesenteric) adipost tissue blood flow. In in vitro cell studies capsaicin has a direct effect on adipocytes. Intravenous capsaicin produces measurable plasma level and subcutaneous capsaicin retards accumulation of adipose tissue. The data on a direct effect of oral capsaicin on adipose tissue at remote sites, however, are conflicting. Capsaicin absorbed from the gut lumen is almost completely metabolized before reaching the general circulation. Oral capsaicin significantly increases transient receptor potential vanilloid type-1 (TRPV1) channel expression as well as TRPV1 messenger ribonucleic acid (mRNA) in visceral adipose tissue. In TRPV1 knockout mice on a high fat diet the body weight was not significantly different in the absence or presence of oral capsaicin. In rodent experiments, daily intragastric administration of capsaicin for two weeks led to defunctionalization of intestinal mucosal afferent nerves, manifested by loss of acute mucosal capsaicin-induced effects; but not the corneal afferent nerves, with preservation of the paw wiping reflex of the eye exposed briefly to dilute capsaicin. The latter indicated the absence of an oral

The anti-asthmatic drug pranlukast suppresses the delayed-phase vomiting and reverses intracellular indices of emesis evoked by cisplatin in the least shrew (Cryptotis parva).

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Darmani, Nissar A; Chebolu, Seetha; Zhong, Weixia; Kim, William D; Narlesky, Matthew; Adams, Joia; Dong, Fanglong

2017-08-15

The introduction of second generation serotonin 5-HT 3 receptor (5-HT 3 ) antagonist palonosetron combined with long-acting substance P neurokinin NK 1 receptor (NK 1 ) antagonists (e.g. netupitant) has substantially improved antiemetic therapy against early- and delayed-phases of emesis caused by highly emetogenic chemotherapeutics such as cisplatin. However, the improved efficacy comes at a cost that many patients cannot afford. We introduce a new class of antiemetic, the antiasthmatic leukotriene CysLT1 receptor antagonist pranlukast for the suppression of cisplatin-evoked vomiting. Pranlukast (10mg/kg) by itself significantly reduced the mean frequency of vomits (70%) and fully protected least shrews from vomiting (46%) during the delayed-phase of cisplatin (10mg/kg)-evoked vomiting. Although, pranlukast tended to substantially reduce both the mean frequency of vomits and the number of shrews vomiting during the early-phase, these reductions failed to attain significance. When combined with a first (tropisetron)- or a second (palonosetron)-generation 5-HT 3 receptor antagonist, pranlukast potentiated their antiemetic efficacy during both phases of vomiting. In addition, pranlukast by itself prevented several intracellular signal markers of cisplatin-evoked delayed-vomiting such as phosphorylation of ERK1/2 and PKA. When pranlukast was combined with either palonosetron or tropisetron, these combinations suppressed the evoked phosphorylation of: i) ERK1/2 during both acute- and delayed-phase, ii) PKCα/β at the peak acute-phase, and iii) PKA at the peak delayed-phase. The current and our published findings suggest that overall behavioral and intracellular signaling effects of pranlukast via blockade of CysLT1 receptors generally appear to be similar to the NK 1 receptor antagonist netupitant with some differences. Copyright © 2017 Elsevier B.V. All rights reserved.

Repeated oral administration of capsaicin increases anxiety-like ...

Indian Academy of Sciences (India)

This study was conducted to examine the psycho-emotional effects of repeated oral exposure to capsaicin, the principal active component of chili peppers. Each rat received 1 mL of 0.02% capsaicin into its oral cavity daily, and was subjected to behavioural tests following 10 daily administrations of capsaicin. Stereotypy ...

Moderate extracellular acidification inhibits capsaicin-induced cell death through regulating calcium mobilization, NF-κB translocation and ROS production in synoviocytes

International Nuclear Information System (INIS)

Hu, Fen; Yang, Shuang; Zhao, Dan; Zhu, Shuyan; Wang, Yuxiang; Li, Junying

2012-01-01

Highlights: ► Moderate extracellular acidification regulates intracellular Ca 2+ mobilization. ► Moderate acidification activates NF-κB nuclear translocation in synoviocytes. ► Moderate acidification depresses the ROS production induced by capsaicin. ► Moderate acidification inhibits capsaicin-caused synoviocyte death. -- Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca 2+ entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca 2+ entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca 2+ release from intracellular stores. The nuclear translocation of NF-κB was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-κB. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca 2+ mobilization, activating NF-κB nuclear translocation and depressing ROS production.

Moderate extracellular acidification inhibits capsaicin-induced cell death through regulating calcium mobilization, NF-{kappa}B translocation and ROS production in synoviocytes

Energy Technology Data Exchange (ETDEWEB)

Hu, Fen; Yang, Shuang; Zhao, Dan; Zhu, Shuyan; Wang, Yuxiang [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China); Li, Junying, E-mail: jyli04@nankai.edu.cn [Department of Biophysics, School of Physics and Key Laboratory of Bioactive Materials of Education Ministry, Nankai University, Tianjin 300071 (China)

2012-07-20

Highlights: Black-Right-Pointing-Pointer Moderate extracellular acidification regulates intracellular Ca{sup 2+} mobilization. Black-Right-Pointing-Pointer Moderate acidification activates NF-{kappa}B nuclear translocation in synoviocytes. Black-Right-Pointing-Pointer Moderate acidification depresses the ROS production induced by capsaicin. Black-Right-Pointing-Pointer Moderate acidification inhibits capsaicin-caused synoviocyte death. -- Abstract: We previously show the expression of transient receptor potential vanilloid 1 (TRPV1) in primary synoviocytes from collagen-induced arthritis (CIA) rats. Capsaicin and lowered extracellular pH from 7.4 to 5.5 induce cell death through TRPV1-mediated Ca{sup 2+} entry and reactive oxygen species (ROS) production. However, under the pathological condition in rheumatoid arthritis, the synovial fluid is acidified to a moderate level (about pH 6.8). In the present study, we examined the effects of pH 6.8 on the TRPV1-mediated cell death. Our finding is different or even opposite from what was observed at pH 5.5. We found that the moderate extracellular acidification (from pH 7.4 to 6.8) inhibited the capsaicin-induced Ca{sup 2+} entry through attenuating the activity of TRPV1. In the mean time, it triggered a phospholipse C (PLC)-related Ca{sup 2+} release from intracellular stores. The nuclear translocation of NF-{kappa}B was found at pH 6.8, and this also depends on PLC activation. Moreover, the capsaicin-evoked massive ROS production and cell death were depressed at pH 6.8, both of which are dependent on the activation of PLC and NF-{kappa}B. Taken together, these results suggested that the moderate extracellular acidification inhibited the capsaicin-induced synoviocyte death through regulating Ca{sup 2+} mobilization, activating NF-{kappa}B nuclear translocation and depressing ROS production.

On the Relationship Between Musicianship and Contralateral Suppression of Transient-Evoked Otoacoustic Emissions.

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Stuart, Andrew; Daughtrey, Emma R

2016-04-01

The medial olivocochlear (MOC) efferent reflex that modulates outer hair cell function has been shown to be more robust in musicians versus nonmusicians as evidenced in greater contralateral suppression of transient-evoked otoacoustic emissions (TEOAEs). All previous research comparing musical ability and MOC efferent strength has defined musicianship dichotomously (i.e., high-level music students or professional classical musicians versus nonmusicians). The objective of the study was to further explore contralateral suppression of TEOAEs among adults with a full spectrum of musicianship ranging from no history of musicianship to professional musicians. Musicianship was defined by both self-report and with an objective test to quantify individual differences in perceptual music skills. A single-factor between-subjects and correlational research designs were employed. Forty-five normal-hearing young adults participated. Participants completed a questionnaire concerning their music experience and completed the Brief Profile of Music Perception Skills (PROMS) to quantify perceptual musical skills across multiple musical domains (i.e., accent, melody, tempo, and tuning). TEOAEs were evaluated with 60 dB peak equivalent sound pressure level click stimuli with and without a contralateral 65 dB sound pressure level white noise suppressor. TEOAE suppression was expressed in two ways, absolute TEOAE suppression in dB and a normalized index of TEOAE suppression (i.e., percentage of suppression). Participants who considered themselves musicians scored significantly higher on all subscales and total Brief PROMS score (p 0.05). There were no statistically significant correlations or linear predictive relationships between subscale or total Brief PROMS scores with absolute and percentage of TEOAE suppression (p > 0.05). The findings do not support the notion of a graded enhancement of MOC efferent suppression among adults with varied degrees of musicianship from nonmusicians to

TRPA1 contributes to capsaicin-induced facial cold hyperalgesia in rats.

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Honda, Kuniya; Shinoda, Masamichi; Furukawa, Akihiko; Kita, Kozue; Noma, Noboru; Iwata, Koichi

2014-12-01

Orofacial cold hyperalgesia is known to cause severe persistent pain in the face following trigeminal nerve injury or inflammation, and transient receptor potential (TRP) vanilloid 1 (TRPV1) and TRP ankylin 1 (TRPA1) are thought to be involved in cold hyperalgesia. However, how these two receptors are involved in cold hyperalgesia is not fully understood. To clarify the mechanisms underlying facial cold hyperalgesia, nocifensive behaviors to cold stimulation, the expression of TRPV1 and TRPA1 in trigeminal ganglion (TG) neurons, and TG neuronal excitability to cold stimulation following facial capsaicin injection were examined in rats. The head-withdrawal reflex threshold (HWRT) to cold stimulation of the lateral facial skin was significantly decreased following facial capsaicin injection. This reduction of HWRT was significantly recovered following local injection of TRPV1 antagonist as well as TRPA1 antagonist. Approximately 30% of TG neurons innervating the lateral facial skin expressed both TRPV1 and TRPA1, and about 64% of TRPA1-positive neurons also expressed TRPV1. The TG neuronal excitability to noxious cold stimulation was significantly increased following facial capsaicin injection and this increase was recovered by pretreatment with TRPA1 antagonist. These findings suggest that TRPA1 sensitization via TRPV1 signaling in TG neurons is involved in cold hyperalgesia following facial skin capsaicin injection. © 2014 Eur J Oral Sci.

Role of Active Listening and Listening Effort on Contralateral Suppression of Transient Evoked Otoacousic Emissions.

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Kalaiah, Mohan Kumar; Theruvan, Nikhitha B; Kumar, Kaushlendra; Bhat, Jayashree S

2017-04-01

The present study aimed to investigate the effect of active listening and listening effort on the contralateral suppression of transient evoked otoacoustic emissions (CSTEOAEs). Twenty eight young adults participated in the study. Transient evoked otoacoustic emissions (TEOAEs) were recorded using 'linear' clicks at 60 dB peSPL, in three contralateral noise conditions. In condition 1, TEOAEs were obtained in the presence of white noise in the contralateral ear. While, in condition 2, speech was embedded into white noise at +3, -3, and -9 dB signal-to-noise ratio (SNR) and delivered to the contralateral ear. The SNR was varied to investigate the effect of listening effort on the CSTEOAE. In condition 3, speech was played backwards and embedded into white noise at -3 dB SNR. The conditions 1 and 3 served as passive listening condition and the condition 2 served as active listening condition. In active listening condition, the participants categorized the words in to two groups (e.g., animal and vehicle). CSTEOAE was found to be largest in the presence of white noise, and the amount of CSTEOAE was not significantly different between active and passive listening conditions (condition 2 and 3). Listening effort had an effect on the CSTEOAE, the amount of suppression increased with listening effort, when SNR was decreased from +3 dB to -3 dB. However, when the SNR was further reduced to -9 dB, there was no further increase in the amount of CSTEOAE, instead there was a reduction in the amount of suppression. The findings of the present study show that listening effort might affect CSTEOAE.

In vitro evaluation of capsaicin inhibitory effects on zonula occludens toxin in vibrio cholerae ATCC14035 strain

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Soroor Erfanimanesh

2014-10-01

Conclusion: Capsaicin is one of the active compounds of red chili that can drastically suppress zot gene expression and shows promising inhibitory effect against V. cholerae zot production. Thus, routine intake of red chilli, which is easily available and inexpensive, may be an alternative approach to prevent and control symptoms of cholera.

The effects of Hot Pepper Extract and Capsaicin on Adipocyte Metabolism

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Ching Sheng, Chu

2008-03-01

Full Text Available Objectives : The purpose of this study is to investigate the effects of hot pepper extract and capsaicin on the adipogenesis in 3T3-L1 cells, lipolysis in rat epididymal adipocytes and histological changes in porcine adipose tissue. Methods : Inhibiton of preadipocyte differentiation and/or stimulation of lipolysis play important roles in reducing obesity. 3T3-L1 preadipocytes were differentiated with adipogenic reagents by incubating for 3 days in the absence or presence of hot pepper extract or capsaicin ranging from 0.01 to 1㎎/㎖. The effects of hot pepper extract and capsaicin on adipogenesis were examined by measuring GPDH activity and by Oil Red O staining. Mature adipocytes from rat epididymal fat pad was incubated with hot pepper extract or capsaicin ranging from 0.01 to 1㎎/㎖ for 3 hrs. The effects of hot pepper extract and capsaicin on lipolysis were examined by measuring free glycerol released. Fat tissue from pig skin was injected with hot pepper extract or capsaicinCFP ranging from 0.1 to 10㎎/㎖ to examine the effects of hot pepper extract and capsaicin on histological changes under light microscopy. Results : The following results were obtained from present study on adipogenesis of preadipocytes, lipolysis of adipocytes and histological changes in fat tissue. 1. Hot pepper extract and capsaicin inhibited adipogenic differentiation at the concentration of 0.1 and 0.01㎎/㎖, respectively, indicating that capsaicin was more effective in inhibiting adipogenesis than hot pepper extract. 2. Hot pepper extract and capsaicin decreased the activity of glycerol-3-phosphate dehydrogenase(GPDH at the concentration of 0.1 and 0.01㎎/㎖, respectively, indicating that capsaicin was more effective in inhibiting adipogenic differentiation than hot pepper extract. 3. Hot pepper extract and capsaicin increased glycerol release at the concentration of 0.1㎎/㎖. There was no difference in lipolytic activity between hot pepper extract and

Dietary Capsaicin Protects Cardiometabolic Organs from Dysfunction

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Fang Sun

2016-04-01

Full Text Available Chili peppers have a long history of use for flavoring, coloring, and preserving food, as well as for medical purposes. The increased use of chili peppers in food is very popular worldwide. Capsaicin is the major pungent bioactivator in chili peppers. The beneficial effects of capsaicin on cardiovascular function and metabolic regulation have been validated in experimental and population studies. The receptor for capsaicin is called the transient receptor potential vanilloid subtype 1 (TRPV1. TRPV1 is ubiquitously distributed in the brain, sensory nerves, dorsal root ganglia, bladder, gut, and blood vessels. Activation of TRPV1 leads to increased intracellular calcium signaling and, subsequently, various physiological effects. TRPV1 is well known for its prominent roles in inflammation, oxidation stress, and pain sensation. Recently, TRPV1 was found to play critical roles in cardiovascular function and metabolic homeostasis. Experimental studies demonstrated that activation of TRPV1 by capsaicin could ameliorate obesity, diabetes, and hypertension. Additionally, TRPV1 activation preserved the function of cardiometabolic organs. Furthermore, population studies also confirmed the beneficial effects of capsaicin on human health. The habitual consumption of spicy foods was inversely associated with both total and certain causes of specific mortality after adjustment for other known or potential risk factors. The enjoyment of spicy flavors in food was associated with a lower prevalence of obesity, type 2 diabetes, and cardiovascular diseases. These results suggest that capsaicin and TRPV1 may be potential targets for the management of cardiometabolic vascular diseases and their related target organs dysfunction.

Effects of capsaicin in the motor nerve.

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Pettorossi, V E; Bortolami, R; Della Torre, G; Brunetti, O

1994-08-01

The injection of capsaicin into the lateral gastrocnemius (LG) muscle of the rat induced an immediate and sustained reduction in the A delta and C components of the compound action potential (CAP) of the LG motor nerve. Conversely, the drug did not immediately affect the CAP wave belonging to fast-conducting fibers or the motor responses to LG nerve stimulation. It seems that capsaicin only affects the group III and IV afferents of LG nerve. However, a week after the injection the capsaicin also altered the motor responses, as shown by the threshold enhancement and amplitude reduction of the muscle twitch and by the decrease of the A alpha-beta CAP components. This late motor impairment was attributed to a central depression following a reduction of capsaicin-sensitive neuron input into the CNS. However, this motor effect was transient since the LG nerve regained the preinjection excitability level in a week and the muscle twitch amplitude reached the control value in a month.

Capsaicin Inhibits Multiple Bladder Cancer Cell Phenotypes by Inhibiting Tumor-Associated NADH Oxidase (tNOX and Sirtuin1 (SIRT1

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Ming-Hung Lin

2016-06-01

Full Text Available Bladder cancer is one of the most frequent cancers among males, and its poor survival rate reflects problems with aggressiveness and chemo-resistance. Recent interest has focused on the use of chemopreventatives (nontoxic natural agents that may suppress cancer progression to induce targeted apoptosis for cancer therapy. Capsaicin, which has anti-cancer properties, is one such agent. It is known to preferentially inhibit a tumor-associated NADH oxidase (tNOX that is preferentially expressed in cancer/transformed cells. Here, we set out to elucidate the correlation between tNOX expression and the inhibitory effects of capsaicin in human bladder cancer cells. We showed that capsaicin downregulates tNOX expression and decreases bladder cancer cell growth by enhancing apoptosis. Moreover, capsaicin was found to reduce the expression levels of several proteins involved in cell cycle progression, in association with increases in the cell doubling time and enhanced cell cycle arrest. Capsaicin was also shown to inhibit the activation of ERK, thereby reducing the phosphorylation of paxillin and FAK, which leads to decreased cell migration. Finally, our results indicate that RNA interference-mediated tNOX depletion enhances spontaneous apoptosis, prolongs cell cycle progression, and reduces cell migration and the epithelial-mesenchymal transition. We also observed a downregulation of sirtuin 1 (SIRT1 in these tNOX-knockdown cells, a deacetylase that is important in multiple cellular functions. Taken together, our results indicate that capsaicin inhibits the growth of bladder cancer cells by inhibiting tNOX and SIRT1 and thereby reducing proliferation, attenuating migration, and prolonging cell cycle progression.

Acidification of rat TRPV1 alters the kinetics of capsaicin responses

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Faltynek Connie R

2005-09-01

Full Text Available Abstract TRPV1 (vanilloid receptor 1 receptors are activated by a variety of ligands such as capsaicin, as well as by acidic conditions and temperatures above 42°C. These activators can enhance the potency of one another, shifting the activation curve for TRPV1 to the left. In this study, for example, we observed an approximately 10-fold shift in the capsaicin EC50 (640 nM to 45 nM for rat TRPV1 receptors expressed in HEK-293 cells when the pH was lowered from 7.4 to 5.5. To investigate potential causes for this shift in capsaicin potency, the rates of current activation and deactivation of whole-cell currents were measured in individual cells exposed to treatments of pH 5.5, 1 μM capsaicin or in combination. Acidic pH was found to both increase the activation rate and decrease the deactivation rate of capsaicin-activated currents providing a possible mechanism for the enhanced potency of capsaicin under acidic conditions. Utilizing a paired-pulse protocol, acidic pH slowed the capsaicin deactivation rate and was readily reversible. Moreover, the effect could occur under modestly acidic conditions (pH 6.5 that did not directly activate TRPV1. When TRPV1 was maximally activated by capsaicin and acidic pH, the apparent affinity of the novel and selective capsaicin-site competitive TRPV1 antagonist, A-425619, was reduced ~35 fold. This shift was overcome by reducing the capsaicin concentration co-applied with acidic pH. Since inflammation is associated with tissue acidosis, these findings enhance understanding of TRPV1 receptor responses in inflammatory pain where tissue acidosis is prevalent.

Capsaicin induces cell cycle arrest and apoptosis in human KB cancer cells.

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Lin, Chia-Han; Lu, Wei-Cheng; Wang, Che-Wei; Chan, Ya-Chi; Chen, Mu-Kuan

2013-02-25

Capsaicin, a pungent phytochemical in a variety of red peppers of the genus Capsicum, has shown an anti-proliferative effect on various human cancer cell lines. In contrast, capsaicin has also been considered to promote the growth of cancer cells. Thus, the effects of capsaicin on various cell types need to be explored. The anti-proliferative effects of capsaicin on human KB cancer cells are still unknown. Therefore, we examined the viability, cell cycle progression, and factors associated with apoptosis in KB cells treated with capsaicin. The cell proliferation/viability and cytotoxicity of KB cells exposed to capsaicin were determined by a sulforhodamine B colorimetric assay and trypan blue exclusion. Apoptosis was detected by Hoechst staining and confirmed by western blot analysis of poly-(ADP-ribose) polymerase cleavage. Cell cycle distribution and changes of the mitochondrial membrane potential were analyzed by flow cytometry. Furthermore, the expression of caspase 3, 8 and 9 was evaluated by immunoblotting. We found that treatment of KB cells with capsaicin significantly reduced cell proliferation/viability and induced cell death in a dose-dependent manner compared with that in the untreated control. Cell cycle analysis indicated that exposure of KB cells to capsaicin resulted in cell cycle arrest at G2/M phase. Capsaicin-induced growth inhibition of KB cells appeared to be associated with induction of apoptosis. Moreover, capsaicin induced disruption of the mitochondrial membrane potential as well as activation of caspase 9, 3 and poly-(ADP-ribose) polymerase in KB cells. Our data demonstrate that capsaicin modulates cell cycle progression and induces apoptosis in human KB cancer cells through mitochondrial membrane permeabilization and caspase activation. These observations suggest an anti-cancer activity of capsaicin.

Effect of experimental diabetes on cholinergic, purinergic and peptidergic motor responses of the isolated rat bladder to electrical field stimulation or capsaicin.

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Benkó, Rita; Lázár, Zsófia; Pórszász, Róbert; Somogyi, George T; Barthó, Loránd

2003-09-30

An attempt has been made to pharmacologically isolate cholinergic, P(2) purinoceptor-mediated and peptidergic (capsaicin-sensitive, tachykinin-mediated) contraction of the guanethidine-treated rat bladder detrusor preparation, in vitro. The effect of experimental diabetes was assessed on these types of contraction. Responses were evoked by electrical field stimulation (single shocks or 1 Hz for 30 s or 10 Hz for 40 s). Single shocks and 1-Hz stimulation were applied in the presence of (a). atropine (1 microM) or (b). P(2) purinoceptor antagonists (50 microM pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid) [PPADS] plus 100 microM suramin. Long-term electrical field stimulation (10 Hz for 40 s) (c). was applied with both atropine and the P(2) purinoceptor antagonists present in the organ bath. The effects of capsaicin (d). and ATP (e). were also studied. Three groups of experimental animals were used: streptozotocin-treated (50 mg.kg(-1) i.p., 8 weeks before the experiment), parallel solvent-treated and untreated rats. (a). Responses to electrical field stimulation in the presence of atropine were reduced by half by PPADS plus suramin, but were resistant to capsaicin tachyphylaxis. They were enhanced in preparations taken from diabetic rats. (b). Contractions to electrical field stimulation in the presence of PPADS plus suramin were reduced by 2/3 by atropine, but were left unchanged by capsaicin or diabetes. (c). Contractions to long-term stimulation had a quick and a sustained phase. Especially the latter was inhibited by capsaicin tachypyhlaxis; it was also strongly reduced in preparations taken from diabetic rats. (d). Contractions to capsaicin (30 nM and 1 microM) were resistant to tetrodotoxin, strongly reduced by a combination of tachykinin NK(1) and NK(2) receptor antagonists, and slightly reduced in preparations from diabetic animals. Capsaicin (1 microM) had no acute inhibitory action on cholinergic or purinergic responses, nor did it cause relaxation

Supercritical CO2 as a reaction medium for synthesis of capsaicin analogues by lipase-catalyzed transacylation of capsaicin.

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Kobata, Kenji; Kobayashi, Mamiko; Kinpara, Sachiyo; Watanabe, Tatsuo

2003-09-01

Capsaicin analogues having different acyl moiety were synthesized by lipase-catalyzed transacylation of capsaicin with a corresponding acyl donor in supercritical CO2 as a reaction medium. Transacylation with methyl tetradecanoate using Novozym 435 as a catalyst gave vanillyl tetradecanamide in a 54% yield at 80 degrees C and 19 MPa over 72 h. Vanillyl (Z)-9-octadecenamide, olvanil, was synthesized from triolein in a 21% yield over 7 d.

In vitro and in vivo evaluation of capsaicin-loaded microemulsion for enhanced oral bioavailability.

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Zhu, Yuan; Zhang, Jiajia; Zheng, Qianfeng; Wang, Miaomiao; Deng, Wenwen; Li, Qiang; Firempong, Caleb Kesse; Wang, Shengli; Tong, Shanshan; Xu, Ximing; Yu, Jiangnan

2015-10-01

Capsaicin, as a food additive, has attracted worldwide concern owing to its pungency and multiple pharmacological effects. However, poor water solubility and low bioavailability have limited its application. This study aims to develop a capsaicin-loaded microemulsion to enhance the oral bioavailability of the anti-neuropathic-pain component, capsaicin, which is poorly water soluble. In this study, the microemulsion consisting of Cremophor EL, ethanol, medium-chain triglycerides (oil phase) and water (external phase) was prepared and characterized (particle size, morphology, stability and encapsulation efficiency). The gastric mucosa irritation test of formulated capsaicin was performed in rats to evaluate its oral feasibility, followed by the pharmacokinetic study in vivo. Under these conditions, the encapsulated capsaicin revealed a faster capsaicin release in vitro coupled with a greater absorption in vivo when compared to the free capsaicin. The oral bioavailability of the formulated capsaicin-loaded microemulsions was 2.64-fold faster than that of free capsaicin. No significant irritation was observed on the mucosa from the pathological section of capsaicin-loaded microemulsion treated stomach. These results indicate that the developed microemulsion represents a safe and orally effective carrier for poorly soluble substances. The formulation could be used for clinical trials and expand the application of capsaicin. © 2014 Society of Chemical Industry.

Harnessing the Therapeutic Potential of Capsaicin and Its Analogues in Pain and Other Diseases

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Shaherin Basith

2016-07-01

Full Text Available Capsaicin is the most predominant and naturally occurring alkamide found in Capsicum fruits. Since its discovery in the 19th century, the therapeutic roles of capsaicin have been well characterized. The potential applications of capsaicin range from food flavorings to therapeutics. Indeed, capsaicin and few of its analogues have featured in clinical research covered by more than a thousand patents. Previous records suggest pleiotropic pharmacological activities of capsaicin such as an analgesic, anti-obesity, anti-pruritic, anti-inflammatory, anti-apoptotic, anti-cancer, anti-oxidant, and neuro-protective functions. Moreover, emerging data indicate its clinical significance in treating vascular-related diseases, metabolic syndrome, and gastro-protective effects. The dearth of potent drugs for management of such disorders necessitates the urge for further research into the pharmacological aspects of capsaicin. This review summarizes the historical background, source, structure and analogues of capsaicin, and capsaicin-triggered TRPV1 signaling and desensitization processes. In particular, we will focus on the therapeutic roles of capsaicin and its analogues in both normal and pathophysiological conditions.

Effects of intra-fourth ventricle injection of crocin on capsaicin-induced orofacial pain in rats.

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Tamaddonfard, Esmaeal; Tamaddonfard, Sina; Pourbaba, Salar

2015-01-01

Crocin, a constituent of saffron and yellow gardenia, possesses anti-nociceptive effects. In the present study, we investigated the effects of intra-fourth ventricle injection of crocin in a rat model of orofacial pain. The contribution of opioid system was assessed using intra-fourth ventricle injection of naloxone, an opioid receptor antagonist. A guide cannula was implanted into the fourth ventricle of brain in anesthetized rats. Orofacial pain was induced by subcutaneous (s.c.) injection of capsaicin (1.5 µg/20 µl) into the right vibrissa pad. The time spent face rubbing/grooming was recorded for a period of 20 min. Locomotor activity was measured using an open-field test. Intra-fourth ventricle injection of crocin (10 and 40 µg/rat) and morphine (10 and 40 µg/rat) and their co-administration (2.5 and 10 µg/rat of each) suppressed capsaicin-induced orofacial pain. The analgesic effect induced by 10 µg/rat of morphine, but not crocin (10 µg/rat), was prevented by 20 µg/rat of naloxone pretreatment. The above-mentioned chemical compounds did not affect locomotor activity. The results of this study showed that the injection of crocin into the cerebral fourth ventricle attenuates capsaicin-induced orofacial pain in rats. The anti-nociceptive effect of crocin was not attributed to the central opioid receptors.

Effects of intra-fourth ventricle injection of crocin on capsaicin-induced orofacial pain in rats

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Esmaeal Tamaddonfard

2015-08-01

Full Text Available Objectives: Crocin, a constituent of saffron and yellow gardenia, possesses anti-nociceptive effects. In the present study, we investigated the effects of intra-fourth ventricle injection of crocin in a rat model of orofacial pain. The contribution of opioid system was assessed using intra-fourth ventricle injection of naloxone, an opioid receptor antagonist. Materials and Methods: A guide cannula was implanted into the fourth ventricle of brain in anesthetized rats. Orofacial pain was induced by subcutaneous (s.c. injection of capsaicin (1.5 µg/20 µl into the right vibrissa pad. The time spent face rubbing/grooming was recorded for a period of 20 min. Locomotor activity was measured using an open-field test. Results: Intra-fourth ventricle injection of crocin (10 and 40 µg/rat and morphine (10 and 40 µg/rat and their co-administration (2.5 and 10 µg/rat of each suppressed capsaicin-induced orofacial pain. The analgesic effect induced by 10 µg/rat of morphine, but not crocin (10 µg/rat, was prevented by 20 µg/rat of naloxone pretreatment. The above-mentioned chemical compounds did not affect locomotor activity. Conclusion: The results of this study showed that the injection of crocin into the cerebral fourth ventricle attenuates capsaicin-induced orofacial pain in rats. The anti-nociceptive effect of crocin was not attributed to the central opioid receptors.

Capsaicin-loaded nanolipoidal carriers for topical application: design, characterization, and in vitro/in vivo evaluation

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Wang XR

2017-05-01

Full Text Available Xia-Rong Wang,1 Si-Qian Gao,1 Xiao-Qian Niu,1 Long-Jian Li,2 Xiao-Ying Ying,1 Zhong-Jie Hu,2 Jian-Qing Gao1,3 1Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 2Zhejiang Provincial Corps Hospital of Chinese People’s Armed Police Forces, Jiaxing, Zhejiang, 3Jiangsu Engineering Research Center for New-Type External and Transdermal Preparations, Jiangsu, People’s Republic of China Abstract: Capsaicin has been used in clinical applications for the treatment of pain disorders and inflammatory diseases. Given the strong pungency and high oil/water partition coefficient of capsaicin, capsaicin-loaded nanolipoidal carriers (NLCs were designed to increase permeation and achieve the analgesic, anti-inflammatory effect with lower skin irritation. Capsaicin-loaded NLCs were prepared and later optimized by the Box–Behnken design. The physicochemical characterizations, morphology, and encapsulation of the capsaicin-loaded NLCs were subsequently confirmed. Capsaicin-loaded NLCs and capsaicin-loaded NLCs gel exhibited sustained release and no cytotoxicity properties. Also, they could significantly enhance the penetration amount, permeation flux, and skin retention amounts of capsaicin due to the application of NLCs. To study the topical permeation mechanism of capsaicin, 3,3'-dioctadecyloxacarbocyanine perchlorate (Dio was used as a fluorescent dye. Dio-loaded NLCs and Dio-loaded NLCs gel could effectively deliver Dio up to a skin depth of 260 and 210 µm, respectively, primarily through the appendage route on the basis of version skin sections compared with Dio solution, which only delivered Dio up to 150 µm. In vivo therapeutic experiments demonstrated that capsaicin-loaded NLCs and capsaicin-loaded NLCs gel could improve the pain threshold in a dose-dependent manner and inhibit inflammation, primarily by reducing the prostaglandin E2 levels in the tissue compared with capsaicin cream and capsaicin solution

Capsaicin: Friend or Foe in Skin Cancer and Other Related Malignancies?

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Georgescu, Simona-Roxana; Sârbu, Maria-Isabela; Matei, Clara; Ilie, Mihaela Adriana; Caruntu, Constantin; Constantin, Carolina; Neagu, Monica; Tampa, Mircea

2017-12-16

Capsaicin is the main pungent in chili peppers, one of the most commonly used spices in the world; its analgesic and anti-inflammatory properties have been proven in various cultures for centuries. It is a lipophilic substance belonging to the class of vanilloids and an agonist of the transient receptor potential vanilloid 1 receptor. Taking into consideration the complex neuro-immune impact of capsaicin and the potential link between inflammation and carcinogenesis, the effect of capsaicin on muco-cutaneous cancer has aroused a growing interest. The aim of this review is to look over the most recent data regarding the connection between capsaicin and muco-cutaneous cancers, with emphasis on melanoma and muco-cutaneous squamous cell carcinoma.

Structural mechanism underlying capsaicin binding and activation of TRPV1 ion channel

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Cheng, Wei; Yang, Wei; Yu, Peilin; Song, Zhenzhen; Yarov-Yarovoy, Vladimir; Zheng, Jie

2015-01-01

Capsaicin bestows spiciness by activating TRPV1 channel with exquisite potency and selectivity. Capsaicin-bound channel structure was previously resolved by cryo-EM at 4.2-to-4.5 Å resolution, however important details required for mechanistic understandings are unavailable: capsaicin was registered as a small electron density, reflecting neither its chemical structure nor specific ligand-channel interactions. We obtained the missing atomic-level details by iterative computation, which were confirmed by systematic site-specific functional tests. We observed that the bound capsaicin takes “tail-up, head-down” configurations. The vanillyl and amide groups form specific interactions to anchor its bound position, while the aliphatic tail may sample a range of conformations, making it invisible in cryo-EM images. Capsaicin stabilizes the open state by “pull-and-contact” interactions between the vanillyl group and the S4-S5 linker. Our study provided a structural mechanism for the agonistic function of capsaicin and its analogs, and demonstrated an effective approach to obtain atomic level information from cryo-EM structures. PMID:26053297

Capsaicin and Dihydrocapsaicin Determination in Chili Pepper Genotypes Using Ultra-Fast Liquid Chromatography

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Magaji G. Usman

2014-05-01

Full Text Available Research was carried out to estimate the levels of capsaicin and dihydrocapsaicin that may be found in some heat tolerant chili pepper genotypes and to determine the degree of pungency as well as percentage capsaicin content of each of the analyzed peppers. A sensitive, precise, and specific ultra fast liquid chromatographic (UFLC system was used for the separation, identification and quantitation of the capsaicinoids and the extraction solvent was acetonitrile. The method validation parameters, including linearity, precision, accuracy and recovery, yielded good results. Thus, the limit of detection was 0.045 µg/kg and 0.151 µg/kg for capsaicin and dihydrocapsaicin, respectively, whereas the limit of quantitation was 0.11 µg/kg and 0.368 µg/kg for capsaicin and dihydrocapsaicin. The calibration graph was linear from 0.05 to 0.50 µg/g for UFLC analysis. The inter- and intra-day precisions (relative standard deviation were <5.0% for capsaicin and <9.9% for dihydrocapsaicin while the average recoveries obtained were quantitative (89.4%–90.1% for capsaicin, 92.4%–95.2% for dihydrocapsaicin, indicating good accuracy of the UFLC method. AVPP0705, AVPP0506, AVPP0104, AVPP0002, C05573 and AVPP0805 showed the highest concentration of capsaicin (12,776, 5,828, 4,393, 4,760, 3,764 and 4,120 µg/kg and the highest pungency level, whereas AVPP9703, AVPP0512, AVPP0307, AVPP0803 and AVPP0102 recorded no detection of capsaicin and hence were non-pungent. All chili peppers studied except AVPP9703, AVPP0512, AVPP0307, AVPP0803 and AVPP0102 could serve as potential sources of capsaicin. On the other hand, only genotypes AVPP0506, AVPP0104, AVPP0002, C05573 and AVPP0805 gave a % capsaicin content that falls within the pungency limit that could make them recommendable as potential sources of capsaicin for the pharmaceutical industry.

Vascular and Psychophysical Effects of Topical Capsaicin Application to Orofacial Tissues

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Boudreau, Shellie A.; Wang, Kelun; Svensson, Peter; Sessle, Barry J.; Arendt-Nielsen, Lars

2011-01-01

Aims To characterize and contrast human sensory and vascular changes produced by topical application of the algesic chemical capsaicin to the glabrous lips and tongue. Methods Applications of 1% capsaicin or vehicle cream to the glabrous lips and tongue were randomized between two two-trial sessions. The capsaicin trial followed the vehicle trial for each session. Before and 5, 15, and 30 minutes after capsaicin or vehicle cream application, six parameters were recorded from the glabrous lips or the tongue dorsum: (1) burning pain intensity, as measured on a visual analog scale; (2) burning pain area, as indicated by subjects on an orofacial drawing; (3) mechanical sensitivity, as measured by a von Frey filament; (4) visual flare; (5) blood flow and temperature, as measured by laser-Doppler imaging and thermography, respectively; and (6) areas of increased temperature (hot spots), as calculated by a digital tracer from the thermographs. Data were analyzed by ANOVAs and Pearson’s correlations. Results Compared to vehicle application, capsaicin elicited burning pain, increases in blood flow and temperature, but no change in mechanical sensitivity in the glabrous lips or tongue. Greater increases in blood flow and temperature paralleled more intense burning pain and larger areas of perceived pain for the lips compared to the tongue. The location of distinct areas of increased temperature within the orofacial area differed between the capsaicin-lip and capsaicin-tongue trials. Conclusion The several differences between these responses to noxious stimulation of the glabrous lips and tongue may have implications for examinations of orofacial somatosensory functions. PMID:19639105

Capsaicin binds to prohibitin 2 and displaces it from the mitochondria to the nucleus

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Kuramori, Chikanori; Azuma, Motoki; Kume, Kanako; Kaneko, Yuki; Inoue, Atsushi; Yamaguchi, Yuki; Kabe, Yasuaki; Hosoya, Takamitsu; Kizaki, Masahiro; Suematsu, Makoto; Handa, Hiroshi

2009-01-01

Capsaicin is widely used as a food additive and as an analgesic agent. Besides its well-known role in nociception, which is mediated by vanilloid receptor 1 specifically expressed in dorsal root ganglion neurons, capsaicin has also been considered as a potential anticancer agent, as it inhibits cell proliferation and induces apoptosis in various types of cancer cells. Here we identified a new molecular target of capsaicin from human myeloid leukemia cells. We show that capsaicin binds to prohibitin (PHB) 2, which is normally localized to the inner mitochondrial membrane, and induces its translocation to the nucleus. PHB2 is implicated in the maintenance of mitochondrial morphology and the control of apoptosis. We also provide evidence suggesting that capsaicin causes apoptosis directly through the mitochondria and that PHB2 contributes to capsaicin-induced apoptosis at multiple levels. This work will serve as an important foundation for further understanding of anticancer activity of capsaicin.

Topical capsaicin for pain in osteoarthritis: A literature review.

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Guedes, Vânia; Castro, João Paulo; Brito, Iva

Osteoarthritis is the most common joint disorder worldwide. The predominant symptom, pain, is usually treated with acetaminophen or oral non-steroidal anti-inflammatory drugs, although they are associated with a significant risk of side effects. Topical capsaicin may represent an effective and safe alternative. The aim of this review is to examine the evidence for the efficacy and safety profile of topical capsaicin in the management of pain caused by osteoarthritis. Databases were searched for articles published between 2004 and 2016, in Portuguese, English or Spanish, using the search terms "capsaicin" and "osteoarthritis". When compared to placebo, it was found that topical capsaicin has a good safety profile and efficacy in reducing osteoarthritis pain of the hand, knee, hip or shoulder. However, the studies have significant limitations, the most important the difficulty of blinding. It is attributed to this review the strength of recommendation B. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

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Huckleberry, Kylie A.; Kane, Gary A.; Mathis, Rita J.; Cook, Sarah G.; Clutton, Jonathan E.; Drew, Michael R.

2015-01-01

Thousands of neurons are born each day in the dentate gyrus (DG), but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in the DG. The immediate-early gene (IEG) zif268 appears to be an important mediator of these effects, as its expression can be induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Richardson et al., 1992; Veyrac et al., 2013). Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs). We first quantified zif268 expression in doublecortin-positive (DCX+) immature neurons and in the general granule cell population after brief exposure to a novel environment (NE). In the general granule cell population, zif268 expression peaked 1 h after NE exposure and returned to baseline by 8 h post-exposure. However, in the DCX+ cells, zif268 expression was suppressed relative to home cage for at least 8 h post-exposure. We next asked whether suppression of zif268 in DCX+ immature cells occurs in other behavioral paradigms that recruit the hippocampus. Exposure to Morris water maze (MWM) training, an enriched environment, or a NE caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 expression among the general granule cell population. The same behavioral procedures activated zif268 expression in 6-week-old BrdU-labeled adult-born neurons, indicating that zif268 suppression is specific to immature neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. NE exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly

Capsaicin: Friend or Foe in Skin Cancer and Other Related Malignancies?

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Simona-Roxana Georgescu

2017-12-01

Full Text Available Capsaicin is the main pungent in chili peppers, one of the most commonly used spices in the world; its analgesic and anti-inflammatory properties have been proven in various cultures for centuries. It is a lipophilic substance belonging to the class of vanilloids and an agonist of the transient receptor potential vanilloid 1 receptor. Taking into consideration the complex neuro-immune impact of capsaicin and the potential link between inflammation and carcinogenesis, the effect of capsaicin on muco-cutaneous cancer has aroused a growing interest. The aim of this review is to look over the most recent data regarding the connection between capsaicin and muco-cutaneous cancers, with emphasis on melanoma and muco-cutaneous squamous cell carcinoma.

Capsaicin-induced neurogenic inflammation in pig skin: A behavioural study

DEFF Research Database (Denmark)

di Giminiani, Pierpaolo; Petersen, Lars Jelstrup; Herskin, Mette S

2014-01-01

Topical capsaicin is a well-established model of experimental hyperalgesia. Its application to the study of animals has been limited to few species. The effect of topical capsaicin on hyperalgesia in porcine skin was evaluated as part of a study of inflammatory pain in the pig. Two experiments were...... carried out on pigs of 27 ± 5 kg (n = 8) and 57 ± 3 kg (n = 16). Thermal and mechanical noxious stimuli were provided (CO2 laser and Pressure Application Measurement device) to assess avoidance behaviours. Capsaicin induced significant thermal hyperalgesia in the smaller pigs (P

Intravesical Capsaicin in Patients with Detrusor Hyper-reflexia. A Placebo-controlled Cross-over Study

DEFF Research Database (Denmark)

Petersen, T; Nielsen, J B; Schrøder, H D

1999-01-01

to anticholinergic treatment underwent intravesical administration of 50 ml 2% lignocaine. followed by either 100 ml 1 mmol/l capsaicin or 100 ml physiological saline for 30 min. Cross-over to the alternative treatment took place after 4 weeks. Varying degrees of burning sensation were experienced by all but one...... patient during the capsaicin treatment and precluded the possibility of conducting studies of this type in a blind manner. No preference for capsaicin treatment was found, and micturition and VAS scores were unchanged after treatment with capsaicin. The mean volume of the contents of the bladder at which...... DH first appeared was 175 ml after saline and 195 ml after capsaicin (mean difference 20 ml with a 5% confidence interval from -25 to 65). Bladder biopsies taken 2 weeks after treatment with capsaicin showed more pronounced inflammation, superficial haemorrhage, squamous epithelial metaplasia...

Behavioral performance follows the time course of neural facilitation and suppression during cued shifts of feature-selective attention.

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Andersen, S K; Müller, M M

2010-08-03

A central question in the field of attention is whether visual processing is a strictly limited resource, which must be allocated by selective attention. If this were the case, attentional enhancement of one stimulus should invariably lead to suppression of unattended distracter stimuli. Here we examine voluntary cued shifts of feature-selective attention to either one of two superimposed red or blue random dot kinematograms (RDKs) to test whether such a reciprocal relationship between enhancement of an attended and suppression of an unattended stimulus can be observed. The steady-state visual evoked potential (SSVEP), an oscillatory brain response elicited by the flickering RDKs, was measured in human EEG. Supporting limited resources, we observed both an enhancement of the attended and a suppression of the unattended RDK, but this observed reciprocity did not occur concurrently: enhancement of the attended RDK started at 220 ms after cue onset and preceded suppression of the unattended RDK by about 130 ms. Furthermore, we found that behavior was significantly correlated with the SSVEP time course of a measure of selectivity (attended minus unattended) but not with a measure of total activity (attended plus unattended). The significant deviations from a temporally synchronized reciprocity between enhancement and suppression suggest that the enhancement of the attended stimulus may cause the suppression of the unattended stimulus in the present experiment.

Structural mechanism underlying capsaicin binding and activation of TRPV1 ion channel

OpenAIRE

Yang, Fan; Xiao, Xian; Cheng, Wei; Yang, Wei; Yu, Peilin; Song, Zhenzhen; Yarov-Yarovoy, Vladimir; Zheng, Jie

2015-01-01

Capsaicin bestows spiciness by activating TRPV1 channel with exquisite potency and selectivity. Capsaicin-bound channel structure was previously resolved by cryo-EM at 4.2-to-4.5 ? resolution, however important details required for mechanistic understandings are unavailable: capsaicin was registered as a small electron density, reflecting neither its chemical structure nor specific ligand-channel interactions. We obtained the missing atomic-level details by iterative computation, which were c...

Behavioral experience induces zif268 expression in mature granule cells but suppresses its expression in immature granule cells

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Kylie A. Huckleberry

2015-08-01

Full Text Available Thousands of neurons are born each day in the dentate gyrus (DG, but many of these cells die before reaching maturity. Both death and survival of adult-born neurons are regulated by neuronal activity in DG. The immediate-early gene (IEG zif268 is an important mediator of these effects, as its expression is induced by neural activity and knockout of zif268 impairs survival of adult-born neurons (Veyrac et al., 2013. Despite the apparent importance of zif268 for adult neurogenesis, its behavior-induced expression has not been fully characterized in adult-born neurons. Here we characterize behavior-evoked expression of zif268 in mature and newborn dentate granule cells (DGCs. In the general granule cell population, zif268 expression peaked 1 hour after novel environment exposure and returned to baseline by 8 hours post-exposure. However, in the doublecortin-positive (DCX+ immature neurons, zif268 expression was suppressed relative to home cage for at least 8 hours post-exposure. We next determined that exposure to water maze training, an enriched environment, or a novel environment caused approximately equal suppression of zif268 expression in DCX+ cells and approximately equal activation of zif268 in the general DGC population and in 6-week-old adult-born neurons. Finally, we asked whether zif268 suppression varied as a function of age within the DCX+ population, which ranges in age from 0 to approximately 4 weeks. Novel environment exposure had no significant effect on zif268 expression in 2- or 4-week-old BrdU-labeled neurons, but it significantly suppressed zif268 expression in 3-week-old neurons. In summary, behavioral experience transiently activated expression of zif268 in mature DGCs but caused a more long-lasting suppression of zif268 expression in immature, adult-born DGCs. We hypothesize that zif268 suppression inhibits memory-related synaptic plasticity in immature DGCs or mediates learning-induced apoptosis of immature adult

Capsaicin Suppresses Cell Proliferation, Induces Cell Cycle Arrest and ROS Production in Bladder Cancer Cells through FOXO3a-Mediated Pathways

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Kaiyu Qian

2016-10-01

Full Text Available Capsaicin (CAP, a highly selective agonist for transient receptor potential vanilloid type 1 (TRPV1, has been widely reported to exhibit anti-oxidant, anti-inflammation and anticancer activities. Currently, several therapeutic approaches for bladder cancer (BCa are available, but accompanied by unfavorable outcomes. Previous studies reported a potential clinical effect of CAP to prevent BCa tumorigenesis. However, its underlying molecular mechanism still remains unknown. Our transcriptome analysis suggested a close link among calcium signaling pathway, cell cycle regulation, ROS metabolism and FOXO signaling pathway in BCa. In this study, several experiments were performed to investigate the effects of CAP on BCa cells (5637 and T24 and NOD/SCID mice. Our results showed that CAP could suppress BCa tumorigenesis by inhibiting its proliferation both in vitro and in vivo. Moreover, CAP induced cell cycle arrest at G0/G1 phase and ROS production. Importantly, our studies revealed a strong increase of FOXO3a after treatment with CAP. Furthermore, we observed no significant alteration of apoptosis by CAP, whereas Catalase and SOD2 were considerably upregulated, which could clear ROS and protect against cell death. Thus, our results suggested that CAP could inhibit viability and tumorigenesis of BCa possibly via FOXO3a-mediated pathways.

Trigeminal ganglion neurons of mice show intracellular chloride accumulation and chloride-dependent amplification of capsaicin-induced responses.

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Nicole Schöbel

Full Text Available Intracellular Cl(- concentrations ([Cl(-](i of sensory neurons regulate signal transmission and signal amplification. In dorsal root ganglion (DRG and olfactory sensory neurons (OSNs, Cl(- is accumulated by the Na(+-K(+-2Cl(- cotransporter 1 (NKCC1, resulting in a [Cl(-](i above electrochemical equilibrium and a depolarizing Cl(- efflux upon Cl(- channel opening. Here, we investigate the [Cl(-](i and function of Cl(- in primary sensory neurons of trigeminal ganglia (TG of wild type (WT and NKCC1(-/- mice using pharmacological and imaging approaches, patch-clamping, as well as behavioral testing. The [Cl(-](i of WT TG neurons indicated active NKCC1-dependent Cl(- accumulation. Gamma-aminobutyric acid (GABA(A receptor activation induced a reduction of [Cl(-](i as well as Ca(2+ transients in a corresponding fraction of TG neurons. Ca(2+ transients were sensitive to inhibition of NKCC1 and voltage-gated Ca(2+ channels (VGCCs. Ca(2+ responses induced by capsaicin, a prototypical stimulus of transient receptor potential vanilloid subfamily member-1 (TRPV1 were diminished in NKCC1(-/- TG neurons, but elevated under conditions of a lowered [Cl(-](o suggesting a Cl(--dependent amplification of capsaicin-induced responses. Using next generation sequencing (NGS, we found expression of different Ca(2+-activated Cl(- channels (CaCCs in TGs of mice. Pharmacological inhibition of CaCCs reduced the amplitude of capsaicin-induced responses of TG neurons in Ca(2+ imaging and electrophysiological recordings. In a behavioral paradigm, NKCC1(-/- mice showed less avoidance of the aversive stimulus capsaicin. In summary, our results strongly argue for a Ca(2+-activated Cl(--dependent signal amplification mechanism in TG neurons that requires intracellular Cl(- accumulation by NKCC1 and the activation of CaCCs.

The capsaicin cough reflex in eczema patients with respiratory symptoms elicited by perfume.

Science.gov (United States)

Elberling, Jesper; Dirksen, Asger; Johansen, Jeanne Duus; Mosbech, Holger

2006-03-01

Respiratory symptoms elicited by perfume are common in the population but have unclear pathophysiology. Increased capsaicin cough responsiveness has been associated with the symptoms, but it is unknown whether the site of the symptoms in the airways influences this association. The aim of this study was to investigate the association between the site of airway symptoms elicited by perfume and cough responsiveness to bronchial challenge with capsaicin. 21 eczema patients with respiratory symptoms elicited by perfume were compared with 21 healthy volunteers in a sex- and age-matched case control study. The participants completed a symptom questionnaire and underwent a bronchial challenge with capsaicin. Lower, but not upper, respiratory symptoms elicited by perfume were associated with increased capsaicin cough responsiveness. Having severe symptoms to perfume (n=11) did not relate to the site of the symptoms in the airways and was not associated with increased capsaicin cough responsiveness. In conclusion, respiratory symptoms elicited by perfume may reflect local hyperreactivity related to defensive reflexes in the airways, and measurements of the capsaicin cough reflex are relevant when patients with lower respiratory symptoms related to environmental perfume exposures are investigated.

Hot Chili Peppers: Extraction, Cleanup, and Measurement of Capsaicin

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Huang, Jiping; Mabury, Scott A.; Sagebiel, John C.

2000-12-01

Capsaicin, the pungent ingredient of the red pepper or Capsicum annuum, is widely used in food preparation. The purpose of this experiment was to acquaint students with the active ingredients of hot chili pepper (capsaicin and dihydrocapsaicin), the extraction, cleanup, and analysis of these chemicals, as a fun and informative analytical exercise. Fresh peppers were prepared and extracted with acetonitrile, removing plant co-extractives by addition to a C-18 solid-phase extraction cartridge. Elution of the capsaicinoids was accomplished with a methanol-acetic acid solution. Analysis was completed by reverse-phase HPLC with diode-array or variable wavelength detection and calibration with external standards. Levels of capsaicin and dihydrocapsaicin were typically found to correlate with literature values for a specific hot pepper variety. Students particularly enjoyed relating concentrations of capsaicinoids to their perceived valuation of "hotness".

Gender differences in pain and secondary hyperalgesia after heat/capsaicin sensitization in healthy volunteers

DEFF Research Database (Denmark)

Jensen, Magnus Thorsten; Petersen, Karin Lottrup

2006-01-01

differences in development of secondary hyperalgesia. Cutaneous hyperalgesia was induced with the heat/capsaicin sensitization model. Outcome measures were areas of secondary hyperalgesia to brush and von Frey hair stimulation after heat and capsaicin sensitization, rating of pain during heat....../capsaicin sensitization, and heat pain detection thresholds. There was a trend toward smaller areas of secondary hyperalgesia in women. After adjusting for estimated gender differences in forearm surface area, areas to brush but not von Frey hair stimulation after capsaicin sensitization were larger in women. Peak pain......, but not total pain, during prolonged noxious thermal stimulation was higher in women. There was no gender difference in pain ratings during capsaicin sensitization or in heat pain detection thresholds. The results provided only limited support to the hypothesis that gender differences in clinical pain syndromes...

A study on the comparison of antioxidant effects between hot pepper extract and capsaicin

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Hyeon Min Gang

2008-03-01

Full Text Available Objective : The objective of this study was to compare the antioxidant effects of hot pepper extract and capsaicin. Methods : In vitro, antioxidant activities were examined by DPPH radical scavenging activity, total antioxidant capacity(TAC, oxygen radical scavenging capacity(ORAC, inhibition of induced lipid peroxidation using liver mitochonria and total phenolic contents. Results : 1. DPPH free radical scavenging actiivities at the concentrations of both 1 and 10㎎/㎖ were 1.2 to 1.9 times higher in capsaicin than in hot pepper extract. The concentration of capsaicin required for 50% radical scavenging was lower than that of hot pepper extract(3.9 vs 5.9㎎/㎖, indicating that capsaicin had higher DPPH radical scavenging activity than hot pepper extract. 2. Total antioxidant capacities of capsaicin at the concentrations of 0.1 and 1mg/ml(13.8 and 41.3 nmol Trolox equivalent were not significantly different from those at the concentrations of 1 and 10㎎/㎖(11.4 and 41.2nmol Trolox equivalent, indicating that capsaicin showed 10 times higher ABTS radical scavenging activity compared to hot pepper extract. 3. ORAC of capsaicin at the concentrations of 1, 5, 10 and 100 mg/ml were 0.04, 0.17, 0.29 and 1.74nmol gallic acid equivalent, respectively. On the other hand, ORAC of hot pepper extract at the concentrations of 1, 5, 10 and 100㎍/㎖ were 0.15, 0.44, 0.75 and 2.49nmol gallic acid equivalent, respectively, indicating that capsaicin showed higher peroxyl radical scavenging activity than hot pepper extract. 4. Inhibition of lipid peroxidation caused by hot pepper extract at the concentrations of 1 and 10mg/㎖ were 12.2 and 61.4%, respectively. Inhibition of lipid peroxidation caused by capsaicin at the concentrations of 1 and 10㎎/㎖l were 64.0 and 96.8%, respectively. Thus capsaicin showed 10 times stronger effect in inhibiton of lipid peroxidation than hot pepper extract. 5. Total phenolic contents of hot pepper extract at the

Involvement of Endoplasmic Reticulum Stress in Capsaicin-Induced Apoptosis of Human Pancreatic Cancer Cells

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Shengzhang Lin

2013-01-01

Full Text Available Capsaicin, main pungent ingredient of hot chilli peppers, has been shown to have anticarcinogenic effect on various cancer cells through multiple mechanisms. In this study, we investigated the apoptotic effect of capsaicin on human pancreatic cancer cells in both in vitro and in vivo systems, as well as the possible mechanisms involved. In vitro, treatment of both the pancreatic cancer cells (PANC-1 and SW1990 with capsaicin resulted in cells growth inhibition, G0/G1 phase arrest, and apoptosis in a dose-dependent manner. Knockdown of growth arrest- and DNA damage-inducible gene 153 (GADD153, a marker of the endoplasmic-reticulum-stress- (ERS- mediated apoptosis pathway, by specific siRNA attenuated capsaicin-induced apoptosis both in PANC-1 and SW1990 cells. Moreover, in vivo studies capsaicin effectively inhibited the growth and metabolism of pancreatic cancer and prolonged the survival time of pancreatic cancer xenograft tumor-induced mice. Furthermore, capsaicin increased the expression of some key ERS markers, including glucose-regulated protein 78 (GRP78, phosphoprotein kinase-like endoplasmic reticulum kinase (phosphoPERK, and phosphoeukaryotic initiation factor-2α (phospho-eIF2α, activating transcription factor 4 (ATF4 and GADD153 in tumor tissues. In conclusion, we for the first time provide important evidence to support the involvement of ERS in the induction of apoptosis in pancreatic cancer cells by capsaicin.

Thermal conditions influence changes in body temperature induced by intragastric administration of capsaicin in mice.

Science.gov (United States)

Mori, Noriyuki; Urata, Tomomi; Fukuwatari, Tsutomu

2016-08-01

Capsaicin has been reported to have unique thermoregulatory actions. However, changes in core temperature after the administration of capsaicin are a controversial point. Therefore, we investigated the effects of environmental thermal conditions on changes in body temperature caused by capsaicin in mice. We showed that intragastric administration of 10 and 15 mg/kg capsaicin increased tail temperature and decreased colonic temperatures in the core temperature (CT)-constant and CT-decreasing conditions. In the CT-increasing condition, 15 mg/kg capsaicin increased tail temperature and decreased colonic temperature. However, 10 mg/kg capsaicin increased colonic temperature. Furthermore, the amount of increase in tail temperature was greater in the CT-decreasing condition and lower in the CT-increasing condition, compared with that of the CT-constant condition. These findings suggest that the changes in core temperature were affected by the environmental thermal conditions and that preliminary thermoregulation state might be more important than the constancy of temperature to evaluate the effects of heat diffusion and thermogensis.

Electrochemical impedance spectroscopy versus cyclic voltammetry for the electroanalytical sensing of capsaicin utilising screen printed carbon nanotube electrodes.

Science.gov (United States)

Randviir, Edward P; Metters, Jonathan P; Stainton, John; Banks, Craig E

2013-05-21

Screen printed carbon nanotube electrodes (SPEs) are explored as electroanalytical sensing platforms for the detection of capsaicin in both synthetic capsaicin solutions and capsaicin extracted from chillies and chilli sauces utilising both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It is found that the technique which is most applicable to the electroanalytical detection of capsaicin depends upon the analyte concentration: for the case of low capsaicin concentrations, CV is a more appropriate method as capsaicin exhibits characteristic voltammetric waves of peak heights relevant to the capsaicin concentration; but for the case of high capsaicin concentrations where the voltammetric waves merge and migrate out of the potential window, EIS is shown to be a more appropriate technique, owing to the observed linear increases in R(ct) with increasing concentration. Furthermore, we explore different types of screen printed carbon nanotube electrodes, namely single- and multi- walled carbon nanotubes, finding that they are technique-specific: for the case of low capsaicin concentrations, single-walled carbon nanotube SPEs are preferable (SW-SPE); yet for the case of EIS at high capsaicin concentrations, multi-walled carbon nanotube SPEs (MW-SPE) are preferred, based upon analytical responses. The analytical performance of CV and EIS is applied to the sensing of capsaicin in grown chillies and chilli sauces and is critically compared to 'gold standard' HPLC analysis.

A modification of a previous model fo r inflammatory tooth pain: Effects of different capsaicin and formalin concentrations and ibuprofen

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Maryam Raoof DDS, MS

2012-09-01

Full Text Available BACKGROUND AND AIM:This study aimed to solve the problems faced with the previous model of inflammatory tooth painin rats.METHODS:After cutting 2 mm of the distal extremities, the polyethylene crownswere placed on the mandibularincisors. In contrast to the original model, we used flow composite instead of wire in order to maximize the retention ofcrowns. Different concentrations of capsaicin (10, 25 and 100 mg/ml and formalin were administrated into the cavitiesunder the crowns. The algesic agent-induced behaviors were evaluated.RESULTS:The modified model had no liquid leakage. Furthermore, composite allowed the crowns to remain for alonger period of time. Capsaicin 25, 100 mg/ml and formalin applications induced significantly more painfulstimulation compared with control groups (P < 0.001. These responses were significantly reduced by theadministration of ibuprofen, 20 minutes prior to the capsaicin 100 mg/ml injection.CONCLUSIONS:This model seems to be adequate for long-term pain related experiments in which fluid leakageelimination is important.

Combined Electrophysiological and Behavioral Evidence for the Suppression of Salient Distractors.

Science.gov (United States)

Gaspelin, Nicholas; Luck, Steven J

2018-05-15

Researchers have long debated how salient-but-irrelevant features guide visual attention. Pure stimulus-driven theories claim that salient stimuli automatically capture attention irrespective of goals, whereas pure goal-driven theories propose that an individual's attentional control settings determine whether salient stimuli capture attention. However, recent studies have suggested a hybrid model in which salient stimuli attract visual attention but can be actively suppressed by top-down attentional mechanisms. Support for this hybrid model has primarily come from ERP studies demonstrating that salient stimuli, which fail to capture attention, also elicit a distractor positivity (P D ) component, a putative neural index of suppression. Other support comes from a handful of behavioral studies showing that processing at the salient locations is inhibited compared with other locations. The current study was designed to link the behavioral and neural evidence by combining ERP recordings with an experimental paradigm that provides a behavioral measure of suppression. We found that, when a salient distractor item elicited the P D component, processing at the location of this distractor was suppressed below baseline levels. Furthermore, the magnitude of behavioral suppression and the magnitude of the P D component covaried across participants. These findings provide a crucial connection between the behavioral and neural measures of suppression, which opens the door to using the P D component to assess the timing and neural substrates of the behaviorally observed suppression.

Role played by acid-sensitive ion channels in evoking the exercise pressor reflex.

Science.gov (United States)

Hayes, Shawn G; McCord, Jennifer L; Rainier, Jon; Liu, Zhuqing; Kaufman, Marc P

2008-10-01

The exercise pressor reflex arises from contracting skeletal muscle and is believed to play a role in evoking the cardiovascular responses to static exercise, effects that include increases in arterial pressure and heart rate. This reflex is believed to be evoked by the metabolic and mechanical stimulation of thin fiber muscle afferents. Lactic acid is known to be an important metabolic stimulus evoking the reflex. Until recently, the only antagonist for acid-sensitive ion channels (ASICs), the receptors to lactic acid, was amiloride, a substance that is also a potent antagonist for both epithelial sodium channels as well as voltage-gated sodium channels. Recently, a second compound, A-317567, has been shown to be an effective and selective antagonist to ASICs in vitro. Consequently, we measured the pressor responses to the static contraction of the triceps surae muscles in decerebrate cats before and after a popliteal arterial injection of A-317567 (10 mM solution; 0.5 ml). We found that this ASIC antagonist significantly attenuated by half (Pacid injection into the popliteal artery. In contrast, A-317567 had no effect on the pressor responses to tendon stretch, a pure mechanical stimulus, and to a popliteal arterial injection of capsaicin, which stimulated transient receptor potential vanilloid type 1 channels. We conclude that ASICs on thin fiber muscle afferents play a substantial role in evoking the metabolic component of the exercise pressor reflex.

The capsaicin cough reflex in eczema patients with respiratory symptoms elicited by perfume

DEFF Research Database (Denmark)

Elberling, Jesper; Dirksen, Asger; Johansen, Jeanne Duus

2006-01-01

Respiratory symptoms elicited by perfume are common in the population but have unclear pathophysiology. Increased capsaicin cough responsiveness has been associated with the symptoms, but it is unknown whether the site of the symptoms in the airways influences this association. The aim of this st......Respiratory symptoms elicited by perfume are common in the population but have unclear pathophysiology. Increased capsaicin cough responsiveness has been associated with the symptoms, but it is unknown whether the site of the symptoms in the airways influences this association. The aim...... of this study was to investigate the association between the site of airway symptoms elicited by perfume and cough responsiveness to bronchial challenge with capsaicin. 21 eczema patients with respiratory symptoms elicited by perfume were compared with 21 healthy volunteers in a sex- and age-matched case...... control study. The participants completed a symptom questionnaire and underwent a bronchial challenge with capsaicin. Lower, but not upper, respiratory symptoms elicited by perfume were associated with increased capsaicin cough responsiveness. Having severe symptoms to perfume (n=11) did not relate...

Inhibition of somatosensory-evoked cortical responses by a weak leading stimulus.

Science.gov (United States)

Nakagawa, Kei; Inui, Koji; Yuge, Louis; Kakigi, Ryusuke

2014-11-01

We previously demonstrated that auditory-evoked cortical responses were suppressed by a weak leading stimulus in a manner similar to the prepulse inhibition (PPI) of startle reflexes. The purpose of the present study was to investigate whether a similar phenomenon was present in the somatosensory system, and also whether this suppression reflected an inhibitory process. We recorded somatosensory-evoked magnetic fields following stimulation of the median nerve and evaluated the extent by which they were suppressed by inserting leading stimuli at an intensity of 2.5-, 1.5-, 1.1-, or 0.9-fold the sensory threshold (ST) in healthy participants (Experiment 1). The results obtained demonstrated that activity in the secondary somatosensory cortex in the hemisphere contralateral to the stimulated side (cSII) was significantly suppressed by a weak leading stimulus with the intensity larger than 1.1-fold ST. This result implied that the somatosensory system had an inhibitory process similar to that of PPI. We then presented two successive leading stimuli before the test stimulus, and compared the extent of suppression between the test stimulus-evoked responses and those obtained with the second prepulse alone and with two prepulses (first and second) (Experiment 2). When two prepulses were preceded, cSII responses to the second prepulse were suppressed by the first prepulse, whereas the ability of the second prepulse to suppress the test stimulus remained unchanged. These results suggested the presence of at least two individual pathways; response-generating and inhibitory pathways. Copyright © 2014 Elsevier Inc. All rights reserved.

Dietary Capsaicin Improves Glucose Homeostasis and Alters the Gut Microbiota in Obese Diabetic ob/ob Mice

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Jun-Xian Song

2017-08-01

Full Text Available Background: The effects of capsaicin on obesity and glucose homeostasis are still controversial and the mechanisms underlying these effects remain largely unknown. This study aimed to investigate the potential relationship between the regulation of obesity and glucose homeostasis by dietary capsaicin and the alterations of gut microbiota in obese diabetic ob/ob mice.Methods: The ob/ob mice were subjected to a normal, low-capsaicin (0.01%, or high-capsaicin (0.02% diet for 6 weeks, respectively. Obesity phenotypes, glucose homeostasis, the gut microbiota structure and composition, short-chain fatty acids, gastrointestinal hormones, and pro-inflammatory cytokines were measured.Results: Both the low- and high-capsaicin diets failed to prevent the increase in body weight, adiposity index, and Lee's obesity index. However, dietary capsaicin at both the low and high doses significantly inhibited the increase of fasting blood glucose and insulin levels. These inhibitory effects were comparable between the two groups. Similarly, dietary capsaicin resulted in remarkable improvement in glucose and insulin tolerance. In addition, neither the low- nor high-capsaicin diet could alter the α-diversity and β-diversity of the gut microbiota. Taxonomy-based analysis showed that both the low- and high-capsaicin diets, acting in similar ways, significantly increased the Firmicutes/Bacteroidetes ratio at the phylum level as well as increased the Roseburia abundance and decreased the Bacteroides and Parabacteroides abundances at the genus level. Spearman's correlation analysis revealed that the Roseburia abundance was negatively while the Bacteroides and Parabacteroides abundances were positively correlated to the fasting blood glucose level and area under the curve by the oral glucose tolerance test. Finally, the low- and high-capsaicin diets significantly increased the fecal butyrate and plasma total GLP-1 levels, but decreased plasma total ghrelin, TNF-α, IL-1�

Synthesis of Capsaicin Glycosides and 8-Nordihydrocapsaicin Glycosides as Potential Weight-Loss Formulations

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Hisashi Katsuragi

2010-03-01

Full Text Available The enzymatic synthesis of capsaicin glycosides and 8-nordihydrocapsaicin glycosides was investigated using almond β-glucosidase and cyclodextrin glucanotransferase (CGTase. Capsaicin and 8-nordihydrocapsaicin were converted into their β-glucoside and β-maltooligosaccharide (amylose conjugate, i.e. β-maltoside and β-maltotrioside, by sequencial glycosylation with almond β-glucosidase and CGTase. The β-glucoside and β-maltoside of capsaicin and β-glucoside of 8-nordihydrocapsaicin showed inhibitory effects on high-fat-diet-induced elevations in body weight of mice.

Synthesis of Capsaicin Glycosides and 8-Nordihydrocapsaicin Glycosides as Potential Weight-Loss Formulations

Directory of Open Access Journals (Sweden)

Hisashi Katsuragi

2010-01-01

Full Text Available The enzymatic synthesis of capsaicin glycosides and 8-nordihydrocapsaicin glycosides was investigated using almond β-glucosidase and cyclodextrin glucanotransferase (CGTase. Capsaicin and 8-nordihydrocapsaicin were converted into their β-glucoside and β-maltooligosaccharide (amylose conjugate, i.e. β-maltoside and β-maltotrioside, by sequencial glycosylation with almond β-glucosidase and CGTase. The β-glucoside and β-maltoside of capsaicin and β-glucoside of 8-nordihydrocapsaicin showed inhibitory effects on high-fat-diet-induced elevations in body weight of mice.

Central projections and entries of capsaicin-sensitive muscle afferents.

Science.gov (United States)

Della Torre, G; Lucchi, M L; Brunetti, O; Pettorossi, V E; Clavenzani, P; Bortolami, R

1996-03-25

The entry pathway and central distribution of A delta and C muscle afferents within the central nervous system (CNS) were investigated by combining electron microscopy and electrophysiological analysis after intramuscular injection of capsaicin. The drug was injected into the rat lateral gastrocnemius (LG) and extraocular (EO) muscles. The compound action potentials of LG nerve and the evoked field potentials recorded in semilunar ganglion showed an immediate and permanent reduction in A delta and C components. The morphological data revealed degenerating unmyelinated axons and terminals in the inner sublamina II and in the border of laminae I-II of the dorsal horn at L4-L5 and C1-C2 (subnucleus caudalis trigemini) spinal cord segments. Most degenerating terminals were the central bouton (C) of type I and II synaptic glomeruli. Furthermore, degenerating peripheral axonal endings (V2) presynaptic to normal C were found. Since V2 were previously found degenerated after cutting the oculomotor nerve (ON) or L4 ventral root, we conclude that some A delta and C afferents from LG and EO muscles entering the CNS by ON or ventral roots make axoaxonic synapses on other primary afferents to promote an afferent control of sensory input.

Capsaicin, a novel inhibitor of the NorA efflux pump, reduces the intracellular invasion of Staphylococcus aureus.

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Kalia, Nitin Pal; Mahajan, Priya; Mehra, Rukmankesh; Nargotra, Amit; Sharma, Jai Parkash; Koul, Surrinder; Khan, Inshad Ali

2012-10-01

To delineate the role of capsaicin (8-methyl-N-vanillyl-6-nonenamide) as an inhibitor of the NorA efflux pump and its impact on invasion of macrophages by Staphylococcus aureus. Capsaicin in combination with ciprofloxacin was tested for activity against S. aureus SA-1199B (NorA overproducing), SA-1199 (wild-type) and SA-K1758 (norA knockout). The role of NorA in the intracellular invasion of S. aureus and the ability of capsaicin to inhibit this invasion was established in J774 macrophage cell lines. The three-dimensional structure of NorA was predicted using an in silico approach and docking studies of capsaicin were performed. Capsaicin significantly reduced the MIC of ciprofloxacin for S. aureus SA-1199 and SA-1199B. Furthermore, capsaicin also extended the post-antibiotic effect of ciprofloxacin by 1.1 h at MIC concentration. There was a decrease in mutation prevention concentration of ciprofloxacin when combined with capsaicin. Inhibition of ethidium bromide efflux by NorA-overproducing S. aureus SA-1199B confirmed the role of capsaicin as a NorA efflux pump inhibitor (EPI). The most significant finding of this study was the ability of capsaicin to reduce the intracellular invasion of S. aureus SA-1199B (NorA overproducing) in J774 macrophage cell lines by 2 log(10). This study, for the first time, has shown that capsaicin, a novel EPI, not only inhibits the NorA efflux pump of S. aureus but also reduces the invasiveness of S. aureus, thereby reducing its virulence.

Influence of repeated infusion of capsaicin-contained red pepper sauce on esophageal secondary peristalsis in humans.

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Liu, T T; Yi, C H; Lei, W Y; Hung, X S; Yu, H C; Chen, C L

2014-10-01

The transient receptor potential vanilloid 1 has been implicated as a target mediator for heartburn perception and modulation of esophageal secondary peristalsis. Our aim was to determine the effect of repeated esophageal infusion of capsaicin-contained red pepper sauce on heartburn perception and secondary peristalsis in healthy adults. Secondary peristalsis was performed with mid-esophageal injections of air in 15 healthy adults. Two separate protocols including esophageal infusion with saline and capsaicin-contained red pepper sauce and 2 consecutive sessions of capsaicin-contained red pepper sauce were randomly performed. After repeated infusion of capsaicin-contained red pepper sauce, the threshold volume to activate secondary peristalsis was significantly increased during slow (p sauce enhanced heartburn perception (p sauce infusion (p = 0.007). Acute infusion of capsaicin-contained red pepper sauce significantly increased pressure wave amplitudes of distal esophagus during slow (p = 0.003) and rapid air injections (p = 0.01), but repeated infusion of capsaicin-contained red pepper sauce significantly decreased pressure wave amplitude of distal esophagus during slow (p = 0.0005) and rapid air injections (p = 0.003). Repeated esophageal infusion of capsaicin appears to attenuate heartburn perception and inhibit distension-induced secondary peristalsis in healthy adults. These results suggest capsaicin-sensitive afferents in modulating sensorimotor function of secondary peristalsis in human esophagus. © 2014 John Wiley & Sons Ltd.

The effect of ACTH analogues on motor behavior and visual evoked responses in rats

NARCIS (Netherlands)

Wolthuis, O.L.; Wied, D. de

1976-01-01

Averaged visual evoked responses (VER) in cortical area 17 were recorded one hour after the administration of 7-l-phe ACTH(4-10) or 7-d-phe ACTH(4-10) to artificially ventilated rats, paralysed with gallamine. In addition, the effects of these peptides on spontaneous motor behavior were analyzed.

Estradiol suppresses ingestive response evoked by activation of 5-HT1A receptors in the lateral hypothalamus of ovariectomized rats.

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Taschetto, Ana P D; Levone, Brunno R; Kochenborger, Larissa; da Silva, Eduardo S; Flores, Rafael A; Faria, Moacir S; Paschoalini, Marta A

2018-03-08

The present study investigated the effects of estradiol (E2) on ingestive behavior after activation of 5-HT1A receptors in the lateral hypothalamus (LH) of female rats habituated to eat a wet mash diet. Ovariectomized rats treated with corn oil (OVX) or estradiol cypionate (OVX+E) received local injections into the LH of vehicle or an agonist of 5-HT1A receptors, 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT; at a dose of 6 nmol). To determine the involvement of these receptors in food intake, some animals were pretreated with N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) cyclohexane carboxamide maleate (WAY-100635, a 5-HT1A receptor full antagonist, at a dose of 0.37 nmol), followed by the injection of the agonist 8-OH-DPAT or its vehicle. The results showed that the injection of 8-OH-DPAT into the LH of OVX rats significantly increased food intake, and the duration and frequency of this behavior. The pretreatment with E2 suppressed the hyperphagic response induced by 8-OH-DPAT in OVX animals. The inhibition of 5-HT1A receptors after pretreatment with WAY-100635 blocked the hyperphagic effects evoked by 8-OH-DPAT in OVX. These results indicate that the activity of LH 5-HT1A receptors could be affected by blood E2 levels.

Antinociceptive interaction between benfotiamine and resveratrol in capsaicin-induced licking.

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Montiel-Ruiz, Rosa Mariana; Reyes-García, Gerardo; Flores-Murrieta, Francisco; Déciga-Campos, Myrna

2009-01-01

In an attempt to provide more direct evidence concerning the possible antinociceptive effect of resveratrol-benfotiamine combination on neurogenic pain, we investigated whether resveratrol and benfotiamine administered alone or in combination decrease capsaicin induced nociception in mice. Before testing, the animals were placed individually in transparent glass cylinders, 20 cm in diameter, serving as observation chambers. After the adaptation period, 20 microL of capsaicin (1.6 microg/paw) were injected under the skin of the dorsal of the right hind paw. Animals were observed individually for 5 min after capsaicin injection. The amount of time spent licking the injected paw was timed with a chronometer and was considered as indicative of nociception. Animals were pretreated with resveratrol (56.2-177 mg/kg, i.p.), benfotiamine (100-1000 mg/kg, p.o.) and their combinations (11:1, 22:2, 44:4; 88:8 mg/kg benfotiamine:resveratrol). It was observed that resveratrol (ED50 = 104 +/- 8.2 mg/kg) was able to produce more important decrement of capsaicin-induced licking than benfotiamine (ED50 = 529.4 +/- 85.2 mg/kg). In addition, a synergistic interaction was observed between benfotiamine and resveratrol, suggesting that this combination could be useful in neurogenic nociception.

Emotion suppression, emotional eating, and eating behavior among parent-adolescent dyads.

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Ferrer, Rebecca A; Green, Paige A; Oh, April Y; Hennessy, Erin; Dwyer, Laura A

2017-10-01

Emotion suppression may lead to ironic increases in emotional experience. More important, suppression is a transactional process, creating stress and disrupting interactions for the suppressor and those in social interactions with individuals who are suppressing emotion. However, no research has examined the behavioral consequences of emotion suppression in close relationships. We examine the possibility that emotion suppression will predict eating behaviors as a secondary emotion regulatory strategy among 1,556 parent-adolescent dyads (N = 3,112), consistent with evidence suggesting that suppression influences eating at the individual-level. Actor-partner interdependence models and structural equation modeling demonstrate that one's own emotion suppression was associated with emotional eating; greater consumption of hedonic-low nutrient, high energy dense-foods; and lower consumption of fruits and vegetables (actor effects). One's partner's emotion suppression was also independently associated with one's own emotional eating; lower consumption of fruits and vegetables; and greater consumption of hedonic foods (partner effects), although this association was most consistent for adolescents' suppression and parents' eating (compared with the converse). These analyses suggest that dyadic emotion regulatory processes have implications on eating behavior. Moreover, analyses suggest that emotion suppression has potential implications on eating behaviors of others within close relationships with a suppressor, consistent with the notion that emotion regulation is a transactional process. These findings suggest that interventions to improve eating habits of parents and their adolescent children should consider dyadic emotion regulatory processes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Capsaicin sensitizes TRAIL-induced apoptosis through Sp1-mediated DR5 up-regulation: Involvement of Ca2+ influx

International Nuclear Information System (INIS)

Moon, Dong-Oh; Kang, Chang-Hee; Kang, Sang-Hyuck; Choi, Yung-Hyun; Hyun, Jin-Won; Chang, Weon-Young; Kang, Hee-Kyoung; Koh, Young-Sang; Maeng, Young-Hee; Kim, Young-Ree; Kim, Gi-Young

2012-01-01

Although tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in various malignant cells, several cancers including human hepatocellular carcinoma (HCC) exhibit potent resistance to TRAIL-induced cell death. The aim of this study is to evaluate the anti-cancer potential of capsaicin in TRAIL-induced cancer cell death. As indicated by assays that measure phosphatidylserine exposure, mitochondrial activity and activation of caspases, capsaicin potentiated TRAIL-resistant cells to lead to cell death. In addition, we found that capsaicin induces the cell surface expression of TRAIL receptor DR5, but not DR4 through the activation Sp1 on its promoter region. Furthermore, we investigated that capsaicin-induced DR5 expression and apoptosis are inhibited by calcium chelator or inhibitors for calmodulin-dependent protein kinase. Taken together, our data suggest that capsaicin sensitizes TRAIL-mediated HCC cell apoptosis by DR5 up-regulation via calcium influx-dependent Sp1 activation. Highlights: ► Capsaicin sensitizes TRAIL-induced apoptosis through activation of caspases. ► Capsaicin induces expression of DR5 through Sp1 activation. ► Capsaicin activates calcium signaling pathway.

Involvement of AMPK signaling cascade in capsaicin-induced apoptosis of HT-29 colon cancer cells.

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Kim, Young Min; Hwang, Jin-Taek; Kwak, Dong Wook; Lee, Yun Kyung; Park, Ock Jin

2007-01-01

Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is activated during ATP-depleting metabolic states, such as hypoxia, heat shock, oxidative stress, and exercise. As a highly conserved heterotrimeric kinase that functions as a major metabolic switch to maintain energy homeostasis, AMPK has been shown to exert as an intrinsic regulator of mammalian cell cycle. Moreover, AMPK cascade has emerged as an important pathway implicated in cancer control. In this article, we have investigated the effects of capsaicin on apoptosis in relation to AMPK activation in colon cancer cell. Capsaicin-induced apoptosis was revealed by the presence of nucleobodies in the capsaicin-treated HT-29 colon cancer cells. Concomitantly, the activation of AMPK and the increased expression of the inactive form of acetyl-CoA carboxylase (ACC) were detected in capsaicin-treated colon cancer cells. We showed that both capsaicin and 5'-aminoimidazole-4-carboxamide-1-beta-D-ribonucleoside (AICAR), an AMPK activator possess the AMPK-activating capacity as well as apoptosis-inducing properties. Evidence of the association between AMPK activation and the increased apoptosis in HT-29 colon cancer cells by capsaicin treatment, and further findings of the correlation of the activated AMPK and the elevated apoptosis by cotreatment of AICAR and capsaicin support AMPK as an important component of apoptosis, as well as a possible target of cancer control.

Extraction and purification of capsaicin from capsicum oleoresin using an aqueous two-phase system combined with chromatography.

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Fan, Yong; Lu, Yan-Min; Yu, Bin; Tan, Cong-Ping; Cui, Bo

2017-09-15

Capsaicin was extracted from capsicum oleoresin using an aqueous two-phase system (ATPS) composed of an ethylene oxide-propylene oxide (EOPO) copolymer, salt and ethanol. Capsaicin was concentrated in the top polymer-rich phase. To determine the optimal conditions, the partitioning of capsaicin in the ATPS was investigated, considering a single-factor experiment including the salt concentration, polymer concentration, buffer pH, ethanol concentration, sample loading and extraction duration. Response surface methodology was applied to investigate the effects of the polymer concentration, buffer pH and sample loading on capsaicin partitioning. A capsaicin yield of 95.5% was obtained using the optimal extraction system, which consisted of 16.3% UCON 50-HB-5100/10% K 2 HPO 4 /1% ethanol, a buffer pH of 4.35 and 0.24g of capsicum oleoresin. Capsaicin was purified from the capsaicinoid extract using a two-step macroporous adsorption resin (MAR) method. After purification using non-polar MAR ADS-17, the recovery and purity of capsaicin were 83.7% and 50.3%, respectively. After purification using weakly polar MAR AB-8, the recovery and purity of capsaicin were 88.0% and 85.1%, respectively. Copyright © 2017. Published by Elsevier B.V.

Novel Approaches to Extraction Methods in Recovery of Capsaicin from Habanero Pepper (CNPH 15.192).

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Martins, Frederico S; Borges, Leonardo L; Ribeiro, Claudia S C; Reifschneider, Francisco J B; Conceição, Edemilson C

2017-07-01

The objective of this study was to compare three capsaicin extraction methods: Shoxlet, Ultrasound-assisted Extraction (UAE), and Shaker-assisted Extraction (SAE) from Habanero pepper, CNPH 15.192. The different parameters evaluated were alcohol degree, time extraction, and solid-solvent ratio using response surface methodology (RSM). The three parameters found significant ( p Soxhlet increased the extraction in 10-25%; however, long extraction times (45 minutes) degraded 2% capsaicin. The extraction of capsaicin was influenced by extraction method and by the operating conditions chosen. The optimized conditions provided savings of time, solvent, and herbal material. Prudent choice of the extraction method is essential to ensure optimal yield of extract, thereby making the study relevant and the knowledge gained useful for further exploitation and application of this resource. Habanero pepper , line CNPH 15.192, possess capsaicin in higher levels when compared with others speciesHigher levels of ethanolic strength are more suitable to obtain a higher levels of capsaicinBox-Behnken design indicates to be useful to explore the best conditions of ultrasound assisted extraction of capsaicin. Abbreviations used: Nomenclature UAE: Ultrasound-assisted Extraction; SAE: Shaker-assisted Extraction.

Suramin affects capsaicin responses and capsaicin-noxious heat interactions in rat dorsal root ganglia neurones

Czech Academy of Sciences Publication Activity Database

Vlachová, Viktorie; Lyfenko, Alla; Vyklický st., Ladislav; Orkand, R. K.

2002-01-01

Roč. 51, č. 2 (2002), s. 193-198 ISSN 0862-8408 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Institutional research plan: CEZ:AV0Z5011922 Keywords : dorsal root ganglia neurones * vanilloid receptor * capsaicin-noxious heat Subject RIV: ED - Physiology Impact factor: 0.984, year: 2002

Effects of Capsaicin on Older Patients with Oropharyngeal Dysphagia: A Double-Blind, Placebo-Controlled, Crossover Study.

Science.gov (United States)

Nakato, Rui; Manabe, Noriaki; Shimizu, Sayako; Hanayama, Kozo; Shiotani, Akiko; Hata, Jiro; Haruma, Ken

2017-01-01

The standard of care for older patients with oropharyngeal dysphagia (OD) is poor. Stimulation of transient receptor potential vanilloid 1 might become a pharmacological strategy for these patients. This study aimed to compare the therapeutic effect of film food containing 0.75 µg of capsaicin in these patients. In a crossover, randomized trial, 49 patients with OD were provided capsaicin or identical placebo at least 7 days apart. Patients' reported symptoms during repeated swallowing, the volume, pH and substance P (SP) concentrations in saliva, and cervical esophageal wall motion evaluated by ultrasonographic tissue Doppler imaging were obtained before and after capsaicin or placebo administration. Significantly more patients with OD who took capsaicin experienced improvement in symptoms than those who took placebo. Salivary SP levels were significantly increased after capsaicin administration compared with placebo in the effective group. The duration of cervical esophageal wall opening was significantly shorter in capsaicin administration in the effective group. Furthermore, a significant negative correlation was found between the duration of cervical esophageal wall opening and salivary SP levels. Elevated salivary SP concentrations stimulated by capsaicin greatly improve the safety and efficacy of swallowing, and shorten the swallow response in older patients with OD. © 2017 S. Karger AG, Basel.

Brain potentials evoked by intraepidermal electrical stimuli reflect the central sensitization of nociceptive pathways.

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Liang, M; Lee, M C; O'Neill, J; Dickenson, A H; Iannetti, G D

2016-08-01

Central sensitization (CS), the increased sensitivity of the central nervous system to somatosensory inputs, accounts for secondary hyperalgesia, a typical sign of several painful clinical conditions. Brain potentials elicited by mechanical punctate stimulation using flat-tip probes can provide neural correlates of CS, but their signal-to-noise ratio is limited by poor synchronization of the afferent nociceptive input. Additionally, mechanical punctate stimulation does not activate nociceptors exclusively. In contrast, low-intensity intraepidermal electrical stimulation (IES) allows selective activation of type II Aδ-mechano-heat nociceptors (II-AMHs) and elicits reproducible brain potentials. However, it is unclear whether hyperalgesia from IES occurs and coexists with secondary mechanical punctate hyperalgesia, and whether the magnitude of the electroencephalographic (EEG) responses evoked by IES within the hyperalgesic area is increased. To address these questions, we explored the modulation of the psychophysical and EEG responses to IES by intraepidermal injection of capsaicin in healthy human subjects. We obtained three main results. First, the intensity of the sensation elicited by IES was significantly increased in participants who developed robust mechanical punctate hyperalgesia after capsaicin injection (i.e., responders), indicating that hyperalgesia from IES coexists with punctate mechanical hyperalgesia. Second, the N2 peak magnitude of the EEG responses elicited by IES was significantly increased after the intraepidermal injection of capsaicin in responders only. Third, a receiver-operator characteristics analysis showed that the N2 peak amplitude is clearly predictive of the presence of CS. These findings suggest that the EEG responses elicited by IES reflect secondary hyperalgesia and therefore represent an objective correlate of CS. Copyright © 2016 the American Physiological Society.

Antimicrobial and anti-virulence activity of capsaicin against erythromycin-resistant, cell-invasive Group A streptococci

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Emanuela eMarini

2015-11-01

Full Text Available Capsaicin (8-methyl-N-vanillyl-6-nonenamide is the active component of Capsicum plants (chilli peppers, which are grown as food and for medicinal purposes since ancient times, and is responsible for the pungency of their fruit. Besides its multiple pharmacological and physiological properties (pain relief, cancer prevention, and beneficial cardiovascular, and gastrointestinal effects capsaicin has recently attracted considerable attention because of its antimicrobial and anti-virulence activity. This is the first study of its in vitro antibacterial and anti-virulence activity against Streptococcus pyogenes [Group A streptococci (GAS], a major human pathogen. The test strains were previously characterized, erythromycin-susceptible (n=5 and erythromycin-resistant (n=27, cell-invasive pharyngeal isolates. The MICs of capsaicin were 64-128 μg/mL (the most common MIC was 128 µg/mL. The action of capsaicin was bactericidal, as suggested by MBC values that were equal or close to the MICs, and by early detection of dead cells in the live/dead assay. No capsaicin-resistant mutants were obtained in single-step resistance selection studies. Interestingly, growth in presence of sublethal capsaicin concentrations induced an increase in biofilm production (p ≤ 0.05 and in the number of bacteria adhering to A549 monolayers, and a reduction in cell-invasiveness and haemolytic activity (both p ≤ 0.05. Cell invasiveness fell so dramatically that a highly invasive strain became non-invasive. The dose-response relationship, characterized by opposite effects of low and high capsaicin doses, suggests a hormetic response. The present study documents that capsaicin has promising bactericidal activity against erythromycin-resistant, cell-invasive pharyngeal GAS isolates. The fact that sublethal concentrations inhibited cell invasion and reduced haemolytic activity, two important virulence traits of GAS, is also interesting, considering that cell

Inhibitory effects of curcumin and capsaicin on phorbol ester-induced activation of eukaryotic transcription factors, NF-kappaB and AP-1.

Science.gov (United States)

Surh, Y J; Han, S S; Keum, Y S; Seo, H J; Lee, S S

2000-01-01

Recently, considerable attention has been focused on identifying dietary and medicinal phytochemicals that can inhibit, retard or reverse the multi-stage carcinogenesis. Spices and herbs contain phenolic substances with potent antioxidative and chemopreventive properties. Curcumin, a yellow colouring agent from turmeric and capsaicin, a pungent principle of red pepper exhibit profound anticarcinogenic and antimutagenic activities. Two well-defined eukaryotic transcription factors, nuclear factor-kappa B (NF-kappaB) and activator protein 1 (AP-1) have been implicated in pathogenesis of many human diseases including cancer. These transcription factors are known to be activated by a wide array of external stimuli, such as tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), tumor necrosis factor, reactive oxygen species, bacterial lipopolysaccharide, and ultraviolet. In the present study, we found that topical application of TPA onto dorsal skin of female ICR mice resulted in marked activation of epidermal NF-kappaB and AP-1. Curcumin and capsaicin, when topically applied prior to TPA, significantly attenuated TPA-induced activation of each transcription factor in mouse skin. Likewise, both compounds inhibited NF-kappaB and AP-1 activation in cultured human promyelocytic leukemia (HL-60) cells stimulated with TPA. Based on these findings, it is likely that curcumin and capsaicin exert anti-tumor promotional effects through suppression of the tumor promoter-induced activation of transcription factors, NF-kappaB and AP-1.

A mixed integer program to model spatial wildfire behavior and suppression placement decisions

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Erin J. Belval; Yu Wei; Michael. Bevers

2015-01-01

Wildfire suppression combines multiple objectives and dynamic fire behavior to form a complex problem for decision makers. This paper presents a mixed integer program designed to explore integrating spatial fire behavior and suppression placement decisions into a mathematical programming framework. Fire behavior and suppression placement decisions are modeled using...

Combined treatment with capsaicin and resveratrol enhances neuroprotection against glutamate-induced toxicity in mouse cerebral cortical neurons

NARCIS (Netherlands)

Lee, J.G.; Yon, J.M.; Lin, C.; Jung, A.Y.; Jung, K.Y.; Nam, S.Y.

2012-01-01

Capsaicin and resveratrol as natural products have a variety of beneficial effects. However, capsaicin is also a neurotoxic agent, rendering its effect on the nervous system confusing. The aim of this study was to investigate whether capsaicin and/or resveratrol have a protective effect against

Application of a capsaicin rinse in the treatment of burning mouth syndrome

Science.gov (United States)

Silvestre-Rangil, Javier; Tamarit-Santafé, Carmen; Bautista, Daniel

2012-01-01

Objective: To examine the efficacy of a new topical capsaicin presentation as an oral rinse in improving the symptoms of burning mouth syndrome (BMS). Study design: A prospective, double-blind, cross-over study was made of 30 patients with BMS. There were 7 dropouts; the final study series thus comprised 23 individuals. The patients were randomized to two groups: (A) capsaicin rinse (0.02%) or (B) placebo rinse, administered during one week. After a one-week washout period, the patients were then assigned to the opposite group. Burning discomfort was scored using a visual analog scale (VAS): in the morning before starting the treatment, in the afternoon on the first day of treatment, and at the end of the week of treatment in the morning and in the afternoon. The same scoring sequence was again applied one week later with the opposite rinse. Results: The mean patient age was 72.65 ± 12.10 years, and the duration of BMS was 5.43 ± 3.23 years on average. Significant differences in VAS score were recorded in the capsaicin group between baseline in the morning (AM1) or afternoon (AA1) and the end of the week of treatment (AA7)(p=0.003 and p=0.002, respectively). Conclusion: The topical application of capsaicin may be useful in treating the discomfort of BMS, but has some limitations. Key words: Burning mouth syndrome, stomatodynia, capsaicin, treatment, clinical management. PMID:21743415

Capsaicin-sensitive muscle afferents modulate the monosynaptic reflex in response to muscle ischemia and fatigue in the rat.

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Della Torre, G; Brunetti, O; Pettorossi, V E

2002-01-01

The role of muscle ischemia and fatigue in modulating the monosynaptic reflex was investigated in decerebrate and spinalized rats. Field potentials and fast motoneuron single units in the lateral gastrocnemious (LG) motor pool were evoked by dorsal root stimulation. Muscle ischemia was induced by occluding the LG vascular supply and muscle fatigue by prolonged tetanic electrical stimulation of the LG motor nerve. Under muscle ischemia the monosynaptic reflex was facilitated since the size of the early and late waves of the field potential and the excitability of the motoneuron units increased. This effect was abolished after L3-L6 dorsal rhizotomy, but it was unaffected after L3-L6 ventral rhizotomy. By contrast, the monosynaptic reflex was inhibited by muscle fatiguing stimulation, and this effect did not fully depend on the integrity of the dorsal root. However, when ischemia was combined with repetitive tetanic muscle stimulation the inhibitory effect of fatigue was significantly enhanced. Both the ischemia and fatigue effects were abolished by capsaicin injected into the LG muscle at a dose that blocked a large number of group III and IV muscle afferents. We concluded that muscle ischemia and fatigue activate different groups of muscle afferents that are both sensitive to capsaicin, but enter the spinal cord through different roots. They are responsible for opposite effects, when given separately: facilitation during ischemia and inhibition during fatigue; however, in combination, ischemia enhances the responsiveness of the afferent fibres to fatigue.

Histologic evaluation of pulpal response to MTA and capsaicin in cats

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Zahrasadat Madani

2012-09-01

Full Text Available Introduction: In direct pup capping, the exposed pulp is directly capped with a capping material to provoke a dentinal bridge formation to seal the exposed area.The aim of this study was to evaluate the pulpal response to MTA and capsaicin in cats. Methods: The sample for this experimental study consisted of 24 canines of cats, weighed approximately 3-4kg. After sedation, the teeth were cut and exposed at 3mm above cementoenamel junction, then divided into two groups: 1 direct pulp capping with MTA 2 direct pulp capping with Capsaicin. The cavities were filled with glass ionomer cement (Fuji IX. The cats were sacrificed in the first, second, and fourth weeks 4 canine teeth were extracted for the purpose of histologic analysis. 6Serial sections were cut parallel to the longitudinal axis of the canines. The sections were stained with hematoxylin & eosin, and were observed and analyzed using a light microscope. Results: In both groups treated with MTA and capsaicin, the inflammation decreased during weeks1, 2, and 4. Less inflammation was seen in MTA group but there was no statistical difference between the two groups (p=0.22. In the group treated with capsaicin, necrosis was observed in every 12 samples, but in the other group treated with MTA, only 1 pulp necrosis was seen in the first week (p=0.000. There was no significant difference in dentinal barrier formation, inflammatory response, and soft tissue changes between the two groups. Conclusions: The results of this study showed that capsaicin can decrease the severity of inflammation, but it is ineffective in dentinal barrier formation.

Prolonged maintenance of capsaicin-induced hyperalgesia by brief daily vibration stimuli

OpenAIRE

Kim, Hee Kee; Schattschneider, Jörn; Lee, Inhyung; Chung, Kyungsoon; Baron, Ralf; Chung, Jin Mo

2006-01-01

This study tests the hypothesis that central sensitization initiated by nociceptive input can be maintained by repeated brief innocuous peripheral inputs. Capsaicin was injected intradermally into the hind paw of adult rats. Three different types of daily cutaneous mechanical stimulations (vibration, soft brush, or pressure) were applied to the capsaicin-injected paw for a period of 2 weeks. Daily stimulation consisted of a 10-second stimulation repeated every 30 seconds for 30 minutes. Foot ...

Analgesic effect of topical oral capsaicin gel in burning mouth syndrome.

Science.gov (United States)

Jørgensen, Mette Rose; Pedersen, Anne Marie Lynge

2017-03-01

To investigate the effectiveness of repeated topical application of oral capsaicin gel in two different concentrations for relief of burning/stinging sensations in patients with burning mouth syndrome (BMS). This randomized double-blind cross-over study included 22 female patients with BMS. The patients were randomized for topical application of either 0.01% or 0.025% oral capsaicin gel on the dorsal part of tongue three times daily for 14 days, followed by 14 days wash-out period, and finally treatment with the other concentration of oral gel three times daily for 14 days. A visual analogue scale (VAS) was used to assess the severity of pain five times during the intervention period. 18 patients completed the intervention. Their VAS score at baseline was 5.5 ± 0.6 cm (mean ± SD). Treatment with the two concentrations of capsaicin gels significantly improved the burning/stinging symptoms assessed on VAS compared with baseline (p = 0.002). There was no statistically significant difference between the two concentrations of the gels on relieving symptoms. Four patients dropped out during the intervention period due to gastrointestinal side-effects. Topical capsaicin might be an alternative for the short-term treatment of BMS. However, further studies are needed to investigate especially the gastro-intestinal side-effects which may limit its long-term use.

Prolonged maintenance of capsaicin-induced hyperalgesia by brief daily vibration stimuli.

Science.gov (United States)

Kim, Hee Kee; Schattschneider, Jörn; Lee, Inhyung; Chung, Kyungsoon; Baron, Ralf; Chung, Jin Mo

2007-05-01

This study tests the hypothesis that central sensitization initiated by nociceptive input can be maintained by repeated brief innocuous peripheral inputs. Capsaicin was injected intradermally into the hind paw of adult rats. Three different types of daily cutaneous mechanical stimulations (vibration, soft brush, or pressure) were applied to the capsaicin-injected paw for a period of 2 weeks. Daily stimulation consisted of a 10-s stimulation repeated every 30s for 30 min. Foot withdrawal thresholds to von Frey stimuli applied to the paw were measured once a day for 4 weeks. The capsaicin-only group (control rats without daily stimulation) showed hyperalgesia lasting for 3 days. In contrast, hyperalgesia persisted for 2 weeks in the group that received vibration stimulation. Neither the soft brush nor the pressure group showed a significant difference in mechanical threshold from the control group (capsaicin only). The vibration-induced prolonged hyperalgesia was significantly reduced by systemic injection of ifenprodil, an NMDA-receptor antagonist, but it was not influenced by either an AMPA-receptor blocker or a reactive oxygen species (ROS) scavenger. Furthermore, a dorsal column lesion did not interfere with the prolongation of hyperalgesia. Data suggest that vibration-induced prolongation of hyperalgesia is mediated by spinal NMDA-receptors, and a similar mechanism may underlie some forms of chronic pain with no obvious causes, such as complex regional pain syndrome type 1 (CRPS-1).

Neurophysiological mechanisms of bradykinin-evoked mucosal chloride secretion in guinea pig small intestine.

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Qu, Mei-Hua; Ji, Wan-Sheng; Zhao, Ting-Kun; Fang, Chun-Yan; Mao, Shu-Mei; Gao, Zhi-Qin

2016-02-15

To investigate the mechanism for bradykinin (BK) to stimulate intestinal secretomotor neurons and intestinal chloride secretion. Muscle-stripped guinea pig ileal preparations were mounted in Ussing flux chambers for the recording of short-circuit current (Isc). Basal Isc and Isc stimulated by BK when preincubated with the BK receptors antagonist and other chemicals were recorded using the Ussing chamber system. Prostaglandin E2 (PGE2) production in the intestine was determined by enzyme immunologic assay (EIA). Application of BK or B2 receptor (B2R) agonist significantly increased the baseline Isc compared to the control. B2R antagonist, tetrodotoxin and scopolamine (blockade of muscarinic receptors) significantly suppressed the increase in Isc evoked by BK. The BK-evoked Isc was suppressed by cyclooxygenase (COX)-1 or COX-2 specific inhibitor as well as nonselective COX inhibitors. Preincubation of submucosa/mucosa preparations with BK for 10 min significantly increased PGE2 production and this was abolished by the COX-1 and COX-2 inhibitors. The BK-evoked Isc was suppressed by nonselective EP receptors and EP4 receptor antagonists, but selective EP1 receptor antagonist did not have a significant effect on the BK-evoked Isc. Inhibitors of PLC, PKC, calmodulin or CaMKII failed to suppress BK-induced PGE2 production. The results suggest that BK stimulates neurogenic chloride secretion in the guinea pig ileum by activating B2R, through COX increasing PGE2 production. The post-receptor transduction cascade includes activation of PLC, PKC, CaMK, IP3 and MAPK.

Development of the acoustically evoked behavioral response in larval plainfin midshipman fish, Porichthys notatus.

Directory of Open Access Journals (Sweden)

Peter W Alderks

Full Text Available The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r(2 = 0.92. The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥ 1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or -15.2 dB re 1 g (z-axis. Lowest AEBR thresholds were 140-150 dB re 1 µPa or -33 to -23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9-2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages.

Development of the acoustically evoked behavioral response in larval plainfin midshipman fish, Porichthys notatus.

Science.gov (United States)

Alderks, Peter W; Sisneros, Joseph A

2013-01-01

The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR) in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r(2) = 0.92). The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥ 1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or -15.2 dB re 1 g (z-axis). Lowest AEBR thresholds were 140-150 dB re 1 µPa or -33 to -23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9-2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages.

(+)-Borneol suppresses conditioned fear recall and anxiety-like behaviors in mice.

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Cao, Bo; Ni, Huan-Yu; Li, Jun; Zhou, Ying; Bian, Xin-Lan; Tao, Yan; Cai, Cheng-Yun; Qin, Cheng; Wu, Hai-Yin; Chang, Lei; Luo, Chun-Xia; Zhu, Dong-Ya

2018-01-08

Fear- and anxiety-related psychiatric disorders have been one of the major chronic diseases afflicting patients for decades, and new compounds for treating such disorders remain to be developed. (+)-Borneol, a bicyclic monoterpene found in several species of Artemisia and Dipterocarpaceae, is widely used for anxiety, pain and anesthesia in Chinese medicine. Meanwhile, it can potentiate GABA (γ-aminobutyric acid) activity directly in recombinant GABAA receptors. The present study was to investigate the effects of (+)-Borneol on both contextual and cued fear recall. Interestingly, microinjection of (+)-Borneol into the dorsal hippocampus inhibited 24 h and 7 d contextual fear, whereas its infusion into ventral hippocampus only reduced 24 h cued fear responses. Moreover, microinjection of (+)-Borneol into dorsal but not ventral hippocampus suppressed anxiety-like behaviors in the open field test, light/dark exploration and the elevated plus maze test. As selective GABA A receptor antagonist bicuculline reversed the effect of (+)-Borneol on contextual fear paradigm and the drug potentiated GABA-evoked currents in acute hippocampus slices, modulation of the GABAergic neurotransmission may explain the effects of (+)-Borneol. Our findings suggest that (+)-Borneol can serve as a new therapeutic in fear- and anxiety-related disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

The TRPV1 channel in rodents is a major target for antinociceptive effect of the probiotic Lactobacillus reuteri DSM 17938

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Perez-Burgos, Azucena; Wang, Lu; McVey Neufeld, Karen-Anne; Mao, Yu-Kang; Ahmadzai, Mustafa; Janssen, Luke J; Stanisz, Andrew M; Bienenstock, John; Kunze, Wolfgang A

2015-01-01

Abstract Certain bacteria exert visceral antinociceptive activity, but the mechanisms involved are not determined. Lactobacillus reuteri DSM 17938 was examined since it may be antinociceptive in children. Since transient receptor potential vanilloid 1 (TRPV1) channel activity may mediate nociceptive signals, we hypothesized that TRPV1 current is inhibited by DSM. We tested this by examining the effect of DSM on the firing frequency of spinal nerve fibres in murine jejunal mesenteric nerve bundles following serosal application of capsaicin. We also measured the effects of DSM on capsaicin-evoked increase in intracellular Ca2+ or ionic current in dorsal root ganglion (DRG) neurons. Furthermore, we tested the in vivo antinociceptive effects of oral DSM on gastric distension in rats. Live DSM reduced the response of capsaicin- and distension-evoked firing of spinal nerve action potentials (238 ± 27.5% vs. 129 ± 17%). DSM also reduced the capsaicin-evoked TRPV1 ionic current in DRG neuronal primary culture from 83 ± 11% to 41 ± 8% of the initial response to capsaicin only. Another lactobacillus (Lactobacillus rhamnosus JB-1) with known visceral anti-nociceptive activity did not have these effects. DSM also inhibited capsaicin-evoked Ca2+ increase in DRG neurons; an increase in Ca2+ fluorescence intensity ratio of 2.36 ± 0.31 evoked by capsaicin was reduced to 1.25 ± 0.04. DSM releasable products (conditioned medium) mimicked DSM inhibition of capsaicin-evoked excitability. The TRPV1 antagonist 6-iodonordihydrocapsaicin or the use of TRPV1 knock-out mice revealed that TRPV1 channels mediate about 80% of the inhibitory effect of DSM on mesenteric nerve response to high intensity gut distension. Finally, feeding with DSM inhibited perception in rats of painful gastric distension. Our results identify a specific target channel for a probiotic with potential therapeutic properties. Key points Certain probiotic bacteria have been shown to reduce distension

Glutamate Receptor GluA1 Subunit Is Implicated in Capsaicin Induced Modulation of Amygdala LTP but Not LTD

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Gebhardt, Christine; Albrecht, Doris

2018-01-01

Capsaicin has been shown to modulate synaptic plasticity in various brain regions including the amygdala. Whereas in the lateral amygdala the modulatory effect of capsaicin on long-term potentiation (LA-LTP) is mediated by TRPV1 channels, we have recently shown that capsaicin-induced enhancement of long term depression (LA-LTD) is mediated by…

The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

DEFF Research Database (Denmark)

Holst, H; Arendt-Nielsen, L; Mosbech, H

2010-01-01

Patients with multiple chemical sensitivity and eczema patients with airway symptoms elicited by odorous chemicals have enhanced cough reflex to capsaicin when applying the tidal breathing method. The aims of the present study were to test whether the capsaicin induced cough reflex was enhanced...... when applying the single breath inhalation method in similar groups of patients with symptoms related to odorous chemicals e.g. other persons wearing of perfume; and to investigate to what extent the reporting of lower airway symptoms influenced the cough reflex. Sixteen patients fulfilling Cullen......'s criteria for multiple chemical sensitivity and 15 eczema patients with airway symptoms elicited by odorous chemicals were compared with 29 age-matched, healthy controls. We measured C5--the capsaicin concentration causing five coughs or more--using the single breath inhalation test. No difference was found...

A capsaicin (8%) patch in the treatment of severe persistent inguinal postherniorrhaphy pain

DEFF Research Database (Denmark)

Bischoff, Joakim M; Ringsted, Thomas K; Petersen, Marian

2014-01-01

BACKGROUND: Persistent pain after inguinal herniorrhaphy is a disabling condition with a lack of evidence-based pharmacological treatment options. This randomized placebo-controlled trial investigated the efficacy of a capsaicin 8% cutaneous patch in the treatment of severe persistent inguinal...... postherniorrhaphy pain. METHODS: Forty-six patients with persistent inguinal postherniorrhaphy pain were randomized to receive either a capsaicin 8% patch or a placebo patch. Pain intensity (Numerical Rating Scale [NRS 0-10]) was evaluated under standardized conditions (at rest, during movement, and during pressure....... The primary outcome was comparisons of summed pain intensity differences (SPIDs) between capsaicin and placebo treatments at 1, 2 and 3 months after patch application (significance level P placebo treatments, was observed at 1 month after...

Involvement of the phosphoinositide 3-kinase/Akt pathway in apoptosis induced by capsaicin in the human pancreatic cancer cell line PANC-1.

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Zhang, Jian-Hong; Lai, Fu-Ji; Chen, Hui; Luo, Jiang; Zhang, Ri-Yuan; Bu, He-Qi; Wang, Zhao-Hong; Lin, Hong-Hai; Lin, Sheng-Zhang

2013-01-01

Capsaicin, one of the major pungent ingredients found in red peppers, has been recently demonstrated to induce apoptosis in various malignant cell lines through an unclear mechanism. In this study, the effect of capsaicin on proliferation and apoptosis in the human pancreatic cancer cell line PANC-1 and its possible mechanism(s) of action were investigated. The results of a Cell Counting Kit-8 (CCK-8) assay revealed that capsaicin significantly decreased the viability of PANC-1 cells in a dose-dependent manner. Capsaicin induced G0/G1 phase cell cycle arrest and apoptosis in PANC-1 cells as demonstrated by a flow cytometric assessment. Caspase-3 expression at both the protein and mRNA level was promoted following capsaicin treatment. Furthermore, we revealed that phospho-PI3 Kinase p85 (Tyr458) and phospho-Akt (Ser473) in PANC-1 cells were downregulated in response to capsaicin. Moreover, capsaicin gavage significantly inhibited the growth of pancreatic cancer PANC-1 cell xenografts in athymic nude mice. An increased number of TUNEL-positive cells and cleaved caspase-3 were observed in capsaicin-treated mice. In vivo, capsaicin downregulated the expression of phospho-PI3 Kinase p85 (Tyr458) and phospho-Akt (Ser473). In conclusion, we have demonstrated that capsaicin is an inhibitor of growth of PANC-1 cells, and downregulation of the phosphoinositide 3-kinase/Akt pathway may be involved in capsaicin-induced apoptosis in vitro and in vivo.

Capsaicin affects brain function in a model of hepatic encephalopathy associated with fulminant hepatic failure in mice

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Avraham, Y; Grigoriadis, NC; Magen, I; Poutahidis, T; Vorobiav, L; Zolotarev, O; Ilan, Y; Mechoulam, R; Berry, EM

2009-01-01

Background and purpose: Hepatic encephalopathy is a neuropsychiatric syndrome caused by liver failure. In view of the effects of cannabinoids in a thioacetamide-induced model of hepatic encephalopathy and liver disease and the beneficial effect of capsaicin (a TRPV1 agonist) in liver disease, we assumed that capsaicin may also affect hepatic encephalopathy. Experimental approach: Fulminant hepatic failure was induced in mice by thioacetamide and 24 h later, the animals were injected with one of the following compound(s): 2-arachidonoylglycerol (CB1, CB2 and TRPV1 receptor agonist); HU308 (CB2 receptor agonist), SR141716A (CB1 receptor antagonist); SR141716A+2-arachidonoylglycerol; SR144528 (CB2 receptor antagonist); capsaicin; and capsazepine (TRPV1 receptor agonist and antagonist respectively). Their neurological effects were evaluated on the basis of activity in the open field, cognitive function in an eight-arm maze and a neurological severity score. The mice were killed 3 or 14 days after thioacetamide administration. 2-arachidonoylglycerol and 5-hydroxytryptamine (5-HT) levels were determined by gas chromatography-mass spectrometry and high-performance liquid chromatography with electrochemical detection, respectively. Results: Capsaicin had a neuroprotective effect in this animal model as shown by the neurological score, activity and cognitive function. The effect of capsaicin was blocked by capsazepine. Thioacetamide induced astrogliosis in the hippocampus and the cerebellum and raised brain 5-hydroxytryptamine levels, which were decreased by capsaicin, SR141716A and HU-308. Thioacetamide lowered brain 2-arachidonoylglycerol levels, an effect reversed by capsaicin. Conclusions: Capsaicin improved both liver and brain dysfunction caused by thioacetamide, suggesting that both the endocannabinoid and the vanilloid systems play important roles in hepatic encephalopathy. Modulation of these systems may have therapeutic value. PMID:19764982

Cancer-promoting effect of capsaicin on DMBA/TPA-induced skin tumorigenesis by modulating inflammation, Erk and p38 in mice.

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Liu, Zhaoguo; Zhu, Pingting; Tao, Yu; Shen, Cunsi; Wang, Siliang; Zhao, Lingang; Wu, Hongyan; Fan, Fangtian; Lin, Chao; Chen, Chen; Zhu, Zhijie; Wei, Zhonghong; Sun, Lihua; Liu, Yuping; Wang, Aiyun; Lu, Yin

2015-07-01

Epidemiologic and animal studies revealed that capsaicin (8-methyl-N-vanillyl-6-noneamide) can act as a carcinogen or cocarcinogen. However, the influence of consumption of capsaicin-containing foods or vegetables on skin cancer patients remains largely unknown. In the present study, we demonstrated that capsaicin has a cocarcinogenic effect on 9, 10-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin tumorigenesis. Our results showed that topical application of capsaicin on the dorsal skin of DMBA-initiated and TPA-promoted mice could significantly accelerate tumor formation and growth and induce more and larger skin tumors than the model group (DMBA + TPA). Moreover, capsaicin could promote TPA-induced skin hyperplasia and tumor proliferation. Mechanistic study found that inflammation-related factors cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) were highly elevated by pretreatment with capsaicin, suggesting an inflammation-dependent mechanism. Furthermore, mice that were administered capsaicin exhibited significant up-regulation of phosphorylation of nuclear factor kappaB (NF-κB), Erk and p38 but had no effect on JNK. Thus, our results indicated that inflammation, Erk and P38 collectively played a crucial role in cancer-promoting effect of capsaicin on carcinogen-induced skin cancer in mice. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chronic Oral Capsaicin Exposure During Development Leads to Adult Rats with Reduced Taste Bud Volumes.

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Omelian, Jacquelyn M; Samson, Kaeli K; Sollars, Suzanne I

2016-09-01

Cross-sensory interaction between gustatory and trigeminal nerves occurs in the anterior tongue. Surgical manipulations have demonstrated that the strength of this relationship varies across development. Capsaicin is a neurotoxin that affects fibers of the somatosensory lingual nerve surrounding taste buds, but not fibers of the gustatory chorda tympani nerve which synapse with taste receptor cells. Since capsaicin is commonly consumed by many species, including humans, experimental use of this neurotoxin provides a naturalistic perturbation of the lingual trigeminal system. Neonatal or adults rats consumed oral capsaicin for 40 days and we examined the cross-sensory effect on the morphology of taste buds across development. Rats received moderate doses of oral capsaicin, with chronic treatments occurring either before or after taste system maturation. Tongue morphology was examined either 2 or 50 days after treatment cessation. Edema, which has been previously suggested as a cause of changes in capsaicin-related gustatory function, was also assessed. Reductions in taste bud volume occurred 50 days, but not 2 days post-treatment for rats treated as neonates. Adult rats at either time post-treatment were unaffected. Edema was not found to occur with the 5 ppm concentration of capsaicin we used. Results further elucidate the cooperative relationship between these discrete sensory systems and highlight the developmentally mediated aspect of this interaction. Chronic exposure to even moderate levels of noxious stimuli during development has the ability to impact the orosensory environment, and these changes may not be evident until long after exposure has ceased.

Ultraviolet radiation-induced lipid peroxidation in liposomal membrane: modification by capsaicin

International Nuclear Information System (INIS)

De, A.K.; Ghosh, J.J.; Mandal, T.K.

1993-01-01

Ultraviolet-radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8-methyl-n-vanillyl-6-nonenamide), the pungent principle of red hot pepper, was shown to modify UV-induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV-induced lipid peroxidation, while high doses (0.1-0.5 μg/mL of PC liposome) caused a significant decrease of UV-induced peroxidation

Ultraviolet radiation-induced lipid peroxidation in liposomal membrane: modification by capsaicin

Energy Technology Data Exchange (ETDEWEB)

De, A. K.; Ghosh, J. J.; Mandal, T. K. [University College of Science, Department of Biochemistry, 35 Ballygunge Circular Road, Calcutta 700-019 (India)

1993-07-01

Ultraviolet-radiation has been reported to cause lipid peroxidation in the liposomal membrane. In the present study, treatment with capsaicin, (8-methyl-n-vanillyl-6-nonenamide), the pungent principle of red hot pepper, was shown to modify UV-induced lipid peroxidation in the liposomal membrane. Treatment with low doses of capsaicin (less than 0.1 μg/mL of phosphatidyl choline liposome) produced a significant increase in UV-induced lipid peroxidation, while high doses (0.1-0.5 μg/mL of PC liposome) caused a significant decrease of UV-induced peroxidation.

Repeated oral administration of capsaicin increases anxiety-like ...

Indian Academy of Sciences (India)

2013-07-22

Jul 22, 2013 ... open arms was reduced in capsaicin-treated rats compared with control rats. In forced ... TRPV1 receptors was also observed in the prefrontal cortex, nucleus ... its implication in the control of psycho-motor activities. Indeed ...

Amphetamine and cocaine suppress social play behavior in rats through distinct mechanisms.

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Achterberg, E J Marijke; Trezza, Viviana; Siviy, Stephen M; Schrama, Laurens; Schoffelmeer, Anton N M; Vanderschuren, Louk J M J

2014-04-01

Social play behavior is a characteristic form of social behavior displayed by juvenile and adolescent mammals. This social play behavior is highly rewarding and of major importance for social and cognitive development. Social play is known to be modulated by neurotransmitter systems involved in reward and motivation. Interestingly, psychostimulant drugs, such as amphetamine and cocaine, profoundly suppress social play, but the neural mechanisms underlying these effects remain to be elucidated. In this study, we investigated the pharmacological underpinnings of amphetamine- and cocaine-induced suppression of social play behavior in rats. The play-suppressant effects of amphetamine were antagonized by the alpha-2 adrenoreceptor antagonist RX821002 but not by the dopamine receptor antagonist alpha-flupenthixol. Remarkably, the effects of cocaine on social play were not antagonized by alpha-2 noradrenergic, dopaminergic, or serotonergic receptor antagonists, administered either alone or in combination. The effects of a subeffective dose of cocaine were enhanced by a combination of subeffective doses of the serotonin reuptake inhibitor fluoxetine, the dopamine reuptake inhibitor GBR12909, and the noradrenaline reuptake inhibitor atomoxetine. Amphetamine, like methylphenidate, exerts its play-suppressant effect through alpha-2 noradrenergic receptors. On the other hand, cocaine reduces social play by simultaneous increases in dopamine, noradrenaline, and serotonin neurotransmission. In conclusion, psychostimulant drugs with different pharmacological profiles suppress social play behavior through distinct mechanisms. These data contribute to our understanding of the neural mechanisms of social behavior during an important developmental period, and of the deleterious effects of psychostimulant exposure thereon.

Electrocorticography and the early maturation of high-frequency suppression within the default mode network.

Science.gov (United States)

Weaver, Kurt E; Poliakov, Andrew; Novotny, Edward J; Olson, Jared D; Grabowski, Thomas J; Ojemann, Jeffrey G

2018-02-01

OBJECTIVE The acquisition and refinement of cognitive and behavioral skills during development is associated with the maturation of various brain oscillatory activities. Most developmental investigations have identified distinct patterns of low-frequency electrophysiological activity that are characteristic of various behavioral milestones. In this investigation, the authors focused on the cross-sectional developmental properties of high-frequency spectral power from the brain's default mode network (DMN) during goal-directed behavior. METHODS The authors contrasted regionally specific, time-evolving high gamma power (HGP) in the lateral DMN cortex between 3 young children (age range 3-6 years) and 3 adults by use of electrocorticography (ECoG) recordings over the left perisylvian cortex during a picture-naming task. RESULTS Across all participants, a nearly identical and consistent response suppression of HGP, which is a functional signature of the DMN, was observed during task performance recordings acquired from ECoG electrodes placed over the lateral DMN cortex. This finding provides evidence of relatively early maturation of the DMN. Furthermore, only HGP relative to evoked alpha and beta band power showed this level of consistency across all participants. CONCLUSIONS Regionally specific, task-evoked suppression of the high-frequency components of the cortical power spectrum is established early in brain development, and this response may reflect the early maturation of specific cognitive and/or computational mechanisms.

Regulation of early and delayed radiation responses in rat small intestine by capsaicin-sensitive nerves

International Nuclear Information System (INIS)

Wang Junru; Zheng Huaien; Kulkarni, Ashwini; Ou Xuemei; Hauer-Jensen, Martin

2006-01-01

Purpose: Mast cells protect against the early manifestations of intestinal radiation toxicity, but promote chronic intestinal wall fibrosis. Intestinal sensory nerves are closely associated with mast cells, both anatomically and functionally, and serve an important role in the regulation of mucosal homeostasis. This study examined the effect of sensory nerve ablation on the intestinal radiation response in an established rat model. Methods and Materials: Rats underwent sensory nerve ablation with capsaicin or sham ablation. Two weeks later, a localized segment of ileum was X-irradiated or sham irradiated. Structural, cellular, and molecular changes were examined 2 weeks (early injury) and 26 weeks (chronic injury) after irradiation. The mast cell dependence of the effect of sensory nerve ablation on intestinal radiation injury was assessed using c-kit mutant (Ws/Ws) mast cell-deficient rats. Results: Capsaicin treatment caused a baseline reduction in mucosal mast cell density, crypt cell proliferation, and expression of substance P and calcitonin gene-related peptide, two neuropeptides released by sensory neurons. Sensory nerve ablation strikingly exacerbated early intestinal radiation toxicity (loss of mucosal surface area, inflammation, intestinal wall thickening), but attenuated the development of chronic intestinal radiation fibrosis (collagen I accumulation and transforming growth factor β immunoreactivity). In mast cell-deficient rats, capsaicin treatment exacerbated postradiation epithelial injury (loss of mucosal surface area), but none of the other aspects of radiation injury were affected by capsaicin treatment. Conclusions: Ablation of capsaicin-sensitive enteric neurons exacerbates early intestinal radiation toxicity, but attenuates development of chronic fibroproliferative changes. The effect of capsaicin treatment on the intestinal radiation response is partly mast cell dependent

Vasomotor response to cold stimulation in human capsaicin-induced hyperalgesic area.

Science.gov (United States)

Pud, Dorit; Andersen, Ole Kaeseler; Arendt-Nielsen, Lars; Eisenberg, Elon; Yarnitsky, David

2005-07-01

Cooling the skin induces sympathetically driven vasoconstriction, with some vasoparalytic dilatation at the lowest temperatures. Neurogenic inflammation, on the other hand, entails vasodilatation. In this study we investigated the balance between vasoconstriction and vasodilatation in an area of experimentally induced secondary hyperalgesia (2 degrees HA), in response to low-temperature stimulations. Fourteen healthy volunteers were exposed to three 30-s long cold stimuli (20, 10, and 0 degrees C) applied, at three adjacent sites, before (baseline) and 8 min after intradermal injection of 50 microg capsaicin to the volar forearm. The cold stimuli were applied distally to the injection site within the 2 degrees HA. Blood flux (BF) and skin temperatures were measured at four different regions (proximally, and distally to the capsaicin injection and at the 0, 10, and 20 degrees C thermode sites) all within the 2 degrees HA. The vascular measurements were conducted five times. Results showed a marked increase in BF after baseline cold stimulation (Peffect (elevated BF) was found following the capsaicin injection compared with baseline for all regions (Pcooled area was dilated by 450+/-5.1%; The vasoconstrictive effect for the 10 and 20 degrees C did not overcome the capsaicin vasodilatation, but did reduce it, with dilatation of 364+/-7.0% and 329+/-7.3%, respectively. For 0 degrees C, a dilatation of 407+/-6.5% was seen. It is concluded that in this experimental model, and potentially in the equivalent clinical syndromes, vasodilatation induced by the inflammation is only slightly reduced by cold stimulation such that it is still dominant, despite some cold-induced vasoconstriction.

Cannabinoid hyperemesis syndrome: potential mechanisms for the benefit of capsaicin and hot water hydrotherapy in treatment.

Science.gov (United States)

Richards, John R; Lapoint, Jeff M; Burillo-Putze, Guillermo

2018-01-01

Cannabinoid hyperemesis syndrome is a clinical disorder that has become more prevalent with increasing use of cannabis and synthetic cannabinoids, and which is difficult to treat. Standard antiemetics commonly fail to alleviate the severe nausea and vomiting characteristic of the syndrome. Curiously, cannabinoid hyperemesis syndrome patients often report dramatic relief of symptoms with hot showers and baths, and topical capsaicin. In this review, we detail the pharmacokinetics and pharmacodynamics of capsaicin and explore possible mechanisms for its beneficial effect, including activation of transient receptor potential vanilloid 1 and neurohumoral regulation. Putative mechanisms responsible for the benefit of hot water hydrotherapy are also investigated. An extensive search of PubMed, OpenGrey, and Google Scholar from inception to April 2017 was performed to identify known and theoretical thermoregulatory mechanisms associated with the endocannabinoid system. The searches resulted in 2417 articles. These articles were screened for relevant mechanisms behind capsaicin and heat activation having potential antiemetic effects. References from the selected articles were also hand-searched. A total of 137 articles were considered relevant and included. Capsaicin: Topical capsaicin is primarily used for treatment of neuropathic pain, but it has also been used successfully in some 20 cases of cannabinoid hyperemesis syndrome. The pharmacokinetics and pharmacodynamics of capsaicin as a transient receptor potential vanilloid 1 agonist may explain this effect. Topical capsaicin has a longer half-life than oral administration, thus its potential duration of benefit is longer. Capsaicin and transient receptor potential vanilloid 1: Topical capsaicin binds and activates the transient receptor potential vanilloid 1 receptor, triggering influx of calcium and sodium, as well as release of inflammatory neuropeptides leading to transient burning, stinging, and itching. This elicits

Protein phosphatase 2A regulates central sensitization in the spinal cord of rats following intradermal injection of capsaicin

Directory of Open Access Journals (Sweden)

Fang Li

2006-03-01

Full Text Available Abstract Background Intradermal injection of capsaicin into the hind paw of rats induces spinal cord central sensititzation, a process in which the responsiveness of central nociceptive neurons is amplified. In central sensitization, many signal transduction pathways composed of several cascades of intracellular enzymes are involved. As the phosphorylation state of neuronal proteins is strictly controlled and balanced by the opposing activities of protein kinases and phosphatases, the involvement of phosphatases in these events needs to be investigated. This study is designed to determine the influence of serine/threonine protein phosphatase type 2A (PP2A on the central nociceptive amplification process, which is induced by intradermal injection of capsaicin in rats. Results In experiment 1, the expression of PP2A protein in rat spinal cord at different time points following capsaicin or vehicle injection was examined using the Western blot method. In experiment 2, an inhibitor of PP2A (okadaic acid, 20 nM or fostriecin, 30 nM was injected into the subarachnoid space of the spinal cord, and the spontaneous exploratory activity of the rats before and after capsaicin injection was recorded with an automated photobeam activity system. The results showed that PP2A protein expression in the spinal cord was significantly upregulated following intradermal injection of capsaicin in rats. Capsaicin injection caused a significant decrease in exploratory activity of the rats. Thirty minutes after the injection, this decrease in activity had partly recovered. Infusion of a phosphatase inhibitor into the spinal cord intrathecal space enhanced the central sensitization induced by capsaicin by making the decrease in movement last longer. Conclusion These findings indicate that PP2A plays an important role in the cellular mechanisms of spinal cord central sensitization induced by intradermal injection of capsaicin in rats, which may have implications in

The effects of cellulase on capsaicin production in freely suspended cells and immobilized cell cultures of capsicum annuum

International Nuclear Information System (INIS)

Islek, C.

2014-01-01

The effect of different concentrations of cellulase on the production of capsaicin in freely suspended cell and immobilized cell cultures of Kahramanmara pepper seeds (Capsicum annuum L.) were studied. Calluses were obtained from in vitro germinated hypocotyl explants of pepper seedlings and cell suspensions were prepared from these calluses. Immobilized cell suspension cultures with calcium alginate and free cell suspension cultures were obtained by using cell suspensions. Elicitor such as cellulase (5-30 micro g/ml), was applied both for the free and immobilized cell suspensions and control group without elicitor was prepared. The concentration of capsaicin in freely suspended cells, immobilized cells and their filtrates were identified by HPLC after extraction with ethyl acetate. It was found that the immobilization process had an increasing effect on the capsaicin accumulation. The concentration of capsaicin in the immobilized cells for both control groups and elicitor added samples was higher than the free cells. In general, capsaicin concentration in the filtrate for free cells was higher than the immobilized cells. When all the cellulase and the sampling hours were compared, the highest capsaicin concentration for the immobilized cells was determined as 362,91 micro g/ml f.w. at the 24th hour for 30 micro g/ml cellulase applied samples. (author)

Differential bitterness in capsaicin, piperine, and ethanol associates with polymorphisms in multiple bitter taste receptor genes.

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Nolden, Alissa A; McGeary, John E; Hayes, John E

2016-03-15

To date, the majority of research exploring associations with genetic variability in bitter taste receptors has understandably focused on compounds and foods that are predominantly or solely perceived as bitter. However, other chemosensory stimuli are also known to elicit bitterness as a secondary sensation. Here we investigated whether TAS2R variation explains individual differences in bitterness elicited by chemesthetic stimuli, including capsaicin, piperine and ethanol. We confirmed that capsaicin, piperine and ethanol elicit bitterness in addition to burning/stinging sensations. Variability in perceived bitterness of capsaicin and ethanol were significantly associated with TAS2R38 and TAS2R3/4/5 diplotypes. For TAS2R38, PAV homozygotes perceived greater bitterness from capsaicin and ethanol presented on circumvallate papillae, compared to heterozygotes and AVI homozygotes. For TAS2R3/4/5, CCCAGT homozygotes rated the greatest bitterness, compared to heterozygotes and TTGGAG homozygotes, for both ethanol and capsaicin when presented on circumvallate papillae. Additional work is needed to determine how these and other chemesthetic stimuli differ in bitterness perception across concentrations and presentation methods. Furthermore, it would be beneficial to determine which TAS2R receptors are activated in vitro by chemesthetic compounds. Copyright © 2016. Published by Elsevier Inc.

Antilithogenic influence of dietary capsaicin and curcumin during experimental induction of cholesterol gallstone in mice.

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Shubha, Malenahalli C; Reddy, Raghunatha R L; Srinivasan, Krishnapura

2011-04-01

Spice bioactive compounds, capsaicin and curcumin, were both individually and in combination examined for antilithogenic potential during experimental induction of cholesterol gallstones in mice. Cholesterol gallstones were induced by feeding mice a high-cholesterol (0.5%) diet for 10 weeks. Groups of mice were maintained on a lithogenic diet that was supplemented with 0.015% capsaicin/0.2% curcumin/0.015% capsaicin + 0.2% curcumin. The lithogenic diet that contained capsaicin, curcumin, or their combination reduced the incidence of cholesterol gallstones by 50%, 66%, and 56%, respectively, compared with lithogenic control. This was accompanied by reduced biliary cholesterol and a marginal increase in phospholipid in these spice-fed groups. Increased cholesterol saturation index and cholesterol : phospholipid ratio in the bile caused by the lithogenic diet was countered by the dietary spice compounds. The antilithogenic influence of spice compounds was attributable to the cholesterol-lowering effect of these dietary spices in blood and liver, as well as a moderate increase in phospholipids. Decreased activities of hepatic glutathione reductase and glutathione-S-transferase caused by the lithogenic diet were countered by the combination of capsaicin and curcumin. The increased lipid peroxidation and the decreased concentration of ascorbic acid in the liver that was caused by the lithogenic diet was countered by the dietary spice compounds, individually or in combination. Thus, while the capsaicin and curcumin combination did not have an additive influence in reducing the incidence of cholesterol gallstones in mice, their combination nevertheless was more beneficial in enhancing the activity of hepatic antioxidant enzyme ─ glutathione reductase in the lithogenic situation. The antioxidant effects of dietary spice compounds are consistent with the observed reduction in cholesterol gallstones formed under lithogenic condition.

Comparison of burrowing and stimuli-evoked pain behaviors as end-points in rat models of inflammatory pain and peripheral neuropathic pain

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Arjun eMuralidharan

2016-05-01

Full Text Available Establishment and validation of ethologically-relevant, non-evoked behavioral end-points as surrogate measures of spontaneous pain in rodent pain models has been proposed as a means to improve preclinical to clinical research translation in the pain field. Here, we compared the utility of burrowing behavior with hypersensitivity to applied mechanical stimuli for pain assessment in rat models of chronic inflammatory and peripheral neuropathic pain. Briefly, groups of male Sprague-Dawley rats were habituated to the burrowing environment and trained over a 5-day period. Rats that burrowed ≤450g of gravel on any two days of the individual training phase were excluded from the study. The remaining rats received either a unilateral intraplantar injection of Freund’s complete adjuvant (FCA or saline, or underwent unilateral chronic constriction injury (CCI of the sciatic nerve- or sham-surgery. Baseline burrowing behavior and evoked pain behaviors were assessed prior to model induction, and twice-weekly until study completion on day 14. For FCA- and CCI-rats, but not the corresponding groups of sham-rats, evoked mechanical hypersensitivity developed in a temporal manner in the ipsilateral hindpaws. Although burrowing behavior also decreased in a temporal manner for both FCA- and CCI-rats, there was considerable inter-animal variability. By contrast, mechanical hyperalgesia and mechanical allodynia in the ipsilateral hindpaws of FCA- and CCI-rats respectively, exhibited minimal inter-animal variability. Our data collectively show that burrowing behavior is altered in rodent models of chronic inflammatory pain and peripheral neuropathic pain. However, large group sizes are needed to ensure studies are adequately powered due to considerable inter-animal variability.

Alterations of autonomic nervous activity and energy metabolism by capsaicin ingestion during aerobic exercise in healthy men.

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Shin, Ki Ok; Moritani, Toshio

2007-04-01

We investigated whether capsaicin ingestion (150 mg) enhances substrate oxidation associated with thermogenic sympathetic activity as an energy metabolic modulator without causing prolongation of the cardiac OT interval during aerobic exercise in humans. Ten healthy males [24.4 (4.3) y] volunteered for this study. The cardiac autonomic nervous activities evaluated by means of heart rate variability of power spectral analysis, energy metabolism, and ECG QT interval were continuously measured during 5-min rest and 30-min exercise at 50% of maximal ventilatory threshold (50% VT(max)) on a stationary ergometer with placebo or capsaicin oral administration chosen at random. The results indicated that there were no significant differences in heart rate during rest or exercise between the two trials. Autonomic nervous activity increased in the capsaicin tablet trial during exercise, but the difference did not reach statistical significance. Capsaicin, however, significantly induced a lower respiratory gas exchange ratio [0.92 (0.02) vs. 0.94 (0.02), means (SE), p means (SE), p < 0.05] during exercise. On the other hand, the data on the cardiac OT interval showed no significant difference, indicating that oral administration of capsaicin did not cause any adverse effect on cardiac depolarization-repolarization. In conclusion, it may be considered that capsaicin consumption 1 h before low intensity exercise (50% VT(max)) is a valuable supplement for the treatment of individuals with hyperlipidemia and/or obesity because it improves lipolysis without any adverse effects on the cardiac depolarization and repolarization process.

Topical Mannitol Reduces Capsaicin-Induced Pain: Results of a Pilot-Level, Double-Blind, Randomized Controlled Trial.

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Bertrand, Helene; Kyriazis, Marylene; Reeves, K Dean; Lyftogt, John; Rabago, David

2015-11-01

Capsaicin specifically activates, and then gradually exhausts, the transient receptor potential vanilloid type 1 (TRPV1) receptor, a key receptor in neuropathic pain. Activation of the TRPV-1 receptor is accompanied by burning pain. A natural substance or medication that can reduce the burning pain resulting from capsaicin application may have therapeutic potential in neuropathic pain. To assess the pain-relieving effects of a mannitol-containing cream in a capsaicin-based pain model. Randomized, placebo-controlled, double-blind clinical trial. Outpatient pain clinic. Twenty-five adults with pain-free lips. Capsaicin .075% cream was applied to both halves of each participant's upper lip, inducing pain via stimulation of the transient receptor potential vanilloid 1 (TRPV1, capsaicin) receptor, then removed after 5 minutes or when participants reported a burning pain of 8/10, whichever came first. A cream containing mannitol and the same cream without mannitol (control) were then immediately applied, 1 on each side of the lip, in an allocation-masked manner. Participants self-recorded a numeric rating scale (NRS, 0-10) pain score for each side of the lip per minute for 10 minutes. A t-test was performed to evaluate the pain score change from baseline between each side of the lip at each recording. Area under the curve (AUC) analysis was used to determine the overall difference between groups. Participants reached a capsaicin-induced pain level of 7.8 ± 1.0 points in 3.3 ± 1.6 minutes that was equal on both sides of the lip. Both groups reported progressive diminution of pain over the 10-minute study period. However, participants reported significantly reduced pain scores on the mannitol cream half-lip compared to control at 3 through 10 minutes (P < .05) and in AUC analysis (P < .001). Mannitol cream reduced self-reported pain scores in a capsaicin pain model more rapidly than a control cream, potentially via a TRPV1 receptor effect. Copyright © 2015 American

The Aversive Agent Lithium Chloride Suppresses Phasic Dopamine Release Through Central GLP-1 Receptors.

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Fortin, Samantha M; Chartoff, Elena H; Roitman, Mitchell F

2016-02-01

Unconditioned rewarding stimuli evoke phasic increases in dopamine concentration in the nucleus accumbens (NAc) while discrete aversive stimuli elicit pauses in dopamine neuron firing and reductions in NAc dopamine concentration. The unconditioned effects of more prolonged aversive states on dopamine release dynamics are not well understood and are investigated here using the malaise-inducing agent lithium chloride (LiCl). We used fast-scan cyclic voltammetry to measure phasic increases in NAc dopamine resulting from electrical stimulation of dopamine cell bodies in the ventral tegmental area (VTA). Systemic LiCl injection reduced electrically evoked dopamine release in the NAc of both anesthetized and awake rats. As some behavioral effects of LiCl appear to be mediated through glucagon-like peptide-1 receptor (GLP-1R) activation, we hypothesized that the suppression of phasic dopamine by LiCl is GLP-1R dependent. Indeed, peripheral pretreatment with the GLP-1R antagonist exendin-9 (Ex-9) potently attenuated the LiCl-induced suppression of dopamine. Pretreatment with Ex-9 did not, however, affect the suppression of phasic dopamine release by the kappa-opioid receptor agonist, salvinorin A, supporting a selective effect of GLP-1R stimulation in LiCl-induced dopamine suppression. By delivering Ex-9 to either the lateral or fourth ventricle, we highlight a population of central GLP-1 receptors rostral to the hindbrain that are involved in the LiCl-mediated suppression of NAc dopamine release.

TRPM7 is required within zebrafish sensory neurons for the activation of touch-evoked escape behaviors

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Low, Sean E.; Amburgey, Kimberly; Horstick, Eric; Linsley, Jeremy; Sprague, Shawn M.; Cui, Wilson W.; Zhou, Weibin; Hirata, Hiromi; Saint-Amant, Louis; Hume, Richard I.; Kuwada, John Y.

2011-01-01

Mutations in the gene encoding TRPM7 (trpm7), a member of the TRP superfamily of cation channels that possesses an enzymatically active kinase at its carboxyl terminus, cause the touch-unresponsive zebrafish mutant touchdown. We identified and characterized a new allele of touchdown, as well as two previously reported alleles, and found that all three alleles harbor mutations which abolish channel activity. Through the selective restoration of TRPM7 expression in sensory neurons we found that TRPM7’s kinase activity, and selectivity for divalent cations over monovalent cations, were dispensable for touch-evoked activation of escape behaviors in zebrafish. Additional characterization revealed that sensory neurons were present and capable of responding to tactile stimuli in touchdown mutants, indicating that TRPM7 is not required for sensory neuron survival or mechanosensation. Finally, exposure to elevated concentrations of divalent cations was found to restore touch-evoked behaviors in touchdown mutants. Collectively these findings are consistent with a role for zebrafish TRPM7 within sensory neurons in the modulation of neurotransmitter release at central synapses, similar to that proposed for mammalian TRPM7 at peripheral synapses. PMID:21832193

Development of 68Ga-SCN-DOTA-Capsaicin as an Imaging Agent Targeting Apoptosis and Cell Cycle Arrest in Breast Cancer.

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Lee, Jun Young; Lee, Sang-Yeun; Kim, Gun Gyun; Hur, Min Goo; Yang, Seung Dae; Park, Jeong-Hoon; Kim, Sang Wook

2017-06-01

68 Ga-labeled capsaicin using a DOTA (1,4,7,10-tetraazocyclododecane-N,N',N″,N'″-tetraacetic acid) derivative [ 68 Ga-SCN-Benzyl(Bn)-DOTA-capsaicin] was studied for the diagnosis of breast cancers, such as MCF-7 and SK-BR-3. The standard compound, 69 Ga-SCN-Bn-DOTA-capsaicin, was also prepared and characterized by spectroscopic analysis. The binding affinity of 68 Ga-SCN-Bn-DOTA-capsaicin was evaluated by using breast cancer cell lines (MCF-7, SK-BR-3) and colon cancer cell (CT-26); the biodistribution was carried out by using MCF-7-bearing nude mice, after which the positron emission tomography (PET) images were obtained at different time intervals (15-120 minutes). 68 Ga-SCN-Bn-DOTA-capsaicin showed a cellular uptake of 0.93% Injected Dose (ID) after 30 minutes of incubation, whereas 68 Ga-SCN-Bn-DOTA showed a lower uptake of 0.25% ID. The tumor-to-blood ID/g% ratios increased and were found to be 0.49, 0.22, and 0.77 for 15, 30, and 60 minutes, respectively. The small-animal PET study showed that the uptake of 68 Ga-SCN-Bn-DOTA-capsaicin was higher in the tumor regions even at 30 minutes after injection. These results suggest that 68 Ga-SCN-Bn-DOTA-capsaicin is a potential targeting agent for PET imaging of MCF-7.

Design, synthesis and biological evaluation of novel hydrogen sulfide releasing capsaicin derivatives.

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Gao, Mingxiang; Li, Jinyu; Nie, Cunbin; Song, Beibei; Yan, Lin; Qian, Hai

2018-05-15

Capsaicin (CAP), the prototypical TRPV1 agonist, is the major active component in chili peppers with health-promoting benefits. However, its use is limited by the low bioavailability and irritating quality. In this study, for improving the activity of CAP and alleviating its irritating effects, a series of H 2 S-releasing CAPs were designed and synthesized by combining capsaicin and dihydro capsaicin with various hydrogen sulfide donors. The resulting compounds were evaluated their TRPV1 agonist activity, analgesic activity, anticancer activities, H 2 S-releasing ability, and gastric mucosa irritation. Biological evaluation indicated that the most active compound B 9 , containing 5-(4-hydroxyphenyl)-3H-1,2-dithiole-3-thione moiety as H 2 S donor, had better analgesic activity and displayed more potent cytotoxic effects on the test cell lines than the lead compound CAP. Furthermore, the preferred compound, B 9 reduced rat gastric mucosa irritation caused by CAP. Notably, the improved properties of this derivative are associated with its H 2 S-releasing capability. Copyright © 2018 Elsevier Ltd. All rights reserved.

Focal Suppression of Distractor Sounds by Selective Attention in Auditory Cortex.

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Schwartz, Zachary P; David, Stephen V

2018-01-01

Auditory selective attention is required for parsing crowded acoustic environments, but cortical systems mediating the influence of behavioral state on auditory perception are not well characterized. Previous neurophysiological studies suggest that attention produces a general enhancement of neural responses to important target sounds versus irrelevant distractors. However, behavioral studies suggest that in the presence of masking noise, attention provides a focal suppression of distractors that compete with targets. Here, we compared effects of attention on cortical responses to masking versus non-masking distractors, controlling for effects of listening effort and general task engagement. We recorded single-unit activity from primary auditory cortex (A1) of ferrets during behavior and found that selective attention decreased responses to distractors masking targets in the same spectral band, compared with spectrally distinct distractors. This suppression enhanced neural target detection thresholds, suggesting that limited attention resources serve to focally suppress responses to distractors that interfere with target detection. Changing effort by manipulating target salience consistently modulated spontaneous but not evoked activity. Task engagement and changing effort tended to affect the same neurons, while attention affected an independent population, suggesting that distinct feedback circuits mediate effects of attention and effort in A1. © The Author 2017. Published by Oxford University Press.

Reaction to topical capsaicin in spinal cord injury patients with and without central pain

DEFF Research Database (Denmark)

Finnerup, Nanna Brix; Pedersen, Louise H.; Terkelsen, Astrid J.

2007-01-01

of a spinal cord injury which already is hyperexcitable, would cause enhanced responses in patients with central pain at the level of injury compared to patients without neuropathic pain and healthy controls. Touch, punctuate stimuli, cold stimuli and topical capsaicin was applied above, at, and below injury......Central neuropathic pain is a debilitating and frequent complication to spinal cord injury (SCI). Excitatory input from hyperexcitable cells around the injured grey matter zone is suggested to play a role for central neuropathic pain felt below the level of a spinal cord injury. Direct evidence...... for this hypothesis is difficult to obtain. Capsaicin, activating TRPV1 receptors on small sensory afferents, induces enhanced cellular activity in dorsal horn neurons and produces a central mediated area of secondary hyperalgesia. We hypothesized that sensory stimuli and capsaicin applied at and just above the level...

Antibacterial effect of silver nanoparticles and capsaicin against MDR-ESBL producing Escherichia coli: An in vitro study

Directory of Open Access Journals (Sweden)

Debasish Kar

2016-10-01

Full Text Available Objective: To evaluate the antibacterial property of silver nanoparticles (AgNPs and capsaicin against multidrug resistant (MDR and extended spectrum beta-lactamase (ESBL producing Escherichia coli of bovine and poultry origin. Methods: Antibacterial efficacy of AgNPs and capsaicin was measured using broth dilution method. Five MDR-ESBL producing E. coli isolates of poultry (PEC4, PEC6, PEC15 and PEC16 and cattle mastitis origin (MEC2 were taken to evaluate the antibacterial effect of AgNPs and capsaicin. Results: At 50 mmol/L AgNPs, the viability of MDR of bacterial pathogens was reduced to almost 80%–90% and at 1000 mmol/L, the viability went down to 0%–3%. The minimum inhibitory concentration (MIC50 of AgNPs against these MDR-ESBL producing isolates was found to vary between 172–218 mmol/L whereas the MIC80 varied between 450–640 mmol/L. Capsaicin showed more prominent bactericidal effect and only at 2.5 mmol/L concentration, the viability was shown to be reduced by 20%–35% whereas at 7.5 mmol/L concentration, there was approximately 60% reduction in viability. Further at 25 mmol/L concentration, the viability was reduced to 0%–8%. The MIC50 and MIC80 of capsaicin against these MDRESBL producing isolates were found to vary between 4.6–7.5 mmol/L and 10.9–16.9 mmol/L, respectively. Conclusions: The results point out that capsaicin and AgNPs could be of use in treating ESBL infection.

Role of the intraluminal contents and the continuity of intrinsic neurons in intracolonic capsaicin-induced contraction and defecation in dogs.

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Kikuchi, Daisuke; Shibata, Chikashi; Imoto, Hirofumi; Someya, Soutoku; Miyachi, Tomohiro; Miura, Koh; Naitoh, Takeshi; Unno, Michiaki

2014-01-01

We, herein, examined the role of the intraluminal contents and continuity of colonic intrinsic neurons in intracolonic capsaicin-induced enhancement of colonic motility and defecation. Five beagle dogs were equipped with three strain gauge force transducers throughout the colon. The colonic contractile activity in response to intracolonic capsaicin was studied in intact dogs, dogs after colonic cleansing and dogs with transection/re-anastomosis (T/R) between the proximal and middle colon. The effects of intravenous yohimbine, a α2 adrenergic antagonist, on the colonic motility and defecation were also studied in the same models. In intact dogs, capsaicin (10 mg) and yohimbine (2 mg/kg) immediately induced contractions throughout the colon, with defecation occurring in all experiments. In dogs after colonic cleansing and T/R, the capsaicin (10 mg)-induced enhancement of colonic motility was decreased in the middle and distal colon, and capsaicin-induced defecation was observed in 0-20 % of experiments (p continuity of the colonic intrinsic nerves as well as the intraluminal contents appear to play an important role in the colonic motor response to intracolonic capsaicin.

Inhibitory effect of chronic oral treatment with fluoxetine on capsaicin-induced external carotid vasodilatation in anaesthetised dogs.

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Muñoz-Islas, Enriqueta; González-Hernández, Abimael; Lozano-Cuenca, Jair; Ramírez-Rosas, Martha Beatríz; Medina-Santillán, Roberto; Centurión, David; MaassenVanDenBrink, Antoinette; Villalón, Carlos M

2015-10-01

During migraine, capsaicin-sensitive trigeminal sensory nerves release calcitonin gene-related peptide (CGRP), resulting in cranial vasodilatation and central nociception. Moreover, 5-HT is involved in the pathophysiology of migraine and depression. Interestingly, some limited lines of evidence suggest that fluoxetine may be effective in migraine prophylaxis, but the underlying mechanisms are uncertain. Hence, this study investigated the canine external carotid vasodilator responses to capsaicin, α-CGRP and acetylcholine before and after acute and chronic oral treatment with fluoxetine. Forty-eight vagosympathectomised male mongrel dogs were prepared to measure blood pressure, heart rate and external carotid blood flow. The thyroid artery was cannulated for infusions of agonists. In 16 of these dogs, a spinal cannula was inserted (C1-C3) for infusions of 5-HT. The external carotid vasodilator responses to capsaicin, α-CGRP and acetylcholine remained unaffected after intracarotid or i.v. fluoxetine. In contrast, the vasodilator responses to capsaicin, but not those to α-CGRP or acetylcholine, were inhibited after chronic oral treatment with fluoxetine (300 µg/kg; for 90 days) or intrathecal 5-HT. Chronic oral fluoxetine inhibited capsaicin-induced external carotid vasodilatation, and this inhibition could partly explain its potential prophylactic antimigraine action. © International Headache Society 2015.

Preparative separation of capsaicin and dihydrocapsaicin from Capsicum frutescens by high-speed counter-current chromatography.

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Peng, Aihua; Ye, Haoyu; Li, Xia; Chen, Lijuan

2009-09-01

Capsaicin and dihydrocapsaicin are two main bioactive components of Capsicum frutescens and are widely used as food additives and drugs in China and India. Due to their similarity in structures, isolation of capsaicin and dihydrocapsaicin with traditional methods such as silica gel column chromatography, normal-phase thin-layer chromatography (TLC) becomes difficult. This study involves separating capsaicin and dihydrocapsaicin with sufficient purity and recovery using high-speed counter-current chromatography (HSCCC) with a solvent system composed of n-hexane-ethyl acetate-methanol-water-acetic acid (20:20:20:20:2, v/v/v/v/v). Separation parameters such as sample volume, and sample concentration were first optimized on analytical HSCCC, and then scaled up to preparative HSCCC. 0.65 g capsaicin and 0.28 g dihydrocapsaicin were obtained from 1.2 g crude extract and their purities were 98.5 and 97.8%, respectively. The recoveries of the two compounds were 86.3 and 85.4%, respectively. The purity of the isolated compounds was analyzed by high-performance liquid chromatography (HPLC) and their structures were identified by (1)H nuclear magnetic resonance (NMR) and (13)C NMR analysis.

The Effects of Pregabalin and the Glial Attenuator Minocycline on the Response to Intradermal Capsaicin in Patients with Unilateral Sciatica

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Sumracki, Nicole M.; Hutchinson, Mark R.; Gentgall, Melanie; Briggs, Nancy; Williams, Desmond B.; Rolan, Paul

2012-01-01

Background Patients with unilateral sciatica have heightened responses to intradermal capsaicin compared to pain-free volunteers. No studies have investigated whether this pain model can screen for novel anti-neuropathic agents in patients with pre-existing neuropathic pain syndromes. Aim This study compared the effects of pregabalin (300 mg) and the tetracycline antibiotic and glial attenuator minocycline (400 mg) on capsaicin-induced spontaneous pain, flare, allodynia and hyperalgesia in patients with unilateral sciatica on both their affected and unaffected leg. Methods/Results Eighteen patients with unilateral sciatica completed this randomised, double-blind, placebo-controlled, three-way cross-over study. Participants received a 10 µg dose of capsaicin into the middle section of their calf on both their affected and unaffected leg, separated by an interval of 75 min. Capsaicin-induced spontaneous pain, flare, allodynia and hyperalgesia were recorded pre-injection and at 5, 20, 40, 60 and 90 min post-injection. Minocycline tended to reduce pre-capsaicin injection values of hyperalgesia in the affected leg by 28% (95% CI 0% to 56%). The area under the effect time curves for capsaicin-induced spontaneous pain, flare, allodynia and hyperalgesia were not affected by either treatment compared to placebo. Significant limb differences were observed for flare (AUC) (−38% in affected leg, 95% CI for difference −19% to −52%). Both hand dominance and sex were significant covariates of response to capsaicin. Conclusions It cannot be concluded that minocycline is unsuitable for further evaluation as an anti-neuropathic pain drug as pregabalin, our positive control, failed to reduce capsaicin-induced neuropathic pain. However, the anti-hyperalgesic effect of minocycline observed pre-capsaicin injection is promising pilot information to support ongoing research into glial-mediated treatments for neuropathic pain. The differences in flare response between limbs may

Capsaicin pretreatment enhanced the bioavailability of fexofenadine in rats by P-glycoprotein modulation: in vitro, in situ and in vivo evaluation.

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Bedada, Satish Kumar; Appani, Ramgopal; Boga, Praveen Kumar

2017-06-01

Capsaicin is the main pungent principle present in chili peppers has been found to possess P-glycoprotein (P-gp) inhibition activity in vitro, which may have the potential to modulate bioavailability of P-gp substrates. Therefore, purpose of this study was to evaluate the effect of capsaicin on intestinal absorption and bioavailability of fexofenadine, a P-gp substrate in rats. The mechanistic evaluation was determined by non-everted sac and intestinal perfusion studies to explore the intestinal absorption of fexofenadine. These results were confirmed by an in vivo pharmacokinetic study of oral administered fexofenadine in rats. The intestinal transport and apparent permeability (P app ) of fexofenadine were increased significantly by 2.8 and 2.6 fold, respectively, in ileum of capsaicin treated rats when compared to control group. Similarly, absorption rate constant (K a ), fraction absorbed (F ab ) and effective permeability (P eff ) of fexofenadine were increased significantly by 2.8, 2.9 and 3.4 fold, respectively, in ileum of rats pretreated with capsaicin when compared to control group. In addition, maximum plasma concentration (C max ) and area under the concentration-time curve (AUC) were increased significantly by 2.3 and 2.4 fold, respectively, in rats pretreated with capsaicin as compared to control group. Furthermore, obtained results in rats pretreated with capsaicin were comparable to verapamil (positive control) treated rats. Capsaicin pretreatment significantly enhanced the intestinal absorption and bioavailability of fexofenadine in rats likely by inhibition of P-gp mediated cellular efflux, suggesting that the combined use of capsaicin with P-gp substrates may require close monitoring for potential drug interactions.

Knee joint mobilization reduces secondary mechanical hyperalgesia induced by capsaicin injection into the ankle joint.

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Sluka, K A; Wright, A

2001-01-01

Joint mobilization is a treatment approach commonly used by physical therapists for the management of a variety of painful conditions. However, the clinical effectiveness when compared to placebo and the neurophysiological mechanism of action are not known. The purpose of this study was to establish that application of a manual therapy technique will produce antihyperalgesia in an animal model of joint inflammation and that the antihyperalgesia produced by joint mobilization depends on the time of treatment application. Capsaicin (0.2%, 50 microl) was injected into the lateral aspect of the left ankle joint and mechanical withdrawal threshold assessed before and after capsaicin injection in Sprague-Dawley rats. Joint mobilization of the ipsilateral knee joint was performed 2 h after capsaicin injection for a total of 3 min, 9 min or 15 min under halothane anaesthesia. Control groups included animals that received halothane for the same time as the group that received joint mobilization and those whose limbs were held for the same duration as the mobilization (no halothane). Capsaicin resulted in a decreased mechanical withdrawal threshold by 2 h after injection that was maintained through 4 h. Both 9 and 15 min of mobilization, but not 3 min of mobilization, increased the withdrawal threshold to mechanical stimuli to baseline values when compared with control groups. The antihyperalgesic effect of joint mobilization lasted 30 min. Thus, joint mobilization (9 or 15 min duration) produces a significant reversal of secondary mechanical hyperalgesia induced by intra-articular injection of capsaicin. Copyright 2001 European Federation of Chapters of the International Association for the Study of Pain.

An automatic algorithm for blink-artifact suppression based on iterative template matching: application to single channel recording of cortical auditory evoked potentials

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Valderrama, Joaquin T.; de la Torre, Angel; Van Dun, Bram

2018-02-01

Objective. Artifact reduction in electroencephalogram (EEG) signals is usually necessary to carry out data analysis appropriately. Despite the large amount of denoising techniques available with a multichannel setup, there is a lack of efficient algorithms that remove (not only detect) blink-artifacts from a single channel EEG, which is of interest in many clinical and research applications. This paper describes and evaluates the iterative template matching and suppression (ITMS), a new method proposed for detecting and suppressing the artifact associated with the blink activity from a single channel EEG. Approach. The approach of ITMS consists of (a) an iterative process in which blink-events are detected and the blink-artifact waveform of the analyzed subject is estimated, (b) generation of a signal modeling the blink-artifact, and (c) suppression of this signal from the raw EEG. The performance of ITMS is compared with the multi-window summation of derivatives within a window (MSDW) technique using both synthesized and real EEG data. Main results. Results suggest that ITMS presents an adequate performance in detecting and suppressing blink-artifacts from a single channel EEG. When applied to the analysis of cortical auditory evoked potentials (CAEPs), ITMS provides a significant quality improvement in the resulting responses, i.e. in a cohort of 30 adults, the mean correlation coefficient improved from 0.37 to 0.65 when the blink-artifacts were detected and suppressed by ITMS. Significance. ITMS is an efficient solution to the problem of denoising blink-artifacts in single-channel EEG applications, both in clinical and research fields. The proposed ITMS algorithm is stable; automatic, since it does not require human intervention; low-invasive, because the EEG segments not contaminated by blink-artifacts remain unaltered; and easy to implement, as can be observed in the Matlab script implemeting the algorithm provided as supporting material.

Identifying the Integrated Neural Networks Involved in Capsaicin-Induced Pain Using fMRI in Awake TRPV1 Knockout and Wild-Type Rats

Directory of Open Access Journals (Sweden)

Jason Richard Yee

2015-02-01

Full Text Available In the present study, we used functional MRI in awake rats to investigate the pain response that accompanies intradermal injection of capsaicin into the hindpaw. To this end, we used BOLD imaging together with a 3D segmented, annotated rat atlas and computational analysis to identify the integrated neural circuits involved in capsaicin-induced pain. The specificity of the pain response to capsaicin was tested in a transgenic model that contains a biallelic deletion of the gene encoding for the transient receptor potential cation channel subfamily V member 1 (TRPV1. Capsaicin is an exogenous ligand for the TRPV1 receptor, and in wild-type rats, activated the putative pain neural circuit. In addition, capsaicin-treated wild-type rats exhibited activation in brain regions comprising the Papez circuit and habenular system, systems that play important roles in the integration of emotional information, and learning and memory of aversive information, respectively. As expected, capsaicin administration to TRPV1-KO rats failed to elicit the robust BOLD activation pattern observed in wild-type controls. However, the intradermal injection of formalin elicited a significant activation of the putative pain pathway as represented by such areas as the anterior cingulate, somatosensory cortex, parabrachial nucleus, and periaqueductal gray. Notably, comparison of neural responses to capsaicin in wild-type versus knock-out rats uncovered evidence that capsaicin may function in an antinociceptive capacity independent of TRPV1 signaling. Our data suggest that neuroimaging of pain in awake, conscious animals has the potential to inform the neurobiological basis of full and integrated perceptions of pain.

Estimation of capsaicin through scanning densitometry and evaluation of different varieties of capsicum in India.

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Gantait, Arunava; Maji, Amal; Barman, Tapu; Banerji, Pratim; Venkatesh, P; Mukherjee, Pulok K

2012-01-01

Capsicum annuum L. (family: Solanaceae) possesses therapeutic benefits for the treatment of rheumatism, neuropathy, psoriasis, flatulence and so on. In this study fruits of four different varieties of C. annuum from four different geographical regions in India were evaluated based on their total content of capsaicin. Ethanol extracts of the fruits were used. HPTLC plates were developed in a mobile phase containing benzene, ethyl acetate and methanol (75:20:5). Densitometric scanning was performed at a wavelength of 283 nm in the absorbance mode. The calibration curve was described by the equation Y=393.587+3.836*X with a correlation coefficient (r) of 0.99890. The content of capsaicin in Nagaland, Manipur, West Bengal and Shimla varieties was found to be 3.71%, 1.78%, 0.54% and 0.06%, respectively. The developed densitometric method was found to be specific, accurate and precise. A recovery study and precision showed low levels of %RSD values. The linearity range of the curve for capsaicin was found to be 300-900 ng per spot. The limit of detection and the limit of quantification values were determined to be 31 and 94 ng, respectively, proving the sensitivity of the method. Thus the method can be used to control the total content of capsaicin on an industrial scale.

[Preliminary protocol for systemic administration of capsaicin for the treatment of the burning mouth syndrome].

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Lauritano, D; Petruzzi, M; Baldoni, M

2003-06-01

Burning mouth syndrome could be considered an expression of atypical facial pain. The recent neuropathological findings in BMS may suggest the need for alternative therapies. This paper aims to evaluate if systemic capsaicin could be used for BMS the- rapy. Eighty-four BMS patients (19 males and 63 females, aged 36 to 74 years, mean 54.6) were referred to the Oral Medicine and Oral Pathology Department, Dental University Institute, Milan-Bicocca University. They were divided in 2 groups: 1(st) Group: the first group (42 patients) received 3 capsules of capsaicin (50 mg of powder of red pepper with 0,25% of capsaicin) a day for one month. 2(nd) Group: the control group (42 patients) received 3 capsules of placebo (empty capsules) a day for one month. The intensity of pain was measured on the visuo-analogical scale VAS. T test of Student was applied to analyse results of VAS. P values of less than 0.05 were interpreted as significant, and the level in confidence intervals was 95%. Significant differences were noted between the two groups at the end of our study (p<0.05). No important side effects were reported. Systemic capsaicin could be considered a successful therapeutical approach for BMS patients.

TRPA1-dependent reversible opening of tight junction by natural compounds with an α,β-unsaturated moiety and capsaicin.

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Kanda, Yusuke; Yamasaki, Youhei; Sasaki-Yamaguchi, Yoshie; Ida-Koga, Noriko; Kamisuki, Shinji; Sugawara, Fumio; Nagumo, Yoko; Usui, Takeo

2018-02-02

The delivery of hydrophilic macromolecules runs into difficulties such as penetration of the cell membrane lipid bilayer. Our prior experiment demonstrated that capsaicin induces the reversible opening of tight junctions (TJs) and enhances the delivery of hydrophilic macromolecules through a paracellular route. Herein, we screened paracellular permeability enhancers other than capsaicin. As TJ opening by capsaicin is associated with Ca 2+ influx, we first screened the compounds that induce Ca 2+ influx in layered MDCK II cells, and then we determined the compounds' abilities to open TJs. Our results identified several natural compounds with α,β-unsaturated moiety. A structure-activity relationship (SAR) analysis and the results of pretreatment with reducing reagent DTT suggested the importance of α,β-unsaturated moiety. We also examined the underlying mechanisms, and our findings suggest that the actin reorganization seen in capsaicin treatment is important for the reversibility of TJ opening. Furthermore, our analyses revealed that TRPA1 is involved in the Ca 2+ influx and TJ permeability increase not only by an α,β-unsaturated compound but also by capsaicin. Our results indicate that the α,β-unsaturated moiety can be a potent pharmacophore for TJ opening.

Conformational analysis of capsaicin using 13C, 15N MAS NMR, GIAO DFT and GA calculations

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Siudem, Paweł; Paradowska, Katarzyna; Bukowicki, Jarosław

2017-10-01

Capsaicin produced by plants from genus Capsicum exerts multiple pharmacological effects and has found applications in food and pharmaceutical industry. The alkaloid was studied by a combined approach: solid-state NMR, GA conformational search and GIAO DFT methods. The 13C CPMAS NMR spectra were recorded using variable contact time and dipolar dephasing experiments. The results of cross-polarization (CP) kinetics, such as TCP values and long T1ρH (100-200 ms), indicated that the capsaicin molecule is fairly mobile, especially at the end of the aliphatic chain. The15N MAS NMR spectrum showed one narrow signal at -255 ppm. Genetic algorithm (GA) search with multi modal optimization was used to find low-energy conformations of capsaicin. Theoretical GIAO DFT calculations were performed using different basis sets to characterize five selected conformations. 13C CPMAS NMR was used as a validation method and the experimental chemical shifts were compared with those calculated for selected stable conformers. Conformational analysis suggests that the side chain can be bent or extended. A comparison of the experimental and the calculated chemical shifts indicates that solid capsaicin does not have the same structure as those established by PWXRD.

Partial transformation from fast to slow muscle fibers induced by deafferentation of capsaicin-sensitive muscle afferents.

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Brunetti, O; Barazzoni, A M; Della Torre, G; Clavenzani, P; Pettorossi, V E; Bortolami, R

1997-11-01

Mechanical and histochemical characteristics of the lateral gastrocnemius (LG) muscle of the rat were examined 21 days after capsaicin injection into the LG muscle. The capsaicin caused a decrease in generation rate of twitch and tetanic tension and an increase in fatigue resistance of LG muscle. The histochemical muscle fiber profile evaluated by myosin adenosine triphosphatase and reduced nicotinamide adenine dinucleotide tetrazolium reductase methods showed an increase of type I and IIC fibers and a decrease of the type IIB in whole muscle, and a decrease of the IIA, IIX fibers in the red part accompanied by their increase in the white part. Therefore the capsaicin treatment, which selectively eliminated fibers belonging to the III and IV groups of muscle afferents, induced muscle fiber transformation from fast contracting fatiguing fibers to slowly contracting nonfatiguing ones.

Effect of Capsaicin Cream on the Secretion of the Submandibular and Parotid Gland in the General Population with Different Chilli-eating Habits.

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Wang, Yang; Wang, Zhen; Yu, Guang Yan; Tang, Zhan Gui; Hu, Ji An

2016-06-01

To investigate the effect of capsaicin cream on the secretion of the submandibular gland (SMG) and the parotid gland (PG) in the general population, with different chilli-eating habits. In two groups with different chilli-eating habits, the salivary flow rate of the SMG and the PG was detected at statics and different times, after application of capsaicin cream. In both groups, the topical application of capsaicin cream could significantly increase the salivary secretion of SMG (P 0.05). On the other hand, although the salivary flow rate of PG also increased after stimulation, the increase had no statistical difference (P > 0.05). The application of capsaicin cream can effectively promote the secretion of the SMG and the PG, and its effect is independent of chilli-eating habits, which indicates that topical application of capsaicin cream can be considered as a potential treatment for the hypofunction of the salivary gland.

Application of the capsaicin 8% cutaneous patch in neuropathic pain of the head and face: A case series.

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Gaul, Charly; Resch, Sonja

2015-05-01

Treatment of neuropathic or neuralgic head and facial pain due to dental, traumatic or surgical nerve lesions or post-herpetic neuropathy is often challenging. We are reporting on four patients with neuropathic pain syndromes successfully treated with a capsaicin 8% patch in the affected area of the head or face. Treatment with the capsaicin 8% patch seems to be effective and safe for application to the facial and head region. The capsaicin 8% patch might be an additional treatment option if first-line treatment with anticonvulsants or antidepressants was ineffective or limited by side effects. © International Headache Society 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Vitamin B complex attenuated heat hyperalgesia following infraorbital nerve constriction in rats and reduced capsaicin in vivo and in vitro effects.

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Kopruszinski, Caroline M; Reis, Renata C; Bressan, Elisangela; Reeh, Peter W; Chichorro, Juliana G

2015-09-05

Vitamins of the B complex attenuate some neuropathic pain sensory aspects in various animal models and in patients, but the mechanisms underlying their effects remain to be elucidated. Herein it was investigated if the treatment with a vitamin B complex (VBC) reduces heat hyperalgesia in rats submitted to infraorbital nerve constriction and the possibility that TRPV1 receptors represent a target for B vitamins. In the present study, the VBC refers to a combination of vitamins B1, B6 and B12 at low- (18, 18 and 1.8mg/kg, respectively) or high- (180, 180 and 18mg/kg, respectively) doses. Acute treatment of rats with either the low- or the high-doses combination reduced heat hyperalgesia after nerve injury, but the high-doses combination resulted in a long-lasting effect. Repeated treatment with the low-dose combination reduced heat hyperalgesia on day four after nerve injury and showed a synergist effect with a single injection of carbamazepine (3 or 10mg/kg), which per se failed to modify the heat threshold. In naïve rats, acute treatment with the high-dose of VBC or B1 and B12 vitamins independently reduced heat hyperalgesia evoked by capsaicin (3µg into the upper lip). Moreover, the VBC, as well as, each one of the B vitamins independently reduced the capsaicin-induced calcium responses in HEK 293 cells transiently transfected with the human TRPV1 channels. Altogether, these results indicate that B vitamins can be useful to control heat hyperalgesia associated with trigeminal neuropathic pain and that modulation of TRPV1 receptors may contribute to their anti-hyperalgesic effects. Copyright © 2015. Published by Elsevier B.V.

Transmitter modulation of spike-evoked calcium transients in arousal related neurons

DEFF Research Database (Denmark)

Kohlmeier, Kristi Anne; Leonard, Christopher S

2006-01-01

Nitric oxide synthase (NOS)-containing cholinergic neurons in the laterodorsal tegmentum (LDT) influence behavioral and motivational states through their projections to the thalamus, ventral tegmental area and a brainstem 'rapid eye movement (REM)-induction' site. Action potential-evoked intracel......Nitric oxide synthase (NOS)-containing cholinergic neurons in the laterodorsal tegmentum (LDT) influence behavioral and motivational states through their projections to the thalamus, ventral tegmental area and a brainstem 'rapid eye movement (REM)-induction' site. Action potential......-evoked intracellular calcium transients dampen excitability and stimulate NO production in these neurons. In this study, we investigated the action of several arousal-related neurotransmitters and the role of specific calcium channels in these LDT Ca(2+)-transients by simultaneous whole-cell recording and calcium...... of cholinergic LDT neurons and that inhibition of spike-evoked Ca(2+)-transients is a common action of neurotransmitters that also activate GIRK channels in these neurons. Because spike-evoked calcium influx dampens excitability, our findings suggest that these 'inhibitory' transmitters could boost firing rate...

CAPSAICIN-SENSITIVE SENSORY NERVE FIBERS CONTRIBUTE TO THE GENERATION AND MAINTENANCE OF SKELETAL FRACTURE PAIN

OpenAIRE

Jimenez-Andrade, Juan Miguel; Bloom, Aaron P.; Mantyh, William G.; Koewler, Nathan J.; Freeman, Katie T.; Delong, David; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.

2009-01-01

Although skeletal pain can have a marked impact on a patient’s functional status and quality of life, relatively little is known about the specific populations of peripheral nerve fibers that drive non-malignant bone pain. In the present report, neonatal male Sprague Dawley rats were treated with capsaicin or vehicle and femoral fracture was produced when the animals were young adults (15–16 weeks old). Capsaicin treatment, but not vehicle, resulted in a significant (>70%) depletion in the de...

Dietary capsaicin and antibiotics act synergistically to reduce non-alcoholic fatty liver disease induced by high fat diet in mice.

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Hu, Jingjuan; Luo, Haihua; Jiang, Yong; Chen, Peng

2017-06-13

The prevalence of non-alcoholic fatty liver disease is increasing rapidly worldwide. However, effective strategies for combating high-fat diet (HFD) induced obesity, fatty liver and metabolic disorder are still limited, and outcomes remain poor. In the present study, we evaluated the combined actions of dietary capsaicin and antibiotics on HFD-induced physiological abnormalities in mice. C57BL/6 male mice were fed with HFD (60% calories from fat) for 17 weeks, and the resultant pathophysiological effects were examined. Antibiotic treatment markedly attenuated gut inflammation and leakiness induced by HFD, whereas capsaicin showed limited effects on the gut. However, dietary capsaicin significantly increased PPAR-α expression in adipose tissue, while antibiotics had no such effect. Animals treated with a combination of capsaicin and antibiotics had the smallest body weight gain and fat pad index, as well as the lowest hepatic fat accumulation. Combination treatment also maximally improved insulin responsiveness, as indicated by insulin tolerance tests. These results suggest the co-treatment of capsaicin and antibiotics, a novel combination strategy, would play synergistically to attenuate the HFD-induced obesity, fatty liver and metabolic disorder.

Norepinephrine-evoked salt-sensitive hypertension requires impaired renal sodium chloride cotransporter activity in Sprague-Dawley rats.

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Walsh, Kathryn R; Kuwabara, Jill T; Shim, Joon W; Wainford, Richard D

2016-01-15

Recent studies have implicated a role of norepinephrine (NE) in the activation of the sodium chloride cotransporter (NCC) to drive the development of salt-sensitive hypertension. However, the interaction between NE and increased salt intake on blood pressure remains to be fully elucidated. This study examined the impact of a continuous NE infusion on sodium homeostasis and blood pressure in conscious Sprague-Dawley rats challenged with a normal (NS; 0.6% NaCl) or high-salt (HS; 8% NaCl) diet for 14 days. Naïve and saline-infused Sprague-Dawley rats remained normotensive when placed on HS and exhibited dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide. NE infusion resulted in the development of hypertension, which was exacerbated by HS, demonstrating the development of the salt sensitivity of blood pressure [MAP (mmHg) NE+NS: 151 ± 3 vs. NE+HS: 172 ± 4; P salt-sensitive animals, increased NE prevented dietary sodium-evoked suppression of peak natriuresis to hydrochlorothiazide, suggesting impaired NCC activity contributes to the development of salt sensitivity [peak natriuresis to hydrochlorothiazide (μeq/min) Naïve+NS: 9.4 ± 0.2 vs. Naïve+HS: 7 ± 0.1; P salt-sensitive component of NE-mediated hypertension, while chronic ANG II type 1 receptor antagonism significantly attenuated NE-evoked hypertension without restoring NCC function. These data demonstrate that increased levels of NE prevent dietary sodium-evoked suppression of the NCC, via an ANG II-independent mechanism, to stimulate the development of salt-sensitive hypertension. Copyright © 2016 the American Physiological Society.

Small-fibre neuropathy in female Fabry patients: reduced allodynia and skin blood flow after topical capsaicin

DEFF Research Database (Denmark)

Møller, Anette Torvin; Feldt-Rasmussen, Ulla; Rasmussen, Åse K.

2006-01-01

affected. Recently, attention has been drawn to female patients whether they also show signs of nerve involvement. An early sign of the disease is painful small-fibre neuropathy. The aim of this study was to evaluate a small-fibre dysfunction in female Fabry patients by using capsaicin applied topically......Fabry disease is a rare X-linked lysosomal storage disorder. The mutations result in a deficiency of the lysosomal enzyme α-galactosidase A causing accumulation of glycosphingolipids in the vascular endothelial cells and many other tissues. Given the X-linked inheritance, male patients are severely....... The response to capsaicin was evaluated by laser Doppler imaging. We found that the female Fabry patients had a significantly smaller increase in blood flow (p = 0.0003) after capsaicin application. The area of static mechanical allodynia and dynamic mechanical hyperalgesia was also significantly smaller (p...

A “burning” therapy for burning mouth syndrome: preliminary results with the administration of topical capsaicin.

Science.gov (United States)

Azzi, L; Croveri, F; Pasina, L; Porrini, M; Vinci, R; Manfredini, M; Tettamanti, L; Tagliabue, A; Silvestre-Rangil, J; Spadari, F

2017-01-01

Burning mouth syndrome is defined as an intraoral burning sensation for which no medical or dental cause can be found. Recently, researchers have demonstrated an altered trophism of the small nerve fibres and alterations in the numbers of TRPV-1 vanilloid receptors. Capsaicin is a molecule that is contained in hot peppers and is specifically detected by TRPV-1 vanilloid receptors that are distributed in the oral mucosae. We aimed at verifying if topical capsaicin could prove to be an effective treatment of Burning Mouth Syndrome. A group of 99 BMS patients were recruited. We subdivided the BMS patients into two groups: the collaborative patients, who expressed a predominantly neuropathic pattern of symptoms, and the non-collaborative patients, who were characterised by stronger psychogenic patterns of the syndrome. Both groups underwent topical therapy with capsaicin in the form of a mouth rinse 3 times a day for a long period. After 1 year of treatment, the final overall success rate was approximately 78%, but with a significant difference in the success rates of the two groups of patients (87% and 20% among the collaborative and non-collaborative patients, respectively; p=0.000). The use of topical capsaicin can improve the oral discomfort of BMS patients, especially during the first month of therapy, but it is more effective for those patients in which the neuropathic component of the syndrome is predominant. Our hypothesis is that chronic stimulation with capsaicin leads to decreases in burning symptoms. This phenomenon is called desensitisation and is accompanied by substantial improvements in oral symptoms.

Tachycardia in response to remote capsaicin injection as a model for nociception in the ball python (Python regius).

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Williams, Catherine J A; James, Lauren E; Bertelsen, Mads F; Wang, Tobias

2016-07-01

To quantify the effect of subcutaneous (SC) capsaicin injection on heart rate (HR) in ball pythons (Python regius) and to assess the efficacy of two opioids (morphine and butorphanol) in modifying this response. Prospective, randomized, unmatched study. Eleven mixed-sex, captive-bred ball pythons. Snakes were randomly assigned to three groups (n = 6) by intramuscular premedication: 1) control: saline (0.9 mL); 2) morphine (10 mg kg(-1) ); and 3) butorphanol (10 mg kg(-1) ). Three snakes were tested twice and another two were tested three times in different treatments administered 1 month apart. Under isoflurane anaesthesia, snakes were instrumented with SC electrocardiogram (ECG) electrodes and an SC catheter for remote stimulus delivery. After recovery from anaesthesia, all snakes, in visual and audial isolation from the experimenter, received a sham stimulus of saline (0.4 mL) via the SC catheter. A nociceptive stimulus of SC capsaicin (3 mg in 0.2 mL saline with 7% Tween 80) was then applied by catheter at 7 hours after premedication. In a subset (n = 3), two sham injections (saline 0.2 mL) preceded the capsaicin treatment. HR was recorded via ECG, and changes in HR (ΔHR) from baseline were calculated for all stimulations. Capsaicin injection was associated with a significant increase in HR [peak ΔHR: saline group: 8.8 ± 7.1 beats minute(-1) ; capsaicin group: 21.1 ± 5.8 beats minute(-1) (p = 0.0055)] and integrated ΔHR as a function of time. The administration of morphine or butorphanol 7 hours prior to nociception failed to significantly reduce the peak and integrated ΔHR. Butorphanol caused marked, long-lasting sedation as assessed by muscle tone. The HR response to an SC capsaicin injection can serve as a nociceptive model in P. regius. Morphine and butorphanol administration did not reduce HR response to capsaicin stimulation but produced significantly different effects on pre-stimulation HR and sedation. © 2015 Association

[Aural Stimulation with Capsaicin Ointment Improved the Swallowing Function in Patients with Dysphagia: Evaluation by the SMRC Scale].

Science.gov (United States)

Kondo, Eiji; Jinnouchi, Osamu; Ohnishi, Hiroki; Kawata, Ikuji; Takeda, Noriaki

2015-11-01

Cough and swallowing reflexes are important airway-protective mechanisms against aspiration. Angiotensin-converting enzyme (ACE) inhibitors, one of the side effects of which is cough, have been reported to reduce the incidence of aspiration pneumonia in hypertensive patients with stroke. ACE inhibitors have also been reported to improve the swallowing function in post-stroke patients. On the other hand, stimulation of the Arnold nerve, the auricular branch of the vagus, triggers the cough reflex (Arnold's ear-cough reflex). Capsaicin, an agonist of Transient Receptor Potential Vanilloid 1 (TRPV1), has been shown to activate the peripheral sensory C-fibers. Stimulation of the sensory branches of the vagus in the laryngotracheal mucosa with capsaicin induces the cough reflex and has been reported to improve the swallowing function in patients with dysphagia. In our previous study, we showed that aural stimulation of the Arnold nerve with 0.025% capsaicin ointment improved the swallowing function, as evaluated by the endoscopic swallowing score, in 26 patients with dysphagia. In the present study, the video images of swallowing recorded in the previous study were re-evaluated using the SMRC scale by an independent otolaryngologist who was blinded to the information about the patients and the endoscopic swallowing score. The SMRC scale is used to evaluate four aspects of the swallowing function: 1) Sensory: the initiation of the swallowing reflex as assessed by the white-out timing; 2) Motion: the ability to hold blue-dyed water in the oral cavity and induce laryngeal elevation; 3) Reflex: glottal closure and the cough reflex induced by touching the epiglottis or arytenoid with the endoscope; 4) Clearance: pharyngeal clearance of the blue-dyed water after swallowing. Accordingly, we demonstrated that a single application of capsaicin ointment to the external auditory canal of patients with dysphagia significantly improved the R, but not the S, M or C scores, and this

Advancing Nursing Practice: Management of Neuropathic Pain With Capsaicin 8% Without Physician Supervision.

Science.gov (United States)

O'Brien, Joanne; Keaveny, Joseph; Pollard, Valerie; Nugent, Linda Elizabeth

The purpose of this study was to examine the management of patient's neuropathic pain with capsaicin 8% in a nurse-led clinic when administered by 1 registered advanced nurse practitioner without physician supervision. A longitudinal, single-group, descriptive research design was used to assess pain scores and quality of life 3 times over 3 months after treatment. Patients with a diagnosis of neuropathic pain were assessed and treated with capsaicin 8% by 1 advanced nurse practitioner with prescriptive authority in a nurse-led clinic. Pain scores were collected at baseline, and self-assessed pain, activity level, and quality of life were assessed at 1 week, 4 weeks, and 3 months after treatment. Twenty-four patients were recruited, and data were analyzed using Friedman's test. In post hoc analysis, Wilcoxon signed-rank test was used with Bonferroni correction. Pain scores differed from pretreatment to posttreatment at each of the 3 time points, at rest (χ3 = 20.54, P = .001) and on movement (χ3 = 23.644, P = .001), and remained significant after Bonferroni correction. Overall, 62.5% (n = 15) of patients achieved at least a 30% reduction in self-reported pain at rest from pretreatment to 3 months, and 54% (n = 13) achieved the same reduction in pain on movement. Most improvements in patient's quality of life occurred between 1 and 4 weeks. Patient satisfaction was high, with 83% stating that they would be happy to have the treatment repeated. Single-dose capsaicin 8% decreased neuropathic pain after being administered in an outpatient setting by an experienced registered advanced nurse practitioner. Further multicenter research led by advanced nurse practitioners is needed to support high-quality, safe treatment of neuropathic pain with high-concentration capsaicin in nurse-led chronic pain clinics.

Aural stimulation with capsaicin ointment improved swallowing function in elderly patients with dysphagia: a randomized, placebo-controlled, double-blind, comparative study.

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Kondo, Eiji; Jinnouchi, Osamu; Nakano, Seiichi; Ohnishi, Hiroki; Kawata, Ikuji; Okamoto, Hidehiko; Takeda, Noriaki

2017-01-01

The aim of this study was to assess whether aural stimulation with ointment containing capsaicin improves swallowing function in elderly patients with dysphagia. A randomized, placebo-controlled, double-blind, comparative study. Secondary hospital. Twenty elderly dysphagic patients with a history of cerebrovascular disorder or Parkinson's disease were randomly divided into two groups: 10 receiving aural stimulation with 0.025% capsaicin ointment and 10 stimulated with placebo. The ointments were applied to the external auditory canal with a cotton swab. Then, swallowing of a bolus of blue-dyed water was recorded using transnasal videoendoscopy, and the swallowing function was evaluated according to both endoscopic swallowing scoring and Sensory-Motor-Reflex-Clearance (SMRC) scale. The sum of endoscopic swallowing scores was significantly decreased 30 and 60 min after a single administration in patients treated with capsaicin, but not with placebo. Reflex score, but not Sensory, Motion and Clearance scores, of the SMRC scale was significantly increased 5, 30 and 60 min after single administration in patients treated with capsaicin, but not with placebo. No patient showed signs of adverse effects. As capsaicin is an agonist of the transient receptor potential vanilloid 1 (TRPV1), these findings suggest that improvement of the swallowing function, especially glottal closure and cough reflexes, in elderly dysphagic patients was due to TRPV1-mediated aural stimulation of vagal Arnold's nerve with capsaicin, but not with a nonspecific mechanical stimulation with a cotton swab.

Ablation of capsaicin sensitive afferent nerves impairs defence but not rapid repair of rat gastric mucosa.

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Pabst, M A; Schöninkle, E; Holzer, P

1993-07-01

Capsaicin sensitive afferent neurones have previously been reported to play a part in gastric mucosal protection. The aim of this study was to investigate whether these nociceptive neurones strengthen mucosal defence against injury or promote rapid repair of the damaged mucosa, or both. This hypothesis was examined in anaesthetised rats whose stomachs were perfused with ethanol (25 or 50% in saline, wt/wt) for 30 minutes. The gastric mucosa was inspected 0 and 180 minutes after ethanol had been given at the macroscopic, light, and scanning electron microscopic level. Rapid repair of the ethanol injured gastric mucosa (reduction of deep injury, partial re-epithelialisation of the denuded surface) took place in rats anaesthetised with phenobarbital, but not in those anaesthetised with urethane. Afferent nerve ablation as a result of treating rats with a neurotoxic dose of capsaicin before the experiment significantly aggravated ethanol induced damage as shown by an increase in the area and depth of mucosal erosions. Rapid repair of the injured mucosa, however, as seen in rats anesthetised with phenobarbital 180 minutes after ethanol was given, was similar in capsaicin and vehicle pretreated animals. Ablation of capsaicin sensitive afferent neurones was verified by a depletion of calcitonin gene related peptide from the gastric corpus wall. These findings indicate that nociceptive neurones control mechanisms of defence against acute injury but are not required for rapid repair of injured mucosa.

High-dose 8% capsaicin patch in treatment of chemotherapy-induced peripheral neuropathy: single-center experience.

Science.gov (United States)

Filipczak-Bryniarska, Iwona; Krzyzewski, Roger M; Kucharz, Jakub; Michalowska-Kaczmarczyk, Anna; Kleja, Justyna; Woron, Jarosław; Strzepek, Katarzyna; Kazior, Lucyna; Wordliczek, Jerzy; Grodzicki, Tomasz; Krzemieniecki, Krzysztof

2017-08-17

High-dose capsaicin patch is effective in treatment of neuropathic pain in HIV-associated neuropathy and diabetic neuropathy. There are no studies assessing effectiveness of high-dose capsaicin patch in treatment of chemotherapy-induced peripheral neuropathy. We sought to determine the effectiveness of treatment of pain associated with chemotherapy-induced peripheral neuropathy with high-dose capsaicin patch. Our study group consisted of 18 patients with clinically confirmed oxaliplatin-induced neuropathy. Baseline characteristic including underling disease, received cumulative dose of neurotoxic agent, neuropathic symptoms, prior treatment and initial pain level were recorded. Pain was evaluated with Numeric Rating Scale prior to treatment with high-dose capsaicin and after 1.8 day and after 8 and 12 weeks after introducing treatment. Patients were divided into two groups accordingly to the amount of neurotoxic agent that caused neuropathy (high sensitivity and low sensitivity group). Most frequent symptoms of chemotherapy-induced neuropathy were: pain (88.89%), paresthesis (100%), sock and gloves sensation (100%) and hypoesthesis (100%). Initial pain level was 7.45 ± 1.14. Mean cumulative dose of oxaliplatin after which patients developed symptoms was 648.07 mg/m 2 . Mean pain level after 12 weeks of treatment was 0.20 ± 0.41. When examined according to high and low sensitivity to neurotoxic agent patients with low sensitivity had higher pain reduction, especially after 8 days after introducing treatment (69.55 ± 12.09 vs. 49.40 ± 20.34%; p = 0.02) and after 12 weeks (96.96 ± 5.56 vs. 83.93 ± 18.59%; p = 0.04). High-dose capsaicin patch is an effective treatment for pain associated with chemotherapy-induced neuropathy in patients treated with oxaliplatin. Patients with lower sensitivity to neurotoxic agents have better response to treatment and pain reduction.

Chemical analysis of freshly prepared and stored capsaicin solutions: implications for tussigenic challenges.

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Kopec, Scott E; DeBellis, Ronald J; Irwin, Richard S

2002-01-01

The purpose of this study was to assess the stability of stored capsaicin solutions and the actual concentrations of prepared solutions. Capsaicin solutions ranging in concentration from 0.5 to 128 microM were mixed and analyzed using high performance liquid chromatography. Samples of varying concentrations were then stored under 4 environmental conditions: 4 degrees C and protected from light, room temperature (RT) exposed to light, RT protected from light, and -20 degrees C and protected from light. The concentrations were measured every other month for 1 year. Actual concentrations of freshly prepared solutions were on average 88.3% of predicted. For solutions stored at 4 degrees C, there was a decrease only in the lower concentrations (0.5, 1, and 2 microM) after 2 months (P=0.003). Solutions stored at RT exposed to light decreased in concentration after 6 months (P=0.020), and solutions stored at RT protected from light decreased in concentration after 4 months (P=0.026). The group stored at -20 degrees C decreased in concentration after 1 year (P=0.033). We conclude that the actual concentration of capsaicin solution is less than predicted, and solutions of 4 microM or higher concentration are stable for 1 year if stored at 4 degrees C protected from light.

The capsaicin cough reflex in patients with symptoms elicited by odorous chemicals

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Holst, H.; Arendt-Nielsen, Lars; Mosbech, H.

2010-01-01

between groups in age, body mass index or pulmonary function. The median C5 were 129 micromol/L (control group), 48 micromol/L (multiple chemical sensitivity patients), 32 micromol/L (eczema patients). The reporting of lower airway symptoms from odorous chemicals was significantly (p......Patients with multiple chemical sensitivity and eczema patients with airway symptoms elicited by odorous chemicals have enhanced cough reflex to capsaicin when applying the tidal breathing method. The aims of the present study were to test whether the capsaicin induced cough reflex was enhanced...... when applying the single breath inhalation method in similar groups of patients with symptoms related to odorous chemicals e.g. other persons wearing of perfume; and to investigate to what extent the reporting of lower airway symptoms influenced the cough reflex. Sixteen patients fulfilling Cullen...

A precise form of divisive suppression supports population coding in the primary visual cortex.

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MacEvoy, Sean P; Tucker, Thomas R; Fitzpatrick, David

2009-05-01

The responses of neurons in the primary visual cortex (V1) to an optimally oriented grating are suppressed when a non-optimal grating is superimposed. Although cross-orientation suppression is thought to reflect mechanisms that maintain a distributed code for orientation, the effect of superimposed gratings on V1 population responses is unknown. Using intrinsic signal optical imaging, we found that patterns of tree shrew V1 activity evoked by superimposed equal-contrast gratings were predicted by the averages of patterns evoked by individual component gratings. This prediction held across contrasts, for summed sinusoidal gratings or nonsumming square-wave gratings, and was evident in single-unit extracellular recordings. Intracellular recordings revealed consistent levels of suppression throughout the time course of subthreshold responses. These results indicate that divisive suppression powerfully governs population responses to multiple orientations. Moreover, the specific form of suppression that we observed appears to support independent population codes for stimulus orientation and strength and calls for a reassessment of mechanisms that underlie cross-orientation suppression.

Is physician supervision of the capsaicin 8% patch administration procedure really necessary? An opinion from health care professionals

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Kern KU

2013-07-01

Full Text Available Kai-Uwe Kern,1 Janice England,2 Andrea Roth-Daniek,3 Till Wagner3 1Institute for Pain Medicine/Pain Practice, Wiesbaden, Germany; 2Pain Medicine and Anaesthesia, The Christie National Health Service Foundation Trust, Manchester, UK; 3Pain Therapy and Palliative Care Department, Medizinisches Zentrum Städteregion Aachen, Aachen, Germany Abstract: Neuropathic pain is difficult to treat and can have a severe effect on quality of life. The capsaicin 8% patch is a novel treatment option that directly targets the source of peripheral neuropathic pain. It can provide pain relief for up to 12 weeks in patients with peripheral neuropathic pain. Treatment with the capsaicin 8% patch follows a clearly defined procedure, and patch application must be carried out by a physician or a health care professional under the supervision of a physician. Nonetheless, in our experience, nurses often take the lead role in capsaicin 8% patch application without the involvement of a physician. We believe that the nurse's key role is of benefit to the patients, as he or she may be better placed, because of time constraints and patient relationships, to support the patient through the application procedure than a physician. Moreover, a number of frequently prescribed drugs, including botulinum toxin and infliximab, can be administered by health care professionals without the requirement for physician supervision. Here we argue that current guidance should be amended to remove the requirement for physician supervision during application of the capsaicin 8% patch. Keywords: capsaicin, neuropathic pain, topical, health care professional, physician, nurse

Reaction to topical capsaicin in spinal cord injury patients with and without central pain

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Finnerup, Nanna Brix; Pedersen, Louise H.; Terkelsen, Astrid J.

2007-01-01

of a spinal cord injury which already is hyperexcitable, would cause enhanced responses in patients with central pain at the level of injury compared to patients without neuropathic pain and healthy controls. Touch, punctuate stimuli, cold stimuli and topical capsaicin was applied above, at, and below injury......Central neuropathic pain is a debilitating and frequent complication to spinal cord injury (SCI). Excitatory input from hyperexcitable cells around the injured grey matter zone is suggested to play a role for central neuropathic pain felt below the level of a spinal cord injury. Direct evidence...... at the level of injury. Keywords: Spinal cord injury; Neuropathic pain; Capsaicin; Neuronal hyperexcitability; Hyperalgesia; Blood flow...

Behavioral and EEG evidence for auditory memory suppression

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Maya Elizabeth Cano

2016-03-01

Full Text Available The neural basis of motivated forgetting using the Think/No-Think (TNT paradigm is receiving increased attention with a particular focus on the mechanisms that enable memory suppression. However, most TNT studies have been limited to the visual domain. To assess whether and to what extent direct memory suppression extends across sensory modalities, we examined behavioral and electroencephalographic (EEG effects of auditory Think/No-Think in healthy young adults by adapting the TNT paradigm to the auditory modality. Behaviorally, suppression of memory strength was indexed by prolonged response times during the retrieval of subsequently remembered No-Think words. We examined task-related EEG activity of both attempted memory retrieval and inhibition of a previously learned target word during the presentation of its paired associate. Event-related EEG responses revealed two main findings: 1 a centralized Think > No-Think positivity during auditory word presentation (from approximately 0-500ms, and 2 a sustained Think positivity over parietal electrodes beginning at approximately 600ms reflecting the memory retrieval effect which was significantly reduced for No-Think words. In addition, word-locked theta (4-8 Hz power was initially greater for No-Think compared to Think during auditory word presentation over fronto-central electrodes. This was followed by a posterior theta increase indexing successful memory retrieval in the Think condition.The observed event-related potential pattern and theta power analysis are similar to that reported in visual Think/No-Think studies and support a modality non-specific mechanism for memory inhibition. The EEG data also provide evidence supporting differing roles and time courses of frontal and parietal regions in the flexible control of auditory memory.

Behavioral and EEG Evidence for Auditory Memory Suppression.

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Cano, Maya E; Knight, Robert T

2016-01-01

The neural basis of motivated forgetting using the Think/No-Think (TNT) paradigm is receiving increased attention with a particular focus on the mechanisms that enable memory suppression. However, most TNT studies have been limited to the visual domain. To assess whether and to what extent direct memory suppression extends across sensory modalities, we examined behavioral and electroencephalographic (EEG) effects of auditory TNT in healthy young adults by adapting the TNT paradigm to the auditory modality. Behaviorally, suppression of memory strength was indexed by prolonged response time (RTs) during the retrieval of subsequently remembered No-Think words. We examined task-related EEG activity of both attempted memory retrieval and inhibition of a previously learned target word during the presentation of its paired associate. Event-related EEG responses revealed two main findings: (1) a centralized Think > No-Think positivity during auditory word presentation (from approximately 0-500 ms); and (2) a sustained Think positivity over parietal electrodes beginning at approximately 600 ms reflecting the memory retrieval effect which was significantly reduced for No-Think words. In addition, word-locked theta (4-8 Hz) power was initially greater for No-Think compared to Think during auditory word presentation over fronto-central electrodes. This was followed by a posterior theta increase indexing successful memory retrieval in the Think condition. The observed event-related potential pattern and theta power analysis are similar to that reported in visual TNT studies and support a modality non-specific mechanism for memory inhibition. The EEG data also provide evidence supporting differing roles and time courses of frontal and parietal regions in the flexible control of auditory memory.

Lack of contralateral suppression in transient-evoked otoacoustic emissions in multiple chemical sensitivity: a clinical correlation study

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Alessandro Micarelli

2016-01-01

Full Text Available Multiple chemical sensitivity (MCS is a chronic disorder characterized by a variety of symptoms associated with the exposure to chemicals at a concentration below the toxic level. Previous studies have demonstrated peculiar responses in brain activity in these patients with respect to sensory stimuli while the association between chemical sensitivity and other environmental intolerances such as noise sensitivity has been questioned by researchers. In this study, a cohort of 18 MCS patients underwent transient-evoked otoacoustic emission (TEOAE testing with and without contralateral suppression to evaluate the functionality of the medial olivocochlear (MOC reflex involved in speech-in-noise sensitivity. Results were compared with an age- and gender-matched control group (n = 20 and correlation analysis with disease onset and quick environmental exposure sensitivity inventory (qEESI symptom severity scale was performed. Subjects affected by MCS showed statistically significant impairment of MOC reflex, and the onset of the disease and several symptom subscales showed to be correlated to such reduction in some of the frequencies tested. These data suggest that alterations of MOC reflex could be part of the complex features of this disease although more studies are needed to further explore auditory perception disorders in environmental intolerances.

The Effects of Dietary Iron and Capsaicin on Hemoglobin, Blood Glucose, Insulin Tolerance, Cholesterol, and Triglycerides, in Healthy and Diabetic Wistar Rats.

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Márquez-Ibarra, Adriana; Huerta, Miguel; Villalpando-Hernández, Salvador; Ríos-Silva, Mónica; Díaz-Reval, María I; Cruzblanca, Humberto; Mancilla, Evelyn; Trujillo, Xóchitl

2016-01-01

Our aim was to assess the effects of dietary iron, and the compound capsaicin, on hemoglobin as well as metabolic indicators including blood glucose, cholesterol, triglycerides, insulin, and glucose tolerance. Our animal model was the Wistar rat, fed a chow diet, with or without experimentally induced diabetes. Diabetic males were fed control, low, or high-iron diets, the latter, with or without capsaicin. Healthy rats were fed identical diets, but without the capsaicin supplement. We then measured the parameters listed above, using the Student t-test and ANOVA, to compare groups. Healthy rats fed a low-iron diet exhibited significantly reduced total cholesterol and triglyceride levels, compared with rats fed a control diet. Significantly reduced blood lipid was also provoked by low dietary iron in diabetic rats, compared with those fed a control diet. Insulin, and glucose tolerance was only improved in healthy rats fed the low-iron diet. Significant increases in total cholesterol were found in diabetic rats fed a high-iron diet, compared with healthy rats fed the same diet, although no statistical differences were found for triglycerides. Hemoglobin levels, which were not statistically different in diabetic versus healthy rats fed the high-iron diet, fell when capsaicin was added. Capsaicin also provoked a fall in the level of cholesterol and triglycerides in diabetic animals, versus diabetics fed with the high iron diet alone. In conclusion, low levels of dietary iron reduced levels of serum triglycerides, hemoglobin, and cholesterol, and significantly improved insulin, and glucose tolerance in healthy rats. In contrast, a high-iron diet increased cholesterol significantly, with no significant changes to triglyceride concentrations. The addition of capsaicin to the high-iron diet (for diabetic rats) further reduced levels of hemoglobin, cholesterol, and triglycerides. These results suggest that capsaicin, may be suitable for the treatment of elevated hemoglobin

AUTONOMIC NERVOUS ACTIVITY AND LIPID OXIDATION POSTEXERCISE WITH CAPSAICIN IN THE HUMANS

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Ki Ok Shin

2010-06-01

Full Text Available This study evaluated the synergistic effects of acute exercise with capsaicin (200mg upon the restoration of cardiac autonomic functions and depolarization- repolarization interval as well as substrate oxidation. Nine healthy males [21.9(0.8 yrs] volunteered for this study. Cardiac autonomic activity, metabolic responses, and the ECG QT intervals were continuously measured during 5 min at rest and postexercise recovery after 30 min exercise at 50% VO2max on a stationary ergometer with placebo (ECON or capsaicin intake (ECAP, and no exercise control (NCON were randomized. Results indicated that the HF power reflecting parasympathetic activity significantly returned to the baseline much faster during ECAP than ECON trial during postexercise [122.1 (23.2 vs. 60.2 (11.7 %, p < 0.05]. The ECAP trial significantly decreased RQ [0.79(0.02 vs. 0.85 (0.03, p < 0.05] with significantly greater fat oxidation [69.3 (6.0 vs. 49.4 (10.8 %, p < 0.05] in comparison to NCON trial during 120 min postexercise recovery without any adverse effects on cardiac electrical stability as determined by trigger-averaged ECG QT interval analyses. We suggest that capsaicin before the exercise may contribute to the improvement of cardio-protective functions and metabolic responses as one of the beneficial supplements accelerating faster restoration of autonomic activity and enhanced lipolysis during postexercise recovery without any adverse effects on cardiac electrical stability

Role of capsaicin- and heat-sensitive afferents in stimulation of acupoint-induced pain and analgesia in humans.

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Lei, Jing; Ye, Gang; Wu, Jiang-Tao; Pertovaara, Antti; You, Hao-Jun

2017-09-01

We investigated role of capsaicin-sensitive afferents within and without the areas of Zusanli (ST36)/Shangjuxu (ST37) acupoints along the stomach (ST) meridian in the perception and modulation of pain assessed by visual analog scale of pain and its distribution rated by subjects, pressure pain threshold (PPT), and heat pain threshold (HPT) in humans. Compared with the treatment of non-acupoint area, capsaicin (100µg/50µl) administered into either ST36 or ST37 acupoint caused the strongest pain intensity and the most extensive pain distribution, followed by rapid onset, bilateral, long-lasting secondary mechanical hyperalgesia and slower onset secondary heat hypoalgesia (1day after the capsaicin treatment). Between treatments of different acupoints, capsaicin administrated into the ST36 acupoint exhibited the stronger pain intensity and more widespread pain distribution compared with the treatment of ST37 acupoint. A period of 30- to 45-min, but not 15-min, 43°C heating-needle stimulation applied to the ST36 acupoint significantly enhanced the HPT, and had no effect on PPT. Upon trapezius muscle pain elicited by the i.m. injection of 5.8% saline, pre-emptive treatment of the contralateral ST36 acupoint with 43°C heating-needle stimulation alleviated the ongoing muscle pain, reduced painful area, and reversed the decrease in HPT. It is suggested that (1) pain elicited from the acupoint and non-acupoint areas differs significantly, which are supposed to be dependent on the different distributions and contributions of capsaicin-sensitive afferents. (2) Non-painful heat stimulation is a valid approach in prevention of ongoing muscle pain with associated post-effects of peripheral and central sensitization. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Identification of Gene-Specific Polymorphisms and Association with Capsaicin Pathway Metabolites in Capsicum annuum L. Collections

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Abburi, Venkata L.; Alaparthi, Suresh Babu; Unselt, Desiree; Hankins, Gerald; Park, Minkyu; Choi, Doil

2014-01-01

Pepper (Capsicum annuum L.) is an economically important crop with added nutritional value. Production of capsaicin is an important quantitative trait with high environmental variance, so the development of markers regulating capsaicinoid accumulation is important for pepper breeding programs. In this study, we performed association mapping at the gene level to identify single nucleotide polymorphisms (SNPs) associated with capsaicin pathway metabolites in a diverse Capsicum annuum collection during two seasons. The genes Pun1, CCR, KAS and HCT were sequenced and matched with the whole-genome sequence draft of pepper to identify SNP locations and for further characterization. The identified SNPs for each gene underwent candidate gene association mapping. Association mapping results revealed Pun1 as a key regulator of major metabolites in the capsaicin pathway mainly affecting capsaicinoids and precursors for acyl moieties of capsaicinoids. Six different SNPs in the promoter sequence of Pun1 were found associated with capsaicin in plants from both seasons. Our results support that CCR is an important control point for the flux of p-coumaric acid to specific biosynthesis pathways. KAS was found to regulate the major precursors for acyl moieties of capsaicinoids and may play a key role in capsaicinoid production. Candidate gene association mapping of Pun1 suggested that the accumulation of capsaicinoids depends on the expression of Pun1, as revealed by the most important associated SNPs found in the promoter region of Pun1. PMID:24475113

Scent-evoked nostalgia.

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Reid, Chelsea A; Green, Jeffrey D; Wildschut, Tim; Sedikides, Constantine

2015-01-01

Can scents evoke nostalgia; what might be the psychological implications of such an evocation? Participants sampled 12 scents and rated the extent to which each scent was familiar, arousing and autobiographically relevant, as well as the extent to which each scent elicited nostalgia. Participants who were high (compared to low) in nostalgia proneness reported more scent-evoked nostalgia, and scents elicited greater nostalgia to the extent that they were arousing, familiar and autobiographically relevant. Scent-evoked nostalgia predicted higher levels of positive affect, self-esteem, self-continuity, optimism, social connectedness and meaning in life. In addition, scent-evoked nostalgia was characterised by more positive emotions than either non-nostalgic autobiographical memories or non-nostalgic non-autobiographical memories. Finally, scent-evoked nostalgia predicted in-the-moment feelings of personal (general or object-specific) nostalgia. The findings represent a foray into understanding the triggers and affective signature of scent-evoked nostalgia.

Pain-relieving effectiveness, quality of life and tolerability of repeated capsaicin 8% patch treatment of peripheral neuropathic pain in Scandinavian clinical practice

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Hansson, P; Jensen, Troels Staehelin; Kvarstein, G

2018-01-01

CONTEXT: Clinical trials have demonstrated the efficacy and safety of the capsaicin 8% patch in patients with peripheral neuropathic pain (PNP); however, few studies have assessed this treatment in a clinical practice. OBJECTIVE: To determine whether treatment and re-treatment with the capsaicin ...

Acute administration of capsaicin increases resting energy expenditure in young obese subjects without affecting energy intake, appetite, and circulating levels of orexigenic/anorexigenic peptides.

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Rigamonti, Antonello E; Casnici, Claudia; Marelli, Ornella; De Col, Alessandra; Tamini, Sofia; Lucchetti, Elisa; Tringali, Gabriella; De Micheli, Roberta; Abbruzzese, Laura; Bortolotti, Mauro; Cella, Silvano G; Sartorio, Alessandro

2018-04-01

Although capsaicin has been reported to reduce energy intake and increase energy expenditure in an adult (normal weight or overweight) population, thus resulting in a net negative energy balance and weight loss, these beneficial effects have not been investigated in young obese subjects. We hypothesize that capsaicin acutely administered in young obese subjects exerts the same effects on energy balance and that these effects are mediated by changes in gastrointestinal peptides regulating appetite. Thus, the aim of the present study was to evaluate the acute effects of capsaicin (2 mg) or placebo on energy intake, hunger, and satiety in obese adolescents and young adults (female-male ratio: 4:6, age: 21.0 ± 5.8 years; body mass index: 41.5 ± 4.3 kg/m 2 ) provided an ad libitum dinner. Furthermore, circulating levels of some orexigenic (ghrelin) and anorexigenic (glucagon-like peptide 1 and peptide YY) peptides were measured after a meal completely consumed (lunch), together with the evaluation of hunger and satiety and assessment of resting energy expenditure (REE) through indirect computerized calorimetry. When compared to placebo, capsaicin did not significantly change either energy intake or hunger/satiety 6 hours after its administration (dinner). No differences in circulating levels of ghrelin, glucagon-like peptide 1, and peptide YY and in hunger/satiety were found in the 3 hours immediately after food ingestion among obese subjects treated with capsaicin or placebo (lunch). By contrast, the meal significantly increased REE in the capsaicin- but not placebo-treated group (capsaicin: from 1957.2 ± 455.1 kcal/d up to 2342.3 ± 562.1 kcal/d, P < .05; placebo: from 2060.1 ± 483.4 kcal/d up to 2296.0 ± 484.5 kcal/d). The pre-post meal difference in REE after capsaicin administration was significantly higher than that observed after placebo (385.1 ± 164.4 kcal/d vs 235.9 ± 166.1 kcal/d, P < .05). In conclusion, although capsaicin does not exert hypophagic

Dihydrocapsaicin (DHC), a saturated structural analog of capsaicin, induces autophagy in human cancer cells in a catalase-regulated manner.

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Oh, Seon Hee; Kim, Young Soon; Lim, Sung Chul; Hou, Yi Feng; Chang, In Youb; You, Ho Jin

2008-11-01

Although capsaicin, a pungent component of red pepper, is known to induce apoptosis in several types of cancer cells, the mechanisms underlying capsaicin-induced cytotoxicity are unclear. Here, we showed that dihydrocapsaicin (DHC), an analog of capsaicin, is a potential inducer of autophagy. DHC was more cytotoxic than capsaicin in HCT116, MCF-7 and WI38 cell lines. Capsaicin and DHC did not affect the sub-G(1) apoptotic peak, but induced G(0)/G(1) arrest in HCT116 and MCF-7 cells. DHC caused the artificial autophagosome marker GFP-LC3 to redistribute and upregulated expression of autophagy-related proteins. Blocking of autophagy by 3-methyladenine (3MA) as well as siRNA Atg5 induced a high level of caspase-3 activation. Although pretreatment with zVAD completely inhibited caspase-3 activation by 3MA, it did not prevent cell death. DHC-induced autophagy was enhanced by zVAD pretreatment, as shown by increased accumulation of LC3-II protein. DHC attenuated basal ROS levels through catalase induction; this effect was enhanced by antioxidants, which increased both LC3-II expression and caspase-3 activation. The catalase inhibitor 3-amino-1,2,4-triazole (3AT) abrogated DHC-induced expression of LC3-II, overexpression of the catalase gene increased expression of LC3-II protein, and knockdown decreased it. Additionally, DHC-induced autophagy was independent of p53 status. Collectively, DHC activates autophagy in a p53-independent manner and that may contribute to cytotoxicity of DHC.

Intradermal capsaicin as a neuropathic pain model in patients with unilateral sciatica

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Aykanat, Verna; Gentgall, Melanie; Briggs, Nancy; Williams, Desmond; Yap, Sharon; Rolan, Paul

2012-01-01

AIM This study compared the responses between patients with unilateral sciatica and pain-free volunteers following administration of intradermal capsaicin. METHODS Fourteen patients with unilateral sciatica and 12 pain-free volunteers received one injection per hour over 4 h of 1 µg and 10 µg capsaicin, into each calf. For each dose, spontaneous pain (10 cm VAS), area of flare (cm2) and the sum of allodynia and hyperalgesia radii across eight axes (cm) were recorded pre-injection and at 5, 15, 30, 45 and 60 min post injection. RESULTS Sciatica subjects experienced higher spontaneous pain and hyperalgesia responses in both legs compared with pain-free volunteers. The largest mean difference in spontaneous pain was 2.8 cm (95% CI 1.6, 3.9) at 5 min in the unaffected leg following 10 µg. The largest mean difference in hyperalgesia was 19.7 cm (95% CI 12.4, 27.0) at 60 min in the unaffected leg following 10 µg. Allodynia was greater in patients than in controls with the largest mean difference of 2.9 cm (95% CI 1, 4.8) at 5 min following 10 µg in the affected leg. Allodynia was also higher in the affected leg compared with the unaffected leg in sciatica patients with the highest mean difference of 3.0 cm (95% CI 1.2, 4.7) at 5 min following 10 µg. CONCLUSIONS The responses to intradermal capsaicin are quantitatively and qualitatively different in unilateral sciatica patients compared with pain-free controls. PMID:21740458

Effect of peripherally and cortically evoked swallows on jaw reflex responses in anesthetized rabbits.

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Suzuki, Taku; Yoshihara, Midori; Sakai, Shogo; Tsuji, Kojun; Nagoya, Kouta; Magara, Jin; Tsujimura, Takanori; Inoue, Makoto

2018-05-03

This study aimed to investigate whether the jaw-opening (JOR) and jaw-closing reflexes (JCR) are modulated during not only peripherally, but also centrally, evoked swallowing. Experiments were carried out on 24 adult male Japanese white rabbits. JORs were evoked by trigeminal stimulation at 1 Hz for 30 sec. In the middle 10 sec, either the superior laryngeal nerve (SLN) or cortical swallowing area (Cx) was simultaneously stimulated to evoke swallowing. The peak-to-peak JOR amplitude was reduced during the middle and late 10-sec periods (i.e., during and after SLN or Cx stimulation), and the reduction was dependent on the current intensity of SLN/Cx stimulation: greater SLN/Cx stimulus current resulted in greater JOR inhibition. The reduction rate was significantly greater during Cx stimulation than during SLN stimulation. The amplitude returned to baseline 2 min after 10-sec SLN/Cx stimulation. The effect of co-stimulation of SLN and Cx was significantly greater than that of SLN stimulation alone. There were no significant differences in any parameters of the JCR between conditions. These results clearly showed that JOR responses were significantly suppressed, not only during peripherally evoked swallowing but also during centrally evoked swallowing, and that the inhibitory effect is likely to be larger during centrally compared with peripherally evoked swallowing. The functional implications of these results are discussed. Copyright © 2018. Published by Elsevier B.V.

Capsaicin effects on blinking Efectos de la capsaicina en el parpadeo

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Fidias E. Leon-Sarmiento

2005-09-01

Full Text Available Blinking is a normal human phenomenom involving trigeminal and facial patways. To gain understanding on the neurobiology of blinking, five normal subjects were investigated before and after application of transdermal capsaicin at the forehead for two weeks. No effects of topical capsaicin were detected in eye blink rates. However, when capsaicin was applied to a female subject with blepharospasm, she showed a dramatic restoration of her vision subsequent to blinking modification. Deactivation of abnormal A-to-C fibers cross talks at the trigeminal-facial pathways seems to be the most likely mechanism of such improvement.El parpadeo es un fenómeno normal en los humanos que involucra las vías trigéminas faciales. Con el fin de conocer un poco más la neurobiología de este fenómeno estudiamos cinco individuos normales antes y después de aplicar capsaicina trasdérmica en la frente de cada uno de ellos, por dos semanas. La frecuencia de parpadeo no se alteró con la aplicación de capsaicina tópica. Sin embargo, cuando la misma sustancia se aplicó a una paciente con blefaroespasmo hubo dramática restauración de su visión, la cual fue secundaria a la modificación de la actividad muscular palpebral. La desactivación del cruce patológico de información que pasa de las fibras A a las fibras C, pertenecientes a las vías trigémino-faciales, parece ser el mecanismo de acción relacionado con la aplicación de capsaicina, el que estaría directamente relacionado con la recuperación clínica observada en la paciente con blefaroespasmo.

Tolerability of the capsaicin 8% patch following pretreatment with lidocaine or tramadol in patients with peripheral neuropathic pain: a multicentre, randomized, assessor-blinded study.

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Jensen, T S; Høye, K; Fricová, J; Vanelderen, P; Ernault, E; Siciliano, T; Marques, S

2014-10-01

Application of the capsaicin 8% patch is associated with treatment-related discomfort. Consequently, pretreatment for 60 min with anaesthetic cream is recommended; however, this may be uncomfortable and time consuming. We conducted a multicentre, randomized (1:1), assessor-blinded study in patients with peripheral neuropathic pain to assess tolerability of the capsaicin patch following topical lidocaine (4%) or oral tramadol (50 mg) pretreatment. The primary endpoint was the proportion of patients tolerating capsaicin patch application (ability to receive ≥90% of a 60-min application). Numeric Pain Rating Scale (NPRS) scores were assessed before, during and after treatment. Overall, 122 patients were included (61 per arm). The capsaicin patch was tolerated by 121 patients. Tolerability of the capsaicin patch was similar following pretreatment with lidocaine and tramadol. Following patch application, pain levels increased up to 55 min (change from baseline of 1.3 for lidocaine and 1.4 for tramadol). After patch removal, tramadol-treated patients experienced greater pain relief up to the end of day 1; in the evening, mean changes in NPRS scores from baseline were 0 for lidocaine and -1 for tramadol. Proportions of patients reporting increases of ≥2 NPRS points or >33% from baseline at one or more time point(s) on the day of treatment were similar between arms. Adverse event incidence was comparable between arms. Capsaicin 8% patch tolerability was similar in the two arms, with comparable results for most secondary endpoints. Tramadol given 30 min before patch application should be considered as an alternative pretreatment option in patients receiving capsaicin patch treatment. © 2014 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC®.

Movement Suppression Time-Out for Undesirable Behavior in Psychotic and Severely Developmentally Delayed Children.

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Rolider, Ahmos; Van Houten, Ron

1985-01-01

Effects of a movement suppression time-out, which involved punishing any movements or verbalization while a client is in the time-out area, were evaluated in four experiments. The procedure produced a larger reduction in the target behavior in all three children and effectiveness was explained in terms of suppression of self-stimulation during…

75 FR 22788 - Garlic Oil and Capsaicin; Registration Review Proposed Decisions; Notice of Availability

Science.gov (United States)

2010-04-30

... food and feed such as vegetables, fruits, nuts, and grains. Garlic oil is also registered for use on... and Capsaicin. Dated: April 22, 2010. W. Michael McDavit, Acting Director, Biopesticides and Pollution...

Activation of TRPV1 by capsaicin induces functional Kinin B1 receptor in rat spinal cord microglia

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Talbot Sébastien

2012-01-01

Full Text Available Abstract Background The kinin B1 receptor (B1R is upregulated by pro-inflammatory cytokines and oxydative stress, which are enhanced by transient receptor potential vanilloid subtype 1 (TRPV1 activation. To examine the link between TRPV1 and B1R in inflammatory pain, this study aimed to determine the ability of TRPV1 to regulate microglial B1R expression in the spinal cord dorsal horn, and the underlying mechanism. Methods B1R expression (mRNA, protein and binding sites was measured in cervical, thoracic and lumbar spinal cord in response to TRPV1 activation by systemic capsaicin (1-50 mg/kg, s.c in rats pre-treated with TRPV1 antagonists (capsazepine or SB-366791, the antioxidant N-acetyl-L-cysteine (NAC, or vehicle. B1R function was assessed using a tail-flick test after intrathecal (i.t. injection of a selective B1R agonist (des-Arg9-BK, and its microglial localization was investigated by confocal microscopy with the selective fluorescent B1R agonist, [Nα-bodipy]-des-Arg9-BK. The effect of i.t. capsaicin (1 μg/site was also investigated. Results Capsaicin (10 to 50 mg/kg, s.c. enhanced time-dependently (0-24h B1R mRNA levels in the lumbar spinal cord; this effect was prevented by capsazepine (10 mg/kg, i.p.; 10 μg/site, i.t. and SB-366791 (1 mg/kg, i.p.; 30 μg/site, i.t.. Increases of B1R mRNA were correlated with IL-1β mRNA levels, and they were significantly less in cervical and thoracic spinal cord. Intrathecal capsaicin (1 μg/site also enhanced B1R mRNA in lumbar spinal cord. NAC (1 g/kg/d × 7 days prevented B1R up-regulation, superoxide anion production and NF-kB activation induced by capsaicin (15 mg/kg. Des-Arg9-BK (9.6 nmol/site, i.t. decreased by 25-30% the nociceptive threshold at 1 min post-injection in capsaicin-treated rats (10-50 mg/kg while it was without effect in control rats. Des-Arg9-BK-induced thermal hyperalgesia was blocked by capsazepine, SB-366791 and by antagonists/inhibitors of B1R (SSR240612, 10 mg/kg, p

Capsaicin induced histological and ultrastructural changes in the submandibular salivary gland of albino rats

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Ahmed Mahmoud Halawa

2016-06-01

From the present work, it could be concluded that chronic capsaicin intake was associated with noticeable histological and ultrastructural changes in acini, granular convoluted tubules and excretory ducts of the SMSG in albino rats.

Deconstructing continuous flash suppression.

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Yang, Eunice; Blake, Randolph

2012-03-08

In this paper, we asked to what extent the depth of interocular suppression engendered by continuous flash suppression (CFS) varies depending on spatiotemporal properties of the suppressed stimulus and CFS suppressor. An answer to this question could have implications for interpreting the results in which CFS influences the processing of different categories of stimuli to different extents. In a series of experiments, we measured the selectivity and depth of suppression (i.e., elevation in contrast detection thresholds) as a function of the visual features of the stimulus being suppressed and the stimulus evoking suppression, namely, the popular "Mondrian" CFS stimulus (N. Tsuchiya & C. Koch, 2005). First, we found that CFS differentially suppresses the spatial components of the suppressed stimulus: Observers' sensitivity for stimuli of relatively low spatial frequency or cardinally oriented features was more strongly impaired in comparison to high spatial frequency or obliquely oriented stimuli. Second, we discovered that this feature-selective bias primarily arises from the spatiotemporal structure of the CFS stimulus, particularly within information residing in the low spatial frequency range and within the smooth rather than abrupt luminance changes over time. These results imply that this CFS stimulus operates by selectively attenuating certain classes of low-level signals while leaving others to be potentially encoded during suppression. These findings underscore the importance of considering the contribution of low-level features in stimulus-driven effects that are reported under CFS.

The effect of wound instillation of a novel purified capsaicin formulation on postherniotomy pain

DEFF Research Database (Denmark)

Aasvang, Eske K; Hansen, Jeanette B; Malmstrøm, Jørgen

2008-01-01

, preclinical, and clinical studies, and may be an effective adjunct to postoperative pain management. METHODS: We performed a single-center, randomized, double-blind, placebo-controlled study of the analgesic efficacy of a single intraoperative wound instillation of 1000 microg ultrapurified capsaicin (ALGRX......BACKGROUND: Acute postoperative pain is common after most surgical procedures. Despite the availability of many analgesic options, postoperative pain management is often unsatisfactory. Purified capsaicin (ALGRX 4975 98% pure) has demonstrated prolong inhibition of C-fiber function in in vitro...... 4975) after open mesh groin hernia repair in 41 adult male patients. The primary end-point was average daily visual analog scale (VAS) pain scores during the first week after surgery assessed as area under the curve (AUC). Pain was recorded twice daily in a pain diary for 4 wk. Physical examination...

The quaternary lidocaine derivative, QX-314, exerts biphasic effects on transient receptor potential vanilloid subtype 1 channels in vitro

DEFF Research Database (Denmark)

Rivera-Acevedo, Ricardo E; Pless, Stephan Alexander; Ahern, Christopher A

2011-01-01

concentrations (less than 1 mM), QX-314 potently inhibited capsaicin-evoked TRPV1 currents with an IC₅₀ of 8.0 ± 0.6 μM. CONCLUSIONS: The results of this study show that the quaternary lidocaine derivative QX-314 exerts biphasic effects on TRPV1 channels, inhibiting capsaicin-evoked TRPV1 currents at lower...... channels. METHODS: The authors conducted an in vitro laboratory study in which they expressed TRPV1 and TRPV4 channels in Xenopus laevis oocytes and recorded cation currents with the two-electrode voltage clamp method. They used confocal microscopy for Ca²⁺ imaging in TRPV1 transient transfected tsA201...

The effect of digital signage on shoppers’ behavior: the role of the evoked experience

OpenAIRE

Dennis, Charles; Brakus, J. Joško; Gupta, Suraksha; Alamanos, Eleftherios

2014-01-01

This paper investigates the role of digital signage as experience provider in retail spaces. The findings of a survey-based field experiment demonstrate that digital signage content high on sensory cues evokes affective experience and strengthens customers' experiential processing route. In contrast, digital signage messages high on “features and benefits” information evoke intellectual experience and strengthen customers' deliberative processing route. The affective experience is more strong...

Odor-evoked inhibition of olfactory sensory neurons drives olfactory perception in Drosophila.

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Cao, Li-Hui; Yang, Dong; Wu, Wei; Zeng, Xiankun; Jing, Bi-Yang; Li, Meng-Tong; Qin, Shanshan; Tang, Chao; Tu, Yuhai; Luo, Dong-Gen

2017-11-07

Inhibitory response occurs throughout the nervous system, including the peripheral olfactory system. While odor-evoked excitation in peripheral olfactory cells is known to encode odor information, the molecular mechanism and functional roles of odor-evoked inhibition remain largely unknown. Here, we examined Drosophila olfactory sensory neurons and found that inhibitory odors triggered outward receptor currents by reducing the constitutive activities of odorant receptors, inhibiting the basal spike firing in olfactory sensory neurons. Remarkably, this odor-evoked inhibition of olfactory sensory neurons elicited by itself a full range of olfactory behaviors from attraction to avoidance, as did odor-evoked olfactory sensory neuron excitation. These results indicated that peripheral inhibition is comparable to excitation in encoding sensory signals rather than merely regulating excitation. Furthermore, we demonstrated that a bidirectional code with both odor-evoked inhibition and excitation in single olfactory sensory neurons increases the odor-coding capacity, providing a means of efficient sensory encoding.

Dose-response characteristics of methylphenidate on locomotor behavior and on sensory evoked potentials recorded from the VTA, NAc, and PFC in freely behaving rats

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Swann Alan C

2006-01-01

Full Text Available Abstract Background Methylphenidate (MPD is a psychostimulant commonly prescribed for attention deficit/hyperactivity disorder. The mode of action of the brain circuitry responsible for initiating the animals' behavior in response to psychostimulants is not well understood. There is some evidence that psychostimulants activate the ventral tegmental area (VTA, nucleus accumbens (NAc, and prefrontal cortex (PFC. Methods The present study was designed to investigate the acute dose-response of MPD (0.6, 2.5, and 10.0 mg/kg on locomotor behavior and sensory evoked potentials recorded from the VTA, NAc, and PFC in freely behaving rats previously implanted with permanent electrodes. For locomotor behavior, adult male Wistar-Kyoto (WKY; n = 39 rats were given saline on experimental day 1 and either saline or an acute injection of MPD (0.6, 2.5, or 10.0 mg/kg, i.p. on experimental day 2. Locomotor activity was recorded for 2-h post injection on both days using an automated, computerized activity monitoring system. Electrophysiological recordings were also performed in the adult male WKY rats (n = 10. Five to seven days after the rats had recovered from the implantation of electrodes, each rat was placed in a sound-insulated, electrophysiological test chamber where its sensory evoked field potentials were recorded before and after saline and 0.6, 2.5, and 10.0 mg/kg MPD injection. Time interval between injections was 90 min. Results Results showed an increase in locomotion with dose-response characteristics, while a dose-response decrease in amplitude of the components of sensory evoked field responses of the VTA, NAc, and PFC neurons. For example, the P3 component of the sensory evoked field response of the VTA decreased by 19.8% ± 7.4% from baseline after treatment of 0.6 mg/kg MPD, 37.8% ± 5.9% after 2.5 mg/kg MPD, and 56.5% ± 3.9% after 10 mg/kg MPD. Greater attenuation from baseline was observed in the NAc and PFC. Differences in the intensity of

Pharmacodynamic analysis of the analgesic effect of capsaicin 8% patch (QutenzaTM in diabetic neuropathic pain patients: detection of distinct response groups

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Martini C

2012-03-01

Full Text Available Christian Martini1,*, Ashraf Yassen2,*, Erik Olofsen1, Paul Passier2, Malcom Stoker3, Albert Dahan1 1Department of Anesthesiology, Leiden University Medical Center, Leiden, The Netherlands; 2Global Clinical Pharmacology and Exploratory Development, Astellas Pharma Global Development Europe, Leiderdorp, The Netherlands; 3Global Medical Sciences, Astellas Pharma Global Development Europe, Leiderdorp, The Netherlands*These authors contributed equally to this workAbstract: Treatment of chronic pain is associated with high variability in the response to pharmacological interventions. A mathematical pharmacodynamic model was developed to quantify the magnitude and onset/offset times of effect of a single capsaicin 8% patch application in the treatment of painful diabetic peripheral neuropathy in 91 patients. In addition, a mixture model was applied to objectively match patterns in pain-associated behavior. The model identified four distinct subgroups that responded differently to treatment: 3.3% of patients (subgroup 1 showed worsening of pain; 31% (subgroup 2 showed no change; 32% (subgroup 3 showed a quick reduction in pain that reached a nadir in week 3, followed by a slow return towards baseline (16% ± 6% pain reduction in week 12; 34% (subgroup 4 showed a quick reduction in pain that persisted (70% ± 5% reduction in week 12. The estimate of the response-onset rate constant, obtained for subgroups 1, 3, and 4, was 0.76 ± 0.12 week-1 (median ± SE, indicating that every 0.91 weeks the pain score reduces or increases by 50% relative to the score of the previous week (= t½. The response-offset rate constant could be determined for subgroup 3 only and was 0.09 ± 0.04 week-1 (t½ 7.8 weeks. The analysis allowed separation of a heterogeneous neuropathic pain population into four homogenous subgroups with distinct behaviors in response to treatment with capsaicin. It is argued that this model-based approach may have added value in analyzing

Do video games evoke specific types of epileptic seizures?

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Piccioli, Marta; Vigevano, Federico; Buttinelli, Carla; Kasteleijn-Nolst Trenité, Dorothée G A

2005-11-01

We determined whether epileptic clinical manifestations evoked by playing video games (VG) differ from those evoked by intermittent photic stimulation (IPS) or striped patterns (P). We exposed nine children who had TV- and VG-evoked seizures in daily life to 12 VG after standardized photic stimulation and pattern stimulation. Their EEGs were recorded continuously, analyzed, and then correlated with a video of their behavior. Similar types of clinical signs were seen during VG, P, and IPS, but the signs we observed were more subtle during the VG. Eight patients showed a clear lateralization. A new observation was the lowering of the eyelids to a state of half-closed. Our study suggests that the type of visual stimulus provoking a photoparoxysmal response or seizure is not particularly relevant. The children belonged to different epilepsy groups, and our findings add to the discussion on the boundaries of the epilepsy types.

Acute cold hypersensitivity characteristically induced by oxaliplatin is caused by the enhanced responsiveness of TRPA1 in mice

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Zhao Meng

2012-07-01

Full Text Available Abstract Background Oxaliplatin, a platinum-based chemotherapeutic agent, causes an unusual acute peripheral neuropathy. Oxaliplatin-induced acute peripheral neuropathy appears in almost all patients rapidly after infusion, and is triggered or exacerbated by cold, while its mechanisms are poorly understood. In this study, the involvement of thermosensitive transient receptor potential channels (TRPA1, TRPM8 and TRPV1 in oxaliplatin-induced acute hypersensitivity was investigated in mice. Results A single intraperitoneal administration of oxaliplatin (1–10 mg/kg induced cold but not mechanical hypersensitivity within 2 h in a dose-dependent manner. Infusion of the oxaliplatin metabolite, oxalate (1.7 mg/kg, also induced acute cold hypersensitivity, while another platinum-based chemotherapeutic agent, cisplatin (5 mg/kg, or the non-platinum-containing chemotherapeutic agent, paclitaxel (6 mg/kg failed to induce mechanical or cold hypersensitivity. The oxaliplatin-induced acute cold hypersensitivity was abolished by the TRPA1 antagonist HC-030031 (100 mg/kg and by TRPA1 deficiency. The nocifensive behaviors evoked by intraplantar injections of allyl-isothiocyanate (AITC; TRPA1 agonist were significantly enhanced in mice treated for 2 h with oxaliplatin (1–10 mg/kg in a dose-dependent manner, while capsaicin (TRPV1 agonist-evoked nocifensive behaviors were not affected. Menthol (TRPM8/TRPA1 agonist-evoked nocifensive-like behaviors were also enhanced by oxaliplatin pretreatment, which were inhibited by TRPA1 deficiency. Similarly, oxalate enhanced, but neither cisplatin nor paclitaxel affected AITC-evoked nocifensive behaviors. Pretreatment of cultured mouse dorsal root ganglia (DRG neurons with oxaliplatin (30–300 μM for 1, 2, or 4 h significantly increased the number of AITC-sensitive neurons in a concentration-dependent manner whereas there was no change in the number of menthol- or capsaicin-sensitive neurons

The effect of transcranial direct current stimulation on contrast sensitivity and visual evoked potential amplitude in adults with amblyopia

OpenAIRE

Ding, Zhaofeng; Li, Jinrong; Spiegel, Daniel P.; Chen, Zidong; Chan, Lily; Luo, Guangwei; Yuan, Junpeng; Deng, Daming; Yu, Minbin; Thompson, Benjamin

2016-01-01

Amblyopia is a neurodevelopmental disorder of vision that occurs when the visual cortex receives decorrelated inputs from the two eyes during an early critical period of development. Amblyopic eyes are subject to suppression from the fellow eye, generate weaker visual evoked potentials (VEPs) than fellow eyes and have multiple visual deficits including impairments in visual acuity and contrast sensitivity. Primate models and human psychophysics indicate that stronger suppression is associated...

Reproducibility of the heat/capsaicin skin sensitization model in healthy volunteers

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Cavallone LF

2013-11-01

Full Text Available Laura F Cavallone,1 Karen Frey,1 Michael C Montana,1 Jeremy Joyal,1 Karen J Regina,1 Karin L Petersen,2 Robert W Gereau IV11Department of Anesthesiology, Washington University in St Louis, School of Medicine, St Louis, MO, USA; 2California Pacific Medical Center Research Institute, San Francisco, CA, USAIntroduction: Heat/capsaicin skin sensitization is a well-characterized human experimental model to induce hyperalgesia and allodynia. Using this model, gabapentin, among other drugs, was shown to significantly reduce cutaneous hyperalgesia compared to placebo. Since the larger thermal probes used in the original studies to produce heat sensitization are now commercially unavailable, we decided to assess whether previous findings could be replicated with a currently available smaller probe (heated area 9 cm2 versus 12.5–15.7 cm2.Study design and methods: After Institutional Review Board approval, 15 adult healthy volunteers participated in two study sessions, scheduled 1 week apart (Part A. In both sessions, subjects were exposed to the heat/capsaicin cutaneous sensitization model. Areas of hypersensitivity to brush stroke and von Frey (VF filament stimulation were measured at baseline and after rekindling of skin sensitization. Another group of 15 volunteers was exposed to an identical schedule and set of sensitization procedures, but, in each session, received either gabapentin or placebo (Part B.Results: Unlike previous reports, a similar reduction of areas of hyperalgesia was observed in all groups/sessions. Fading of areas of hyperalgesia over time was observed in Part A. In Part B, there was no difference in area reduction after gabapentin compared to placebo.Conclusion: When using smaller thermal probes than originally proposed, modifications of other parameters of sensitization and/or rekindling process may be needed to allow the heat/capsaicin sensitization protocol to be used as initially intended. Standardization and validation of

Cortical stimulation evokes abnormal responses in the dopamine-depleted rat basal ganglia.

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Kita, Hitoshi; Kita, Takako

2011-07-13

The motor cortex (MC) sends massive projections to the basal ganglia. Motor disabilities in patients and animal models of Parkinson's disease (PD) may be caused by dopamine (DA)-depleted basal ganglia that abnormally process the information originating from MC. To study how DA depletion alters signal transfer in the basal ganglia, MC stimulation-induced (MC-induced) unitary responses were recorded from the basal ganglia of control and 6-hydroxydopamine-treated hemi-parkinsonian rats anesthetized with isoflurane. This report describes new findings about how DA depletion alters MC-induced responses. MC stimulation evokes an excitation in normally quiescent striatal (Str) neurons projecting to the globus pallidus external segment (GPe). After DA-depletion, the spontaneous firing of Str-GPe neurons increases, and MC stimulation evokes a shorter latency excitation followed by a long-lasting inhibition that was invisible under normal conditions. The increased firing activity and the newly exposed long inhibition generate tonic inhibition and a disfacilitation in GPe. The disfacilitation in GPe is then amplified in basal ganglia circuitry and generates a powerful long inhibition in the basal ganglia output nucleus, the globus pallidus internal segment. Intra-Str injections of a behaviorally effective dose of DA precursor l-3,4-dihydroxyphenylalanine effectively reversed these changes. These newly observed mechanisms also support the generation of pauses and burst activity commonly observed in the basal ganglia of parkinsonian subjects. These results suggest that the generation of abnormal response sequences in the basal ganglia contributes to the development of motor disabilities in PD and that intra-Str DA supplements effectively suppress abnormal signal transfer.

Acute effects of capsaicin on energy expenditure and fat oxidation in negative energy balance.

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Pilou L H R Janssens

Full Text Available BACKGROUND: Addition of capsaicin (CAPS to the diet has been shown to increase energy expenditure; therefore capsaicin is an interesting target for anti-obesity therapy. AIM: We investigated the 24 h effects of CAPS on energy expenditure, substrate oxidation and blood pressure during 25% negative energy balance. METHODS: Subjects underwent four 36 h sessions in a respiration chamber for measurements of energy expenditure, substrate oxidation and blood pressure. They received 100% or 75% of their daily energy requirements in the conditions '100%CAPS', '100%Control', '75%CAPS' and '75%Control'. CAPS was given at a dose of 2.56 mg (1.03 g of red chili pepper, 39,050 Scoville heat units (SHU with every meal. RESULTS: An induced negative energy balance of 25% was effectively a 20.5% negative energy balance due to adapting mechanisms. Diet-induced thermogenesis (DIT and resting energy expenditure (REE at 75%CAPS did not differ from DIT and REE at 100%Control, while at 75%Control these tended to be or were lower than at 100%Control (p = 0.05 and p = 0.02 respectively. Sleeping metabolic rate (SMR at 75%CAPS did not differ from SMR at 100%CAPS, while SMR at 75%Control was lower than at 100%CAPS (p = 0.04. Fat oxidation at 75%CAPS was higher than at 100%Control (p = 0.03, while with 75%Control it did not differ from 100%Control. Respiratory quotient (RQ was more decreased at 75%CAPS (p = 0.04 than at 75%Control (p = 0.05 when compared with 100%Control. Blood pressure did not differ between the four conditions. CONCLUSION: In an effectively 20.5% negative energy balance, consumption of 2.56 mg capsaicin per meal supports negative energy balance by counteracting the unfavorable negative energy balance effect of decrease in components of energy expenditure. Moreover, consumption of 2.56 mg capsaicin per meal promotes fat oxidation in negative energy balance and does not increase blood pressure significantly. TRIAL REGISTRATION

Evoked traveling alpha waves predict visual-semantic categorization-speed

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Fellinger, Robert; Gruber, Walter; Zauner, Andrea; Freunberger, Roman; Klimesch, Wolfgang

2012-01-01

In the present study we have tested the hypothesis that evoked traveling alpha waves are behaviorally significant. The results of a visual-semantic categorization task show that three early ERP components including the P1–N1 complex had a dominant frequency characteristic in the alpha range and behaved like traveling waves do. They exhibited a traveling direction from midline occipital to right lateral parietal sites. Phase analyses revealed that this traveling behavior of ERP components could be explained by phase-delays in the alpha but not theta and beta frequency range. Most importantly, we found that the speed of the traveling alpha wave was significantly and negatively correlated with reaction time indicating that slow traveling speed was associated with fast picture-categorization. We conclude that evoked alpha oscillations are functionally associated with early access to visual-semantic information and generate – or at least modulate – the early waveforms of the visual ERP. PMID:22100769

Purinergic receptors are involved in tooth-pulp evoked nocifensive behavior and brainstem neuronal activity

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Sessle Barry J

2010-09-01

Full Text Available Abstract Background To evaluate whether P2X receptors are involved in responses to noxious pulp stimulation, the P2X3 and P2X2/3 receptor agonist α,β-methyleneATP (α,β-meATP was applied to the molar tooth pulp and nocifensive behavior and extracellular-signal regulated kinase (ERK phosphorylation in trigeminal spinal subnucleus caudalis (Vc, trigeminal spinal subnucleus interpolaris (Vi, upper cervical spinal cord (C1/C2 and paratrigeminal nucleus (Pa5 neurons were analyzed in rats. Results Genioglossus (GG muscle activity was evoked by pulpal application of 100 mM α,β-meATP and was significantly larger than GG activity following vehicle (phosphate-buffered saline PBS application (p 1, P2X3 and, P2X2/3 antagonist. A large number of pERK-LI cells were expressed in the Vc, Vi/Vc, C1/C2 and Pa5 at 5 min following pulpal application of 100 mM α,β-meATP compared to PBS application to the pulp (p Conclusions The present findings suggest that activation of P2X3 and P2X2/3 receptors in the tooth pulp is sufficient to elicit nociceptive behavioral responses and trigeminal brainstem neuronal activity.

Acupuncture suppresses reinstatement of morphine-seeking behavior induced by a complex cue in rats.

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Lee, Bong Hyo; Lim, Sung Chul; Jeon, Hyeon Jeong; Kim, Jae Su; Lee, Yun Kyu; Lee, Hyun Jong; In, Sunghyun; Kim, Hee Young; Yoon, Seong Shoon; Yang, Chae Ha

2013-08-26

Morphine causes physical and psychological dependence for individuals after repeated-use. Above all, our previous study showed that acupuncture attenuated reinstatement of morphine-seeking behavior induced by pharmacological cue. In this study, we investigated whether acupuncture could suppress the reinstatement of morphine-seeking behavior induced by the combination of environmental and pharmacological cues and the possible neuronal involvement. Male Sprague-Dawley rats were trained to self-administer morphine (1.0 mg/kg) for 3 weeks. Following the withdrawal phase (7 days), the effects of acupuncture on reinstatement of morphine-seeking behavior were investigated. For the investigation of neuronal involvement, the GABAA receptor antagonist bicuculline and the GABAB receptor antagonist SCH 50911 were pre-treated. Morphine-seeking behavior induced by combination of re-exposure to the operant chamber and morphine injection was suppressed perfectly by acupuncture at SI5, but not at the control acupoint LI5 and this effect was blocked by pre-treatment with the GABA receptor antagonists. This study suggests that acupuncture at SI5 can be considered as a predominant therapy for the reinstatement of morphine-seeking behavior in humans. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Natural hazards and motivation for mitigation behavior: people cannot predict the affect evoked by a severe flood.

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Siegrist, Michael; Gutscher, Heinz

2008-06-01

Past research indicates that personal flood experience is an important factor in motivating mitigation behavior. It is not fully clear, however, why such experience is so important. This study tested the hypothesis that people without flooding experience underestimate the negative affect evoked by such an event. People who were affected by a severe recent flood disaster were compared with people who were not affected, but who also lived in flood-prone areas. Face-to-face interviews with open and closed questions were conducted (n= 201). Results suggest that people without flood experience envisaged the consequences of a flood differently from people who had actually experienced severe losses due to a flood. People who were not affected strongly underestimated the negative affect associated with a flood. Based on the results, it can be concluded that risk communication must not focus solely on technical aspects; in order to trigger motivation for mitigation behavior, successful communication must also help people to envisage the negative emotional consequences of natural disasters.

Enhanced biofouling resistance of polyethersulfone membrane surface modified with capsaicin derivative and itaconic acid

Energy Technology Data Exchange (ETDEWEB)

Wang, Jian [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Gao, Xueli, E-mail: gxl_ouc@126.com [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Wang, Qun; Sun, Haijing; Wang, Xiaojuan [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China); Gao, Congjie, E-mail: gaocjie@ouc.edu.cn [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao 266100 (China)

2015-11-30

Graphical abstract: - Highlights: • PES membrane was modified with a capsaicin derivative. • UV-assisted graft polymerization was carried out on membrane surface. • The capsaicin derivative modified membrane shows better antibiofouling property. - Abstract: The culprit of biofouling is the reproduction of viable microorganisms on the membrane surface. Recently, functionalization of membrane surface with natural antibacterial agents has drawn great attention. This work presents the fabrication of antibiofouling polyethersulfone (PES) ultrafiltration (UF) membranes by UV-assisted photo grafting of capsaicin derivative (N-(4-hydroxy-3-methoxy-benzyl)-acrylamide, HMBA) and itaconic acid (IA) on the surface of PES membrane. Results of FTIR-ATR, water static contact angle (WSCA) and atomic force microscopy (AFM) analysis confirmed the successful grafting of HMBA and IA on the membrane surface. We investigated the antifouling and antibacterial properties of these membranes using BSA and Escherichia coli as the test model, respectively. During a 150-min test, the modified membranes show much lower flux decline (42.7% for PES-g-1H0I, 22.2% for PES-g-1H1I and 7.7% for PES-g-1H5I) when compared with the pristine membrane (flux declined by 77%). The modified membranes exhibit excellent antibacterial activity (nearly 100%) when UV irradiation time was 6 min. The morphological study suggested that the E. coli on the pristine membrane showed a regular and smooth surface while that on the modified membrane was disrupted, which validated the antibacterial activity of the modified membranes.

Enhanced biofouling resistance of polyethersulfone membrane surface modified with capsaicin derivative and itaconic acid

International Nuclear Information System (INIS)

Wang, Jian; Gao, Xueli; Wang, Qun; Sun, Haijing; Wang, Xiaojuan; Gao, Congjie

2015-01-01

Graphical abstract: - Highlights: • PES membrane was modified with a capsaicin derivative. • UV-assisted graft polymerization was carried out on membrane surface. • The capsaicin derivative modified membrane shows better antibiofouling property. - Abstract: The culprit of biofouling is the reproduction of viable microorganisms on the membrane surface. Recently, functionalization of membrane surface with natural antibacterial agents has drawn great attention. This work presents the fabrication of antibiofouling polyethersulfone (PES) ultrafiltration (UF) membranes by UV-assisted photo grafting of capsaicin derivative (N-(4-hydroxy-3-methoxy-benzyl)-acrylamide, HMBA) and itaconic acid (IA) on the surface of PES membrane. Results of FTIR-ATR, water static contact angle (WSCA) and atomic force microscopy (AFM) analysis confirmed the successful grafting of HMBA and IA on the membrane surface. We investigated the antifouling and antibacterial properties of these membranes using BSA and Escherichia coli as the test model, respectively. During a 150-min test, the modified membranes show much lower flux decline (42.7% for PES-g-1H0I, 22.2% for PES-g-1H1I and 7.7% for PES-g-1H5I) when compared with the pristine membrane (flux declined by 77%). The modified membranes exhibit excellent antibacterial activity (nearly 100%) when UV irradiation time was 6 min. The morphological study suggested that the E. coli on the pristine membrane showed a regular and smooth surface while that on the modified membrane was disrupted, which validated the antibacterial activity of the modified membranes.

Capsaicin 8% Patch for Central and Peripheral Neuropathic Pain of Persons with Incomplete Spinal Cord Injury: Two Case Reports.

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Trbovich, Michelle; Yang, Huiqing

2015-08-01

Neuropathic pain after spinal cord injury is common and often refractory to standard treatments. The capsaicin 8% patch is a Food and Drug Administration-approved treatment of neuropathic pain in postherpetic neuralgia and has demonstrated significant efficacy in human immunodeficiency virus-autonomic neuropathy. The patch defunctionalizes transient receptor potential vanilloid 1 receptors, impairing cutaneous nociceptors for a prolonged period (i.e., 8-12 wks) with no systemic side effects. A retrospective review was conducted on the effects of the patch in two patients with spinal cord injury and neuropathic pain refractory to standard treatments. Two weeks after application, both patients reported complete pain relief. Average onset of relief of 4 days and average duration of relief of 197 days, requiring only one to four applications per year, paralleled findings reported in postherpetic neuralgia and human immunodeficiency virus-autonomic neuropathy trials. Upregulation of capsaicin-sensitive transient receptor potential vanilloid 1 receptors after spinal cord injury has been reported. The capsaicin 8% patch is a promising therapeutic agent for neuropathic pain in spinal cord injury.

Synthesis and characterization of manganese diselenide nanoparticles (MnSeNPs): Determination of capsaicin by using MnSeNP-modified glassy carbon electrode.

Science.gov (United States)

Sukanya, Ramaraj; Sakthivel, Mani; Chen, Shen-Ming; Chen, Tse-Wei; Al-Hemaid, Fahad M A; Ajmal Ali, M; Elshikh, Mohamed Soliman

2018-06-02

A new type of manganese diselenide nanoparticles (MnSeNPs) was synthesized by using a hydrothermal method. Their surface morphology, crystallinity and elemental distribution were characterized by using transmission electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy which scrutinize the formation of the NPs. The NPs were coated on a glassy carbon electrode (GCE), and electrochemical impedance spectroscopy, cyclic voltammetry and differential pulse voltammetry were applied to study the electroanalytical properties towards the oxidation of the food additive capsaicin. The modified GCE displays lower charge transfer resistance (R ct  = 29.52 Ω), a larger active surface area (0.089 cm 2 /g, and more efficient electrochemical oxidation of capsaicin compared to a MnS 2 /GCE and a bare GCE. The oxidation peak potential is 0.43 V (vs. Ag/AgCl) which is lower than that of previously reported GCEs. The sensor has a detection limit as low as 0.05 μM and an electrochemical sensitivity of 2.41 μA μM -1  cm -2 . The method was applied to the determination of capsaicin in pepper samples. Graphical abstract Electrochemical determination of capsaicin in pepper extract by using MnSeNPs modified electrode.

Adverse Weather Evokes Nostalgia.

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van Tilburg, Wijnand A P; Sedikides, Constantine; Wildschut, Tim

2018-03-01

Four studies examined the link between adverse weather and the palliative role of nostalgia. We proposed and tested that (a) adverse weather evokes nostalgia (Hypothesis 1); (b) adverse weather causes distress, which predicts elevated nostalgia (Hypothesis 2); (c) preventing nostalgia exacerbates weather-induced distress (Hypothesis 3); and (d) weather-evoked nostalgia confers psychological benefits (Hypothesis 4). In Study 1, participants listened to recordings of wind, thunder, rain, and neutral sounds. Adverse weather evoked nostalgia. In Study 2, participants kept a 10-day diary recording weather conditions, distress, and nostalgia. We also obtained meteorological data. Adverse weather perceptions were positively correlated with distress, which predicted higher nostalgia. Also, adverse natural weather was associated with corresponding weather perceptions, which predicted elevated nostalgia. (Results were mixed for rain.) In Study 3, preventing nostalgia (via cognitive load) increased weather-evoked distress. In Study 4, weather-evoked nostalgia was positively associated with psychological benefits. The findings pioneer the relevance of nostalgia as source of comfort in adverse weather.

Studies on the in vitro absorption of spice principles--curcumin, capsaicin and piperine in rat intestines.

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Suresh, D; Srinivasan, K

2007-08-01

A comparative evaluation of the absorbability of three structurally similar and physiologically active spice principles in an in vitro system consisting of everted rat intestinal sacs was made. When everted sacs of rat intestines were incubated with 50-1000 microg of curcumin in 10 ml incubation medium, absorption of the spice principle was maximum at 100 microg concentration. The amount of absorbed curcumin present in the serosal fluid was negligible. This and the comparatively lower recovery of the original compound suggested that curcumin to some extent undergoes a modification during absorption. For similar concentrations of added piperine, about 44-63% of piperine disappeared from the mucosal side. Absorption of piperine which was maximum at 800 microg per 10 ml was about 63%. The absolute amounts of piperine absorbed in this in vitro system exceeded the amounts of curcumin. The absorbed piperine could be traced in both the serosal fluid and in the intestinal tissue, indicating that piperine did not undergo any metabolic change during the process of absorption. 7-12% of the absorbed piperine was found in the serosal fluid. When everted sacs of rat intestines were incubated with 10-500 microg of capsaicin, a maximum of 82-88% absorption could be seen in the lower concentrations, and the amount of absorbed capsaicin did not proportionately increase at higher concentrations. A relatively higher percentage of the absorbed capsaicin could be seen in the serosal fluid as compared to curcumin or piperine. When these spice active principles were associated with mixed micelles, their in vitro intestinal absorption was relatively higher. Curcumin absorption in everted intestinal sac increased from 48.7% to 56.1% when the same was present in micelles. In the case of capsaicin and piperine, increase in absorption was 27.8-44.4% and 43.4-57.4%, respectively, when they were present in micelles as compared to its native form.

Effect of inter-train interval on the induction of repetition suppression of motor-evoked potentials using transcranial magnetic stimulation.

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Minna Pitkänen

Full Text Available Repetition suppression (RS is evident as a weakened response to repeated stimuli after the initial response. RS has been demonstrated in motor-evoked potentials (MEPs induced with transcranial magnetic stimulation (TMS. Here, we investigated the effect of inter-train interval (ITI on the induction of RS of MEPs with the attempt to optimize the investigative protocols. Trains of TMS pulses, targeted to the primary motor cortex by neuronavigation, were applied at a stimulation intensity of 120% of the resting motor threshold. The stimulus trains included either four or twenty pulses with an inter-stimulus interval (ISI of 1 s. The ITI was here defined as the interval between the last pulse in a train and the first pulse in the next train; the ITIs used here were 1, 3, 4, 6, 7, 12, and 17 s. RS was observed with all ITIs except with the ITI of 1 s, in which the ITI was equal to ISI. RS was more pronounced with longer ITIs. Shorter ITIs may not allow sufficient time for a return to baseline. RS may reflect a startle-like response to the first pulse of a train followed by habituation. Longer ITIs may allow more recovery time and in turn demonstrate greater RS. Our results indicate that RS can be studied with confidence at relatively short ITIs of 6 s and above.

Peripheral and central mediators of lipopolysaccharide induced suppression of defensive rage behavior in the cat.

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Bhatt, S; Bhatt, R S; Zalcman, S S; Siegel, A

2009-11-10

Based upon recent findings in our laboratory that cytokines microinjected into the medial hypothalamus or periaqueductal gray (PAG) powerfully modulate defensive rage behavior in cat, the present study determined the effects of peripherally released cytokines following lipopolysaccharide (LPS) challenge upon defensive rage. The study involved initial identification of the effects of peripheral administration of LPS upon defensive rage by electrical stimulation from PAG and subsequent determination of the peripheral and central mechanisms governing this process. The results revealed significant elevation in response latencies for defensive rage from 60 to 300 min, post LPS injection, with no detectable signs of sickness behavior present at 60 min. In contrast, head turning behavior elicited by stimulation of adjoining midbrain sites was not affected by LPS administration, suggesting a specificity of the effects of LPS upon defensive rage. Direct administration of LPS into the medial hypothalamus had no effect on defensive rage, suggesting that the effects of LPS were mediated by peripheral cytokines rather than by any direct actions upon hypothalamic neurons. Complete blockade of the suppressive effects of LPS by peripheral pretreatment with an Anti-tumor necrosis factor-alpha (TNFalpha) antibody but not with an anti- interleukin-1 (IL-1) antibody demonstrated that the effects of LPS were mediated through TNF-alpha rather than through an IL-1 mechanism. A determination of the central mechanisms governing LPS suppression revealed that pretreatment of the medial hypothalamus with PGE(2) or 5-HT(1A) receptor antagonists each completely blocked the suppressive effects of LPS, while microinjections of a TNF-alpha antibody into the medial hypothalamus were ineffective. Microinjections of -Iodo-N-[2-[4-(methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl) benzamide monohydrochloride (p-MPPI) into lateral hypothalamus (to test for anatomical specificity) had no effect upon

Effect of gibberellin, auxin and kinetin treatments combined with foliar applied NPK on the yield of Capsicum annuum L. fruits and their capsaicin content

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Tomasz J. Nowak

2013-12-01

Full Text Available The Wrocław version of hydroponic culture was applied. Under optimal conditions of root fertilization the plants were sprayed with growth regulators sueh as gibberellins, auxins and kinetins, and .their mixtures. Each growth regulator treatment was applied with or without NPK added. The influence of these treatments on the fresh and dry weight of the fruit, percentage of ripe fruits and content and yield of capsaicin was studied. The highest yield of fruits and capsaicin. was obtained from plants sprayed with gibberellic acid and kinetin (in concentrations of 10 and 5 mg/l, respectively together with NPK foliar application. No influence of ,growth regulators and foliar-applied NPK was noted on capsaicin content and dry weight of fruits.

Music evokes vivid autobiographical memories.

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Belfi, Amy M; Karlan, Brett; Tranel, Daniel

2016-08-01

Music is strongly intertwined with memories-for example, hearing a song from the past can transport you back in time, triggering the sights, sounds, and feelings of a specific event. This association between music and vivid autobiographical memory is intuitively apparent, but the idea that music is intimately tied with memories, seemingly more so than other potent memory cues (e.g., familiar faces), has not been empirically tested. Here, we compared memories evoked by music to those evoked by famous faces, predicting that music-evoked autobiographical memories (MEAMs) would be more vivid. Participants listened to 30 songs, viewed 30 faces, and reported on memories that were evoked. Memories were transcribed and coded for vividness as in Levine, B., Svoboda, E., Hay, J. F., Winocur, G., & Moscovitch, M. [2002. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677-689]. In support of our hypothesis, MEAMs were more vivid than autobiographical memories evoked by faces. MEAMs contained a greater proportion of internal details and a greater number of perceptual details, while face-evoked memories contained a greater number of external details. Additionally, we identified sex differences in memory vividness: for both stimulus categories, women retrieved more vivid memories than men. The results show that music not only effectively evokes autobiographical memories, but that these memories are more vivid than those evoked by famous faces.

Comparison of voiding function and nociceptive behavior in two rat models of cystitis induced by cyclophosphamide or acetone

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Saitoh, Chikashi; Yokoyama, Hitoshi; Chancellor, Michael B.; de Groat, William C.; Yoshimura, Naoki

2009-01-01

Aims Nociceptive behavior and its relationship with bladder dysfunction were investigated in two cystitis models, which were induced by intraperitoneal (ip) injection of cyclophosphamide (CYP) or intravesical instillation of acetone, using freely moving, non-catheterized conscious rats. Methods Female Sprague-Dawley rats were used. Cystitis was induced by ip injection of CYP (100 and 200mg/kg) or intravesical instillation of acetone (10, 30 and 50%) via a polyethylene catheter temporarily inserted into the bladder through the urethra. Then the incidence of nociceptive behavior (immobility with decreased breathing rates) was scored. Voided urine was collected simultaneously and continuously to measure bladder capacity. The plasma extravasation in the bladder was quantified by an evans blue (EB) dye leakage technique. Results CYP (100mg/kg, ip) induced nociceptive behavior without affecting bladder capacity or EB concentration in the bladder. A higher dose of CYP (200mg/kg, ip) decreased bladder capacity and increased EB levels as well as nociceptive behavior. In contrast, intravesical instillation of acetone (30%) decreased bladder capacity and increased EB levels, but evoked nociceptive behavior less frequently compared with CYP-treated animals. In capsaicin pretreated rats, nociceptive behavior induced by CYP or acetone was reduced; however, the overall effects of CYP or acetone on bladder capacity and bladder EB levels were unaffected. Conclusions These results suggest that there is a difference in the induction process of nociceptive behavior and small bladder capacity after two different types of bladder irritation and that C-fiber sensitization is more directly involved in pain sensation than reduced bladder capacity. PMID:19618450

Organization of pERK-immunoreactive cells in trigeminal spinal nucleus caudalis, upper cervical cord, NTS and Pa5 following capsaicin injection into masticatory and swallowing-related muscles in rats.

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Tsujimura, Takanori; Shinoda, Masamichi; Honda, Kuniya; Hitomi, Suzuro; Kiyomoto, Masaaki; Matsuura, Shingo; Katagiri, Ayano; Tsuji, Kojun; Inoue, Makoto; Shiga, Yoshi; Iwata, Koichi

2011-10-12

Many phosphorylated extracellular signal-regulated kinase (pERK)-immunoreactive (IR) cells are expressed in the trigeminal spinal subnucleus caudalis (Vc), upper cervical spinal cord (C1-C2), nucleus tractus solitarii (NTS) and paratrigeminal nucleus (Pa5) after capsaicin injection into the whisker pad (WP), masseter muscle (MM), digastric muscle (DM) or sternohyoideus muscle (SM). The pERK-IR cells also showed NeuN immunoreactivity, indicating that ERK phosphorylation occurs in neurons. The pERK-IR cells were significantly reduced after intrathecal injection of MEK 1/2 inhibitor PD98059. The pERK-IR cells expressed bilaterally in the Vc and C1-C2 after capsaicin injection into the unilateral DM or SM, whereas unilaterally in the Vc and C1-C2 after unilateral WP or MM injection. After capsaicin injection into the WP or MM, the pERK-IR cell expression in the Vc was restricted rostrocaudally within a narrow area. However, the distribution of pERK-IR cells was more wide spread without a clear peak in the Vc and C1-C2 after capsaicin injection into the DM or SM. In the NTS, the unimodal pERK-IR cell expression peaked at 0-720μm rostral from the obex following capsaicin injection into WP, MM, DM or SM. In the ipsilateral Pa5, many pERK-IR cells were observed following capsaicin injection into the SM. The number of swallows elicited by distilled water administration was significantly smaller after capsaicin injection into the WP, MM or DM but not SM compared to that of vehicle-injected rats. Various noxious inputs due to the masticatory or swallowing-related muscle inflammation may be differentially involved in muscle pain and swallowing reflex activity. Copyright © 2011 Elsevier B.V. All rights reserved.

Task-specific modulation of human auditory evoked responses in a delayed-match-to-sample task

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Feng eRong

2011-05-01

Full Text Available In this study, we focus our investigation on task-specific cognitive modulation of early cortical auditory processing in human cerebral cortex. During the experiments, we acquired whole-head magnetoencephalography (MEG data while participants were performing an auditory delayed-match-to-sample (DMS task and associated control tasks. Using a spatial filtering beamformer technique to simultaneously estimate multiple source activities inside the human brain, we observed a significant DMS-specific suppression of the auditory evoked response to the second stimulus in a sound pair, with the center of the effect being located in the vicinity of the left auditory cortex. For the right auditory cortex, a non-invariant suppression effect was observed in both DMS and control tasks. Furthermore, analysis of coherence revealed a beta band (12 ~ 20 Hz DMS-specific enhanced functional interaction between the sources in left auditory cortex and those in left inferior frontal gyrus, which has been shown to involve in short-term memory processing during the delay period of DMS task. Our findings support the view that early evoked cortical responses to incoming acoustic stimuli can be modulated by task-specific cognitive functions by means of frontal-temporal functional interactions.

β-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum

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Wang, Guo-Du; Wang, Xi-Yu; Liu, Sumei; Xia, Yun; Zou, Fei; Qu, Meihua; Needleman, Bradley J.; Mikami, Dean J.

2015-01-01

Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to β-nicotinamide adenine dinucleotide (β-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, β-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. β-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of β-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of β-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for β-NAD at intestinal neuromuscular junctions. The data suggest that β-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of β-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions. PMID:25813057

Dose-dependent suppression by ethanol of transient auditory 40-Hz response.

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Jääskeläinen, I P; Hirvonen, J; Saher, M; Pekkonen, E; Sillanaukee, P; Näätänen, R; Tiitinen, H

2000-02-01

Acute alcohol (ethanol) challenge is known to induce various cognitive disturbances, yet the neural basis of the effect is poorly known. The auditory transient evoked gamma-band (40-Hz) oscillatory responses have been suggested to be associated with various perceptual and cognitive functions in humans; however, alcohol effects on auditory 40-Hz responses have not been investigated to date. The objective of the study was to test the dose-related impact of alcohol on auditory transient evoked 40-Hz responses during a selective-attention task. Ten healthy social drinkers ingested, in four separate sessions, 0.00, 0. 25, 0.50, or 0.75 g/kg of 10% (v/v) alcohol solution. The order of the sessions was randomized and a double-blind procedure was employed. During a selective attention task, 300-Hz standard and 330-Hz deviant tones were presented to the left ear, and 1000-Hz standards and 1100-Hz deviants to the right ear of the subjects (P=0. 425 for each standard, P=0.075 for each deviant). The subjects attended to a designated ear, and were to detect the deviants therein while ignoring tones to the other ear. The auditory transient evoked 40-Hz responses elicited by both the attended and unattended standard tones were significantly suppressed by the 0.50 and 0.75 g/kg alcohol doses. Alcohol suppresses auditory transient evoked 40-Hz oscillations already with moderate blood alcohol concentrations. Given the putative role of gamma-band oscillations in cognition, this finding could be associated with certain alcohol-induced cognitive deficits.

Can a static nonlinearity account for the dynamics of otoacoustic emission suppression?

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Verhulst, Sarah; Shera, Christopher A.; Harte, James

2011-01-01

This study investigates whether time-dependent compression mechanisms in the cochlea are necessary to explain dynamic properties of otoacoustic emissions (OAEs). Dynamic properties of click-evoked OAEs (CEOAEs) have been observed in temporal suppression; the effect where the CEOAE magnitude is re...

Capsaicin on the viability of random-pattern skin flaps in rats Capsaicina na viabilidade de retalhos isquêmicos randômicos em ratos

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Gustavo Roberto de Godoy

2010-10-01

Full Text Available PURPOSE: To evaluate the effects of capsaicin on the viability of ischemic random-pattern skin flaps in rats. METHODS:Forty EPM1-Wistar rats were randomized into two groups of 20 animals each, the capsaicin group and the control group. A random-pattern skin flap measuring 10 x 4cm was raised and a plastic barrier was placed between the flap and the donor site. After the surgical procedure, the control group was treated with an inert vehicle in the form of a cream applied uniformly to a rayon bandage which, in turn, was applied to the surface of the skin flap. The capsaicin group was treated in the same way, but in this case capsaicin was added to the cream. This procedure was repeated for two consecutive days. RESULTS: There was a significantly smaller amount of flap necrosis in the capsaicin group (35.07% than in the control group (44.75% (p=0.035. CONCLUSION:Topical administration of capsaicin improved the viability of ischemic random-pattern skin flaps in rats.OBJETIVO: Avaliar os efeitos da capsaicina na viabilidade de retalhos isquêmicos randômicos em ratos. MÉTODOS: Quarenta ratos EPM1-Wistar foram distribuídos ao acaso em dois grupos de 20 animais cada, um grupo capsaicina e um grupo controle. Um retalho isquêmico randômico medindo 10 x 4cm foi elevado e uma barreira plástica foi colocada entre o retalho e a área doadora. Após o procedimento cirúrgico, o grupo controle foi tratado com um veículo inerte sob a forma creme aplicado uniformemente sobre uma atadura de rayon, que, por sua vez, foi aplicada à superfície do retalho. O grupo capsaicina foi tratado da mesma forma, porém a capsaicina foi adicionada ao creme. Este procedimento foi repetido por dois dias consecutivos. RESULTADOS: Houve uma quantidade significativamente menor da necrose do retalho no grupo capsaicina (35,07% comparado ao grupo controle (44,75% (p=0,035. CONCLUSÃO: A administração tópica da capsaicina melhorou a viabilidade de retalhos isquêmicos rand

Upregulation of T-type Ca2+ channels in long-term diabetes determines increased excitability of a specific type of capsaicin-insensitive DRG neurons.

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Duzhyy, Dmytro E; Viatchenko-Karpinski, Viacheslav Y; Khomula, Eugen V; Voitenko, Nana V; Belan, Pavel V

2015-05-20

Previous studies have shown that increased excitability of capsaicin-sensitive DRG neurons and thermal hyperalgesia in rats with short-term (2-4 weeks) streptozotocin-induced diabetes is mediated by upregulation of T-type Ca(2+) current. In longer-term diabetes (after the 8th week) thermal hyperalgesia is changed to hypoalgesia that is accompanied by downregulation of T-type current in capsaicin-sensitive small-sized nociceptors. At the same time pain symptoms of diabetic neuropathy other than thermal persist in STZ-diabetic animals and patients during progression of diabetes into later stages suggesting that other types of DRG neurons may be sensitized and contribute to pain. In this study, we examined functional expression of T-type Ca(2+) channels in capsaicin-insensitive DRG neurons and excitability of these neurons in longer-term diabetic rats and in thermally hypoalgesic diabetic rats. Here we have demonstrated that in STZ-diabetes T-type current was upregulated in capsaicin-insensitive low-pH-sensitive small-sized nociceptive DRG neurons of longer-term diabetic rats and thermally hypoalgesic diabetic rats. This upregulation was not accompanied by significant changes in biophysical properties of T-type channels suggesting that a density of functionally active channels was increased. Sensitivity of T-type current to amiloride (1 mM) and low concentration of Ni(2+) (50 μM) implicates prevalence of Cav3.2 subtype of T-type channels in the capsaicin-insensitive low-pH-sensitive neurons of both naïve and diabetic rats. The upregulation of T-type channels resulted in the increased neuronal excitability of these nociceptive neurons revealed by a lower threshold for action potential initiation, prominent afterdepolarizing potentials and burst firing. Sodium current was not significantly changed in these neurons during long-term diabetes and could not contribute to the diabetes-induced increase of neuronal excitability. Capsaicin-insensitive low-pH-sensitive type

TRPV1 marks synaptic segregation of multiple convergent afferents at the rat medial solitary tract nucleus.

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James H Peters

Full Text Available TRPV1 receptors are expressed on most but not all central terminals of cranial visceral afferents in the caudal solitary tract nucleus (NTS. TRPV1 is associated with unmyelinated C-fiber afferents. Both TRPV1+ and TRPV1- afferents enter NTS but their precise organization remains poorly understood. In horizontal brainstem slices, we activated solitary tract (ST afferents and recorded ST-evoked glutamatergic excitatory synaptic currents (ST-EPSCs under whole cell voltage clamp conditions from neurons of the medial subnucleus. Electrical shocks to the ST produced fixed latency EPSCs (jitter<200 µs that identified direct ST afferent innervation. Graded increases in shock intensity often recruited more than one ST afferent and ST-EPSCs had consistent threshold intensity, latency to onset, and unique EPSC waveforms that characterized each unitary ST afferent contact. The TRPV1 agonist capsaicin (100 nM blocked the evoked TRPV1+ ST-EPSCs and defined them as either TRPV1+ or TRPV1- inputs. No partial responses to capsaicin were observed so that in NTS neurons that received one or multiple (2-5 direct ST afferent inputs--all were either blocked by capsaicin or were unaltered. Since TRPV1 mediates asynchronous release following TRPV1+ ST-evoked EPSCs, we likewise found that recruiting more than one ST afferent further augmented the asynchronous response and was eliminated by capsaicin. Thus, TRPV1+ and TRPV1- afferents are completely segregated to separate NTS neurons. As a result, the TRPV1 receptor augments glutamate release only within unmyelinated afferent pathways in caudal medial NTS and our work indicates a complete separation of C-type from A-type afferent information at these first central neurons.

Explicit episodic memory for sensory-discriminative components of capsaicin-induced pain: immediate and delayed ratings.

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Jantsch, H H F; Gawlitza, M; Geber, C; Baumgärtner, U; Krämer, H H; Magerl, W; Treede, R D; Birklein, F

2009-05-01

Pain memory is thought to affect future pain sensitivity and thus contribute to clinical pain conditions. Systematic investigations of the human capacity to remember sensory features of experimental pain are sparse. In order to address long-term pain memory, nine healthy male volunteers received intradermal injections of three doses of capsaicin (0.05, 1 and 20 microg, separated by 15 min breaks), each given three times in a balanced design across three sessions at one week intervals. Pain rating was performed using a computerized visual analogue scale (0-100) digitized at 1/s, either immediately online or one hour or one day after injection. Subjects also recalled their pains one week later. Capsaicin injection reliably induced a dose-dependent flare (pmemory traces. These results indicate a reliable memory for magnitude and duration of experimentally induced pain. The data further suggest that the consolidation of this memory is an important interim stage, and may take up to one day.

Proprioceptive evoked gamma oscillations

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Arnfred, S.M.; Hansen, Lars Kai; Parnas, J.

2007-01-01

A proprioceptive stimulus consisting of a weight change of a handheld load has recently been shown to elicit an evoked potential. Previously, somatosensory gamma oscillations have only been evoked by electrical stimuli. We conjectured that a natural proprioceptive stimulus also would be able...... to evoke gamma oscillations. EEG was recorded using 64 channels in 14 healthy subjects. In each of three runs a stimulus of 100 g load increment in each hand was presented in 120 trials. Data were wavelet transformed and runs collapsed. Inter-trial phase coherence (ITPC) was computed as the best measure...

Comparison of topical capsaicin and topical turpentine oil for treatment of painful diabetic neuropathy

International Nuclear Information System (INIS)

Musharraf, M.U.; Ahmed, Z.

2017-01-01

Background: Diabetes Mellitus is a pandemic of the modern era owing to our rapidly deteriorating lifestyle. Painful diabetic neuropathy is one of the costliest and disabling complications of diabetes mellitus. No single treatment exists to prevent or reverse neuropathic changes or to provide total pain relief. Topical Capsaicin and Turpentine Oil are found to be effective in treatment of painful diabetic neuropathy. Methods: Patients of either gender with ages between 18 and 70 years having painful diabetic neuropathy already taking one oral drug for painful neuropathy and treatment for diabetes mellitus and an HbA1C less than 8.5% were included while Pregnant or lactating mothers, patients with chronic liver disease and patients with renal insufficiency (creatinine >3.0 mg/dl) and peripheral arterial disease were excluded from study. Patients were randomly divided into two groups (A and B) using computer generated random number table. Group A was given topical application of capsaicin while Group B was given topical application of commercially available turpentine oil over painful site on feet. Results: 300 patients were equally divided in two groups. The patients in group A had a Visual Analog Pain Score of 7.91±5.10 at baseline and 5.10±1.343 after 3 months of treatment (p-value 0.0001). The patients in group B had a Visual Analog Pain Score of 7.83±1.012 at baseline and 5.20±1.187 after 3 months of treatment (p-value 0.0001). Chi Square test was applied to compare efficacy of both groups. It was noted that 71 (53%) had efficacy in group A and 63 (47%) had efficacy in the group B but the difference was not statistically significant. (p-value=0.399). Conclusion: It has been concluded that turpentine oil is effective in managing diabetic neuropathic pain similar to capsaicin cream.

Whisker motor cortex reorganization after superior colliculus output suppression in adult rats.

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Veronesi, Carlo; Maggiolini, Emma; Franchi, Gianfranco

2013-10-01

The effect of unilateral superior colliculus (SC) output suppression on the ipsilateral whisker motor cortex (WMC) was studied at different time points after tetrodotoxin and quinolinic acid injections, in adult rats. The WMC output was assessed by mapping the movement evoked by intracortical microstimulation (ICMS) and by recording the ICMS-evoked electromyographic (EMG) responses from contralateral whisker muscles. At 1 h after SC injections, the WMC showed: (i) a strong decrease in contralateral whisker sites, (ii) a strong increase in ipsilateral whisker sites and in ineffective sites, and (iii) a strong increase in threshold current values. At 6 h after injections, the WMC size had shrunk to 60% of the control value and forelimb representation had expanded into the lateral part of the normal WMC. Thereafter, the size of the WMC recovered, returning to nearly normal 12 h later (94% of control) and persisted unchanged over time (1-3 weeks). The ICMS-evoked EMG response area decreased at 1 h after SC lesion and had recovered its baseline value 12 h later. Conversely, the latency of ICMS-evoked EMG responses had increased by 1 h and continued to increase for as long as 3 weeks following the lesion. These findings provide physiological evidence that SC output suppression persistently withdrew the direct excitatory drive from whisker motoneurons and induced changes in the WMC. We suggest that the changes in the WMC are a form of reversible short-term reorganization that is induced by SC lesion. The persistent latency increase in the ICMS-evoked EMG response suggested that the recovery of basic WMC excitability did not take place with the recovery of normal explorative behaviour. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Perceptual learning of acoustic noise generates memory-evoked potentials.

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Andrillon, Thomas; Kouider, Sid; Agus, Trevor; Pressnitzer, Daniel

2015-11-02

Experience continuously imprints on the brain at all stages of life. The traces it leaves behind can produce perceptual learning [1], which drives adaptive behavior to previously encountered stimuli. Recently, it has been shown that even random noise, a type of sound devoid of acoustic structure, can trigger fast and robust perceptual learning after repeated exposure [2]. Here, by combining psychophysics, electroencephalography (EEG), and modeling, we show that the perceptual learning of noise is associated with evoked potentials, without any salient physical discontinuity or obvious acoustic landmark in the sound. Rather, the potentials appeared whenever a memory trace was observed behaviorally. Such memory-evoked potentials were characterized by early latencies and auditory topographies, consistent with a sensory origin. Furthermore, they were generated even on conditions of diverted attention. The EEG waveforms could be modeled as standard evoked responses to auditory events (N1-P2) [3], triggered by idiosyncratic perceptual features acquired through learning. Thus, we argue that the learning of noise is accompanied by the rapid formation of sharp neural selectivity to arbitrary and complex acoustic patterns, within sensory regions. Such a mechanism bridges the gap between the short-term and longer-term plasticity observed in the learning of noise [2, 4-6]. It could also be key to the processing of natural sounds within auditory cortices [7], suggesting that the neural code for sound source identification will be shaped by experience as well as by acoustics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rapid and Persistent Suppression of Feeding Behavior Induced by Sensitization Training in "Aplysia"

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Acheampong, Ama; Kelly, Kathleen; Shields-Johnson, Maria; Hajovsky, Julie; Wainwright, Marcy; Mozzachiodi, Riccardo

2012-01-01

In "Aplysia," noxious stimuli induce sensitization of defensive responses. However, it remains largely unknown whether such stimuli also alter nondefensive behaviors. In this study, we examined the effects of noxious stimuli on feeding. Strong electric shocks, capable of inducing sensitization, also led to the suppression of feeding. The use of…

Self-initiated actions result in suppressed auditory but amplified visual evoked components in healthy participants.

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Mifsud, Nathan G; Oestreich, Lena K L; Jack, Bradley N; Ford, Judith M; Roach, Brian J; Mathalon, Daniel H; Whitford, Thomas J

2016-05-01

Self-suppression refers to the phenomenon that sensations initiated by our own movements are typically less salient, and elicit an attenuated neural response, compared to sensations resulting from changes in the external world. Evidence for self-suppression is provided by previous ERP studies in the auditory modality, which have found that healthy participants typically exhibit a reduced auditory N1 component when auditory stimuli are self-initiated as opposed to externally initiated. However, the literature investigating self-suppression in the visual modality is sparse, with mixed findings and experimental protocols. An EEG study was conducted to expand our understanding of self-suppression across different sensory modalities. Healthy participants experienced either an auditory (tone) or visual (pattern-reversal) stimulus following a willed button press (self-initiated), a random interval (externally initiated, unpredictable onset), or a visual countdown (externally initiated, predictable onset-to match the intrinsic predictability of self-initiated stimuli), while EEG was continuously recorded. Reduced N1 amplitudes for self- versus externally initiated tones indicated that self-suppression occurred in the auditory domain. In contrast, the visual N145 component was amplified for self- versus externally initiated pattern reversals. Externally initiated conditions did not differ as a function of their predictability. These findings highlight a difference in sensory processing of self-initiated stimuli across modalities, and may have implications for clinical disorders that are ostensibly associated with abnormal self-suppression. © 2016 Society for Psychophysiological Research.

Noise-evoked otoacoustic emissions in humans

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Maat, B; Wit, HP; van Dijk, P

2000-01-01

Click-evoked otoacoustic emissions (CEOAEs) and acoustical responses evoked by bandlimited Gaussian noise (noise-evoked otoacoustic emissions; NEOAEs) were measured in three normal-hearing subjects. For the NEOAEs the first- and second-order Wiener kernel and polynomial correlation functions up to

Analgesic effect of topical oral capsaicin gel in burning mouth syndrome

DEFF Research Database (Denmark)

Jørgensen, Mette Rose; Pedersen, Anne Marie Lynge

2017-01-01

OBJECTIVE: To investigate the effectiveness of repeated topical application of oral capsaicin gel in two different concentrations for relief of burning/stinging sensations in patients with burning mouth syndrome (BMS). MATERIAL AND METHODS: This randomized double-blind cross-over study included 22...... improved the burning/stinging symptoms assessed on VAS compared with baseline (p = 0.002). There was no statistically significant difference between the two concentrations of the gels on relieving symptoms. Four patients dropped out during the intervention period due to gastrointestinal side...

The Inhibitory Effect of Somatostatin Receptor Activation on Bee Venom-Evoked Nociceptive Behavior and pCREB Expression in Rats

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Li Li

2014-01-01

Full Text Available The present study examined nociceptive behaviors and the expression of phosphorylated cAMP response element-binding protein (pCREB in the dorsal horn of the lumbar spinal cord and the dorsal root ganglion (DRG evoked by bee venom (BV. The effect of intraplantar preapplication of the somatostatin analog octreotide on nociceptive behaviors and pCREB expression was also examined. Subcutaneous injection of BV into the rat unilateral hindpaw pad induced significant spontaneous nociceptive behaviors, primary mechanical allodynia, primary thermal hyperalgesia, and mirror-thermal hyperalgesia, as well as an increase in pCREB expression in the lumbar spinal dorsal horn and DRG. Octreotide pretreatment significantly attenuated the BV-induced lifting/licking response and mechanical allodynia. Local injection of octreotide also significantly reduced pCREB expression in the lumbar spinal dorsal horn and DRG. Furthermore, pretreatment with cyclosomatostatin, a somatostatin receptor antagonist, reversed the octreotide-induced inhibition of the lifting/licking response, mechanical allodynia, and the expression of pCREB. These results suggest that BV can induce nociceptive responses and somatostatin receptors are involved in mediating the antinociception, which provides new evidence for peripheral analgesic action of somatostatin in an inflammatory pain state.

Phase-specific Surround suppression in Mouse Primary Visual Cortex Correlates with Figure Detection Behavior Based on Phase Discontinuity.

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Li, Fengling; Jiang, Weiqian; Wang, Tian-Yi; Xie, Taorong; Yao, Haishan

2018-05-21

In the primary visual cortex (V1), neuronal responses to stimuli within the receptive field (RF) are modulated by stimuli in the RF surround. A common effect of surround modulation is surround suppression, which is dependent on the feature difference between stimuli within and surround the RF and is suggested to be involved in the perceptual phenomenon of figure-ground segregation. In this study, we examined the relationship between feature-specific surround suppression of V1 neurons and figure detection behavior based on figure-ground feature difference. We trained freely moving mice to perform a figure detection task using figure and ground gratings that differed in spatial phase. The performance of figure detection increased with the figure-ground phase difference, and was modulated by stimulus contrast. Electrophysiological recordings from V1 in head-fixed mice showed that the increase in phase difference between stimuli within and surround the RF caused a reduction in surround suppression, which was associated with an increase in V1 neural discrimination between stimuli with and without RF-surround phase difference. Consistent with the behavioral performance, the sensitivity of V1 neurons to RF-surround phase difference could be influenced by stimulus contrast. Furthermore, inhibiting V1 by optogenetically activating either parvalbumin (PV)- or somatostatin (SOM)-expressing inhibitory neurons both decreased the behavioral performance of figure detection. Thus, the phase-specific surround suppression in V1 represents a neural correlate of figure detection behavior based on figure-ground phase discontinuity. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Impact of maternal melatonin suppression on forced swim and tail suspension behavioral despair tests in adult offspring.

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Voiculescu, S E; Rosca, A E; Zeca, V; Zagrean, L; Zagrean, A M

2015-01-01

Melatonin is an essential hormone, which regulates circadian rhythms and has antioxidative and anticarcinogenic effects. As melatonin secretion is suppressed by light, this effect was examined on the offspring of the Wistar rat females exposed to continuous light (500 lux) during the second half of the pregnancy (day 12 to 21). Control rats were kept under a 12:12 light-dark cycle. The resulted male offspring have been behaviorally assessed for depression after postnatal day 60 by using Forced Swim Test (FST) and Tail Suspension Test (TST). Animals resulted from the melatonin deprived pregnancies have developed an abnormal response in the TST, but a normal FST behavior. Also, TST active movement was different in the melatonin suppression group compared to the control group. These findings suggest that intrauterine melatonin deprivation might be linked to the depressive like behavior in adult male offspring.

Inhibition of muscle spindle afferent activity during masseter muscle fatigue in the rat.

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Brunetti, Orazio; Della Torre, Giovannella; Lucchi, Maria Luisa; Chiocchetti, Roberto; Bortolami, Ruggero; Pettorossi, Vito Enrico

2003-09-01

The influence of muscle fatigue on the jaw-closing muscle spindle activity has been investigated by analyzing: (1) the field potentials evoked in the trigeminal motor nucleus (Vmot) by trigeminal mesencephalic nucleus (Vmes) stimulation, (2) the orthodromic and antidromic responses evoked in the Vmes by stimulation of the peripheral and central axons of the muscle proprioceptive afferents, and (3) the extracellular unitary discharge of masseter muscle spindles recorded in the Vmes. The masseter muscle was fatigued by prolonged tetanic masseter nerve electrical stimulation. Pre- and postsynaptic components of the potentials evoked in the Vmot showed a significant reduction in amplitude following muscle fatigue. Orthodromic and antidromic potentials recorded in the Vmes also showed a similar amplitude decrease. Furthermore, muscle fatigue caused a decrease of the discharge frequency of masseter muscle spindle afferents in most of the examined units. The inhibition of the potential amplitude and discharge frequency was strictly correlated with the extent of muscle fatigue and was mediated by the group III and IV afferent muscle fibers activated by fatigue. In fact, the inhibitory effect was abolished by capsaicin injection in the masseter muscle that provokes selective degeneration of small afferent muscle fibers containing neurokinins. We concluded that fatigue signals originating from the muscle and traveling through capsaicin-sensitive fibers are able to diminish the proprioceptive input by a central presynaptic influence. In the second part of the study, we examined the central projection of the masseter small afferents sensitive to capsaicin at the electron-microscopic level. Fiber degeneration was induced by injecting capsaicin into the masseter muscle. Degenerating terminals were found on the soma and stem process in Vmes and on the dendritic tree of neurons in Vmot. This suggests that small muscle afferents may influence the muscle spindle activity through

Simultaneous Determination of Piperine, Capsaicin, and Dihydrocapsaicin in Korean Instant-Noodle (Ramyun) Soup Base Using High-Performance Liquid Chromatography with Ultraviolet Detection.

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Shim, You-Shin; Kim, Jong-Chan; Jeong, Seung-Weon

2016-01-01

A simultaneous analytical method for piperine, capsaicin, and dihydrocapsaicin in Korean instant-noodle soup base using HPLC was validated in terms of precision, accuracy, sensitivity, and linearity. The HPLC separation was performed on a reversed-phase C18 column (5 μm particle size, 4.6 mm id, 250 mm length) using a UV detector fixed at 280 nm. The LOD and LOQ of the HPLC analyses ranged from 0.25 to 1.03 mg/kg. The intraday and interday precisions of the individual piperine, capsaicin, and dihydrocapsaicin were instant noodles based on their levels of spiciness.

Assessing the Electrode-Neuron Interface with the Electrically Evoked Compound Action Potential, Electrode Position, and Behavioral Thresholds.

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DeVries, Lindsay; Scheperle, Rachel; Bierer, Julie Arenberg

2016-06-01

Variability in speech perception scores among cochlear implant listeners may largely reflect the variable efficacy of implant electrodes to convey stimulus information to the auditory nerve. In the present study, three metrics were applied to assess the quality of the electrode-neuron interface of individual cochlear implant channels: the electrically evoked compound action potential (ECAP), the estimation of electrode position using computerized tomography (CT), and behavioral thresholds using focused stimulation. The primary motivation of this approach is to evaluate the ECAP as a site-specific measure of the electrode-neuron interface in the context of two peripheral factors that likely contribute to degraded perception: large electrode-to-modiolus distance and reduced neural density. Ten unilaterally implanted adults with Advanced Bionics HiRes90k devices participated. ECAPs were elicited with monopolar stimulation within a forward-masking paradigm to construct channel interaction functions (CIF), behavioral thresholds were obtained with quadrupolar (sQP) stimulation, and data from imaging provided estimates of electrode-to-modiolus distance and scalar location (scala tympani (ST), intermediate, or scala vestibuli (SV)) for each electrode. The width of the ECAP CIF was positively correlated with electrode-to-modiolus distance; both of these measures were also influenced by scalar position. The ECAP peak amplitude was negatively correlated with behavioral thresholds. Moreover, subjects with low behavioral thresholds and large ECAP amplitudes, averaged across electrodes, tended to have higher speech perception scores. These results suggest a potential clinical role for the ECAP in the objective assessment of individual cochlear implant channels, with the potential to improve speech perception outcomes.

Investigation of the predictive validity of laser-EPs in normal, UVB-inflamed and capsaicin-irritated skin with four analgesic compounds in healthy volunteers.

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Schaffler, Klaus; Nicolas, Laurent B; Borta, Andreas; Brand, Tobias; Reitmeir, Peter; Roebling, Robert; Scholpp, Joachim

2017-07-01

The aim of the present study was to assess the predictivity of laser-(radiant-heat)-evoked potentials (LEPs) from the vertex electroencephalogram, using an algesimetric procedure, testing the anti-nociceptive/anti-hyperalgesic effects of single oral doses of four marketed analgesics (of different compound classes) vs. placebo, in healthy volunteers with three skin types. This was a randomized, placebo-controlled, single-blind, five-way-crossover trial. Twenty-five healthy male/female Caucasians were included (receiving celecoxib 200 mg, pregabalin 150 mg, duloxetine 60 mg, lacosamide 100 mg or placebo) in a Williams design, with CO 2 laser-induced painful stimuli to normal, ultraviolet (UV) B-inflamed and capsaicin-irritated skin. LEPs and visual analogue scale ratings were taken at baseline and hourly for 6 h postdose from all three skin types. In normal skin, the averaged postdose LEP peak-to-peak-(PtP)-amplitudes were reduced by pregabalin (-2.68 μV; 95% confidence interval (CI) -4.16, 1.19) and duloxetine (-1.73 μV; 95% CI -3.21, -0.26) but not by lacosamide and celecoxib vs. placebo. On UVB-irradiated skin, reflecting inflammatory pain, celecoxib induced a pronounced reduction in LEP PtP amplitudes vs. placebo (-6.2 μV; 95% CI -7.88, -4.51), with a smaller reduction by duloxetine (-4.54 μV; 95% CI -6.21, -2.87) and pregabalin (-3.72 μV; 95% CI -5.40, -2.04), whereas lacosamide was inactive. LEP PtP amplitudes on capsaicin-irritated skin, reflecting peripheral/spinal sensitization, as in neuropathic pain, were reduced by pregabalin (-3.78 μV; 95% CI -5.31, -2.25) and duloxetine (-2.32 μV; 95% CI -3.82, -0.82) but not by celecoxib or lacosamide vs. placebo, which was in agreement with known clinical profiles. Overall, PtP amplitude reductions were in agreement with subjective ratings. LEP algesimetry is sensitive to analgesics with different modes of action and may enable the effects of novel analgesics to be assessed during early clinical

Tris-hydroxymethyl-aminomethane enhances capsaicin-induced intracellular Ca2+ influx through transient receptor potential V1 (TRPV1 channels

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Satoshi Murakami

2016-02-01

Full Text Available Non-selective transient receptor potential vanilloid (TRPV cation channels are activated by various insults, including exposure to heat, acidity, and the compound capsaicin, resulting in sensations of pain in the skin, visceral organs, and oral cavity. Recently, TRPV1 activation was also demonstrated in response to basic pH elicited by ammonia and intracellular alkalization. Tris-hydroxymethyl aminomethane (THAM is widely used as an alkalizing agent; however, the effects of THAM on TRPV1 channels have not been defined. In this study, we characterized the effects of THAM-induced TRPV1 channel activation in baby hamster kidney cells expressing human TRPV1 (hTRPV1 and the Ca2+-sensitive fluorescent sensor GCaMP2 by real-time confocal microscopy. Notably, both capsaicin (1 μM and pH 6.5 buffer elicited steep increases in the intracellular Ca2+ concentration ([Ca2+]i, while treatment with THAM (pH 8.5 alone had no effect. However, treatment with THAM (pH 8.5 following capsaicin application elicited a profound, long-lasting increase in [Ca2+]i that was completely inhibited by the TRPV1 antagonist capsazepine. Taken together, these results suggest that hTRPV1 pre-activation is required to provoke enhanced, THAM-induced [Ca2+]i increases, which could be a mechanism underlying pain induced by basic pH.

Conditioned suppression of sexual behavior in stallions and reversal with diazepam.

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McDonnell, S M; Kenney, R M; Meckley, P E; Garcia, M C

1985-06-01

Sexual behavior dysfunction unaccompanied by detectable physical or endocrine abnormality is an important cause of reproductive failure among domestic stallions. Several authors have suggested that such dysfunction may be psychogenic, related to negative experience associated with intense handling and training. An experimental model of experience-related dysfunction was developed by exposing pony stallions to erection-contingent aversive conditioning. This resulted in rapid, specific suppression of sexual arousal and response similar to spontaneously occurring dysfunction. Subsequently, treatment with a CNS-active benzodiazepine derivative (diazepam) reversed these effects.

Evoked emotions predict food choice.

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Dalenberg, Jelle R; Gutjar, Swetlana; Ter Horst, Gert J; de Graaf, Kees; Renken, Remco J; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well scores from emotion-profiling methods predict actual food choice and/or consumption. To test this, we proposed to decompose emotion scores into valence and arousal scores using Principal Component Analysis (PCA) and apply Multinomial Logit Models (MLM) to estimate food choice using liking, valence, and arousal as possible predictors. For this analysis, we used an existing data set comprised of liking and food-evoked emotions scores from 123 participants, who rated 7 unlabeled breakfast drinks. Liking scores were measured using a 100-mm visual analogue scale, while food-evoked emotions were measured using 2 existing emotion-profiling methods: a verbal and a non-verbal method (EsSense Profile and PrEmo, respectively). After 7 days, participants were asked to choose 1 breakfast drink from the experiment to consume during breakfast in a simulated restaurant environment. Cross validation showed that we were able to correctly predict individualized food choice (1 out of 7 products) for over 50% of the participants. This number increased to nearly 80% when looking at the top 2 candidates. Model comparisons showed that evoked emotions better predict food choice than perceived liking alone. However, the strongest predictive strength was achieved by the combination of evoked emotions and liking. Furthermore we showed that non-verbal food-evoked emotion scores more accurately predict food choice than verbal food-evoked emotions scores.

Suppression of anomalous synchronization and nonstationary behavior of neural network under small-world topology

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Boaretto, B. R. R.; Budzinski, R. C.; Prado, T. L.; Kurths, J.; Lopes, S. R.

2018-05-01

It is known that neural networks under small-world topology can present anomalous synchronization and nonstationary behavior for weak coupling regimes. Here, we propose methods to suppress the anomalous synchronization and also to diminish the nonstationary behavior occurring in weakly coupled neural network under small-world topology. We consider a network of 2000 thermally sensitive identical neurons, based on the model of Hodgkin-Huxley in a small-world topology, with the probability of adding non local connection equal to p = 0 . 001. Based on experimental protocols to suppress anomalous synchronization, as well as nonstationary behavior of the neural network dynamics, we make use of (i) external stimulus (pulsed current); (ii) biologic parameters changing (neuron membrane conductance changes); and (iii) body temperature changes. Quantification analysis to evaluate phase synchronization makes use of the Kuramoto's order parameter, while recurrence quantification analysis, particularly the determinism, computed over the easily accessible mean field of network, the local field potential (LFP), is used to evaluate nonstationary states. We show that the methods proposed can control the anomalous synchronization and nonstationarity occurring for weak coupling parameter without any effect on the individual neuron dynamics, neither in the expected asymptotic synchronized states occurring for large values of the coupling parameter.

Intrathecal dihydroergotamine inhibits capsaicin-induced vasodilatation in the canine external carotid circulation via GR127935- and rauwolscine-sensitive receptors.

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Marichal-Cancino, Bruno A; González-Hernández, Abimael; Manrique-Maldonado, Guadalupe; Ruiz-Salinas, Inna I; Altamirano-Espinoza, Alain H; MaassenVanDenBrink, Antoinette; Villalón, Carlos M

2012-10-05

It has been suggested that during a migraine attack trigeminal nerves release calcitonin gene-related peptide (CGRP), producing central nociception and vasodilatation of cranial arteries, including the extracranial branches of the external carotid artery. Since trigeminal inhibition may prevent this vasodilatation, the present study has investigated the effects of intrathecal dihydroergotamine on the external carotid vasodilatation to capsaicin, α-CGRP and acetylcholine. Anaesthetized vagosympathectomized dogs were prepared to measure blood pressure, heart rate and external carotid conductance. A catheter was inserted into the right common carotid artery for the continuous infusion of phenylephrine (to restore the carotid vascular tone), whereas the corresponding thyroid artery was cannulated for one-min intracarotid infusions of capsaicin, α-CGRP and acetylcholine (which dose-dependently increased the external carotid conductance). Another cannula was inserted intrathecally (C(1)-C(3)) for the administration of dihydroergotamine, the α(2)-adrenoceptor antagonist rauwolscine or the serotonin 5-HT(1B/1D) receptor antagonist GR127935 (N-[4-methoxy-3-(4-methyl-1-piperazinyl) phenyl]-2'-methyl-4'-(5-methyl-1,2,4-oxadiazol-3-yl)[1,1-biphenyl]-4-carboxamide hydrochloride monohydrate). Intrathecal dihydroergotamine (10, 31 and 100μg) inhibited the vasodilatation to capsaicin, but not that to α-CGRP or acetylcholine. This inhibition was: (i) unaffected by 10μg GR127935 or 100μg rauwolscine, but abolished by 31μg GR127935 or 310μg rauwolscine at 10μg dihydroergotamine; and (ii) abolished by the combination 10μg GR127935+100μg rauwolscine at 100μg dihydroergotamine. Thus, intrathecal (C(1)-C(3)) dihydroergotamine seems to inhibit the external carotid vasodilatation to capsaicin by spinal activation of serotonin 5-HT(1B/1D) (probably 5-HT(1B)) receptors and α(2) (probably α(2A/2C))-adrenoceptors. Copyright © 2012 Elsevier B.V. All rights reserved.

Cold urticaria. Dissociation of cold-evoked histamine release and urticara following cold challenge.

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Keahey, T M; Greaves, M W

1980-02-01

Nine patients with acquired cold urticaria were studied to assess the effects of beta-adrenergic agents, xanthines, and corticosteroids on cold-evoked histamine release from skin in vivo. The patients, in all of whom an immediate urticarial response developed after cooling of the forearm, demonstrated release of histamine into the venous blood draining that forearm. Following treatment with aminophylline and albuterol in combination or prednisone alone, suppression of histamine release occurred in all but one patient. In some patients, this was accompanied by a subjective diminution in pruritus or buring, but there was no significant improvement in the ensuing edema or erythema. In one patient, total suppression of histamine release was achieved without any effect on whealing and erythema in response to cold challenge. Our results suggest that histamine is not central to the pathogenesis of vascular changes in acquired cold urticaria.

Increased Evoked Potentials and Behavioral Indices in Response to Pain Among Individuals with Intellectual Disability.

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Benromano, Tali; Pick, Chaim G; Granovsky, Yelena; Defrin, Ruth

2017-09-01

Previous studies on the sensitivity and reactivity to pain of individuals with intellectual disability (ID) are inconsistent. The inconsistency may result from the reliance on self-reports and facial expressions of pain that are subject to internal and external biases. The aim was therefore to evaluate the reactivity to pain of individuals with ID by recording pain-evoked potentials (EPs), here for the first time, and testing their association with behavioral pain indices. Forty-one healthy adults, 16 with mild-moderate ID and 25 controls. Subjects received series of phasic heat stimuli and rated their pain on self-report scales. Changes in facial expressions and in pain EPs were recorded and analyzed offline. Pain self-reports, facial expressions, and the N2P2 amplitudes of the EPs exhibited stimulus-response relationship with stimulation intensity in both groups. The facial expressions and N2P2 amplitudes of individuals with ID were increased and N2P2 latency prolonged compared with controls. N2P2 amplitudes correlated with self-reports only in controls. Individuals with ID are hypersensitive/reactive to pain, a finding bearing clinical implications. Although pain EPs may reflect a somewhat different aspect of pain than the behavioral indices do, there is evidence to support their use to record pain in noncommunicative individuals, pending further validation. © 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Effects of the CGRP receptor antagonist BIBN4096BS on capsaicin-induced carotid haemodynamic changes in anaesthetised pigs.

NARCIS (Netherlands)

K. Kapoor (Kapil); U. Arulmani (Udayasankar); J.P. Heiligers (Jan); I.M. Garrelds (Ingrid); E.W. Willems (Edwin); H. Doods (Henri); C.M. Villalón (Carlos); P.R. Saxena (Pramod Ranjan)

2003-01-01

textabstract1. Calcitonin gene-related peptide (CGRP), a potent vasodilator released from capsaicin-sensitive trigeminal sensory nerves, seems to be involved in the pathogenesis of migraine. Hence, CGRP receptor antagonists may serve as a novel treatment for migraine. This study

Effects of action of ultrasound with capsaicin in the treatment of post traumatic pathology

Directory of Open Access Journals (Sweden)

Ioan OSWALD

2007-05-01

Full Text Available There are numerous methods of administering drugs to the body,both passive and active. A recent review of the literature on phonophoresis reports that 75 % of the studies reviewed reported positive effects, ultrasound energy with drugs like gel or cream can travel through body tissue. Capsaicin was the active ingredient in hot chilli peppers has selection actions on unmyelinated C fibres and thinly myelinated A primary sensory neurones.

Characterization of music-evoked autobiographical memories.

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Janata, Petr; Tomic, Stefan T; Rakowski, Sonja K

2007-11-01

Despite music's prominence in Western society and its importance to individuals in their daily lives, very little is known about the memories and emotions that are often evoked when hearing a piece of music from one's past. We examined the content of music-evoked autobiographical memories (MEAMs) using a novel approach for selecting stimuli from a large corpus of popular music, in both laboratory and online settings. A set of questionnaires probed the cognitive and affective properties of the evoked memories. On average, 30% of the song presentations evoked autobiographical memories, and the majority of songs also evoked various emotions, primarily positive, that were felt strongly. The third most common emotion was nostalgia. Analyses of written memory reports found both general and specific levels of autobiographical knowledge to be represented, and several social and situational contexts for memory formation were common across many memories. The findings indicate that excerpts of popular music serve as potent stimuli for studying the structure of autobiographical memories.

A randomized placebo controlled trial to evaluate the effects of butamirate and dextromethorphan on capsaicin induced cough in healthy volunteers.

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Faruqi, Shoaib; Wright, Caroline; Thompson, Rachel; Morice, Alyn H

2014-12-01

The examination of cough reflex sensitivity through inhalational challenge can be utilized to demonstrate pharmacological end points. Here we compare the effect of butamirate, dextromethorphan and placebo on capsaicin-induced cough in healthy volunteers. In this randomized, placebo-controlled, six way crossover study the effect of dextromethrophan 30 mg, four doses of butamirate and placebo was evaluated on incremental capsaicin challenges performed at baseline and 2, 4, 6, 8, 12 and 24 h following dosing. The primary end point was the area under the curve (AUC(0,12h)) of log10 C5 from pre-dose to 12 h after dosing. Plasma butamirate metabolites were analyzed to evaluate pharmacokinetic and pharmacodynamic relationships. Thirty-four subjects (13 males, median age 25 years) completed the study. Cough sensitivity decreased from baseline in all arms of the study. Dextromethorphan was superior to placebo (P = 0.01) but butamirate failed to show significant activity with maximum attenuation at the 45 mg dose. There was no apparent relationship between pharmacokinetic and pharmacodynamic parameters for butamirate. We have demonstrated for the first time that dextromethorphan attenuates capsaicin challenge confirming its broad activity on the cough reflex. The lack of efficacy of butamirate could be due to formulation issues at higher doses. © 2014 The British Pharmacological Society.

Infringement of the barriers of cancer via dietary phytoconstituents capsaicin through novel drug delivery system.

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Giri, Tapan Kumar; Alexander, Amit; Ajazuddin; Barman, Tapan Kumar; Maity, Subhasis

2016-01-01

Cancer is the major cause of fatality and the number of new cases is increasing incessantly. Conventional therapies and existing anticancer agents cause serious side effects and expand the patient's lifespan by a few years. There is the need to exploit alternative anticancer agents and novel drug delivery system to deliver these agents to the tumor site for the prevention of cancer. Recently, biologically active compounds isolated from plants used for the management of cancer have been the heart of interest. Capsaicin is a major pungent agent present in the chili peppers that is heavily consumed in the world. Capsaicin has demonstrated effectiveness as an anticancer agent, but a restraining factor is its pungency, extremely low aqueous solubility, and poor oral bioavailability which impede its use as an anticancer agent. Many technologies have been developed and applied to conquer this drawback. We bring to light the benefits of this phytoconstituent for treating different types of cancer. We also discussed some of the delivery approaches that have already made an impact by either delivering a drug to target tissue or increasing its bioavailability by many folds.

Why expressive suppression does not pay? Cognitive costs of negative emotion suppression: The mediating role of subjective tense-arousal

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Szczygieł Dorota

2015-09-01

Full Text Available The aim of this paper was to contribute to a broader understanding of the cognitive consequences of expressive suppression. Specifically, we examined whether the deteriorating effect of expressive suppression on cognitive functioning is caused by tense arousal enhanced by suppression. Two experiments were performed in order to test this prediction. In both studies we tested the effect of expressive suppression on working memory, as measured with a backwards digit-span task (Study 1, N = 43 and anagram problem-solving task (Study 2, N = 60. In addition, in Study 2 we tested whether expressive suppression degrades memory of the events that emerged during the period of expressive suppression. Both studies were conducted in a similar design: Participants watched a film clip which evoked negative emotions (i.e. disgust in Study 1 and a combination of sadness and anxiety in Study 2 under the instruction to suppress those negative emotions or (in the control condition to simply watch the film. The results of these experiments lead to three conclusions. First, the results reveal that expressive suppression degrades memory of the events that emerged during the period of expressive suppression and leads to poorer performance on working memory tasks, as measured with a backwards digit-span task and anagram problem-solving task. Second, the results indicate that expressive suppression leads to a significant increase in subjective tense arousal. Third, the results support our prediction that expressive suppression decreases cognitive performance through its effects on subjective tense arousal. The results of the Study 1 show that tense arousal activated during expressive suppression of disgust fully mediates the negative effect of suppression on working memory as measured with a backwards digit-span task. The results of Study 2 reveal that subjective tense arousal elicited while suppressing sadness and anxiety mediates both the effect of suppression on

Modulatory Action by the Serotonergic System: Behavior and Neurophysiology in Drosophila melanogaster.

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Majeed, Zana R; Abdeljaber, Esraa; Soveland, Robin; Cornwell, Kristin; Bankemper, Aubrey; Koch, Felicitas; Cooper, Robin L

2016-01-01

Serotonin modulates various physiological processes and behaviors. This study investigates the role of 5-HT in locomotion and feeding behaviors as well as in modulation of sensory-motor circuits. The 5-HT biosynthesis was dysregulated by feeding Drosophila larvae 5-HT, a 5-HT precursor, or an inhibitor of tryptophan hydroxylase during early stages of development. The effects of feeding fluoxetine, a selective serotonin reuptake inhibitor, during early second instars were also examined. 5-HT receptor subtypes were manipulated using RNA interference mediated knockdown and 5-HT receptor insertional mutations. Moreover, synaptic transmission at 5-HT neurons was blocked or enhanced in both larvae and adult flies. The results demonstrate that disruption of components within the 5-HT system significantly impairs locomotion and feeding behaviors in larvae. Acute activation of 5-HT neurons disrupts normal locomotion activity in adult flies. To determine which 5-HT receptor subtype modulates the evoked sensory-motor activity, pharmacological agents were used. In addition, the activity of 5-HT neurons was enhanced by expressing and activating TrpA1 channels or channelrhodopsin-2 while recording the evoked excitatory postsynaptic potentials (EPSPs) in muscle fibers. 5-HT2 receptor activation mediates a modulatory role in a sensory-motor circuit, and the activation of 5-HT neurons can suppress the neural circuit activity, while fluoxetine can significantly decrease the sensory-motor activity.

Modulatory Action by the Serotonergic System: Behavior and Neurophysiology in Drosophila melanogaster

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Zana R. Majeed

2016-01-01

Full Text Available Serotonin modulates various physiological processes and behaviors. This study investigates the role of 5-HT in locomotion and feeding behaviors as well as in modulation of sensory-motor circuits. The 5-HT biosynthesis was dysregulated by feeding Drosophila larvae 5-HT, a 5-HT precursor, or an inhibitor of tryptophan hydroxylase during early stages of development. The effects of feeding fluoxetine, a selective serotonin reuptake inhibitor, during early second instars were also examined. 5-HT receptor subtypes were manipulated using RNA interference mediated knockdown and 5-HT receptor insertional mutations. Moreover, synaptic transmission at 5-HT neurons was blocked or enhanced in both larvae and adult flies. The results demonstrate that disruption of components within the 5-HT system significantly impairs locomotion and feeding behaviors in larvae. Acute activation of 5-HT neurons disrupts normal locomotion activity in adult flies. To determine which 5-HT receptor subtype modulates the evoked sensory-motor activity, pharmacological agents were used. In addition, the activity of 5-HT neurons was enhanced by expressing and activating TrpA1 channels or channelrhodopsin-2 while recording the evoked excitatory postsynaptic potentials (EPSPs in muscle fibers. 5-HT2 receptor activation mediates a modulatory role in a sensory-motor circuit, and the activation of 5-HT neurons can suppress the neural circuit activity, while fluoxetine can significantly decrease the sensory-motor activity.

CAPSAICIN SUPPLEMENTATION FAILS TO MODULATE AUTONOMIC AND CARDIAC ELECTROPHYSIOLOGIC ACTIVITY DURING EXERCISE IN THE OBESE: WITH VARIANTS OF UCP2 AND UCP3 POLYMORPHISM

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Ki Ok Shin

2008-09-01

Full Text Available We investigated the effects of capsaicin supplementation (150mg on alterations of autonomic nervous system (ANS activity associated with adverse effects of cardiac depolarization-repolarization intervals during aerobic exercise in obese humans. Nine obese males (26.1 ± 1.5 yrs volunteered between study designed. The cardiac ANS activities evaluated by means of heart rate variability of power spectral analysis and cardiac QT interval were continuously measured during 5-min rest and 30-min exercise at 50% of maximal ventilation threshold (50%VTmax on stationary ergometer with placebo (CON or capsaicin (CAP oral administration chosen at random. The uncoupling protein (UCP 2 and UCP 3 genetic variants of the subjects were analyzed by noninvasive genotyping method from collecting buccal mucosa cells. The results indicated that there were no significant differences in cardiac ANS activities during rest and exercise between CON and CAP trials. Although no significant difference, A/A allele of UCP2 polymorphism showed a reduced sympathetic nervous system (SNS index activity compared to G/G + G/A allele during exercise intervention in our subjects. On the other hand, the data on cardiac QT interval showed no significant difference, indicating that oral administration of capsaicin did not cause any adverse effect on cardiac depolarization-repolarization. In conclusion, our results suggest that capsaicin supplementation 1 h before exercise intervention has no effect on cardiac ANS activities and cardiac electrical stability during exercise in obese individuals. Further studies should also consider genetic variants for exercise efficacy against obesity

[Recognition of the spatially transformed objects in men and women: an analysis of the behavior and evoked potentials].

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Slavutskaia, A V; Gerasimenko, N Iu; Mikhaĭlova, E S

2012-01-01

In 16 men and 15 women analyzed the accuracy, reaction time and visual evoked potentials during the recognition of familiar objects at different levels of spatial transformation. We used the three levels of transformation: in a fixed position relative to each other details were carried out (1) the displacement of all the details in the radial direction and (2 and 3) a similar shift in conjunction with the rotation of all the details of the figure by +/- 0-45 and +/- 45-90 degrees. The task performance was not dependent on gender: the transformation of the image led to a deterioration of identification with the most identification impairment in the case of maximal details' rotation. Changes in evoked potentials (ERP) are different for men and women. Only in men early (100 ms after stimulus) response of the parietal cortex associated with the level of figure transformation: the more rotation evoked the higher the response. In women figure transformation evoked the ERP changes in the time window of negativity N170, they are associated with figure ungrouping but not with details rotation, and are localized in other visual areas--occipital and temporal. The data obtained are discussed in light of theory of gender specificity of the visual representations of space.

Effects of oral stimulation with capsaicin on salivary secretion and neural activities in the autonomic system and the brain

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Yoko Kono

2018-06-01

Conclusion: These results suggest that oral stimulation with capsaicin may be effective in improving oral conditions by increasing salivary flow and SIgA secretion, and in enhancing physical and mental conditions as indicated by sympathetic nerve and EEG changes.

Antinociceptive effect and interaction of uncompetitive and competitive NMDA receptor antagonists upon capsaicin and paw pressure testing in normal and monoarthritic rats.

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Pelissier, Teresa; Infante, Claudio; Constandil, Luis; Espinosa, Jeannette; Lapeyra, Carolina De; Hernández, Alejandro

2008-01-01

We assessed whether intrathecal administration of the uncompetitive and competitive NMDA receptor antagonists ketamine and (+/-)CPP, respectively, could produce differential modulation on chemical and mechanical nociception in normal and monoarthritic rats. In addition, the antinociceptive interaction of ketamine and (+/-)CPP on monoarthritic pain was also studied using isobolographic analysis. Monoarthritis was produced by intra-articular injection of complete Freund's adjuvant into the tibio-tarsal joint. Four weeks later, the antinociceptive effect of intrathecal administration of the drugs alone or combined was evaluated by using the intraplantar capsaicin and the paw pressure tests. Ketamine (0.1, 1, 10, 30, 100, 300 and 1000 microg i.t.) and (+/-)CPP (0.125, 2.5, 7.5, 12.5, 25 and 50 microg i.t.) produced significantly greater dose-dependent antinociception in the capsaicin than in the paw pressure test. Irrespective of the nociceptive test employed, both antagonists showed greater antinociceptive activity in monoarthritic than in healthy rats. Combinations produced synergy of a supra-additive nature in the capsaicin test, but only additive antinociception in paw pressure testing. The efficacy of the drugs, alone or combined, is likely to depend on the differential sensitivity of tonic versus phasic pain and/or chemical versus mechanical pain to NMDA antagonists.

Cyclophosphamide-induced cystitis reduces ASIC channel but enhances TRPV1 receptor function in rat bladder sensory neurons.

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Dang, Khoa; Bielefeldt, Klaus; Gebhart, G F

2013-07-01

Using patch-clamp techniques, we studied the plasticity of acid-sensing ion channels (ASIC) and transient receptor potential V1 (TRPV1) channel function in dorsal root ganglia (DRG) neurons retrogradely labeled from the bladder. Saline (control) or cyclophosphamide (CYP) was given intraperitoneally on days 1, 3, and 5. On day 6, lumbosacral (LS, L6-S2) or thoracolumbar (TL, T13-L2) DRG were removed and dissociated. Bladders and bladder DRG neurons from CYP-treated rats showed signs of inflammation (greater myeloperoxidase activity; lower intramuscular wall pH) and increased size (whole cell capacitance), respectively, compared with controls. Most bladder neurons (>90%) responded to protons and capsaicin. Protons produced multiphasic currents with distinct kinetics, whereas capsaicin always triggered a sustained response. The TRPV1 receptor antagonist A-425619 abolished capsaicin-triggered currents and raised the threshold of heat-activated currents. Prolonged exposure to an acidic environment (pH range: 7.2 to 6.6) inhibited proton-evoked currents, potentiated the capsaicin-evoked current, and reduced the threshold of heat-activated currents in LS and TL bladder neurons. CYP treatment reduced density but not kinetics of all current components triggered by pH 5. In contrast, CYP-treatment was associated with an increased current density in response to capsaicin in LS and TL bladder neurons. Correspondingly, heat triggered current at a significantly lower temperature in bladder neurons from CYP-treated rats compared with controls. These results reveal that cystitis differentially affects TRPV1- and ASIC-mediated currents in both bladder sensory pathways. Acidification of the bladder wall during inflammation may contribute to changes in nociceptive transmission mediated through the TRPV1 receptor, suggesting a role for TRPV1 in hypersensitivity associated with cystitis.

Capsaicin-Sensitive Sensory Nerves Indirectly Modulate Motor Function of the Urinary Bladder

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Hsi-Hsien Chang

2018-06-01

Full Text Available Purpose The urinary bladder (UB is innervated by both sensory and autonomic nerves. Recent studies have shown that sensory neuropeptides induced contractions in the detrusor muscle. Therefore, in a mouse model, we investigated the presence of interactions between the submucosal sensory nerves and the autonomic nerves that regulate the motor function of the detrusor muscle. Methods UB samples from male C57BL/6 mice were isolated, cut into strips, and mounted in an organ bath. Dose-response curves to norepinephrine and phenylephrine were studied in UB strips with and without mucosa, and the effects of preincubation with a receptor antagonist and various drugs on relaxation were also studied using tissue bath myography. Results Phenylephrine-induced relaxation of the UB strips showed concentration-related effects. This relaxation appeared in both mucosa-intact and mucosa-denuded UB strips, and was significantly inhibited by lidocaine, silodosin, and guanethidine (an adrenergic neuronal blocker. Meanwhile, phenylephrine-induced relaxation was inhibited by pretreatment with propranolol and calcitonin gene-related peptide (CGRP–depletory capsaicin in UB strips with and without mucosa. Conclusions The present study suggests that phenylephrine activates the α-1A adrenergic receptor (AR of the sensory nerve, and then activates capsaicin-sensitive sensory nerves to release an unknown substance that facilitates the release of norepinephrine from adrenergic nerves. Subsequently, norepinephrine stimulates β-ARs in the detrusor muscle in mice, leading to neurogenic relaxation of the UB. Further animal and human studies are required to prove this concept and to validate its clinical usefulness.

New animal model of emotional stress: Behavioral, neuroendocrine and immunological consequences

Institute of Scientific and Technical Information of China (English)

LIN Wenjuan; WANG Weiwen; SHAO Feng

2003-01-01

This report describes a new model of emotional stress, which was induced by randomly giving an empty water bottle to rats during watering periods per day for 14 consecutive days. The behavioral, endocrinological and immunological consequences were investigated. The data showed that the emotional stress activated both the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, leading to the increased blood levels of corticosterone and catecholamine. It also elicited attacking and exploring behavior, suppressed the immune function of the rats, including leukocyte counts, weight of the spleen, and the level of specific anti-ovalbumin IgG antibody production. Presenting no water and no empty bottle to rats only evoked the exploring behavior, increased the corticosterone level and decreased the leukocyte counts. These findings demonstrate a role of psychological factors on behavioral, endocrinological and immunological functioning. The animal model described in the present study may serve as an analogue mimicking emotional stress experienced in humans (e.g. anger and/or anxiety), and may be useful for further studying the complex relationships among emotional stress, behavior, and immune function.

The role of capsaicin-sensitive muscle afferents in fatigue-induced modulation of the monosynaptic reflex in the rat.

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Pettorossi, V E; Della Torre, G; Bortolami, R; Brunetti, O

1999-03-01

1. The role of group III and IV afferent fibres of the lateral gastrocnemious muscle (LG) in modulating the homonymous monosynaptic reflex was investigated during muscle fatigue in spinalized rats. 2. Muscle fatigue was induced by a series of increasing tetanic electrical stimuli (85 Hz, 600 ms) delivered to the LG muscle nerve. Series consisted of increasing train numbers from 1 to 60. 3. Potentials from the spinal cord LG motor pool and from the ventral root were recorded in response to proprioceptive afferent stimulation and analysed before and during tetanic muscle activations. Both the pre- and postsynaptic waves showed an initial enhancement and, after a '12-train' series, an increasing inhibition. 4. The enhancement of the responses to muscle fatiguing stimulation disappeared after L3-L6 dorsal root section, while a partial reflex inhibition was still present. Conversely, after section of the corresponding ventral root, there was only a reduction in the inhibitory effect. 5. The monosynaptic reflex was also studied in animals in which a large number of group III and IV muscle afferents were eliminated by injecting capsaicin (10 mM) into the LG muscle. As a result of capsaicin treatment, the fatigue-induced inhibition of the pre- and postsynaptic waves disappeared, while the response enhancement remained. 6. We concluded that the monosynaptic reflex inhibition, but not the enhancement, was mediated by those group III and IV muscle afferents that are sensitive to the toxic action of capsaicin. The afferents that are responsible for the response enhancement enter the spinal cord through the dorsal root, while those responsible for the inhibition enter the spinal cord through both the ventral and dorsal roots.

Effect of corticotropin-releasing factor receptor antagonist on psychologically suppressed masculine sexual behavior in rats.

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Miwa, Yoshiji; Nagase, Keiko; Oyama, Nobuyuki; Akino, Hironobu; Yokoyama, Osamu

2011-03-01

Corticotropin-releasing factor (CRF) coordinates various responses of the body to stress, and CRF receptors are important targets of treatment for stress-related disorders. To investigate the effect of a nonselective CRF receptor antagonist, astressin, on suppression of masculine sexual behavior by psychological stress in rats. First, we investigated the influence of psychological stress, induced 2 hours per day for three consecutive days, on sexual behavior. Then, rats were divided into 4 groups: a control group, an astressin administration group (A), a psychological stress loading group (PS), and a psychological stress loading and astressin administration group (PS + A). The rats were exposed to sham or psychological stress for three consecutive days. After the last stress loading, the rats were injected with vehicle or astressin, and their sexual behavior was observed. We also measured serum levels of adrenocorticotropic hormone (ACTH). The effects of astressin on sexual behavior and serum levels of ACTH in rats affected by psychological stress were determined. Sexual behavior was reduced after psychological stress loading. The PS rats had significantly longer mount, intromission, and ejaculation latencies and lower ejaculation frequency than did the control, A, and PS + A rats. The intromission latency and ejaculation frequency in the PS + A rats did not achieve the level observed in the controls. There was no significant difference in these parameters between the control and A rats. Serum ACTH levels were significantly lower in PS + A rats than in PS rats. Psychologically suppressed masculine sexual behavior could be partially recovered with astressin administration in rats. These data provide a rationale for the further study of CRF receptor antagonists as novel agents for treating psychological sexual disorders. © 2010 International Society for Sexual Medicine.

Visceral hyperalgesia induced by forebrain-specific suppression of native Kv7/KCNQ/M-current in mice

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Bian Xiling

2011-10-01

Full Text Available Abstract Background Dysfunction of brain-gut interaction is thought to underlie visceral hypersensitivity which causes unexplained abdominal pain syndromes. However, the mechanism by which alteration of brain function in the brain-gut axis influences the perception of visceral pain remains largely elusive. In this study we investigated whether altered brain activity can generate visceral hyperalgesia. Results Using a forebrain specific αCaMKII promoter, we established a line of transgenic (Tg mice expressing a dominant-negative pore mutant of the Kv7.2/KCNQ2 channel which suppresses native KCNQ/M-current and enhances forebrain neuronal excitability. Brain slice recording of hippocampal pyramidal neurons from these Tg mice confirmed the presence of hyperexcitable properties with increased firing. Behavioral evaluation of Tg mice exhibited increased sensitivity to visceral pain induced by intraperitoneal (i.p. injection of either acetic acid or magnesium sulfate, and intracolon capsaicin stimulation, but not cutaneous sensation for thermal or inflammatory pain. Immunohistological staining showed increased c-Fos expression in the somatosensory SII cortex and insular cortex of Tg mice that were injected intraperitoneally with acetic acid. To mimic the effect of cortical hyperexcitability on visceral hyperalgesia, we injected KCNQ/M channel blocker XE991 into the lateral ventricle of wild type (WT mice. Intracerebroventricular injection of XE991 resulted in increased writhes of WT mice induced by acetic acid, and this effect was reversed by co-injection of the channel opener retigabine. Conclusions Our findings provide evidence that forebrain hyperexcitability confers visceral hyperalgesia, and suppression of central hyperexcitability by activation of KCNQ/M-channel function may provide a therapeutic potential for treatment of abdominal pain syndromes.

Experimental investigation on the behavior of pressure suppression containment systems by the SOPRE-1 facility

International Nuclear Information System (INIS)

Cerullo, N.; Delli Gatti, A.; Marinelli, M.; Mazzini, M.; Mazzoni, A.; Sbrana, A.; Todisco, P.

1977-01-01

The SOPRE-1 test facility is an integral model (scale 1:13) of a MARK II pressure suppression containment system. It was set up at the University of Pisa in order to study the pressure-temperature transient in pressure suppression containment systems during LOCAs. Knowledge of this transient is necessary to perform a correct structural analysis of reactor containment. The containment system behavior is studied by changing the principal parameters which affect the transient (blow-down mass and energy release, suppression pool water temperature, vent pipe number and submergence, heat transfer coefficients). The first series of tests involved: A) 13 tests with break area of 1.8 cm 2 , B) 8 tests with break area of 20.0 cm 2 . The following experimental conditions were changed: position of the simulated break (from liquid or steam zone), water pressure (20-85 Kg/cm 2 ) and mass (45-70 Kg) in the vessel model. Tests A): the CONTEMPT codes correctly forecast the pressure-temperature history, both in dry- and in wet-well. Tests B): the experimental runs have shown that increasing of blow-down flowrate produces dry-well pressure spatial differences and anomalous vent pipe behavior. This results in damped oscillations of dry- and wet-well pressure, probably due to alternating air bubble over-expansion and collapse, and in vent pipe opening and reclosing. Dry-well pressure maxima at the end of blow-down are greater than those forecasted by currently applied codes: these codes use an homogeneous model, and do not take into account the above mentioned dynamic phenomena. In some tests other interesting phenomena were observed, such as some local pressure peaks in the suppression pool greater than dry-well pessure maxima at the end of blow-down. At present, all these phenomena are under study; they could be important for the structural analysis of containment systems

Suppression of Subsequent N1m Amplitude When the Masker Frequency is Different from the Signal

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Yuka Uratani

2014-01-01

Full Text Available When two tones are presented in a short interval of time, the presentation of the preceding tone (masker suppresses the response evoked by the subsequent tone (signal. To address the processing in forward suppression, we applied 2- and 4-kHz maskers, followed by a 1-kHz signal at varying signal delays (0 to 320 ms and measured the signal-evoked N1m. A two-way analysis of variance revealed a statistically significant effect for signal delay in both masker presentation conditions. The N1m peak amplitude at the signal delay of 320 ms was significantly larger than those of 10, 20, 40, and 80 ms ( p < 0.05. No significant enhancement for the very short signal delay was observed. The results suggest that the enhancement of N1m peak amplitude for short signal delay conditions is maximized when the frequency of the masker is identical to that of the signal.

IGF-1 Receptor Differentially Regulates Spontaneous and Evoked Transmission via Mitochondria at Hippocampal Synapses

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Gazit, Neta; Vertkin, Irena; Shapira, Ilana; Helm, Martin; Slomowitz, Edden; Sheiba, Maayan; Mor, Yael; Rizzoli, Silvio; Slutsky, Inna

2016-01-01

Summary The insulin-like growth factor-1 receptor (IGF-1R) signaling is a key regulator of lifespan, growth, and development. While reduced IGF-1R signaling delays aging and Alzheimer’s disease progression, whether and how it regulates information processing at central synapses remains elusive. Here, we show that presynaptic IGF-1Rs are basally active, regulating synaptic vesicle release and short-term plasticity in excitatory hippocampal neurons. Acute IGF-1R blockade or transient knockdown suppresses spike-evoked synaptic transmission and presynaptic cytosolic Ca2+ transients, while promoting spontaneous transmission and resting Ca2+ level. This dual effect on transmitter release is mediated by mitochondria that attenuate Ca2+ buffering in the absence of spikes and decrease ATP production during spiking activity. We conclude that the mitochondria, activated by IGF-1R signaling, constitute a critical regulator of information processing in hippocampal neurons by maintaining evoked-to-spontaneous transmission ratio, while constraining synaptic facilitation at high frequencies. Excessive IGF-1R tone may contribute to hippocampal hyperactivity associated with Alzheimer’s disease. Video Abstract PMID:26804996

Beyond the evoked/intrinsic neural process dichotomy

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Taylor Bolt

2018-03-01

Full Text Available Contemporary functional neuroimaging research has increasingly focused on characterization of intrinsic or “spontaneous” brain activity. Analysis of intrinsic activity is often contrasted with analysis of task-evoked activity that has traditionally been the focus of cognitive neuroscience. But does this evoked/intrinsic dichotomy adequately characterize human brain function? Based on empirical data demonstrating a close functional interdependence between intrinsic and task-evoked activity, we argue that the dichotomy between intrinsic and task-evoked activity as unobserved contributions to brain activity is artificial. We present an alternative picture of brain function in which the brain’s spatiotemporal dynamics do not consist of separable intrinsic and task-evoked components, but reflect the enaction of a system of mutual constraints to move the brain into and out of task-appropriate functional configurations. According to this alternative picture, cognitive neuroscientists are tasked with describing both the temporal trajectory of brain activity patterns across time, and the modulation of this trajectory by task states, without separating this process into intrinsic and task-evoked components. We argue that this alternative picture of brain function is best captured in a novel explanatory framework called enabling constraint. Overall, these insights call for a reconceptualization of functional brain activity, and should drive future methodological and empirical efforts.

Recording visual evoked potentials and auditory evoked P300 at 9.4T static magnetic field.

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Arrubla, Jorge; Neuner, Irene; Hahn, David; Boers, Frank; Shah, N Jon

2013-01-01

Simultaneous recording of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has shown a number of advantages that make this multimodal technique superior to fMRI alone. The feasibility of recording EEG at ultra-high static magnetic field up to 9.4 T was recently demonstrated and promises to be implemented soon in fMRI studies at ultra high magnetic fields. Recording visual evoked potentials are expected to be amongst the most simple for simultaneous EEG/fMRI at ultra-high magnetic field due to the easy assessment of the visual cortex. Auditory evoked P300 measurements are of interest since it is believed that they represent the earliest stage of cognitive processing. In this study, we investigate the feasibility of recording visual evoked potentials and auditory evoked P300 in a 9.4 T static magnetic field. For this purpose, EEG data were recorded from 26 healthy volunteers inside a 9.4 T MR scanner using a 32-channel MR compatible EEG system. Visual stimulation and auditory oddball paradigm were presented in order to elicit evoked related potentials (ERP). Recordings made outside the scanner were performed using the same stimuli and EEG system for comparison purposes. We were able to retrieve visual P100 and auditory P300 evoked potentials at 9.4 T static magnetic field after correction of the ballistocardiogram artefact using independent component analysis. The latencies of the ERPs recorded at 9.4 T were not different from those recorded at 0 T. The amplitudes of ERPs were higher at 9.4 T when compared to recordings at 0 T. Nevertheless, it seems that the increased amplitudes of the ERPs are due to the effect of the ultra-high field on the EEG recording system rather than alteration in the intrinsic processes that generate the electrophysiological responses.

A suppression hierarchy among competing motor programs drives sequential grooming in Drosophila.

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Seeds, Andrew M; Ravbar, Primoz; Chung, Phuong; Hampel, Stefanie; Midgley, Frank M; Mensh, Brett D; Simpson, Julie H

2014-08-19

Motor sequences are formed through the serial execution of different movements, but how nervous systems implement this process remains largely unknown. We determined the organizational principles governing how dirty fruit flies groom their bodies with sequential movements. Using genetically targeted activation of neural subsets, we drove distinct motor programs that clean individual body parts. This enabled competition experiments revealing that the motor programs are organized into a suppression hierarchy; motor programs that occur first suppress those that occur later. Cleaning one body part reduces the sensory drive to its motor program, which relieves suppression of the next movement, allowing the grooming sequence to progress down the hierarchy. A model featuring independently evoked cleaning movements activated in parallel, but selected serially through hierarchical suppression, was successful in reproducing the grooming sequence. This provides the first example of an innate motor sequence implemented by the prevailing model for generating human action sequences. Copyright © 2014, Seeds et al.

Rivalry of homeostatic and sensory-evoked emotions: Dehydration attenuates olfactory disgust and its neural correlates.

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Meier, Lea; Friedrich, Hergen; Federspiel, Andrea; Jann, Kay; Morishima, Yosuke; Landis, Basile Nicolas; Wiest, Roland; Strik, Werner; Dierks, Thomas

2015-07-01

Neural correlates have been described for emotions evoked by states of homeostatic imbalance (e.g. thirst, hunger, and breathlessness) and for emotions induced by external sensory stimulation (such as fear and disgust). However, the neurobiological mechanisms of their interaction, when they are experienced simultaneously, are still unknown. We investigated the interaction on the neurobiological and the perceptional level using subjective ratings, serum parameters, and functional magnetic resonance imaging (fMRI) in a situation of emotional rivalry, when both a homeostatic and a sensory-evoked emotion were experienced at the same time. Twenty highly dehydrated male subjects rated a disgusting odor as significantly less repulsive when they were thirsty. On the neurobiological level, we found that this reduction in subjective disgust during thirst was accompanied by a significantly reduced neural activity in the insular cortex, a brain area known to be considerably involved in processing of disgust. Furthermore, during the experience of disgust in the satiated condition, we observed a significant functional connectivity between brain areas responding to the disgusting odor, which was absent during the stimulation in the thirsty condition. These results suggest interference of conflicting emotions: an acute homeostatic imbalance can attenuate the experience of another emotion evoked by the sensory perception of a potentially harmful external agent. This finding offers novel insights with regard to the behavioral relevance of biologically different types of emotions, indicating that some types of emotions are more imperative for behavior than others. As a general principle, this modulatory effect during the conflict of homeostatic and sensory-evoked emotions may function to safeguard survival. Copyright © 2015 Elsevier Inc. All rights reserved.

The effects of capsaicin and capsaicinoid analogs on metabolic molecular targets in highly energetic tissues and cell types.

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Gannon, Nicholas P; Lambalot, Emily L; Vaughan, Roger A

2016-05-01

There is increasing interest in dietary chemicals that may provide benefits for pathologies such as diabetes and obesity. Capsaicinoids found in chili peppers and pepper extracts, are responsible for the "hot" or "spicy" sensation associated with these foods. Capsaicinoid consumption is also associated with enhanced metabolism, making them potentially therapeutic for metabolic disease by promoting weight loss. This review summarizes much of the current experimental evidence (ranging from basic to applied investigations) of the biochemical and molecular metabolic effects of capsaicinoids in metabolically significant cell types. Along with influencing metabolic rate, findings demonstrate capsaicinoids appear to alter molecular metabolic signaling, regulate hunger and satiety, blood metabolites, and catecholamine release. Notably, the majority of the experiments summarized herein utilized isolated supplemental or research grade capsaicinoids rather than natural food sources for experimental interventions. Additional work should be conducted using primary food sources of capsaicin to explore pharmacological, physiological, and metabolic benefits of both chronic and acute capsaicin consumption. © 2016 BioFactors, 42(3):229-246, 2016. © 2016 International Union of Biochemistry and Molecular Biology.

Burst-suppression is reactive to photic stimulation in comatose children with acquired brain injury

DEFF Research Database (Denmark)

Nita, Dragos A.; Moldovan, Mihai; Sharma, Roy

2016-01-01

reactivity. We quantified reactivity by measuring the change in the burst ratio (fraction of time in burst) following photic stimulation. Results: Photic stimulation evoked bursts in all patients, resulting in a transient increase in the burst ratio, while the mean heart rate remained unchanged......Objective: Burst-suppression is an electroencephalographic pattern observed during coma. In individuals without known brain pathologies undergoing deep general anesthesia, somatosensory stimulation transiently increases the occurrence of bursts. We investigated the reactivity of burst......-suppression in children with acquired brain injury. Methods: Intensive care unit electroencephalographic monitoring recordings containing burst-suppression were obtained from 5 comatose children with acquired brain injury of various etiologies. Intermittent photic stimulation was performed at 1 Hz for 1 min to assess...

Normalization of auditory evoked potential and visual evoked potential in patients with idiot savant.

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Chen, X; Zhang, M; Wang, J; Lou, F; Liang, J

1999-03-01

To investigate the variations of auditory evoked potentials (AEP) and visual evoked potentials (VEP) of patients with idiot savant (IS) syndrome. Both AEP and VEP were recorded from 7 patients with IS syndrome, 21 mentally retarded (MR) children without the syndrome and 21 normally age-matched controls, using a Dantec concerto SEEG-16 BEAM instrument. Both AEP and VEP of MR group showed significantly longer latencies (P1 and P2 latencies of AEP, P savant syndrome presented normalized AEP and VEP.

Suppression of oxidative stress and 5-lipoxygenase activation by edaravone improves depressive-like behavior after concussion.

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Higashi, Youichirou; Hoshijima, Michihiro; Yawata, Toshio; Nobumoto, Atsuya; Tsuda, Masayuki; Shimizu, Takahiro; Saito, Motoaki; Ueba, Tetuya

2014-10-15

Brain concussions are a serious public concern and are associated with neuropsychiatric disorders, such as depression. Patients with concussion who suffer from depression often experience distress. Nevertheless, few pre-clinical studies have examined concussion-induced depression, and there is little information regarding its pharmacological management. Edaravone, a free radical scavenger, can exert neuroprotective effects in several animal models of neurological disorders. However, the effectiveness of edaravone in animal models of concussion-induced depression remains unclear. In this study, we examined whether edaravone could prevent concussion-induced depression. Mice were subjected to a weight-drop injury and intravenously administered edaravone (3.0 mg/kg) or vehicle immediately after impact. Serial magnetic resonance imaging showed no abnormalities of the cerebrum on diffusion T1- and T2-weighted images. We found that edaravone suppressed concussion-induced depressive-like behavior in the forced swim test, which was accompanied by inhibition of increased hippocampal and cortical oxidative stress (OS) and suppression of 5-lipoxygenase (5-LOX) translocation to the nuclear envelope in hippocampal astrocytes. Hippocampal OS in concussed mice was also prevented by the nicotinamide adenine dinucleotide phosphate oxidase inhibitor, apocynin, and administration of BWB70C, a 5-LOX inhibitor, immediately and 24 h after injury prevented depressive-like behaviors in concussed mice. Further, antidepressant effects of edaravone were observed in mice receiving 1.0 or 3.0 mg/kg of edaravone immediately after impact, but not at a lower dose of 0.1 mg/kg. This antidepressant effect persisted up to 1 h after impact, whereas edaravone treatment at 3 h after impact had no effect on concussion-induced depressive-like behavior. These results suggest that edaravone protects against concussion-induced depression, and this protection is mediated by suppression of OS and 5

Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

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Huys, Raoul; Jirsa, Viktor K.; Darokhan, Ziauddin; Valentiniene, Sonata; Roland, Per E.

2016-01-01

Neurons in the primary visual cortex spontaneously spike even when there are no visual stimuli. It is unknown whether the spiking evoked by visual stimuli is just a modification of the spontaneous ongoing cortical spiking dynamics or whether the spontaneous spiking state disappears and is replaced by evoked spiking. This study of laminar recordings of spontaneous spiking and visually evoked spiking of neurons in the ferret primary visual cortex shows that the spiking dynamics does not change: the spontaneous spiking as well as evoked spiking is controlled by a stable and persisting fixed point attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization is that it avoids the need for a system reorganization following visual stimulation, and impedes the transition of spontaneous spiking to evoked spiking and the propagation of spontaneous spiking from layer 4 to layers 2–3. PMID:26778982

Psychophysical evaluation of a sanshool derivative (alkylamide and the elucidation of mechanisms subserving tingle.

Directory of Open Access Journals (Sweden)

Kelly C Albin

2010-03-01

Full Text Available Previous studies investigated the neural and molecular underpinnings of the tingle sensation evoked by sanshool and other natural or synthetic alkylamides. Currently, we sought to characterize the psychophysical properties associated with administration of these compounds. Like other chemesthetic stimuli, the synthetic tingle analog isobutylalkylamide (IBA evoked a sensation that was temporally dynamic. Repeated IBA application at short (30 sec interstimulus intervals (ISI resulted in a tingle sensation that increased across trials. Application at longer ISIs (approximately 30 min resulted in a sensation of decreased intensity consistent with self-desensitization. Prior treatment with the TRPV1 or TRPA1 agonists, capsaicin and mustard oil did not cross-desensitize the tingle sensation evoked by IBA suggesting that neither TRPV1 nor TRPA1 participate in the transduction mechanism sub-serving tingle. When evaluated over 30-min time period, lingual IBA evoked a sensation that was described initially as tingling and pungent but after approximately 15 min, as a cooling sensation. Further, we found that the sensation evoked by lingual IBA was potentiated by simultaneous application of cold (0 degrees C and cool (21 degrees C thermal stimuli but was unaffected by warm (33 degrees C and hot (41 degrees C temperatures. Finally, to test the hypothesis that the tingling sensation is subserved by the activation of mechanosensitve fibers, we evaluated lingual tactile thresholds in the presence and absence of lingual IBA. The presence of IBA significantly raised lingual tactile thresholds, whereas capsaicin did not, identifying a role for mechanosensitive fibers in conveying the tingle sensation evoked by sanshool-like compounds. Collectively, these results show that lingual alkylamide evokes a complex sensation that is temporally dynamic and consistent with in vitro and in vivo experiments suggesting these compounds activate mechanosensitve neurons via

N-[(1,3-Benzodioxol-5-ylmethyl]benzenesulfonamide: an analogue of capsaicin

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Stella H. Maganhi

2013-11-01

Full Text Available The title compound, C14H13NO4S, an analogue of capsaicin, differs from the latter by having a 1,3-benzodioxole ring rather than a 2-methoxyphenol moiety, and having a benzenesulfonamide group instead of an aliphatic amide chain. The five-membered ring is in an envelope conformation with the methylene C atom lying 0.221 (6 Å out of the plane formed by the other four atoms. The dihedral angle between the phenyl ring and the mean plane of the 1,3-benzodioxole fused-ring system is 84.65 (4°. In the crystal, molecules aggregate into supramolecular layers in the ac plane through C—H...O, N—H...O and C—H...π interactions.

Brain-immune interaction accompanying odor-evoked autobiographic memory.

Science.gov (United States)

Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

2013-01-01

The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

Brain–Immune Interaction Accompanying Odor-Evoked Autobiographic Memory

Science.gov (United States)

Matsunaga, Masahiro; Bai, Yu; Yamakawa, Kaori; Toyama, Asako; Kashiwagi, Mitsuyoshi; Fukuda, Kazuyuki; Oshida, Akiko; Sanada, Kazue; Fukuyama, Seisuke; Shinoda, Jun; Yamada, Jitsuhiro; Sadato, Norihiro; Ohira, Hideki

2013-01-01

The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET) recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC) and precuneus/posterior cingulate cortex (PCC) were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions. PMID:23977312

Brain-immune interaction accompanying odor-evoked autobiographic memory.

Directory of Open Access Journals (Sweden)

Masahiro Matsunaga

Full Text Available The phenomenon in which a certain smell evokes a specific memory is known as the Proust phenomenon. Odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli. The results of our previous study indicated that odor-evoked autobiographic memory accompanied by positive emotions has remarkable effects on various psychological and physiological activities, including the secretion of cytokines, which are immune-signaling molecules that modulate systemic inflammation. In this study, we aimed to clarify the neural substrates associated with the interaction between odor-evoked autobiographic memory and peripheral circulating cytokines. We recruited healthy male and female volunteers and investigated the association between brain responses and the concentration of several cytokines in the plasma by using positron emission tomography (PET recordings when an autographic memory was evoked in participants by asking them to smell an odor that was nostalgic to them. Participants experienced positive emotions and autobiographic memories when nostalgic odors were presented to them. The levels of peripheral proinflammatory cytokines, such as the tumor necrosis factor-α (TNF-α and interferon-γ (IFN-γ, were significantly reduced after experiencing odor-evoked autobiographic memory. Subtraction analysis of PET images indicated that the medial orbitofrontal cortex (mOFC and precuneus/posterior cingulate cortex (PCC were significantly activated during experiences of odor-evoked autobiographic memory. Furthermore, a correlation analysis indicated that activities of the mOFC and precuneus/PCC were negatively correlated with IFN-γ concentration. These results indicate that the neural networks including the precuneus/PCC and mOFC might regulate the secretion of peripheral proinflammatory cytokines during the experience of odor-evoked autobiographic memories accompanied with positive emotions.

Effect of Capsaicin Cream on Chronic Low Back Pain in Patients With Inter-Vertebral Disc Herniation

OpenAIRE

Fayazi; Farokhpyam; Talali

2015-01-01

Background Low back pain is one of the most common debilitating disorders worldwide and the third cause of visiting a physician. One of the most common causes of low back pain is spinal disc herniation. Still there is no general agreement on the most effective treatment for it. Objectives This study aimed to determine the effect of Capsaicin cream on low back pain in patients with inter-vertebral disc herniation in Ahvaz. ...

Acute Stress Suppresses Synaptic Inhibition and Increases Anxiety via Endocannabinoid Release in the Basolateral Amygdala.

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Di, Shi; Itoga, Christy A; Fisher, Marc O; Solomonow, Jonathan; Roltsch, Emily A; Gilpin, Nicholas W; Tasker, Jeffrey G

2016-08-10

Stress and glucocorticoids stimulate the rapid mobilization of endocannabinoids in the basolateral amygdala (BLA). Cannabinoid receptors in the BLA contribute to anxiogenesis and fear-memory formation. We tested for rapid glucocorticoid-induced endocannabinoid regulation of synaptic inhibition in the rat BLA. Glucocorticoid application to amygdala slices elicited a rapid, nonreversible suppression of spontaneous, but not evoked, GABAergic synaptic currents in BLA principal neurons; the effect was also seen with a membrane-impermeant glucocorticoid, but not with intracellular glucocorticoid application, implicating a membrane-associated glucocorticoid receptor. The glucocorticoid suppression of GABA currents was not blocked by antagonists of nuclear corticosteroid receptors, or by inhibitors of gene transcription or protein synthesis, but was blocked by inhibiting postsynaptic G-protein activity, suggesting a postsynaptic nongenomic steroid signaling mechanism that stimulates the release of a retrograde messenger. The rapid glucocorticoid-induced suppression of inhibition was prevented by blocking CB1 receptors and 2-arachidonoylglycerol (2-AG) synthesis, and it was mimicked and occluded by CB1 receptor agonists, indicating it was mediated by the retrograde release of the endocannabinoid 2-AG. The rapid glucocorticoid effect in BLA neurons in vitro was occluded by prior in vivo acute stress-induced, or prior in vitro glucocorticoid-induced, release of endocannabinoid. Acute stress also caused an increase in anxiety-like behavior that was attenuated by blocking CB1 receptor activation and inhibiting 2-AG synthesis in the BLA. Together, these findings suggest that acute stress causes a long-lasting suppression of synaptic inhibition in BLA neurons via a membrane glucocorticoid receptor-induced release of 2-AG at GABA synapses, which contributes to stress-induced anxiogenesis. We provide a cellular mechanism in the basolateral amygdala (BLA) for the rapid stress

Antihyperalgesic efficacy of 5% lidocaine medicated plaster in capsaicin and sunburn pain models--two randomized, double-blinded, placebo-controlled crossover trials in healthy volunteers.

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Gustorff, Burkhard; Hauer, David; Thaler, Johannes; Seis, Astrid; Draxler, Julia

2011-12-01

The aim of this research is to analyze analgesic efficacy of the 5% lidocaine medicated plaster in two randomized, double-blinded, placebo-controlled, crossover studies in 16 healthy volunteers using capsaicin and sunburn pain models. Lidocaine and placebo plasters were simultaneously applied to forearms and thighs at contralateral body sites for three alternating 12-h plaster-on/plaster-off periods. Between the second and third plaster-on period, 4.2-cm circular spots on both pretreated thighs were irradiated with three times the individual minimal erythema dose of UVB light. After the last plaster-on period, 20 μl of 0.1% capsaicin was injected intradermally into both forearms. The study was repeated using a single 12-h plaster application. The area of pinprick hyperalgesia was diminished by 53% (p sunburn model; the intensity of mechanical hyperalgesia to rigid filaments (8 - 512 mN) was reduced in both models. Cold pain perception threshold was reduced (19.7°C ± 8.0 vs 21.8°C ± 6.8 for placebo, p sunburn). Similar effects were observed in the 12-h exposure study. No effect was seen on capsaicin-induced spontaneous pain and flare size, or blood flow in the sunburn area, and heat hyperalgesia in either study. Lidocaine plaster effectively treats mechanical hyperalgesia and cold pain.

Towards a neural basis of music-evoked emotions.

Science.gov (United States)

Koelsch, Stefan

2010-03-01

Music is capable of evoking exceptionally strong emotions and of reliably affecting the mood of individuals. Functional neuroimaging and lesion studies show that music-evoked emotions can modulate activity in virtually all limbic and paralimbic brain structures. These structures are crucially involved in the initiation, generation, detection, maintenance, regulation and termination of emotions that have survival value for the individual and the species. Therefore, at least some music-evoked emotions involve the very core of evolutionarily adaptive neuroaffective mechanisms. Because dysfunctions in these structures are related to emotional disorders, a better understanding of music-evoked emotions and their neural correlates can lead to a more systematic and effective use of music in therapy. Copyright 2010 Elsevier Ltd. All rights reserved.

Spontaneous and evoked cerebral activity modifications on whole-body γ irradiated adult rabbit

International Nuclear Information System (INIS)

Court, L.; Dufour, R.; Bassant, M.H.; Fatome, M.

1976-01-01

Whole-body γ-exposure from 150 to 850 rads (dose-rate: 14 rads.min -1 ) delivered to adult rabbits chronically implanted with electrodes resulted in prompt and delayed changes of behavior, arousal and spontaneous and evoked electrical activities. Electrophysiological techniques of polygraphic recording and signal processing showed that the alterations were related to the absorbed dose. The threshold dose accompanied with transient changes of arousal should be in the range of 50-100 rads; below this range, to the exclusion of some possible behavior changes, exposure should act as a stimulation that would become nociceptive at higher doses only [fr

The effects of capsaicin and acidity on currents generated by noxious heat in cultured neonatal rat dorsal root ganglion neurones

Czech Academy of Sciences Publication Activity Database

Vlachová, Viktorie; Lyfenko, Alla; Orkand, R. K.; Vyklický st., Ladislav

2001-01-01

Roč. 533, č. 3 (2001), s. 717-728 ISSN 0022-3751 R&D Projects: GA ČR GA305/00/1639; GA MŠk LN00B122 Institutional research plan: CEZ:AV0Z5011922 Keywords : capsaicin * dorsal root ganglion neurones * neonatal rat Subject RIV: FH - Neurology Impact factor: 4.476, year: 2001

Action Potential Broadening in Capsaicin-Sensitive DRG Neurons from Frequency-Dependent Reduction of Kv3 Current.

Science.gov (United States)

Liu, Pin W; Blair, Nathaniel T; Bean, Bruce P

2017-10-04

Action potential (AP) shape is a key determinant of cellular electrophysiological behavior. We found that in small-diameter, capsaicin-sensitive dorsal root ganglia neurons corresponding to nociceptors (from rats of either sex), stimulation at frequencies as low as 1 Hz produced progressive broadening of the APs. Stimulation at 10 Hz for 3 s resulted in an increase in AP width by an average of 76 ± 7% at 22°C and by 38 ± 3% at 35°C. AP clamp experiments showed that spike broadening results from frequency-dependent reduction of potassium current during spike repolarization. The major current responsible for frequency-dependent reduction of overall spike-repolarizing potassium current was identified as Kv3 current by its sensitivity to low concentrations of 4-aminopyridine (IC 50 action potentials of small-diameter rat DRG neurons showed spike broadening at frequencies as low as 1 Hz and that spike broadening resulted predominantly from frequency-dependent inactivation of Kv3 channels. Spike width helps to control transmitter release, conduction velocity, and firing patterns and understanding the role of particular potassium channels can help to guide new pharmacological strategies for targeting pain-sensing neurons selectively. Copyright © 2017 the authors 0270-6474/17/379705-10$15.00/0.

Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P.

Science.gov (United States)

Smith, Ewan St John; Blass, Gregory R C; Lewin, Gary R; Park, Thomas J

2010-05-24

Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber) and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG) neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP) in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

Absence of histamine-induced itch in the African naked mole-rat and "rescue" by Substance P

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Lewin Gary R

2010-05-01

Full Text Available Abstract Recent research has proposed a pathway in which sensory neurons expressing the capsaicin activated ion channel TRPV1 are required for histamine-induced itch and subsequent scratching behavior. We examined histamine-induced itch in the African naked mole-rat (Heterocephalus glaber and found that although naked mole-rats display innate scratching behavior, histamine was unable to evoke increased scratching as is observed in most mouse strains. Using calcium imaging, we examined the histamine sensitivity of naked mole-rat dorsal root ganglia (DRG neurons and identified a population of small diameter neurons activated by histamine, the majority of which are also capsaicin-sensitive. This suggested that naked mole-rat sensory neurons are activated by histamine, but that spinal dorsal horn processing of sensory information is not the same as in other rodents. We have previously shown that naked mole-rats naturally lack substance P (SP in cutaneous C-fibers, but that the neurokinin-1 receptor is expressed in the superficial spinal cord. This led us to investigate if SP deficiency plays a role in the lack of histamine-induced scratching in this species. After intrathecal administration of SP into the spinal cord we observed robust scratching behavior in response to histamine injection. Our data therefore support a model in which TRPV1-expressing sensory neurons are important for histamine-induced itch. In addition, we demonstrate a requirement for active, SP-induced post-synaptic drive to enable histamine sensitive afferents to drive itch-related behavior in the naked mole-rat. These results illustrate that it is altered dorsal horn connectivity of nociceptors that underlies the lack of itch and pain-related behavior in the naked mole-rat.

Use of the novel contact heat evoked potential stimulator (CHEPS for the assessment of small fibre neuropathy: correlations with skin flare responses and intra-epidermal nerve fibre counts

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Chizh Boris A

2007-08-01

Full Text Available Abstract Background The Contact Heat Evoked Potential Stimulator (CHEPS rapidly stimulates cutaneous small nerve fibres, and resulting evoked potentials can be recorded from the scalp. We have studied patients with symptoms of sensory neuropathy and controls using CHEPS, and validated the findings using other objective measures of small nerve fibres i.e. the histamine-induced skin flare response and intra-epidermal fibres (IEF, and also quantitative sensory testing (QST, a subjective measure. Methods In patients with symptoms of sensory neuropathy (n = 41 and healthy controls (n = 9 we performed clinical examination, QST (monofilament, vibration and thermal perception thresholds, nerve conduction studies, histamine-induced skin flares and CHEPS. Skin punch biopsies were immunostained using standard ABC immunoperoxidase for the nerve marker PGP 9.5 or the heat and capsaicin receptor TRPV1. Immunoreactive IEF were counted per length of tissue section and epidermal thickness recorded. Results Amplitudes of Aδ evoked potentials (μV following face, arm or leg stimulation were reduced in patients (e.g. for the leg: mean ± SEM – controls 11.7 ± 1.95, patients 3.63 ± 0.85, p = 0.0032. Patients showed reduced leg skin flare responses, which correlated with Aδ amplitudes (rs = 0.40, p = 0.010. In patient leg skin biopsies, PGP 9.5- and TRPV1-immunoreactive IEF were reduced and correlated with Aδ amplitudes (PGP 9.5, rs = 0.51, p = 0.0006; TRPV1, rs = 0.48, p = 0.0012. Conclusion CHEPS appears a sensitive measure, with abnormalities observed in some symptomatic patients who did not have significant IEF loss and/or QST abnormalities. Some of the latter patients may have early small fibre dysfunction or ion channelopathy. CHEPS provides a clinically practical, non-invasive and objective measure, and can be a useful additional tool for the assessment of sensory small fibre neuropathy. Although further evaluation is required, the technique shows

[Communication and auditory behavior obtained by auditory evoked potentials in mammals, birds, amphibians, and reptiles].

Science.gov (United States)

Arch-Tirado, Emilio; Collado-Corona, Miguel Angel; Morales-Martínez, José de Jesús

2004-01-01

amphibians, Frog catesbiana (frog bull, 30 animals); reptiles, Sceloporus torcuatus (common small lizard, 22 animals); birds: Columba livia (common dove, 20 animals), and mammals, Cavia porcellus, (guinea pig, 20 animals). With regard to lodging, all animals were maintained at the Institute of Human Communication Disorders, were fed with special food for each species, and had water available ad libitum. Regarding procedure, for carrying out analysis of auditory evoked potentials of brain stem SPL amphibians, birds, and mammals were anesthetized with ketamine 20, 25, and 50 mg/kg, by injection. Reptiles were anesthetized by freezing (6 degrees C). Study subjects had needle electrodes placed in an imaginary line on the half sagittal line between both ears and eyes, behind right ear, and behind left ear. Stimulation was carried out inside a no noise site by means of a horn in free field. The sign was filtered at between 100 and 3,000 Hz and analyzed in a computer for provoked potentials (Racia APE 78). In data shown by amphibians, wave-evoked responses showed greater latency than those of the other species. In reptiles, latency was observed as reduced in comparison with amphibians. In the case of birds, lesser latency values were observed, while in the case of guinea pigs latencies were greater than those of doves but they were stimulated by 10 dB, which demonstrated best auditory threshold in the four studied species. Last, it was corroborated that as the auditory threshold of each species it descends conforms to it advances in the phylogenetic scale. Beginning with these registrations, we care able to say that response for evoked brain stem potential showed to be more complex and lesser values of absolute latency as we advance along the phylogenetic scale; thus, the opposing auditory threshold is better agreement with regard to the phylogenetic scale among studied species. These data indicated to us that seeking of auditory information is more complex in more

Fear Expression Suppresses Medial Prefrontal Cortical Firing in Rats.

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Thomas F Giustino

Full Text Available The medial prefrontal cortex (mPFC plays a crucial role in emotional learning and memory in rodents and humans. While many studies suggest a differential role for the prelimbic (PL and infralimbic (IL subdivisions of mPFC, few have considered the relationship between neural activity in these two brain regions recorded simultaneously in behaving animals. Importantly, how concurrent PL and IL activity relate to conditioned freezing behavior is largely unknown. Here we used single-unit recordings targeting PL and IL in awake, behaving rats during the acquisition and expression of conditioned fear. On Day 1, rats received either signaled or unsignaled footshocks in the recording chamber; an auditory conditioned stimulus (CS preceded signaled footshocks. Twenty-four hours later, animals were returned to the recording chamber (modified to create a novel context where they received 5 CS-alone trials. After fear conditioning, both signaled and unsignaled rats exhibited high levels of post-shock freezing that was associated with an enduring suppression of mPFC spontaneous firing, particularly in the IL of signaled rats. Twenty-four hours later, CS presentation produced differential conditioned freezing in signaled and unsignaled rats: freezing increased in rats that had received signaled shocks, but decreased in animals in the unsignaled condition (i.e., external inhibition. This group difference in CS-evoked freezing was mirrored in the spontaneous firing rate of neurons in both PL and IL. Interestingly, differences in PL and IL firing rate highly correlated with freezing levels. In other words, in the signaled group IL spontaneous rates were suppressed relative to PL, perhaps limiting IL-mediated suppression of fear and allowing PL activity to dominate performance, resulting in high levels of freezing. This was not observed in the unsignaled group, which exhibited low freezing. These data reveal that the activity of mPFC neurons is modulated by both

D1 and D2 antagonists reverse the effects of appetite suppressants on weight loss, food intake, locomotion, and rebalance spiking inhibition in the rat NAc shell

Science.gov (United States)

Kalyanasundar, B.; Perez, Claudia I.; Luna, Alvaro; Solorio, Jessica; Moreno, Mario G.; Elias, David; Simon, Sidney A.

2015-01-01

Obesity is a worldwide health problem that has reached epidemic proportions. To ameliorate this problem, one approach is the use of appetite suppressants. These compounds are frequently amphetamine congeners such as diethylpropion (DEP), phentermine (PHEN), and bupropion (BUP), whose effects are mediated through serotonin, norepinephrine, and dopaminergic pathways. The nucleus accumbens (NAc) shell receives dopaminergic inputs and is involved in feeding and motor activity. However, little is known about how appetite suppressants modulate its activity. Therefore, we characterized behavioral and neuronal NAc shell responses to short-term treatments of DEP, PHEN, and BUP. These compounds caused a transient decrease in weight and food intake while increasing locomotion, stereotypy, and insomnia. They evoked a large inhibitory imbalance in NAc shell spiking activity that correlated with the onset of locomotion and stereotypy. Analysis of the local field potentials (LFPs) showed that all three drugs modulated beta, theta, and delta oscillations. These oscillations do not reflect an aversive-malaise brain state, as ascertained from taste aversion experiments, but tracked both the initial decrease in weight and food intake and the subsequent tolerance to these drugs. Importantly, the appetite suppressant-induced weight loss and locomotion were markedly reduced by intragastric (and intra-NAc shell) infusions of dopamine antagonists SCH-23390 (D1 receptor) or raclopride (D2 receptor). Furthermore, both antagonists attenuated appetite suppressant-induced LFP oscillations and partially restored the imbalance in NAc shell activity. These data reveal that appetite suppressant-induced behavioral and neuronal activity recorded in the NAc shell depend, to various extents, on dopaminergic activation and thus point to an important role for D1/D2-like receptors (in the NAc shell) in the mechanism of action for these anorexic compounds. PMID:25972577

Brainstem Auditory Evoked Potential in HIV-Positive Adults.

Science.gov (United States)

Matas, Carla Gentile; Samelli, Alessandra Giannella; Angrisani, Rosanna Giaffredo; Magliaro, Fernanda Cristina Leite; Segurado, Aluísio C

2015-10-20

To characterize the findings of brainstem auditory evoked potential in HIV-positive individuals exposed and not exposed to antiretroviral treatment. This research was a cross-sectional, observational, and descriptive study. Forty-five HIV-positive individuals (18 not exposed and 27 exposed to the antiretroviral treatment - research groups I and II, respectively - and 30 control group individuals) were assessed through brainstem auditory evoked potential. There were no significant between-group differences regarding wave latencies. A higher percentage of altered brainstem auditory evoked potential was observed in the HIV-positive groups when compared to the control group. The most common alteration was in the low brainstem. HIV-positive individuals have a higher percentage of altered brainstem auditory evoked potential that suggests central auditory pathway impairment when compared to HIV-negative individuals. There was no significant difference between individuals exposed and not exposed to antiretroviral treatment.

Sleep deprivation suppresses aggression in Drosophila

Science.gov (United States)

Kayser, Matthew S; Mainwaring, Benjamin; Yue, Zhifeng; Sehgal, Amita

2015-01-01

Sleep disturbances negatively impact numerous functions and have been linked to aggression and violence. However, a clear effect of sleep deprivation on aggressive behaviors remains unclear. We find that acute sleep deprivation profoundly suppresses aggressive behaviors in the fruit fly, while other social behaviors are unaffected. This suppression is recovered following post-deprivation sleep rebound, and occurs regardless of the approach to achieve sleep loss. Genetic and pharmacologic approaches suggest octopamine signaling transmits changes in aggression upon sleep deprivation, and reduced aggression places sleep-deprived flies at a competitive disadvantage for obtaining a reproductive partner. These findings demonstrate an interaction between two phylogenetically conserved behaviors, and suggest that previous sleep experiences strongly modulate aggression with consequences for reproductive fitness. DOI: http://dx.doi.org/10.7554/eLife.07643.001 PMID:26216041

Psychological and physiological responses to odor-evoked autobiographic memory.

Science.gov (United States)

Matsunaga, Masahiro; Isowa, Tokiko; Yamakawa, Kaori; Kawanishi, Yoko; Tsuboi, Hirohito; Kaneko, Hiroshi; Sadato, Norihiro; Oshida, Akiko; Katayama, Atsushi; Kashiwagi, Mitsuyoshi; Ohira, Hideki

2011-01-01

The "Proust phenomenon" occurs when a certain smell evokes a specific memory. Recent studies have demonstrated that odor-evoked autobiographic memories are more emotional than those elicited by other sensory stimuli because of the direct neural communication between the olfactory system and the amygdala. The amygdala is known to regulate various physiological activities including the endocrine and immune systems; therefore, odor-evoked autobiographic memory may trigger various psychological and physiological responses; however, the responses elicited by this memory remains obscure. In this study, we aimed to investigate the psychological and physiological responses accompanying odor-evoked autobiographic memory. We recruited healthy male and female volunteers and investigated changes in their mood states and autonomic nervous, endocrine, and immune activities when autobiographic memory was evoked in the participants by asking them to smell an odor(s) that was nostalgic to them. The autobiographic memories associated with positive emotion resulted in increased positive mood states, such as comfort and happiness, and decreased negative mood states, such as anxiety. Furthermore, heart rate was decreased, skin-conductance level was increased, and peripheral interleukin-2 level was decreased after smelling the nostalgic odor. These psychological and physiological responses were significantly correlated. The present study suggests that odor-evoked autobiographic memory along with a positive feeling induce various physiological responses, including the autonomic nervous and immune activities. To the best of our knowledge, the present study is the first to observe an interaction between odor-evoked autobiographic memories and immune function.

Evoked acoustic emission

DEFF Research Database (Denmark)

Elberling, C; Parbo, J; Johnsen, N J

1985-01-01

Stimulated acoustic emissions were recorded in response to tonal stimuli at 60 dB p.e. SPL in a small group of normal-hearing adults. Power spectral analysis reveals that the evoked activity from each ear contains energy in preferential frequency bands and the change of stimulus frequency has only...

Tolerability of the capsaicin 8% patch following pretreatment with lidocaine or tramadol in patients with peripheral neuropathic pain: A multicentre, randomized, assessor-blinded study

NARCIS (Netherlands)

Jensen, T.S.; Hoye, K.; Fricova, J.; Vanelderen, P.J.L.; Ernault, E.; Siciliano, T.; Marques, S.

2014-01-01

BACKGROUND: Application of the capsaicin 8% patch is associated with treatment-related discomfort. Consequently, pretreatment for 60 min with anaesthetic cream is recommended; however, this may be uncomfortable and time consuming. METHODS: We conducted a multicentre, randomized (1:1),

Light evokes melanopsin-dependent vocalization and neural activation associated with aversive experience in neonatal mice.

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Anton Delwig

Full Text Available Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs are the only functional photoreceptive cells in the eye of newborn mice. Through postnatal day 9, in the absence of functional rods and cones, these ipRGCs mediate a robust avoidance behavior to a light source, termed negative phototaxis. To determine whether this behavior is associated with an aversive experience in neonatal mice, we characterized light-induced vocalizations and patterns of neuronal activation in regions of the brain involved in the processing of aversive and painful stimuli. Light evoked distinct melanopsin-dependent ultrasonic vocalizations identical to those emitted under stressful conditions, such as isolation from the litter. In contrast, light did not evoke the broad-spectrum calls elicited by acute mechanical pain. Using markers of neuronal activation, we found that light induced the immediate-early gene product Fos in the posterior thalamus, a brain region associated with the enhancement of responses to mechanical stimulation of the dura by light, and thought to be the basis for migrainous photophobia. Additionally, light induced the phosphorylation of extracellular-related kinase (pERK in neurons of the central amygdala, an intracellular signal associated with the processing of the aversive aspects of pain. However, light did not activate Fos expression in the spinal trigeminal nucleus caudalis, the primary receptive field for painful stimulation to the head. We conclude that these light-evoked vocalizations and the distinct pattern of brain activation in neonatal mice are consistent with a melanopsin-dependent neural pathway involved in processing light as an aversive but not acutely painful stimulus.

Pharmacokinetic-Pharmacodynamic Relationship of Erenumab (AMG 334) and Capsaicin-Induced Dermal Blood Flow in Healthy and Migraine Subjects.

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Vu, Thuy; Ma, Peiming; Chen, Jiyun Sunny; de Hoon, Jan; Van Hecken, Anne; Yan, Lucy; Wu, Liviawati Sutjandra; Hamilton, Lisa; Vargas, Gabriel

2017-09-01

Capsaicin-induced dermal blood flow (CIDBF) is a validated biomarker used to evaluate the target engagement of potential calcitonin gene-related peptide-blocking therapeutics for migraine. To characterize the pharmacokinetics (PK) and quantify the inhibitory effects of erenumab (AMG 334) on CIDBF, CIDBF data were pooled from a single- and a multiple-dose study in healthy and migraine subjects. Repeated capsaicin challenges and DBF measurements were performed and serum erenumab concentrations determined. A population analysis was conducted using a nonlinear mixed-effects modeling approach. Effects of body weight, gender, and age on model parameters were evaluated. Two-compartment target-mediated drug disposition (TMDD) model assuming binding of erenumab in the central compartment best described the nonlinear PK of erenumab. Subcutaneous absorption half-life was 1.6 days and bioavailability was 74%. Erenumab produced a maximum inhibition of 89% (95% confidence interval: 87-91%). Erenumab concentrations required for 50% and 99% of maximum inhibition were 255 ng/mL and 1134 ng/mL, respectively. Increased body weight was associated with increased erenumab clearance but had no effect on the inhibitory effect on CIDBF. Our results show that erenumab pharmacokinetics was best characterized by a TMDD model and resulted in potent inhibition of CIDBF.

Development-dependent behavioral change toward pups and synaptic transmission in the rhomboid nucleus of the bed nucleus of the stria terminalis.

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Amano, Taiju; Shindo, Sayaka; Yoshihara, Chihiro; Tsuneoka, Yousuke; Uki, Haruka; Minami, Masabumi; Kuroda, Kumi O

2017-05-15

Sexually naïve male C57BL/6 mice aggressively bite unfamiliar pups. This behavior, called infanticide, is considered an adaptive reproductive strategy of males of polygamous species. We recently found that the rhomboid nucleus of the bed nucleus of the stria terminalis (BSTrh) is activated during infanticide and that the bilateral excitotoxic lesions of BSTrh suppress infanticidal behavior. Here we show that 3-week-old male C57BL/6 mice rarely engaged in infanticide and instead, provided parental care toward unfamiliar pups, consistent with observations in rats and other rodent species. This inhibition of infanticide at the periweaning period is functional because the next litter will be born at approximately the time of weaning of the previous litter through maternal postpartum ovulation. However, the mechanism of this age-dependent behavioral change is unknown. Therefore, we performed whole-cell patch clamp recordings of BSTrh and compared evoked neurotransmission in response to the stimulation of the stria terminalis of adult and 3-week-old male mice. Although we were unable to detect a significant difference in the amplitudes of inhibitory neurotransmission, the amplitudes and the paired-pulse ratio of evoked excitatory postsynaptic currents differed between adult and 3-week-old mice. These data suggest that maturation of the synaptic terminal in BSTrh that occurred later than 3 weeks after birth may mediate by the adaptive change from parental to infanticidal behavior in male mice. Copyright © 2016 Elsevier B.V. All rights reserved.

A Novel Operant-based Behavioral Assay of Mechanical Allodynia in the Orofacial Region of Rats

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Rohrs, Eric L.; Kloefkorn, Heidi E.; Lakes, Emily H.; Jacobs, Brittany Y.; Neubert, John K.; Caudle, Robert M.; Allen, Kyle D.

2015-01-01

Background Detecting behaviors related to orofacial pain in rodent models often relies on subjective investigator grades or methods that place the animal in a stressful environment. In this study, an operant-based behavioral assay is presented for the assessment of orofacial tactile sensitivity in the rat. New Methods In the testing chamber, rats are provided access to a sweetened condensed milk bottle; however, a 360° array of stainless steel wire loops impedes access. To receive the reward, an animal must engage the wires across the orofacial region. Contact with the bottle triggers a motor, requiring the animal to accept increasing pressure on the face during the test. To evaluate this approach, tolerated bottle distance was measured for 10 hairless Sprague-Dawley rats at baseline and 30 minutes after application of capsaicin cream (0.1%) to the face. The experiment was repeated to evaluate the ability of morphine to reverse this effect. Results The application of capsaicin cream reduced tolerated bottle distance measures relative to baseline (porofacial sensitivity is presented using an operant system. Conclusions This operant device allows for consistent measurement of heightened tactile sensitivity in the orofacial regions of the rat. PMID:25823368

Brainstem evoked potentials in infantile spasms

International Nuclear Information System (INIS)

Miyazaki, Masahito; Hashimoto, Toshiaki; Murakawa, Kazuyoshi; Tayama, Masanobu; Kuroda, Yasuhiro

1992-01-01

In ten patients with infantile spasms, brainstem evoked potentials and MRI examinations were performed to evaluate the brainstem involvement. The result of short latency somatosensory evoked potentials (SSEP) following the right median nerve stimulation revealed abnormal findings including the absence or low amplitudes of the waves below wave P3 and delayed central conduction time in 7 of the ten patients. The result of auditory brainstem responses (ABR) revealed abnormal findings including low amplitudes of wave V, prolonged interpeak latency of waves I-V and absence of the waves below wave IV in 5 of the ten patients. The result of the MRI examinations revealed various degrees of the brainstem atrophy in 6 of the ten patients, all of whom showed abnormal brainstem evoked potentials. The result of this study demonstrates that patients with infantile spasms are frequently associated with brainstem dysfunction and raises the possibility that brainstem atrophy might be a cause of infantile spasms. (author)

Can visual evoked potentials be used in biometric identification?

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Power, Alan J; Lalor, Edmund C; Reilly, Richard B

2006-01-01

Due to known differences in the anatomical structure of the visual pathways and generators in different individuals, the use of visual evoked potentials offers the possibility of an alternative to existing biometrics methods. A study based on visual evoked potentials from 13 individuals was carried out to assess the best combination of temporal, spectral and AR modeling features to realize a robust biometric. From the results it can be concluded that visual evoked potentials show considerable biometric qualities, with classification accuracies reaching a high of 86.54% and that a specific temporal and spectral combination was found to be optimal. Based on these results the visual evoked potential may be a useful tool in biometric identification when used in conjunction with more established biometric methods.

Addition of visual noise boosts evoked potential-based brain-computer interface.

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Xie, Jun; Xu, Guanghua; Wang, Jing; Zhang, Sicong; Zhang, Feng; Li, Yeping; Han, Chengcheng; Li, Lili

2014-05-14

Although noise has a proven beneficial role in brain functions, there have not been any attempts on the dedication of stochastic resonance effect in neural engineering applications, especially in researches of brain-computer interfaces (BCIs). In our study, a steady-state motion visual evoked potential (SSMVEP)-based BCI with periodic visual stimulation plus moderate spatiotemporal noise can achieve better offline and online performance due to enhancement of periodic components in brain responses, which was accompanied by suppression of high harmonics. Offline results behaved with a bell-shaped resonance-like functionality and 7-36% online performance improvements can be achieved when identical visual noise was adopted for different stimulation frequencies. Using neural encoding modeling, these phenomena can be explained as noise-induced input-output synchronization in human sensory systems which commonly possess a low-pass property. Our work demonstrated that noise could boost BCIs in addressing human needs.

Extracting the basal extracellular dopamine concentrations from the evoked responses: re-analysis of the dopamine kinetics.

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Chen, Kevin C; Budygin, Evgeny A

2007-08-15

Fast-scan cyclic voltammetry in conjunction with carbon fiber microelectrode has been used to study dopamine (DA) release and uptake mechanisms in rat brains because of the smaller size of the electrode and the subsecond resolution. Current voltammetry data were analyzed by a DA kinetic model assuming a zero baseline, which is in conflict with existing microdialysis findings and a recent claim of the striatal extracellular DA concentration at micromolar levels. This work applied a new analysis approach based on a modified DA kinetic model to analyze the kinetics of electrically evoked DA overflow in the caudate-putamen of anesthetized rats. The DA uptake parameters were fitted from the electrical stimulation phase, and subsequently used to calculate theoretical DA uptake rates. Comparison of the theoretical uptake rates with experimental clearance rates allows for the study of the tonic DA release process following electrical stimulations. Analyses of DA voltammetry data suggest that the locally averaged basal level of extracellular DA in the rat striatum might be confined between 95 and 220 nM. The disparate time scales in the clearance kinetics of endogenous and exogenous DA were investigated. Long-distance diffusion could only partially explain the slow clearance time course of exogenous DA. Model simulations and parameter analyses on evoked DA responses indicate that suppression of the nonevoked DA release process immediately following electrical stimulation cannot completely account for the rapid clearance of the electrically evoked DA. Inconsistency in the measured uptake strengths in the literature studying endogenous and exogenous DA remains to be investigated in the future.

Sub-second changes in accumbal dopamine during sexual behavior in male rats.

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Robinson, D L; Phillips, P E; Budygin, E A; Trafton, B J; Garris, P A; Wightman, R M

2001-08-08

Transient (200--900 ms), high concentrations (200--500 nM) of dopamine, measured using fast-scan cyclic voltammetry, occurred in the nucleus accumbens core of male rats at the presentation of a receptive female. Additional dopamine signals were observed during subsequent approach behavior. Background-subtracted cyclic voltammograms of the naturally-evoked signals matched those of electrically-evoked dopamine measured at the same recording sites. Administration of nomifensine amplified natural and evoked dopamine release, and increased the frequency of detectable signals. While gradual changes in dopamine concentration during sexual behavior have been well established, these findings dramatically improve the time resolution. The observed dopamine transients, probably resulting from neuronal burst firing, represent the first direct correlation of dopamine with sexual behavior on a sub-second time scale.

Binaural interaction in auditory evoked potentials: Brainstem, middle- and long-latency components

OpenAIRE

McPherson, DL; Starr, A

1993-01-01

Binaural interaction occurs in the auditory evoked potentials when the sum of the monaural auditory evoked potentials are not equivalent to the binaural evoked auditory potentials. Binaural interaction of the early- (0-10 ms), middle- (10-50 ms) and long-latency (50-200 ms) auditory evoked potentials was studied in 17 normal young adults. For the early components, binaural interaction was maximal at 7.35 ms accounting for a reduction of 21% of the amplitude of the binaural evoked potentials. ...

Is the auditory evoked P2 response a biomarker of learning?

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Kelly eTremblay

2014-02-01

Full Text Available Even though auditory training exercises for humans have been shown to improve certain perceptual skills of individuals with and without hearing loss, there is a lack of knowledge pertaining to which aspects of training are responsible for the perceptual gains, and which aspects of perception are changed. To better define how auditory training impacts brain and behavior, electroencephalography and magnetoencephalography have been used to determine the time course and coincidence of cortical modulations associated with different types of training. Here we focus on P1-N1-P2 auditory evoked responses (AEP, as there are consistent reports of gains in P2 amplitude following various types of auditory training experiences; including music and speech-sound training. The purpose of this experiment was to determine if the auditory evoked P2 response is a biomarker of learning. To do this, we taught native English speakers to identify a new pre-voiced temporal cue that is not used phonemically in the English language so that coinciding changes in evoked neural activity could be characterized. To differentiate possible effects of repeated stimulus exposure and a button-pushing task from learning itself, we examined modulations in brain activity in a group of participants who learned to identify the pre-voicing contrast and compared it to participants, matched in time, and stimulus exposure, that did not. The main finding was that the amplitude of the P2 auditory evoked response increased across repeated EEG sessions for all groups, regardless of any change in perceptual performance. What’s more, these effects were retained for months. Changes in P2 amplitude were attributed to changes in neural activity associated with the acquisition process and not the learned outcome itself. A further finding was the expression of a late negativity (LN wave 600-900 ms post-stimulus onset, post-training, exclusively for the group that learned to identify the pre

Scopolamine Reduces Electrophysiological Indices of Distractor Suppression: Evidence from a Contingent Capture Task

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Inga Laube

2017-12-01

Full Text Available Limited resources for the in-depth processing of external stimuli make it necessary to select only relevant information from our surroundings and to ignore irrelevant stimuli. Attentional mechanisms facilitate this selection via top-down modulation of stimulus representations in the brain. Previous research has indicated that acetylcholine (ACh modulates this influence of attention on stimulus processing. However, the role of muscarinic receptors as well as the specific mechanism of cholinergic modulation remains unclear. Here we investigated the influence of ACh on feature-based, top-down control of stimulus processing via muscarinic receptors by using a contingent capture paradigm which specifically tests attentional shifts toward uninformative cue stimuli which display one of the target defining features In a double-blind, placebo controlled study we measured the impact of the muscarinic receptor antagonist scopolamine on behavioral and electrophysiological measures of contingent attentional capture. The results demonstrated all the signs of functional contingent capture, i.e., attentional shifts toward cued locations reflected in increased amplitudes of N1 and N2Pc components, under placebo conditions. However, scopolamine did not affect behavioral or electrophysiological measures of contingent capture. Instead, scopolamine reduced the amplitude of the distractor-evoked Pd component which has recently been associated with active suppression of irrelevant distractor information. The findings suggest a general cholinergic modulation of top-down control during distractor processing.

[Selective feeding in fish: Effect of feeding and defensive motivations evoked by natural odors].

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Kasumyan, A O; Marusov, E A

2015-01-01

The effect of feeding and defensive motivations evoked by natural olfactory signals (the food odor, the alarm pheromone) on choice and consumption of food items different in color and taste, and the manifestation of foraging behavior were examined in fish (koi Cyprinus carpio, roach Rutilus rutilus). The agar-agar pellets of red and green color having one of the amino acids (glycine, L-proline, L-alanine; all in concentration of 0.1 M) were simultaneously offered to single fishes in pure water, and in water extract of Chironomidae larvae or in water extract of fish skin. It was found out that odors used have different effects on fish foraging activity and on pellet selection for both pellet choice and consumption. On background of food odor, fish grasped pellets more often than in pure water. The equal choice of red and green pellets in pure water shifted to the preference of red ones in the presence of food odor. Despite the increase in the absolute number of pellets grasped, the relative consumption reduced and was replaced by selective consumption of pellets with glycine regardless of their color. Increasing demand for the food quality, due to the increased feeding motivation in response to food odor, is an important adaptation enhancing selection and consumption of food with more appropriate sensory qualities for fish. Defensive motivation caused by alarm pheromone suppressed predisposition. of fish to feed. Fish grasped pellets several times less often than in pure water and refused most of them. Any changes in the color or taste preferences were absent. Feeding behavior of fish of both species was characterized by repeated intraoral pellet testing, but in koi handling was less typical than in roach. In both species, handling activity was higher in those cases when the pellet was finally rejected. This activity was enhanced also on the background of food odor.

4-aminopyridine in scala media reversibly alters the cochlear potentials and suppresses electrically evoked oto-acoustic emissions.

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Kirk, D L; Yates, G K

1998-01-01

Iontophoresis of 4-aminopyridine into scala media of the guinea pig cochlea caused elevation of the thresholds of the compound action potential of the auditory nerve, loss of amplitude of the extracellular cochlear microphonic response (CM), increase in the endocochlear potential (EP) and reduction in the amplitude of electrically evoked oto-acoustic emissions (EEOAEs). These changes were reversible over 10-20 min. The reciprocity of the changes in the CM and the EP was consistent with an interruption of both DC and AC currents through outer hair cells (OHCs), probably by blockade of mechano-electrical transduction (MET) channels in OHCs. Reductions in EEOAEs were consistent with the extrinsically applied generating current entering the OHC via the MET channels. Implications for the activation of OHC electromotility in vivo are discussed.

Capsaicin increases sensation of fullness in energy balance, and decreases desire to eat after dinner in negative energy balance.

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Janssens, Pilou L H R; Hursel, Rick; Westerterp-Plantenga, Margriet S

2014-06-01

Addition of capsaicin (CAPS) to the diet has been shown to increase satiety; therefore, CAPS is of interest for anti-obesity therapy. We investigated the effects of CAPS on appetite profile and ad libitum energy intake in relation to energy balance. Fifteen subjects (seven women and eight men, age: 29.7 ± 10.8yrs, BMI: 23.3 ± 2.9 kg/m(2)) underwent four conditions in a randomized crossover design in 36 hour sessions in a respiration chamber; they received 100% of their daily energy requirements in the conditions "100%Control" and "100%CAPS", and 75% of their daily energy requirements in the conditions "75%Control" and "75%CAPS", followed by an ad libitum dinner. In the 100%CAPS and 75%CAPS conditions, CAPS was given at a dose of 2.56 mg (1.03 g of red chili pepper, 39,050 Scoville heat units) with every meal. Satiety (P dinner desire to eat, satiety and fullness did not differ between 75%CAPS and 100%Control, while desire to eat was higher (P dinner, capsaicin prevents the effects of the negative energy balance on desire to eat. Copyright © 2014. Published by Elsevier Ltd.

Slow cortical evoked potentials after noise exposure

Energy Technology Data Exchange (ETDEWEB)

von Wedel, H; Opitz, H J

1979-07-01

Human cortical evoked potentials under conditions of stimuation are registrated in the post-stimulatory phase of a five minutes lasting equally masking white noise (90 dB HL). Changes of the evoked potentials during adaptation, possible analogy with high tone losses after noise representation and the origin of tinnitus are examined. Stimulation was started 3 sec after the off-effect of the noise. For five minutes periodically tone bursts were represented. Each train of stimulation consists of tone bursts of three frequencies: 2 kcs, 4 kcs, 8 kcs. The 0.5 sec lasting tones were separated by pauses of 2 sec. During the experiment stimulation and analysis were controlled by a computer. Changes in latency and amplitudes of the cortical evoked potentials were registered. Changes of the adaptation patterns as a function of the poststimulatory time are discussed.

p-Cymene reduces orofacial nociceptive response in mice

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Michele F. Santana

2011-12-01

Full Text Available This study investigated the possible antinociceptive effect of p-cymene in different tests of orofacial nociception. The animals (mice were pretreated (i.p. with p-cymene (25, 50, 100 mg/kg, morphine (5 mg/kg, or vehicle (0.2% Tween 80+saline, and were then subsequently administered, subcutaneously into their upper lip: formalin, capsaicin, and glutamate. The nociceptive behavior response was characterized by the time in s that the mice remained rubbing the orofacial region, for a period of 40 min in the formalin test (first phase, 0-6 min; and second phase, 21-40 min, and for 42 and 15 min in the capsaicin and glutamate tests, respectively. To verify the possible opioid involvement in the antinociceptive effects, naloxone (i.p. was administered into the mice 15 min prior to the pretreatment with p-cymene (100 mg/kg. Finally, whether or not the p-cymene evoked any change in motor performance in the Rota-rod test was evaluated. The results showed that the treatment with p-cymene, at all doses, reduced (p<0.001 the nociceptive behavior in all nociception tests. The antinociceptive effect of p-cymene was antagonized by naloxone (1.5 mg/kg. Additionally, mice treated with p-cymene did not show any change in motor performance. In conclusion, p-cymene attenuated orofacial nociception, suggesting an involvement of the opioid system in this effect. Thus, p-cymene might represent an important biomolecule for management and/or treatment of orofacial pain.

The Paradox of Music-Evoked Sadness: An Online Survey

Science.gov (United States)

Taruffi, Liila; Koelsch, Stefan

2014-01-01

This study explores listeners’ experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no “real-life” implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life. PMID:25330315

The paradox of music-evoked sadness: an online survey.

Directory of Open Access Journals (Sweden)

Liila Taruffi

Full Text Available This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772. The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

The paradox of music-evoked sadness: an online survey.

Science.gov (United States)

Taruffi, Liila; Koelsch, Stefan

2014-01-01

This study explores listeners' experience of music-evoked sadness. Sadness is typically assumed to be undesirable and is therefore usually avoided in everyday life. Yet the question remains: Why do people seek and appreciate sadness in music? We present findings from an online survey with both Western and Eastern participants (N = 772). The survey investigates the rewarding aspects of music-evoked sadness, as well as the relative contribution of listener characteristics and situational factors to the appreciation of sad music. The survey also examines the different principles through which sadness is evoked by music, and their interaction with personality traits. Results show 4 different rewards of music-evoked sadness: reward of imagination, emotion regulation, empathy, and no "real-life" implications. Moreover, appreciation of sad music follows a mood-congruent fashion and is greater among individuals with high empathy and low emotional stability. Surprisingly, nostalgia rather than sadness is the most frequent emotion evoked by sad music. Correspondingly, memory was rated as the most important principle through which sadness is evoked. Finally, the trait empathy contributes to the evocation of sadness via contagion, appraisal, and by engaging social functions. The present findings indicate that emotional responses to sad music are multifaceted, are modulated by empathy, and are linked with a multidimensional experience of pleasure. These results were corroborated by a follow-up survey on happy music, which indicated differences between the emotional experiences resulting from listening to sad versus happy music. This is the first comprehensive survey of music-evoked sadness, revealing that listening to sad music can lead to beneficial emotional effects such as regulation of negative emotion and mood as well as consolation. Such beneficial emotional effects constitute the prime motivations for engaging with sad music in everyday life.

Corticosteroid therapy in regressive autism: a retrospective study of effects on the Frequency Modulated Auditory Evoked Response (FMAER), language, and behavior.

Science.gov (United States)

Duffy, Frank H; Shankardass, Aditi; McAnulty, Gloria B; Eksioglu, Yaman Z; Coulter, David; Rotenberg, Alexander; Als, Heidelise

2014-05-15

Up to a third of children with Autism Spectrum Disorder (ASD) manifest regressive autism (R-ASD).They show normal early development followed by loss of language and social skills. Absent evidence-based therapies, anecdotal evidence suggests improvement following use of corticosteroids. This study examined the effects of corticosteroids for R-ASD children upon the 4 Hz frequency modulated evoked response (FMAER) arising from language cortex of the superior temporal gyrus (STG) and upon EEG background activity, language, and behavior. An untreated clinical convenience sample of ASD children served as control sample. Twenty steroid-treated R-ASD (STAR) and 24 not-treated ASD patients (NSA), aged 3 - 5 years, were retrospectively identified from a large database. All study participants had two sequential FMAER and EEG studies;Landau-Kleffner syndrome diagnosis was excluded. All subjects' records contained clinical receptive and expressive language ratings based upon a priori developed metrics. The STAR group additionally was scored behaviorally regarding symptom severity as based on the Diagnostic and Statistical Manual IV (DSM-IV) ASD criteria list. EEGs were visually scored for abnormalities. FMAER responses were assessed quantitatively by spectral analysis. Treated and untreated group means and standard deviations for the FMAER, EEG, language, and behavior, were compared by paired t-test and Fisher's exact tests. The STAR group showed a significant increase in the 4 Hz FMAER spectral response and a significant reduction in response distortion compared to the NSA group. Star group subjects' language ratings were significantly improved and more STAR than NSA group subjects showed significant language improvement. Most STAR group children showed significant behavioral improvement after treatment. STAR group language and behavior improvement was retained one year after treatment. Groups did not differ in terms of minor EEG abnormalities. Steroid treatment produced no

Genetic influence demonstrated for MEG-recorded somatosensory evoked responses

NARCIS (Netherlands)

van 't Ent, D.; van Soelen, I.L.C.; Stam, K.J.; de Geus, E.J.C.; Boomsma, D.I.

2010-01-01

We tested for a genetic influence on magnetoencephalogram (MEG)-recorded somatosensory evoked fields (SEFs) in 20 monozygotic (MZ) and 14 dizygotic (DZ) twin pairs. Previous electroencephalogram (EEG) studies that demonstrated a genetic contribution to evoked responses generally focused on

Liposomal topical capsaicin in post-herpetic neuralgia: a safety pilot study

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Manoel Jacobsen Teixeira

2015-03-01

Full Text Available Topical treatments have gained popularity for general use as an adjunct to systemic drugs in neuropathic pain, but their use produces variable clinical results and local adverse events. Objective To evaluate the safety and analgesic effect of a formulation of liposomal capsaicin (LC (0.025% in patients with post herpetic neuralgia (PHN. Method Patients who remained symptomatic after first-and second-line treatment were randomized to receive LC for six weeks in a placebo-controlled, crossover design study. Clinical assessment was performed at baseline, in the second, fourth and sixth week of treatment. Results Thirteen patients completed both treatment periods. Visual Analog Scale (VAS was significantly decreased after the end of the study (p = 0.008, however the effect of treatment was not significant (p = 0.076. There was no difference on global impression of change and other pain characteristics. LC was safe and well tolerated. However, at the concentration used, its analgesic effects were marginal and not significant.

Visually Evoked Spiking Evolves While Spontaneous Ongoing Dynamics Persist

DEFF Research Database (Denmark)

Huys, Raoul; Jirsa, Viktor K; Darokhan, Ziauddin

2016-01-01

attractor. Its existence guarantees that evoked spiking return to the spontaneous state. However, the spontaneous ongoing spiking state and the visual evoked spiking states are qualitatively different and are separated by a threshold (separatrix). The functional advantage of this organization...

Joint angle affects volitional and magnetically-evoked neuromuscular performance differentially.

Science.gov (United States)

Minshull, C; Rees, D; Gleeson, N P

2011-08-01

This study examined the volitional and magnetically-evoked neuromuscular performance of the quadriceps femoris at functional knee joint angles adjacent to full extension. Indices of volitional and magnetically-evoked neuromuscular performance (N=15 healthy males, 23.5 ± 2.9 years, 71.5 ± 5.4 kg, 176.5 ± 5.5 cm) were obtained at 25°, 35° and 45° of knee flexion. Results showed that volitional and magnetically-evoked peak force (PF(V) and P(T)F(E), respectively) and electromechanical delay (EMD(V) and EMD(E), respectively) were enhanced by increased knee flexion. However, greater relative improvements in volitional compared to evoked indices of neuromuscular performance were observed with increasing flexion from 25° to 45° (e.g. EMD(V), EMD(E): 36% vs. 11% improvement, respectively; F([2,14])=6.8, pjoint positions. These findings suggest that the extent of the relative differential between volitional and evoked neuromuscular performance capabilities is joint angle-specific and not correlated with performance capabilities at adjacent angles, but tends to be smaller with increased flexion. As such, effective prediction of volitional from evoked performance capabilities at both analogous and adjacent knee joint positions would lack robustness. Copyright © 2011 Elsevier Ltd. All rights reserved.

International Evoked Potentials Symposium

CERN Document Server

1980-01-01

The past decade has seen great progress in the measurement of evoked potentials in man; a steady increase in our understanding of their charac­ teristics, their origins and their usefulness; and a growing application in the field of clinical diagnosis. The topic is a truly multidisciplinary one. Important research contributions have been made by workers of many different backgrounds and clinical applications span the specialities. This book represents a revised and updated version of the work originally presented at the international evoked potential symposium held in Nottingham 4-6 1978. The Nottingham Symposium provided a forum for a state-of-the-art discussion amongst workers from many different disciplines and from many different countries. For each major topic in the field an expert review set the scene for discussion of current research presentations. This format is retained in the book: the chapters in Part A provide the context in which the research presented in Part B is set. The task of selecting m...

Expressive suppression and neural responsiveness to nonverbal affective cues.

Science.gov (United States)

Petrican, Raluca; Rosenbaum, R Shayna; Grady, Cheryl

2015-10-01

Optimal social functioning occasionally requires concealment of one's emotions in order to meet one's immediate goals and environmental demands. However, because emotions serve an important communicative function, their habitual suppression disrupts the flow of social exchanges and, thus, incurs significant interpersonal costs. Evidence is accruing that the disruption in social interactions, linked to habitual expressive suppression use, stems not only from intrapersonal, but also from interpersonal causes, since the suppressors' restricted affective displays reportedly inhibit their interlocutors' emotionally expressive behaviors. However, expressive suppression use is not known to lead to clinically significant social impairments. One explanation may be that over the lifespan, individuals who habitually suppress their emotions come to compensate for their interlocutors' restrained expressive behaviors by developing an increased sensitivity to nonverbal affective cues. To probe this issue, the present study used functional magnetic resonance imaging (fMRI) to scan healthy older women while they viewed silent videos of a male social target displaying nonverbal emotional behavior, together with a brief verbal description of the accompanying context, and then judged the target's affect. As predicted, perceivers who reported greater habitual use of expressive suppression showed increased neural processing of nonverbal affective cues. This effect appeared to be coordinated in a top-down manner via cognitive control. Greater neural processing of nonverbal cues among perceivers who habitually suppress their emotions was linked to increased ventral striatum activity, suggestive of increased reward value/personal relevance ascribed to emotionally expressive nonverbal behaviors. These findings thus provide neural evidence broadly consistent with the hypothesized link between habitual use of expressive suppression and compensatory development of increased responsiveness to

Single high-concentration capsaicin application prevents c-Fos expression in spinothalamic and postsynaptic dorsal column neurons after surgical incision

Czech Academy of Sciences Publication Activity Database

Uchytilová, Eva; Špicarová, Diana; Paleček, Jiří

2015-01-01

Roč. 19, č. 10 (2015), s. 1496-1505 ISSN 1090-3801 R&D Projects: GA ČR(CZ) GBP304/12/G069; GA MŠk(CZ) LH12058; GA ČR(CZ) GPP303/12/P510; GA MŠk(CZ) EE2.3.30.0025; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:67985823 Keywords : pain * spinothalamic * capsaicin * TRPV1 * PSDC Subject RIV: FH - Neurology Impact factor: 2.900, year: 2015

Cortical evoked potentials to an auditory illusion: binaural beats.

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Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

2009-08-01

To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

Brain correlates of music-evoked emotions.

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Koelsch, Stefan

2014-03-01

Music is a universal feature of human societies, partly owing to its power to evoke strong emotions and influence moods. During the past decade, the investigation of the neural correlates of music-evoked emotions has been invaluable for the understanding of human emotion. Functional neuroimaging studies on music and emotion show that music can modulate activity in brain structures that are known to be crucially involved in emotion, such as the amygdala, nucleus accumbens, hypothalamus, hippocampus, insula, cingulate cortex and orbitofrontal cortex. The potential of music to modulate activity in these structures has important implications for the use of music in the treatment of psychiatric and neurological disorders.

Two-day fasting evokes stress, but does not affect mood, brain activity, cognitive, psychomotor, and motor performance in overweight women.

Science.gov (United States)

Solianik, Rima; Sujeta, Artūras

2018-02-15

The physiological, cognitive state, and motor behavior changes that occur during acute fasting are not completely understood. Thus, the aim of this study was to estimate the effect of 2-day total fasting on evoked stress, mood, brain activity, and cognitive, psychomotor, and motor function in overweight women. Eleven overweight women (body mass index above 25kg/m 2 ) aged 20-30 years were tested under two conditions allocated randomly: 2-day zero-calorie diet with water provided ad libitum and 2-day usual diet. One week before the experiment, aerobic fitness was evaluated. Subjective stress ratings in relation to the diet, autonomic function, prefrontal cortex activity, cognitive performance, psychomotor coordination, and grip strength were evaluated before and after each diet. The study demonstrated that fasting decreased log-transformed high-frequency (HF) power, without affecting heart rate. The relative maximum oxygen uptake was negatively correlated with subjective stress rating and changes in log-transformed HF. Fasting did not affect mood, brain activity, and cognitive, motor, and psychomotor performance. Thus, 2-day total fasting evoked moderate stress with a shift of the autonomic nervous system balance toward sympathetic activity in overweight women. Better aerobic endurance is likely to facilitate the capacity for dealing with acute fasting. Regardless of the evoked stress, cognitive state and motor behavior remained intact. Copyright © 2017 Elsevier B.V. All rights reserved.

An inventory and update of jealousy-evoking partner behaviours in modern society.

NARCIS (Netherlands)

Dijkstra, Pieternel; Barelds, Dick P. H.; Groothof, Hinke A. K.

2010-01-01

The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's

1-methylmalate from camu-camu (Myrciaria dubia) suppressed D-galactosamine-induced liver injury in rats.

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Akachi, Toshiyuki; Shiina, Yasuyuki; Kawaguchi, Takumi; Kawagishi, Hirokazu; Morita, Tatsuya; Sugiyama, Kimio

2010-01-01

To evaluate the protective effects of fruit juices against D-galactosamine (GalN)-induced liver injury, lyophilized fruit juices (total 12 kinds) were fed to rats for 7 d, and then we evoked liver injury by injecting GalN. The juice of camu-camu (Myrciaria dubia) significantly suppressed GalN-induced liver injury when the magnitude of liver injury was assessed by plasma alanine aminotransferase and aspartate aminotransferase activities, although some other juices (acerola, dragon fruit, shekwasha, and star fruit) also tended to have suppressive effects. An active compound was isolated from camu-camu juice by solvent fractionation and silica gel column chromatography. The structure was determined to be 1-methylmalate. On the other hand, malate, 1,4-dimethylmalate, citrate, and tartrate had no significant effect on GalN-induced liver injury. It is suggested that 1-methylmalate might be a rather specific compound among organic acids and their derivatives in fruit juices in suppressing GalN-induced liver injury.

Phencyclidine administration during neurodevelopment alters network activity in prefrontal cortex and hippocampus in adult rats.

Science.gov (United States)

Kjaerby, Celia; Hovelsø, Nanna; Dalby, Nils Ole; Sotty, Florence

2017-08-01

Symptoms of schizophrenia have been linked to insults during neurodevelopment such as NMDA receptor (NMDAR) antagonist exposure. In animal models, this leads to schizophrenia-like behavioral symptoms as well as molecular and functional changes within hippocampal and prefrontal regions. The aim of this study was to determine how administration of the NMDAR antagonist phencyclidine (PCP) during neurodevelopment affects functional network activity within the hippocampus and medial prefrontal cortex (mPFC). We recorded field potentials in vivo after electrical brain stem stimulation and observed a suppression of evoked theta power in ventral hippocampus, while evoked gamma power in mPFC was enhanced in rats administered with PCP neonatally. In addition, increased gamma synchrony elicited by acute administration of the NMDAR antagonist MK-801 was exaggerated in neonatal PCP animals. These data suggest that NMDAR antagonist exposure during brain development alters functional networks within hippocampus and mPFC possibly contributing to the reported behavioral symptoms of this animal model of schizophrenia. NEW & NOTEWORTHY We show that insults with a NMDA receptor antagonist during neurodevelopment lead to suppressed evoked theta oscillations in ventral hippocampus in adult rats, while evoked gamma oscillations are enhanced and hypersensitive to an acute challenge with a NMDA receptor antagonist in prefrontal cortex. These observations reveal the significance of neurodevelopmental disturbances in the evolvement of schizophrenia-like symptoms and contribute to the understanding of the functional deficits underlying aberrant behavior in this disease. Copyright © 2017 the American Physiological Society.

Music-evoked emotions: principles, brain correlates, and implications for therapy.

Science.gov (United States)

Koelsch, Stefan

2015-03-01

This paper describes principles underlying the evocation of emotion with music: evaluation, resonance, memory, expectancy/tension, imagination, understanding, and social functions. Each of these principles includes several subprinciples, and the framework on music-evoked emotions emerging from these principles and subprinciples is supposed to provide a starting point for a systematic, coherent, and comprehensive theory on music-evoked emotions that considers both reception and production of music, as well as the relevance of emotion-evoking principles for music therapy. © 2015 New York Academy of Sciences.

Effect of Capsaicin Cream on Chronic Low Back Pain in Patients With Inter-Vertebral Disc Herniation

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Fayazi

2015-07-01

Full Text Available Background Low back pain is one of the most common debilitating disorders worldwide and the third cause of visiting a physician. One of the most common causes of low back pain is spinal disc herniation. Still there is no general agreement on the most effective treatment for it. Objectives This study aimed to determine the effect of Capsaicin cream on low back pain in patients with inter-vertebral disc herniation in Ahvaz. Patients and Methods This was a double blind clinical trial in which 43 patients with chronic low back pain, according to characteristics of the subjects, were randomly divided into two groups of treatment (n = 23 and control (n = 20. Data collection instruments included demographic specifications and visual analogue scale (VAS questionnaire completed on arrival and at the first, second and third weeks after intervention. The treatment and placebo groups used the ointment for three weeks and three times a day as a thin layer on the painful position. Data entered SPSS (version 18 and analyzed using the analytical descriptive statistics. Results There was a significant difference in the average pain intensity between the groups of study pre-and post-intervention (P = 0.0001 and the rate of using analgesics in the treatment group significantly decreased (P = 0.008. Also patients’ satisfaction was significantly different between the two groups using the ointment (P = 0.0001. Conclusions Capsaicin cream has beneficial effects on pain relieving and reducing analgesic use in patients with inter-vertebral disc herniation. Therefore, the ointment can be recommended in the treatment of low back pain caused by inter-vertebral disc herniation.

Sputtering effect of low-energy ions on biological target: The analysis of sputtering product of urea and capsaicin

International Nuclear Information System (INIS)

Zhang, Lili; Xu, Xue; Wu, Yuejin

2013-01-01

Sputtering is a process whereby atoms are ejected from a solid target material due to bombardment of the target by energetic particles. Recent years, ion implantation was successfully applied to biological research based on the fragments sputtering and form open paths in cell structure caused by ion sputtering. In this study, we focused on urea and chilli pepper pericarp samples implanted with N + and Ar + ions. To investigate the sputtering effect, we designed a collecting unit containing a disk sample and a glass pipe. The urea content and capsaicin content recovered from glass pipes were adopted to represent the sputtering product. The result of urea showed that the sputtering effect is positively correlated with the ion energy and dose, also affected by the ion type. The result of capsaicin was different from that of urea at 20 keV and possibly due to biological complex composition and structure. Therefore the sputtering yield depended on both the parameters of incident ions and the state of target materials. The sputtering yield of urea was also simulated by computational method achieved through the TRIM program. The trajectories of primary and recoiled atoms were calculated on the basis of the binary collision approximation using Monte Carlo method. The experimental results were much higher than the calculated results. The possible explanation is that in the physical model the target were assumed as a disordered lattice and independent atoms, which is much less complicated than that of the biological models

The Comparison Study of Contralateral Transient Evoked Otoacoustic Emission (TEOAE Suppression in Normal Hearing Subjects and Multiple Sclerosis Patients

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KH Mohamadkhani

2007-01-01

Full Text Available ABSTRACT: Introduction & Objective: A common auditory complaint of multiple sclerosis patients, is misunderstanding speech in the presence of background noise. Evidence from animal and human studies has suggested that the medial olivocochlear bundle may play an important role in hearing noise. The medial olivocochlear bundle function can be evaluated by the suppression effect of transient otoacoustic emission in response to contralateral acoustic stimulation. The present study was conducted to investigate the suppression effect of transient otoacoustic emission in multiple sclerosis patients. Materials & Methods: This analytical case-control study was conducted on 34 multiple sclerosis patients (24 female, 10 male, aged 20-50 years and 34 controls matched for age and gender in Faculty of Rehabilitation, Tehran University of Medical Sciences in 2006. All cases were selected in simple random manner. The suppression effect of transient otoacoustic emission was evaluated by comparing the transient otoacoustic emission levels with and without contralateral acoustic stimulation. Data were analyzed using SPSS software and independent T- test. Results:There was no significant difference in transient otoacoustic emission levels of two groups, but a significantly reduced suppression effect of transient otoacoustic emission was found in multiple sclerosis patients, in compare with the controls. Conclusion: Outer hair cells activity in multiple sclerosis patients was normal but these patients presented low activity of the medial olivocochlear bundle system which could affect their ability to hear in the presence of background noise.

Vibration and muscle contraction affect somatosensory evoked potentials

OpenAIRE

Cohen, LG; Starr, A

1985-01-01

We recorded potentials evoked by specific somatosensory stimuli over peripheral nerve, spinal cord, and cerebral cortex. Vibration attenuated spinal and cerebral potentials evoked by mixed nerve and muscle spindle stimulation; in one subject that was tested, there was no effect on cutaneous input. Presynaptic inhibition of Ia input in the spinal cord and muscle spindle receptor occupancy are probably the responsible mechanisms. In contrast, muscle contraction attenuated cerebral potentials to...

Dissociating the influence of response selection and task anticipation on corticospinal suppression during response preparation.

Science.gov (United States)

Duque, Julie; Labruna, Ludovica; Cazares, Christian; Ivry, Richard B

2014-12-01

Motor behavior requires selecting between potential actions. The role of inhibition in response selection has frequently been examined in tasks in which participants are engaged in some advance preparation prior to the presentation of an imperative signal. Under such conditions, inhibition could be related to processes associated with response selection, or to more general inhibitory processes that are engaged in high states of anticipation. In Experiment 1, we manipulated the degree of anticipatory preparation. Participants performed a choice reaction time task that required choosing between a movement of the left or right index finger, and used transcranial magnetic stimulation (TMS) to elicit motor evoked potentials (MEPs) in the left hand agonist. In high anticipation blocks, a non-informative cue (e.g., fixation marker) preceded the imperative; in low anticipation blocks, there was no cue and participants were required to divide their attention between two tasks to further reduce anticipation. MEPs were substantially reduced before the imperative signal in high anticipation blocks. In contrast, in low anticipation blocks, MEPs remained unchanged before the imperative signal but showed a marked suppression right after the onset of the imperative. This effect occurred regardless of whether the imperative had signalled a left or right hand response. After this initial inhibition, left MEPs increased when the left hand was selected and remained suppressed when the right hand was selected. We obtained similar results in Experiment 2 except that the persistent left MEP suppression when the left hand was not selected was attenuated when the alternative response involved a non-homologous effector (right foot). These results indicate that, even in the absence of an anticipatory period, inhibitory mechanisms are engaged during response selection, possibly to prevent the occurrence of premature and inappropriate responses during a competitive selection process. Copyright

Dissociating the Influence of Response Selection and Task Anticipation on Corticospinal Suppression During Response Preparation

Science.gov (United States)

Duque, Julie; Labruna, Ludovica; Cazares, Christian; Ivry, Richard B.

2014-01-01

Motor behavior requires selecting between potential actions. The role of inhibition in response selection has frequently been examined in tasks in which participants are engaged in some advance preparation prior to the presentation of an imperative signal. Under such conditions, inhibition could be related to processes associated with response selection, or to more general inhibitory processes that are engaged in high states of anticipation. In Experiment 1, we manipulated the degree of anticipatory preparation. Participants performed a choice reaction time task that required choosing between a movement of the left or right index finger, and used transcranial magnetic stimulation (TMS) to elicit motor evoked potentials (MEPs) in the left hand agonist. In high anticipation blocks, a non-informative cue (e.g., fixation marker) preceded the imperative; in low anticipation blocks, there was no cue and participants were required to divide their attention between two tasks to further reduce anticipation. MEPs were substantially reduced before the imperative signal in high anticipation blocks. In contrast, in low anticipation blocks, MEPs remained unchanged before the imperative signal but showed a marked suppression right after the onset of the imperative. This effect occurred regardless of whether the imperative had signaled a left or right hand response. After this initial inhibition, left MEPs increased when the left hand was selected and remained suppressed when the right hand was selected. We obtained similar results in Experiment 2 except that the persistent left MEP suppression when the left hand was not selected was attenuated when the alternative response involved a non-homologous effector (right foot). These results indicate that, even in the absence of an anticipatory period, inhibitory mechanisms are engaged during response selection, possibly to prevent the occurrence of premature and inappropriate responses during a competitive selection process. PMID

The involuntary nature of music-evoked autobiographical memories in Alzheimer's disease.

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El Haj, Mohamad; Fasotti, Luciano; Allain, Philippe

2012-03-01

The main objective of this paper was to examine the involuntary nature of music-evoked autobiographical memories. For this purpose, young adults, older adults, and patients with a clinical diagnosis of probable Alzheimer's disease (AD) were asked to remember autobiographical events in two conditions: after being exposed to their own chosen music, and in silence. Compared to memories evoked in silence, memories evoked in the "Music" condition were found to be more specific, accompanied by more emotional content and impact on mood, and retrieved faster. In addition, these memories engaged less executive processes. Thus, with all these characteristics and the fact that they are activated by a perceptual cue (i.e., music), music-evoked autobiographic memories have all the features to be considered as involuntary memories. Our paper reveals several characteristics of music-evoked autobiographical memories in AD patients and offers a theoretical background for this phenomenon. Copyright © 2012 Elsevier Inc. All rights reserved.

Awake intranasal insulin delivery modifies protein complexes and alters memory, anxiety, and olfactory behaviors.

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Marks, David R; Tucker, Kristal; Cavallin, Melissa A; Mast, Thomas G; Fadool, Debra A

2009-05-20

The role of insulin pathways in olfaction is of significant interest with the widespread pathology of diabetes mellitus and its associated metabolic and neuronal comorbidities. The insulin receptor (IR) kinase is expressed at high levels in the olfactory bulb, in which it suppresses a dominant Shaker ion channel (Kv1.3) via tyrosine phosphorylation of critical N- and C-terminal residues. We optimized a 7 d intranasal insulin delivery (IND) in awake mice to ascertain the biochemical and behavioral effects of insulin to this brain region, given that nasal sprays for insulin have been marketed notwithstanding our knowledge of the role of Kv1.3 in olfaction, metabolism, and axon targeting. IND evoked robust phosphorylation of Kv1.3, as well as increased channel protein-protein interactions with IR and postsynaptic density 95. IND-treated mice had an increased short- and long-term object memory recognition, increased anxiolytic behavior, and an increased odor discrimination using an odor habituation protocol but only moderate change in odor threshold using a two-choice paradigm. Unlike Kv1.3 gene-targeted deletion that alters metabolism, adiposity, and axonal targeting to defined olfactory glomeruli, suppression of Kv1.3 via IND had no effect on body weight nor the size and number of M72 glomeruli or the route of its sensory axon projections. There was no evidence of altered expression of sensory neurons in the epithelium. In mice made prediabetic via diet-induced obesity, IND was no longer effective in increasing long-term object memory recognition nor increasing anxiolytic behavior, suggesting state dependency or a degree of insulin resistance related to these behaviors.

Olfactory LOVER: Behavioral and neural correlates of autobiographical odor memory

Directory of Open Access Journals (Sweden)

Maria eLarsson

2014-04-01

Full Text Available Autobiographical memories (AMs are personally experienced events that may be localized in time and space. In the present work we present an overview targeting memories evoked by the sense of smell. Overall, research indicates that autobiographical odor memory is different than memories evoked by our primary sensory systems; sight and hearing. Here, observed differences from a behavioral and neuroanatomical perspective are presented. The key features of an olfactory evoked AM may be referred to the LOVER acronym - Limbic, Old, Vivid, Emotional, and Rare.

Intrinsic resting-state activity predicts working memory brain activation and behavioral performance.

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Zou, Qihong; Ross, Thomas J; Gu, Hong; Geng, Xiujuan; Zuo, Xi-Nian; Hong, L Elliot; Gao, Jia-Hong; Stein, Elliot A; Zang, Yu-Feng; Yang, Yihong

2013-12-01

Although resting-state brain activity has been demonstrated to correspond with task-evoked brain activation, the relationship between intrinsic and evoked brain activity has not been fully characterized. For example, it is unclear whether intrinsic activity can also predict task-evoked deactivation and whether the rest-task relationship is dependent on task load. In this study, we addressed these issues on 40 healthy control subjects using resting-state and task-driven [N-back working memory (WM) task] functional magnetic resonance imaging data collected in the same session. Using amplitude of low-frequency fluctuation (ALFF) as an index of intrinsic resting-state activity, we found that ALFF in the middle frontal gyrus and inferior/superior parietal lobules was positively correlated with WM task-evoked activation, while ALFF in the medial prefrontal cortex, posterior cingulate cortex, superior frontal gyrus, superior temporal gyrus, and fusiform gyrus was negatively correlated with WM task-evoked deactivation. Further, the relationship between the intrinsic resting-state activity and task-evoked activation in lateral/superior frontal gyri, inferior/superior parietal lobules, superior temporal gyrus, and midline regions was stronger at higher WM task loads. In addition, both resting-state activity and the task-evoked activation in the superior parietal lobule/precuneus were significantly correlated with the WM task behavioral performance, explaining similar portions of intersubject performance variance. Together, these findings suggest that intrinsic resting-state activity facilitates or is permissive of specific brain circuit engagement to perform a cognitive task, and that resting activity can predict subsequent task-evoked brain responses and behavioral performance. Copyright © 2012 Wiley Periodicals, Inc.

Inhibitory effect of dietary capsaicin on liver fibrosis in mice.

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Bitencourt, Shanna; Stradiot, Leslie; Verhulst, Stefaan; Thoen, Lien; Mannaerts, Inge; van Grunsven, Leo A

2015-06-01

Virtually all chronic liver injuries result in the activation of hepatic stellate cells (HSCs). In their activated state, these cells are the main collagen-producing cells implicated in liver fibrosis. Capsaicin (CPS), the active compound of chili peppers, can modulate the activation and migration of HSCs in vitro. Here, we evaluated the potential protective and prophylactic effects of CPS related to cholestatic and hepatotoxic-induced liver fibrosis and its possible underlying mechanism of action. Male Balb/c mice received dietary CPS after 3 days of bile duct ligation (BDL) or before and during carbon tetrachloride (CCl4 ) injections. Mice receiving dietary CPS after BDL had a significant improvement of liver fibrosis accompanied by a decrease in collagen deposition and downregulation of activation markers in isolated HSCs. In the CCl4 model, dietary CPS inhibited the upregulation of profibrogenic markers. However, CPS could not attenuate the CCl4 -induced fibrosis when it was already established. Furthermore, in vitro CPS treatment inhibited the autophagic process during HSC activation. Dietary CPS has potential benefits in the therapy of cholestatic liver fibrosis and in the prophylaxis of hepatotoxic-induced liver injury. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

International Nuclear Information System (INIS)

Miletich, R.S.

1985-01-01

The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and 3 H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by α-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period, phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S 2 episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. 3 H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system

Gender differences in binaural speech-evoked auditory brainstem response: are they clinically significant?

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Jalaei, Bahram; Azmi, Mohd Hafiz Afifi Mohd; Zakaria, Mohd Normani

2018-05-17

Binaurally evoked auditory evoked potentials have good diagnostic values when testing subjects with central auditory deficits. The literature on speech-evoked auditory brainstem response evoked by binaural stimulation is in fact limited. Gender disparities in speech-evoked auditory brainstem response results have been consistently noted but the magnitude of gender difference has not been reported. The present study aimed to compare the magnitude of gender difference in speech-evoked auditory brainstem response results between monaural and binaural stimulations. A total of 34 healthy Asian adults aged 19-30 years participated in this comparative study. Eighteen of them were females (mean age=23.6±2.3 years) and the remaining sixteen were males (mean age=22.0±2.3 years). For each subject, speech-evoked auditory brainstem response was recorded with the synthesized syllable /da/ presented monaurally and binaurally. While latencies were not affected (p>0.05), the binaural stimulation produced statistically higher speech-evoked auditory brainstem response amplitudes than the monaural stimulation (p0.80), substantive gender differences were noted in most of speech-evoked auditory brainstem response peaks for both stimulation modes. The magnitude of gender difference between the two stimulation modes revealed some distinct patterns. Based on these clinically significant results, gender-specific normative data are highly recommended when using speech-evoked auditory brainstem response for clinical and future applications. The preliminary normative data provided in the present study can serve as the reference for future studies on this test among Asian adults. Copyright © 2018 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Suppressive mechanisms in visual motion processing: From perception to intelligence.

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Tadin, Duje

2015-10-01

Perception operates on an immense amount of incoming information that greatly exceeds the brain's processing capacity. Because of this fundamental limitation, the ability to suppress irrelevant information is a key determinant of perceptual efficiency. Here, I will review a series of studies investigating suppressive mechanisms in visual motion processing, namely perceptual suppression of large, background-like motions. These spatial suppression mechanisms are adaptive, operating only when sensory inputs are sufficiently robust to guarantee visibility. Converging correlational and causal evidence links these behavioral results with inhibitory center-surround mechanisms, namely those in cortical area MT. Spatial suppression is abnormally weak in several special populations, including the elderly and individuals with schizophrenia-a deficit that is evidenced by better-than-normal direction discriminations of large moving stimuli. Theoretical work shows that this abnormal weakening of spatial suppression should result in motion segregation deficits, but direct behavioral support of this hypothesis is lacking. Finally, I will argue that the ability to suppress information is a fundamental neural process that applies not only to perception but also to cognition in general. Supporting this argument, I will discuss recent research that shows individual differences in spatial suppression of motion signals strongly predict individual variations in IQ scores. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Presence of pups suppresses hunger-induced feeding in virgin adult mice of both sexes.

Science.gov (United States)

Han, Ying; Li, Xing-Yu; Wang, Shao-Ran; Wei, Yi-Chao; Xu, Xiao-Hong

2017-10-24

Despite recent progress on neural pathways underlying individual behaviors, how an animal balances and prioritizes behavioral outputs remains poorly understood. While studying the relationship between hunger-induced feeding and pup-induced maternal behaviors in virgin female mice, we made the unexpected discovery that presence of pups strongly delayed and decreased food consumption. Strikingly, presence of pups also suppressed feeding induced by optogenetic activation of Agrp neurons. Such a suppressive effect inversely correlated with the extents of maternal behaviors, but did not rely on the display of these behaviors, and was also present in virgin males. Furthermore, chemogenetic activation of Vglut2+ neurons in the medial preoptic area (mPOA), a region critical for maternal behaviors and motivation, was sufficient to suppress hunger-induced feeding. However, muscimol inhibition of the mPOA, while disrupting maternal behaviors, did not prevent pup suppression of feeding, indicating that neural pathways in other brain regions may also mediate such an effect. Together, these results provide novel insights into neural coordination of pup care and feeding in mice and organizations of animal behaviors in general. Copyright © 2017. Published by Elsevier Ltd.

RPF101, a new capsaicin-like analogue, disrupts the microtubule network accompanied by arrest in the G2/M phase, inducing apoptosis and mitotic catastrophe in the MCF-7 breast cancer cells

International Nuclear Information System (INIS)

Sá-Júnior, Paulo Luiz de; Pasqualoto, Kerly Fernanda Mesquita; Ferreira, Adilson Kleber; Tavares, Maurício Temotheo; Damião, Mariana Celestina Frojuello Costa Bernstorff; Azevedo, Ricardo Alexandre de; Câmara, Diana Aparecida Dias; Pereira, Alexandre; Madeiro de Souza, Dener; Parise Filho, Roberto

2013-01-01

Breast cancer is the world's leading cause of death among women. This situation imposes an urgent development of more selective and less toxic agents. The use of natural molecular fingerprints as sources for new bioactive chemical entities has proven to be a quite promising and efficient method. Capsaicin, which is the primary pungent compound in red peppers, was reported to selectively inhibit the growth of a variety tumor cell lines. Here, we report for the first time a novel synthetic capsaicin-like analogue, RPF101, which presents a high antitumor activity on MCF-7 cell line, inducing arrest of the cell cycle at the G2/M phase through a disruption of the microtubule network. Furthermore, it causes cellular morphologic changes characteristic of apoptosis and a decrease of Δψm. Molecular modeling studies corroborated the biological findings and suggested that RPF101, besides being a more reactive molecule towards its target, may also present a better pharmacokinetic profile than capsaicin. All these findings support the fact that RPF101 is a promising anticancer agent. -- Highlights: ► We report for the first time that RPF101 possesses anticancer properties. ► RPF101 induces apoptosis of human breast cancer cells. ► RPF 101 decreases mitochondrial potential and induces DNA fragmentation.

Increase in cortical pyramidal cell excitability accompanies depression-like behavior in mice: a transcranial magnetic stimulation study.

Science.gov (United States)

Sun, Peng; Wang, Furong; Wang, Li; Zhang, Yu; Yamamoto, Ryo; Sugai, Tokio; Zhang, Qing; Wang, Zhengda; Kato, Nobuo

2011-11-09

Clinical evidence suggests that cortical excitability is increased in depressives. We investigated its cellular basis in a mouse model of depression. In a modified version of forced swimming (FS), mice were initially forced to swim for 5 consecutive days and then were treated daily with repetitive transcranial magnetic stimulation (rTMS) or sham treatment for the following 4 weeks without swimming. On day 2 through day 5, the mice manifested depression-like behaviors. The next and last FS was performed 4 weeks later, which revealed a 4 week maintenance of depression-like behavior in the sham mice. In slices from the sham controls, excitability in cingulate cortex pyramidal cells was elevated in terms of membrane potential and frequencies of spikes evoked by current injection. Depolarized resting potential was shown to depend on suppression of large conductance calcium-activated potassium (BK) channels. This BK channel suppression was confirmed by measuring spike width, which depends on BK channels. Chronic rTMS treatment during the 4 week period significantly reduced the depression-like behavior. In slices obtained from the rTMS mice, normal excitability and BK channel activity were recovered. Expression of a scaffold protein Homer1a was reduced by the FS and reversed by rTMS in the cingulate cortex. Similar recovery in the same behavioral, electrophysiological, and biochemical features was observed after chronic imipramine treatment. The present study demonstrated that manifestation and disappearance of depression-like behavior are in parallel with increase and decrease in cortical neuronal excitability in mice and suggested that regulation of BK channels by Homer1a is involved in this parallelism.

The functional neuroanatomy of odor evoked autobiographical memories cued by odors and words.

Science.gov (United States)

Arshamian, Artin; Iannilli, Emilia; Gerber, Johannes C; Willander, Johan; Persson, Jonas; Seo, Han-Seok; Hummel, Thomas; Larsson, Maria

2013-01-01

Behavioral evidence indicates that odor evoked autobiographical memories (OEAMs) are older, more emotional, less thought of and induce stronger time traveling characteristics than autobiographical memories (AMs) evoked by other modalities. The main aim of this study was to explore the neural correlates of AMs evoked by odors as a function of retrieval cue. Participants were screened for specific OEAMs and later presented with the odor cue and its verbal referent in an fMRI paradigm. Because the same OEAM was retrieved across both cue formats (odor and word), potential cue dependent brain activations were investigated. The overall results showed that odor and word cued OEAMs activated regions typically associated with recollection of autobiographical information. Although no odors were presented, a verbal cuing of the OEAMs activated areas associated with olfactory perception (e.g., piriform cortex). However, relative to word cuing, an odor cuing of OEAMs resulted in more activity in MTL regions such as the parahippocampus, and areas involved in visual vividness (e.g., occipital gyrus and precuneus). Furthermore, odor cues activated areas related to emotional processing, such as limbic and tempopolar regions significantly more. In contrast, word cues relative to odor cues recruited a more widespread and bilateral prefrontal activity. Hippocampus activity did not vary as function of the remoteness of the memory, but recollection of OEAMs from the 1(st) vs the 2(nd) decade of life showed specific activation in the right OFC, whereas the 2(nd) reflected a higher activation in the left inferior frontal gyrus. Copyright © 2012 Elsevier Ltd. All rights reserved.

Opioid modulation of facial itch- and pain-related responses and grooming behavior in rats.

Science.gov (United States)

Spradley, Jessica M; Davoodi, Auva; Carstens, Mirela Iodi; Carstens, Earl

2012-09-01

Intradermal facial injections of pruritogens or algogens elicit distinct behavioral hindlimb scratch or forelimb wiping responses in rodents. We systematically investigated the parameters and opioid modulation of these evoked behaviors and spontaneous facial grooming in rats. Serotonin (5-HT) elicited hindlimb scratch bouts with few wipes. Scratching was attenuated by the µ-opiate antagonist naltrexone but not morphine. In contrast, cheek injection of mustard oil (allyl-isothiocyanate (AITC)) elicited ipsilateral forelimb wipes but little hindlimb scratching. AITC-evoked wiping was significantly attenuated by morphine but not naltrexone. Spontaneous facial grooming by the forepaws was attenuated by naltrexone, whereas morphine did not affect grooming behavior before or after cheek injections of 5-HT or AITC. These data validate that the rodent "cheek" model discriminates between itch- and pain-related behaviors. Naltrexone sensitivity of facial grooming and 5-HT-evoked scratch-ing suggests a common functionality. Forelimb wipes may represent a nocifensive response akin to rubbing an injury to relieve pain.

Music-Evoked Emotions—Current Studies

Science.gov (United States)

Schaefer, Hans-Eckhardt

2017-01-01

The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields. PMID:29225563

Mothers' responses to children's negative emotions and child emotion regulation: the moderating role of vagal suppression.

Science.gov (United States)

Perry, Nicole B; Calkins, Susan D; Nelson, Jackie A; Leerkes, Esther M; Marcovitch, Stuart

2012-07-01

The current study examined the moderating effect of children's cardiac vagal suppression on the association between maternal socialization of negative emotions (supportive and nonsupportive responses) and children's emotion regulation behaviors. One hundred and ninety-seven 4-year-olds and their mothers participated. Mothers reported on their reactions to children's negative emotions and children's regulatory behaviors. Observed distraction, an adaptive self-regulatory strategy, and vagal suppression were assessed during a laboratory task designed to elicit frustration. Results indicated that children's vagal suppression moderated the association between mothers' nonsupportive emotion socialization and children's emotion regulation behaviors such that nonsupportive reactions to negative emotions predicted lower observed distraction and lower reported emotion regulation behaviors when children displayed lower levels of vagal suppression. No interaction was found between supportive maternal emotion socialization and vagal suppression for children's emotion regulation behaviors. Results suggest physiological regulation may serve as a buffer against nonsupportive emotion socialization. Copyright © 2011 Wiley Periodicals, Inc.

Stimulator with arbitrary waveform for auditory evoked potentials

International Nuclear Information System (INIS)

Martins, H R; Romao, M; Placido, D; Provenzano, F; Tierra-Criollo, C J

2007-01-01

The technological improvement helps many medical areas. The audiometric exams involving the auditory evoked potentials can make better diagnoses of auditory disorders. This paper proposes the development of a stimulator based on Digital Signal Processor. This stimulator is the first step of an auditory evoked potential system based on the ADSP-BF533 EZ KIT LITE (Analog Devices Company - USA). The stimulator can generate arbitrary waveform like Sine Waves, Modulated Amplitude, Pulses, Bursts and Pips. The waveforms are generated through a graphical interface programmed in C++ in which the user can define the parameters of the waveform. Furthermore, the user can set the exam parameters as number of stimuli, time with stimulation (Time ON) and time without stimulus (Time OFF). In future works will be implemented another parts of the system that includes the acquirement of electroencephalogram and signal processing to estimate and analyze the evoked potential

Stimulator with arbitrary waveform for auditory evoked potentials

Energy Technology Data Exchange (ETDEWEB)

Martins, H R; Romao, M; Placido, D; Provenzano, F; Tierra-Criollo, C J [Universidade Federal de Minas Gerais (UFMG), Departamento de Engenharia Eletrica (DEE), Nucleo de Estudos e Pesquisa em Engenharia Biomedica NEPEB, Av. Ant. Carlos, 6627, sala 2206, Pampulha, Belo Horizonte, MG, 31.270-901 (Brazil)

2007-11-15

The technological improvement helps many medical areas. The audiometric exams involving the auditory evoked potentials can make better diagnoses of auditory disorders. This paper proposes the development of a stimulator based on Digital Signal Processor. This stimulator is the first step of an auditory evoked potential system based on the ADSP-BF533 EZ KIT LITE (Analog Devices Company - USA). The stimulator can generate arbitrary waveform like Sine Waves, Modulated Amplitude, Pulses, Bursts and Pips. The waveforms are generated through a graphical interface programmed in C++ in which the user can define the parameters of the waveform. Furthermore, the user can set the exam parameters as number of stimuli, time with stimulation (Time ON) and time without stimulus (Time OFF). In future works will be implemented another parts of the system that includes the acquirement of electroencephalogram and signal processing to estimate and analyze the evoked potential.

Evoking prescribed spike times in stochastic neurons

Science.gov (United States)

Doose, Jens; Lindner, Benjamin

2017-09-01

Single cell stimulation in vivo is a powerful tool to investigate the properties of single neurons and their functionality in neural networks. We present a method to determine a cell-specific stimulus that reliably evokes a prescribed spike train with high temporal precision of action potentials. We test the performance of this stimulus in simulations for two different stochastic neuron models. For a broad range of parameters and a neuron firing with intermediate firing rates (20-40 Hz) the reliability in evoking the prescribed spike train is close to its theoretical maximum that is mainly determined by the level of intrinsic noise.

Visual evoked potentials in patients after methanol poisoning.

Science.gov (United States)

Urban, Pavel; Zakharov, Sergey; Diblík, Pavel; Pelclová, Daniela; Ridzoň, Petr

2016-01-01

We report the results of the visual evoked potentials (VEP) examination in patients after severe poisoning by methanol. The group of 47 patients (38 males and 9 females) was assembled out of persons who survived an outbreak of poisoning by the methanol adulterated alcohol beverages, which happened in the Czech Republic in 2012-2013. The visual evoked potentials examination was performed using monocular checkerboard pattern-reversal stimulation. Two criteria of abnormality were chosen: missing evoked response, and wave P1 latency > 117 ms. Non-parametric statistical methods (median, range, and the median test) were used to analyze factors influencing the VEP abnormality. The visual evoked potential was abnormal in 20 patients (43%), 5 of them had normal visual acuity on the Snellen chart. The VEP abnormality did not correlate significantly with initial serum concentrations of methanol, formic acid or lactate; however, it showed statistically significant inverse relation to the initial serum pH: the subgroup with the abnormal VEP had significantly lower median pH in comparison with the subgroup with the normal VEP (7.16 vs. 7.34, p = 0.04). The abnormality was not related to chronic alcohol abuse. The visual evoked potentials examination appeared sensitive enough to detected even subclinical impairment of the optic system. Metabolic acidosis is likely to be the key factor related to the development of visual damage induced by methanol. The examination performed with a delay of 1-9 months after the poisoning documented the situation relatively early after the event. It is considered as a baseline for the planned long-term follow-up of the patients, which will make it possible to assess the dynamics of the observed changes, their reversibility, and the occurrence of potential late sequelae. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Moral and Sexual Disgust Suppress Sexual Risk Behaviors among Men Who Have Sex with Men in China

Science.gov (United States)

Zhang, Jing; Zheng, Lijun; Zheng, Yong

2017-01-01

Increasingly more men who have sex with men (MSM) are engaging in sexual risk taking in China in recent years. Given the high rates of HIV infection among MSM in China, it is urgent that we understand the factors that influence MSM's practice of sexual risk taking. Disgust sensitivity, which elicits a behavioral avoidance response, has the potential to influence risky sexual behavior. The present study examined the relationship between disgust sensitivity and sexual risk behavior among MSM in China. Men (n = 584) who reported having anal intercourse in the previous 6 months were recruited from the Internet. Two indicators of sexual risk behaviors were measured: condom use and the number of sex partners. The results indicated that moral disgust was positively associated with condom use, with MSM who had higher moral disgust being more likely to use condoms than others did. Sexual disgust was positively associated with the number of sex partners, with MSM who had higher sexual disgust having fewer male sex partners than others did. Sexual and moral disgust sensitivity significantly predicted HIV testing. Our study verified that sexual and moral disgust suppressed sexual risk behaviors and promoted HIV testing. Moral and sexual education should be incorporated in future strategies for HIV prevention and encouragement of safe sex behaviors among MSM in China. PMID:28119646

Sleep duration and RSA suppression as predictors of internalizing and externalizing behaviors.

Science.gov (United States)

Cho, Sunghye; Philbrook, Lauren E; Davis, Elizabeth L; Buss, Kristin A

2017-01-01

Although the conceptual interplay among the biological and clinical features of sleep, arousal, and emotion regulation has been noted, little is understood about how indices of sleep duration and parasympathetic reactivity operate jointly to predict adjustment in early childhood. Using a sample of 123 toddlers, the present study examined sleep duration and RSA reactivity as predictors of internalizing and externalizing behaviors. Parents reported on children's sleep duration and adjustment. RSA reactivity was assessed via children's responses to fear-eliciting stimuli and an inhibitory control challenge. Findings demonstrated that greater RSA suppression to both types of tasks in combination with longer sleep duration was concurrently associated with less internalizing. In contrast, greater RSA augmentation to an inhibitory control task in the context of shorter sleep duration predicted more externalizing 1 year later. The significance of duration of toddlers' sleep as well as the context in which physiological regulatory difficulties occurs is discussed. © 2016 Wiley Periodicals, Inc.

Evoked Emotions Predict Food Choice

NARCIS (Netherlands)

Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments.

The effects of curiosity-evoking events on activity enjoyment.

Science.gov (United States)

Isikman, Elif; MacInnis, Deborah J; Ülkümen, Gülden; Cavanaugh, Lisa A

2016-09-01

Whereas prior literature has studied the positive effects of curiosity-evoking events that are integral to focal activities, we explore whether and how a curiosity-evoking event that is incidental to a focal activity induces negative outcomes for enjoyment. Four experiments and 1 field study demonstrate that curiosity about an event that is incidental to an activity in which individuals are engaged, significantly affects enjoyment of a concurrent activity. The reason why is that curiosity diverts attention away from the concurrent activity and focuses attention on the curiosity-evoking event. Thus, curiosity regarding an incidental event decreases enjoyment of a positive focal activity but increases enjoyment of a negative focal activity. PsycINFO Database Record (c) 2016 APA, all rights reserved

The effect of transcranial direct current stimulation on contrast sensitivity and visual evoked potential amplitude in adults with amblyopia.

Science.gov (United States)

Ding, Zhaofeng; Li, Jinrong; Spiegel, Daniel P; Chen, Zidong; Chan, Lily; Luo, Guangwei; Yuan, Junpeng; Deng, Daming; Yu, Minbin; Thompson, Benjamin

2016-01-14

Amblyopia is a neurodevelopmental disorder of vision that occurs when the visual cortex receives decorrelated inputs from the two eyes during an early critical period of development. Amblyopic eyes are subject to suppression from the fellow eye, generate weaker visual evoked potentials (VEPs) than fellow eyes and have multiple visual deficits including impairments in visual acuity and contrast sensitivity. Primate models and human psychophysics indicate that stronger suppression is associated with greater deficits in amblyopic eye contrast sensitivity and visual acuity. We tested whether transcranial direct current stimulation (tDCS) of the visual cortex would modulate VEP amplitude and contrast sensitivity in adults with amblyopia. tDCS can transiently alter cortical excitability and may influence suppressive neural interactions. Twenty-one patients with amblyopia and twenty-seven controls completed separate sessions of anodal (a-), cathodal (c-) and sham (s-) visual cortex tDCS. A-tDCS transiently and significantly increased VEP amplitudes for amblyopic, fellow and control eyes and contrast sensitivity for amblyopic and control eyes. C-tDCS decreased VEP amplitude and contrast sensitivity and s-tDCS had no effect. These results suggest that tDCS can modulate visual cortex responses to information from adult amblyopic eyes and provide a foundation for future clinical studies of tDCS in adults with amblyopia.

High frequency oscillations evoked by peripheral magnetic stimulation.

Science.gov (United States)

Biller, S; Simon, L; Fiedler, P; Strohmeier, D; Haueisen, J

2011-01-01

The analysis of somatosensory evoked potentials (SEP) and / or fields (SEF) is a well-established and important tool for investigating the functioning of the peripheral and central human nervous system. A standard technique to evoke SEPs / SEFs is the stimulation of the median nerve by using a bipolar electrical stimulus. We aim at an alternative stimulation technique enabling stimulation of deep nerve structures while reducing patient stress and error susceptibility. In the current study, we apply a commercial transcranial magnetic stimulation system for peripheral magnetic stimulation of the median nerve. We compare the results of simultaneously recorded EEG signals to prove applicability of our technique to evoke SEPs including low frequency components (LFC) as well as high frequency oscillations (HFO). Therefore, we compare amplitude, latency and time-frequency characteristics of the SEP of 14 healthy volunteers after electric and magnetic stimulation. Both low frequency components and high frequency oscillations were detected. The HFOs were superimposed onto the primary cortical response N20. Statistical analysis revealed significantly lower amplitudes and increased latencies for LFC and HFO components after magnetic stimulation. The differences indicate the inability of magnetic stimulation to elicit supramaximal responses. A psycho-perceptual evaluation showed that magnetic stimulation was less unpleasant for 12 out of the 14 volunteers. In conclusion, we showed that LFC and HFO components related to median nerve stimulation can be evoked by peripheral magnetic stimulation.

Suppression of EMG activity by transcranial magnetic stimulation in human subjects during walking

DEFF Research Database (Denmark)

Petersen, Nicolas Caesar; Butler, Jane E; Marchand-Pauvert, Veronique

2001-01-01

1. The involvement of the motor cortex during human walking was evaluated using transcranial magnetic stimulation (TMS) of the motor cortex at a variety of intensities. Recordings of EMG activity in tibialis anterior (TA) and soleus muscles during walking were rectified and averaged. 2. TMS of low...... intensity (below threshold for a motor-evoked potential, MEP) produced a suppression of ongoing EMG activity during walking. The average latency for this suppression was 40.0 +/- 1.0 ms. At slightly higher intensities of stimulation there was a facilitation of the EMG activity with an average latency of 29.......5 +/- 1.0 ms. As the intensity of the stimulation was increased the facilitation increased in size and eventually a MEP was clear in individual sweeps. 3. In three subjects TMS was replaced by electrical stimulation over the motor cortex. Just below MEP threshold there was a clear facilitation at short...

Thirst is associated with suppression of LHB outputs and active stress coping: Is there a role for a non-canonical vasopressin-glutamate pathway?

Directory of Open Access Journals (Sweden)

Limei eZhang

2016-03-01

Full Text Available Water-homeostasis is a fundamental physiological process for terrestrial life. In vertebrates, thirst drives water intake, but the neuronal circuits that connect the physiology of water regulation with emotional context are poorly understood. Vasopressin (VP is a prominent messenger in this circuit, as well as L-glutamate. We have investigated the role of a VP circuit and interaction between thirst and motivational behaviors evoked by life-threatening stimuli in rats. We demonstrate a direct pathway from hypothalamic paraventricular VP-expressing, glutamatergic magnocellular neurons to the medial division of lateral habenula (LHbM, a region containing GABAergic neurons. In vivo recording and juxtacellular labeling revealed that GABAergic neurons in the LHbM had locally branching axons, and received VP-positive axon terminal contacts on their dendrites. Water deprivation significantly reduced freezing and immobility behaviors evoked by innate fear and behavioral despair respectively, accompanied by decreased Fos expression in the lateral habenula. Our results reveal a novel VP-expressing hypothalamus to the LHbM circuit that is likely to evoke GABA-mediated inhibition in the LHbM, which promotes escape behavior during stress coping.

Fluoxetine, an antidepressant, suppresses glioblastoma by evoking AMPAR-mediated calcium-dependent apoptosis

Science.gov (United States)

Liu, Kao-Hui; Yang, Shun-Tai; Lin, Yen-Kuang; Lin, Jia-Wei; Lee, Yi-Hsuan; Wang, Jia-Yi; Hu, Chaur-Jong; Lin, En-Yuan; Chen, Shu-Mei; Then, Chee-Kin; Shen, Shing-Chuan

2015-01-01

The efficacy of glioblastoma chemotherapy is not satisfactory; therefore, a new medication is expected to improve outcomes. As much evidence shows that antidepressants decrease cancer incidence and improve patients' quality of life, we therefore attempted to explore the potential for fluoxetine to be used to treat GBM and its possible underlying mechanism. The expression level of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) was determined using immunohistochemical staining and PCR analysis. The mechanism of fluoxetine-induced apoptosis of gliomas was elucidated. Computer modeling and a binding assay were conducted to investigate the interaction of fluoxetine with the AMPAR. The therapeutic effect of fluoxetine was evaluated using an animal model. We found that fluoxetine directly bound to AMPAR, thus inducing transmembrane Ca2+ influx. The rise in the intracellular calcium concentration ([Ca2+]i) causes mitochondrial Ca2+ overload, thereby triggering apoptosis. AMPARs are excessively expressed in glioma tissues, suggesting that fluoxetine specifically executes glioma cells. Our in vivo study revealed that fluoxetine suppressed the growth of glioblastomas in brains of Nu/Nu mice, an effect similar to that produced by temozolomide. Our preclinical studies suggest fluoxetine, a commonly used antidepressant, might be selectively toxic to gliomas and could provide a new approach for managing this disease. PMID:25671301

Steady-state evoked potentials possibilities for mental-state estimation

Science.gov (United States)

Junker, Andrew M.; Schnurer, John H.; Ingle, David F.; Downey, Craig W.

1988-01-01

The use of the human steady-state evoked potential (SSEP) as a possible measure of mental-state estimation is explored. A method for evoking a visual response to a sum-of-ten sine waves is presented. This approach provides simultaneous multiple frequency measurements of the human EEG to the evoking stimulus in terms of describing functions (gain and phase) and remnant spectra. Ways in which these quantities vary with the addition of performance tasks (manual tracking, grammatical reasoning, and decision making) are presented. Models of the describing function measures can be formulated using systems engineering technology. Relationships between model parameters and performance scores during manual tracking are discussed. Problems of unresponsiveness and lack of repeatability of subject responses are addressed in terms of a need for loop closure of the SSEP. A technique to achieve loop closure using a lock-in amplifier approach is presented. Results of a study designed to test the effectiveness of using feedback to consciously connect humans to their evoked response are presented. Findings indicate that conscious control of EEG is possible. Implications of these results in terms of secondary tasks for mental-state estimation and brain actuated control are addressed.

Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

Energy Technology Data Exchange (ETDEWEB)

Miletich, R.S.

1985-01-01

The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and /sup 3/H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by ..cap alpha..-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period, phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S/sub 2/ episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. /sup 3/H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system.

Evoked bioelectrical brain activity following exposure to ionizing radiation.

Science.gov (United States)

Loganovsky, K; Kuts, K

2017-12-01

The article provides an overview of modern physiological evidence to support the hypothesis on cortico limbic sys tem dysfunction due to the hippocampal neurogenesis impairment as a basis of the brain interhemispheric asym metry and neurocognitive deficit after radiation exposure. The importance of the research of both evoked poten tials and fields as a highly sensitive and informative method is emphasized.Particular attention is paid to cerebral sensor systems dysfunction as a typical effect of ionizing radiation. Changes in functioning of the central parts of sensory analyzers of different modalities as well as the violation of brain integrative information processes under the influence of small doses of ionizing radiation can be critical when determining the radiation risks of space flight. The possible long term prospects for manned flights into space, including to Mars, given the effects identified are discussed. Potential risks to the central nervous system during space travel comprise cognitive functions impairment, including the volume of short term memory short ening, impaired motor functions, behavioral changes that could affect human performance and health. The remote risks for CNS are considered to be the following possible neuropsychiatric disorders: accelerated brain aging, Alzheimer's disease and other types of dementia. The new radiocerebral dose dependent effect, when applied cog nitive auditory evoked potentials P300 technique with a possible threshold dose of 0.05 Gy, manifesting in a form of disruption of information processing in the Wernicke's area is under discussion. In order to identify neurophys iological biological markers of ionizing radiation further international researches with adequate dosimetry support are necessary. K. Loganovsky, K. Kuts.

Norepinephrine-evoked pain in fibromyalgia. A randomized pilot study [ISRCTN70707830

Directory of Open Access Journals (Sweden)

Casanova Jose-Miguel

2002-01-01

Full Text Available Abstract Background Fibromyalgia syndrome displays sympathetically maintained pain features such as frequent post-traumatic onset and stimuli-independent pain accompanied by allodynia and paresthesias. Heart rate variability studies showed that fibromyalgia patients have changes consistent with ongoing sympathetic hyperactivity. Norepinephrine-evoked pain test is used to assess sympathetically maintained pain syndromes. Our objective was to define if fibromyalgia patients have norepinephrine-evoked pain. Methods Prospective double blind controlled study. Participants: Twenty FM patients, and two age/sex matched control groups; 20 rheumatoid arthritis patients and 20 healthy controls. Ten micrograms of norepinephrine diluted in 0.1 ml of saline solution were injected in a forearm. The contrasting substance, 0.1 ml of saline solution alone, was injected in the opposite forearm. Maximum local pain elicited during the 5 minutes post-injection was graded on a visual analog scale (VAS. Norepinephrine-evoked pain was diagnosed when norepinephrine injection induced greater pain than placebo injection. Intensity of norepinephrine-evoked pain was calculated as the difference between norepinephrine minus placebo-induced VAS scores. Results Norepinephrine-evoked pain was seen in 80 % of FM patients (95% confidence intervals 56.3 – 94.3%, in 30 % of rheumatoid arthritis patients and in 30 % of healthy controls (95% confidence intervals 11.9 – 54.3 (p Conclusions Fibromyalgia patients have norepinephrine-evoked pain. This finding supports the hypothesis that fibromyalgia may be a sympathetically maintained pain syndrome.

Objective correlate of subjective pain perception by contact heat-evoked potentials.

Science.gov (United States)

Granovsky, Yelena; Granot, Michal; Nir, Rony-Reuven; Yarnitsky, David

2008-01-01

The method of pain-evoked potentials has gained considerable acceptance over the last 3 decades regarding its objectivity, repeatability, and quantifiability. The present study explored whether the relationship between pain-evoked potentials and pain psychophysics obtained by contact heat stimuli is similar to those observed for the conventionally used laser stimulation. Evoked potentials (EPs) were recorded in response to contact heat stimuli at different body sites in 24 healthy volunteers. Stimuli at various temperatures were applied to the forearm (43 degrees C, 46 degrees C, 49 degrees C, and 52 degrees C) and leg (46 degrees C and 49 degrees C). The amplitudes of both components (N2 and P2) were strongly associated with the intensity of the applied stimuli and with subjective pain perception. Yet, regression analysis revealed pain perception and not stimulus intensity as the major contributing factor. A significant correlation was found between the forearm and the leg for both psychophysics and EPs amplitude. Contact heat can generate readily distinguishable evoked potentials on the scalp, consistent between upper and lower limbs. Although these potentials bear positive correlation with both stimulus intensity and pain magnitude, the latter is the main contributor to the evoked brain response.

Effects of single cycle binaural beat duration on auditory evoked potentials.

Science.gov (United States)

Mihajloski, Todor; Bohorquez, Jorge; Özdamar, Özcan

2014-01-01

Binaural beat (BB) illusions are experienced as continuous central pulsations when two sounds with slightly different frequencies are delivered to each ear. It has been shown that steady-state auditory evoked potentials (AEPs) to BBs can be captured and investigated. The authors recently developed a new method of evoking transient AEPs to binaural beats using frequency modulated stimuli. This methodology was able to create single BBs in predetermined intervals with varying carrier frequencies. This study examines the effects of the BB duration and the frequency modulating component of the stimulus on the binaural beats and their evoked potentials. Normal hearing subjects were tested with a set of four durations (25, 50, 100, and 200 ms) with two stimulation configurations, binaural dichotic (binaural beats) and diotic (frequency modulation). The results obtained from the study showed that out of the given durations, the 100 ms beat, was capable of evoking the largest amplitude responses. The frequency modulation effect showed a decrease in peak amplitudes with increasing beat duration until their complete disappearance at 200 ms. Even though, at 200 ms, the frequency modulation effects were not present, the binaural beats were still perceived and captured as evoked potentials.

Suppression of beam-excited electron waves by an externally applied RF signal

International Nuclear Information System (INIS)

Fukumasa, Osamu; Itatani, Ryohei

1980-11-01

Suppression of the beam-excited electron wave in a bounded system is investigated in connection with the beam distribution function. Wave suppression has two different processes depending on whether injected beams are reflected at the other end or not. In the absence of reflected beam electrons, deformation of the beam distribution function is observed in relation to the suppression of the electron wave. However, when beam electrons are reflected, the external wave suppresses the electron wave but distribution function shows no appreciable change. These experimental results show that nonlinear behaviors of beam electrons, namely behaviors of reflected beams, are quite important for wave suppression. By using the method of partial simulation, interaction between two waves in the bounded system including nonlinear motions of beam electrons is studied numerically. Qualitative agreement between experimental and numerical results is obtained. (author)

Objective assessment of subjective tinnitus through contralateral suppression of otoacoustic emissions by white noise; suggested cut-off points.

Science.gov (United States)

Riga, M; Komis, A; Maragkoudakis, P; Korres, G; Danielides, V

2016-12-01

Normative otoacoustic emission (OAE) suppression values are currently lacking and the role of cochlear efferent innervation in tinnitus is controversial. The aim of this study was to investigate the association between tinnitus and medial olivocochlear bundle (MOCB) malfunction. Potential suppression amplitude cut-off criteria that could differentiate participants with tinnitus from those without were sought. Mean suppression amplitudes of transient evoked OAEs and distortion product OAEs by contralateral white noise (50 dBSL) were recorded. Six mean suppression amplitudes criteria were validated as possible cut-off points. The population consisted of normal hearing (n = 78) or presbycusic adults (n = 19) with tinnitus or without (n = 28 and 13, respectively) chronic tinnitus (in total, n = 138 78 females/60males, aged 49 ± 14 years). Participants with mean suppression values lower than 0.5-1 dBSPL seem to present a high probability to report tinnitus (specificity 88-97%). On the other hand, participants with mean suppression values larger than 2-2.5dBSPL seem to present a high probability of the absence of tinnitus (sensitivity 87-99%). Correlations were stronger among participants with bilateral presence or absence of tinnitus. This study seem to confirm an association between tinnitus and low suppression amplitudes (<1 dBSPL), which might evolve into an objective examination tool, supplementary to conventional audiological testing.

Oral delivery of capsaicin using MPEG-PCL nanoparticles.

Science.gov (United States)

Peng, Wei; Jiang, Xin-yi; Zhu, Yuan; Omari-Siaw, E; Deng, Wen-wen; Yu, Jiang-nan; Xu, Xi-ming; Zhang, Wei-ming

2015-01-01

To prepare a biodegradable polymeric carrier for oral delivery of a water-insoluble drug capsaicin (CAP) and evaluate its quality. CAP-loaded methoxy poly (ethylene glycol)-poly(ε-caprolactone) nanoparticles (CAP/NPs) were prepared using a modified emulsification solvent diffusion technique. The quality of CAP/NPs were evaluated using transmission electron microscopy, powder X-ray diffraction, differential scanning calorimetry and Fourier transform infrared techniques. A dialysis method was used to analyze the in vitro release profile of CAP from the CAP/NPs. Adult male rats were orally administered CAP/NPs (35 mg/kg), and the plasma concentrations of CAP were measured with a validated HPLC method. The morphology of rat gastric mucosa was studied with HE staining. CAP/NPs had an average diameter of 82.54 ± 0.51 nm, high drug-loading capacity of 14.0% ± 0.13% and high stability. CAP/NPs showed a biphasic release profile in vitro: the burst release was less than 25% of the loaded drug within 12 h followed by a more sustained release for 60 h. The pharmacokinetics study showed that the mean maximum plasma concentration was observed 4 h after oral administered of CAP/NPs, and approximately 90 ng/mL of CAP was detected in serum after 36 h. The area under the curve for the CAP/NPs group was approximately 6-fold higher than that for raw CAP suspension. Histological studies showed that CAP/NPs markedly reduced CAP-caused gastric mucosa irritation. CAP/NPs significantly enhance the bioavailability of CAP and markedly reduce gastric mucosa irritation in rats.

Non-disruptive tactics of suppression are superior in countering terrorism, insurgency, and financial panics.

Science.gov (United States)

Siegel, David A

2011-04-13

Suppressing damaging aggregate behaviors such as insurgency, terrorism, and financial panics are important tasks of the state. Each outcome of these aggregate behaviors is an emergent property of a system in which each individual's action depends on a subset of others' actions, given by each individual's network of interactions. Yet there are few explicit comparisons of strategies for suppression, and none that fully incorporate the interdependence of individual behavior. Here I show that suppression tactics that do not require the removal of individuals from networks of interactions are nearly always more effective than those that do. I find using simulation analysis of a general model of interdependent behavior that the degree to which such less disruptive suppression tactics are superior to more disruptive ones increases in the propensity of individuals to engage in the behavior in question. Thus, hearts-and-minds approaches are generally more effective than force in counterterrorism and counterinsurgency, and partial insurance is usually a better tactic than gag rules in quelling financial panics. Differences between suppression tactics are greater when individual incentives to support terrorist or insurgent groups, or susceptibilities to financial panic, are higher. These conclusions have utility for policy-makers seeking to end bloody conflicts and prevent financial panics. As the model also applies to mass protest, its conclusions provide insight as well into the likely effects of different suppression strategies undertaken by authoritarian regimes seeking to hold on to power in the face of mass movements seeking to end them.

Glechoma hederacea Suppresses RANKL-mediated Osteoclastogenesis.

Science.gov (United States)

Hwang, J K; Erkhembaatar, M; Gu, D R; Lee, S H; Lee, C H; Shin, D M; Lee, Y R; Kim, M S

2014-07-01

Glechoma hederacea (GH), commonly known as ground-ivy or gill-over-the-ground, has been extensively used in folk remedies for relieving symptoms of inflammatory disorders. However, the molecular mechanisms underlying the therapeutic action of GH are poorly understood. Here, we demonstrate that GH constituents inhibit osteoclastogenesis by abrogating receptor activator of nuclear κ-B ligand (RANKL)-induced free cytosolic Ca(2+) ([Ca(2+)]i) oscillations. To evaluate the effect of GH on osteoclastogenesis, we assessed the formation of multi-nucleated cells (MNCs), enzymatic activity of tartrate-resistant acidic phosphatase (TRAP), expression of nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), and [Ca(2+)]i alterations in response to treatment with GH ethanol extract (GHE) in primarily cultured bone marrow-derived macrophages (BMMs). Treatment of RANKL-stimulated or non-stimulated BMMs with GHE markedly suppressed MNC formation, TRAP activity, and NFATc1 expression in a dose-dependent manner. Additionally, GHE treatment induced a large transient elevation in [Ca(2+)]i while suppressing RANKL-induced [Ca(2+)]i oscillations, which are essential for NFATc1 activation. GHE-evoked increase in [Ca(2+)]i was dependent on extracellular Ca(2+) and was inhibited by 1,4-dihydropyridine (DHP), inhibitor of voltage-gated Ca(2+) channels (VGCCs), but was independent of store-operated Ca(2+) channels. Notably, after transient [Ca(2+)] elevation, treatment with GHE desensitized the VGCCs, resulting in an abrogation of RANKL-induced [Ca(2+)]i oscillations and MNC formation. These findings demonstrate that treatment of BMMs with GHE suppresses RANKL-mediated osteoclastogenesis by activating and then desensitizing DHP-sensitive VGCCs, suggesting potential applications of GH in the treatment of bone disorders, such as periodontitis, osteoporosis, and rheumatoid arthritis. © International & American Associations for Dental Research.

Peripheral afferent mechanisms underlying acupuncture inhibition of cocaine behavioral effects in rats.

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Seol Ah Kim

Full Text Available Administration of cocaine increases locomotor activity by enhancing dopamine transmission. To explore the peripheral mechanisms underlying acupuncture treatment for drug addiction, we developed a novel mechanical acupuncture instrument (MAI for objective mechanical stimulation. The aim of this study was to evaluate whether acupuncture inhibition of cocaine-induced locomotor activity is mediated through specific peripheral nerves, the afferents from superficial or deep tissues, or specific groups of nerve fibers. Mechanical stimulation of acupuncture point HT7 with MAI suppressed cocaine-induced locomotor activity in a stimulus time-dependent manner, which was blocked by severing the ulnar nerve or by local anesthesia. Suppression of cocaine-induced locomotor activity was elicited after HT7 stimulation at frequencies of either 50 (for Meissner corpuscles or 200 (for Pacinian corpuscles Hz and was not affected by block of C/Aδ-fibers in the ulnar nerve with resiniferatoxin, nor generated by direct stimulation of C/Aδ-fiber afferents with capsaicin. These findings suggest that HT7 inhibition of cocaine-induced locomotor activity is mediated by A-fiber activation of ulnar nerve that originates in superficial and deep tissue.

A Telehealth System for Remote Auditory Evoked Potential Monitoring

OpenAIRE

Millan, Jorge; Yunda, Leonardo

2013-01-01

A portable, Internet-based EEG/Auditory Evoked Potential (AEP) monitoring system was developed for remote electrophysiological studies during sleep. The system records EEG/AEP simultaneously at the subject?s home for increased comfort and flexibility. The system provides simultaneous recording and remote viewing of EEG, EMG and EOG waves and allows on-line averaging of auditory evoked potentials. The design allows the recording of all major AEP components (brainstem, middle and late latency E...

The Role of Odor-Evoked Memory in Psychological and Physiological Health.

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Herz, Rachel S

2016-07-19

This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing.

The Role of Odor-Evoked Memory in Psychological and Physiological Health

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Rachel S. Herz

2016-07-01

Full Text Available This article discusses the special features of odor-evoked memory and the current state-of-the-art in odor-evoked memory research to show how these unique experiences may be able to influence and benefit psychological and physiological health. A review of the literature leads to the conclusion that odors that evoke positive autobiographical memories have the potential to increase positive emotions, decrease negative mood states, disrupt cravings, and reduce physiological indices of stress, including systemic markers of inflammation. Olfactory perception factors and individual difference characteristics that would need to be considered in therapeutic applications of odor-evoked-memory are also discussed. This article illustrates how through the experimentally validated mechanisms of odor-associative learning and the privileged neuroanatomical relationship that exists between olfaction and the neural substrates of emotion, odors can be harnessed to induce emotional and physiological responses that can improve human health and wellbeing.

Thought-evoking approaches in engineering problems

CERN Document Server

2014-01-01

In creating the value-added product in not distant future, it is necessary and inevitable to establish a holistic and though-evoking approach to the engineering problem, which should be at least associated with the inter-disciplinary knowledge and thought processes across the whole engineering spheres. It is furthermore desirable to integrate it with trans-disciplinary aspects ranging from manufacturing culture, through liberal-arts engineering, and industrial sociology.   The thought-evoking approach can be exemplified and typified by representative engineering problems: unveiling essential features in ‘Tangential Force Ratio and Interface Pressure’, prototype development for ‘Bio-mimetic Needle’ and application of ‘Water-jet Machining to Artificial Hip Joint’, product innovation in ‘Heat Sink for Computer’, application of ‘Graph Theory’ to similarity evaluation of production systems, leverage among reciprocity attributes in ‘Industrial and Engineering Designs for Machine Enclosure’,...

Agmatine suppresses peripheral sympathetic tone by inhibiting N-type Ca(2+) channel activity via imidazoline I2 receptor activation.

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Kim, Young-Hwan; Jeong, Ji-Hyun; Ahn, Duck-Sun; Chung, Seungsoo

2016-08-26

Agmatine, a putative endogenous ligand of imidazoline receptors, suppresses cardiovascular function by inhibiting peripheral sympathetic tone. However, the molecular identity of imidazoline receptor subtypes and its cellular mechanism underlying the agmatine-induced sympathetic suppression remains unknown. Meanwhile, N-type Ca(2+) channels are important for the regulation of NA release in the peripheral sympathetic nervous system. Therefore, it is possible that agmatine suppresses NA release in peripheral sympathetic nerve terminals by inhibiting Ca(2+) influx through N-type Ca(2+) channels. We tested this hypothesis by investigating agmatine effect on electrical field stimulation (EFS)-evoked contraction and NA release in endothelium-denuded rat superior mesenteric arterial strips. We also investigated the effect of agmatine on the N-type Ca(2+) current in superior cervical ganglion (SCG) neurons in rats. Our study demonstrates that agmatine suppresses peripheral sympathetic outflow via the imidazoline I2 receptor in rat mesenteric arteries. In addition, the agmatine-induced suppression of peripheral vascular sympathetic tone is mediated by modulating voltage-dependent N-type Ca(2+) channels in sympathetic nerve terminals. These results suggest a potential cellular mechanism for the agmatine-induced suppression of peripheral sympathetic tone. Furthermore, they provide basic and theoretical information regarding the development of new agents to treat hypertension. Copyright © 2016 Elsevier Inc. All rights reserved.

Multifocal visual evoked responses to dichoptic stimulation using virtual reality goggles: Multifocal VER to dichoptic stimulation.

Science.gov (United States)

Arvind, Hemamalini; Klistorner, Alexander; Graham, Stuart L; Grigg, John R

2006-05-01

Multifocal visual evoked potentials (mfVEPs) have demonstrated good diagnostic capabilities in glaucoma and optic neuritis. This study aimed at evaluating the possibility of simultaneously recording mfVEP for both eyes with dichoptic stimulation using virtual reality goggles and also to determine the stimulus characteristics that yield maximum amplitude. ten healthy volunteers were recruited and temporally sparse pattern pulse stimuli were presented dichoptically using virtual reality goggles. Experiment 1 involved recording responses to dichoptically presented checkerboard stimuli and also confirming true topographic representation by switching off specific segments. Experiment 2 involved monocular stimulation and comparison of amplitude with Experiment 1. In Experiment 3, orthogonally oriented gratings were dichoptically presented. Experiment 4 involved dichoptic presentation of checkerboard stimuli at different levels of sparseness (5.0 times/s, 2.5 times/s, 1.66 times/s and 1.25 times/s), where stimulation of corresponding segments of two eyes were separated by 16.7, 66.7,116.7 & 166.7 ms respectively. Experiment 1 demonstrated good traces in all regions and confirmed topographic representation. However, there was suppression of amplitude of responses to dichoptic stimulation by 17.9+/-5.4% compared to monocular stimulation. Experiment 3 demonstrated similar suppression between orthogonal and checkerboard stimuli (p = 0.08). Experiment 4 demonstrated maximum amplitude and least suppression (4.8%) with stimulation at 1.25 times/s with 166.7 ms separation between eyes. It is possible to record mfVEP for both eyes during dichoptic stimulation using virtual reality goggles, which present binocular simultaneous patterns driven by independent sequences. Interocular suppression can be almost eliminated by using a temporally sparse stimulus of 1.25 times/s with a separation of 166.7 ms between stimulation of corresponding segments of the two eyes.

Speech-evoked auditory brainstem responses in children with hearing loss.

Science.gov (United States)

Koravand, Amineh; Al Osman, Rida; Rivest, Véronique; Poulin, Catherine

2017-08-01

The main objective of the present study was to investigate subcortical auditory processing in children with sensorineural hearing loss. Auditory Brainstem Responses (ABRs) were recorded using click and speech/da/stimuli. Twenty-five children, aged 6-14 years old, participated in the study: 13 with normal hearing acuity and 12 with sensorineural hearing loss. No significant differences were observed for the click-evoked ABRs between normal hearing and hearing-impaired groups. For the speech-evoked ABRs, no significant differences were found for the latencies of the following responses between the two groups: onset (V and A), transition (C), one of the steady-state wave (F), and offset (O). However, the latency of the steady-state waves (D and E) was significantly longer for the hearing-impaired compared to the normal hearing group. Furthermore, the amplitude of the offset wave O and of the envelope frequency response (EFR) of the speech-evoked ABRs was significantly larger for the hearing-impaired compared to the normal hearing group. Results obtained from the speech-evoked ABRs suggest that children with a mild to moderately-severe sensorineural hearing loss have a specific pattern of subcortical auditory processing. Our results show differences for the speech-evoked ABRs in normal hearing children compared to hearing-impaired children. These results add to the body of the literature on how children with hearing loss process speech at the brainstem level. Copyright © 2017 Elsevier B.V. All rights reserved.

Suppression of bulboreticular unit responses to noxious stimuli by analgesic mesencephalic stimulation.

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Morrow, T J; Casey, K L

1983-01-01

The responses of 302 neurons in the medial medullary reticular formation (MRF) to a variety of noxious and innocuous somatic stimuli were studied in anesthetized and awake rats. In addition, the effects of analgesic electrical stimulation in the mesencephalon (MES) on unit responses were examined. Tail shock was the most effective stimulus, exciting more than 80% of all units recorded. This stimulus was considered separately during data analysis, since it could not be classified as noxious or innocuous. Noxious somatic stimuli (including pinch, firm pressure, pin prick, and radiant heating of the tail above 45 degrees C were especially effective in eliciting discharge in a significant fraction of all cells in both awake (123/205) and anesthetized (45/97) animals. Nociceptive neurons could be classified as nociceptive specific (NS) or wide dynamic range (WDR) depending on their responses to all somatic stimuli tested. Nociceptive neurons showed no preferential anatomical distribution. Most neurons, including those responsive to noxious inputs, exhibited large, often bilateral receptive fields which frequently covered the tail, one or more limbs, and extensive areas of the body or head. Electrical stimulation within or adjacent to the mesencephalic periaqueductal gray matter depressed the spontaneous and evoked discharge of MRF neurons in both acute and chronic preparations. This inhibition showed a significant preference (p less than 0.001, chi-square statistic) for units that were excited by somatic and especially noxious stimuli. No units were facilitated by MES stimulation. In the awake rat, unit suppression closely followed the time course and level of MES-induced analgesia. Excitability data from the acute experiments suggest that this response inhibition may be the result of a direct action on MRF neurons. Anesthesia severely depressed the spontaneous discharge of MRF neurons as well as the activity evoked by innocuous somatic stimulation. Our data suggest

Physiological function of gastrin-releasing peptide and neuromedin B receptors in regulating itch scratching behavior in the spinal cord of mice.

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Devki D Sukhtankar

Full Text Available Pruritus (itch is a severe side effect associated with the use of drugs as well as hepatic and hematological disorders. Previous studies in rodents suggest that bombesin receptor subtypes i.e. receptors for gastrin-releasing peptide (GRPr and neuromedin B (NMBr differentially regulate itch scratching. However, to what degree spinal GRPr and NMBr regulate scratching evoked by intrathecally administered bombesin-related peptides is not known. The first aim of this study was to pharmacologically compare the dose-response curves for scratching induced by intrathecally administered bombesin-related peptides versus morphine, which is known to elicit itch in humans. The second aim was to determine if spinal GRPr and NMBr selectively or generally mediate scratching behavior. Mice received intrathecal injection of bombesin (0.01-0.3 nmol, GRP (0.01-0.3 nmol, NMB (0.1-1 nmol or morphine (0.3-3 nmol and were observed for one hour for scratching activity. Bombesin elicited most profound scratching over one hour followed by GRP and NMB, whereas morphine failed to evoke scratching response indicating the insensitivity of mouse models to intrathecal opioid-induced itch. Intrathecal pretreatment with GRPr antagonist RC-3095 (0.03-0.1 nmol produced a parallel rightward shift in the dose response curve of GRP-induced scratching but not NMB-induced scratching. Similarly, PD168368 (1-3 nmol only attenuated NMB but not GRP-induced scratching. Individual or co-administration of RC-3095 and PD168368 failed to alter bombesin-evoked scratching. A higher dose of RC-3095 (0.3 nmol generally suppressed scratching induced by all three peptides but also compromised motor function in the rotarod test. Together, these data indicate that spinal GRPr and NMBr independently drive itch neurotransmission in mice and may not mediate bombesin-induced scratching. GRPr antagonists at functionally receptor-selective doses only block spinal GRP-elicited scratching but the suppression of

Chaotic Dynamics in Smart Grid and Suppression Scheme via Generalized Fuzzy Hyperbolic Model

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Qiuye Sun

2014-01-01

Full Text Available This paper presents a method to control chaotic behavior of a typical Smart Grid based on generalized fuzzy hyperbolic model (GFHM. As more and more distributed generations (DG are incorporated into the Smart Grid, the chaotic behavior occurs increasingly. To verify the behavior, a dynamic model which describes a power system with DG is presented firstly. Then, the simulation result shows that the power system can lead to chaos under certain initial conditions. Based on the universal approximation of GFHM, we confirm that the chaotic behavior could be suppressed by a new controller, which is designed by means of solving a linear matrix inequality (LMI. This approach could make a good application to suppress the chaos in Smart Grid. Finally, a numerical example is given to demonstrate the effectiveness of the proposed chaotic suppression strategy.

Interaction between Mu and Delta Opioid Receptor Agonists in an Assay of Capsaicin-Induced Thermal Allodynia in Rhesus Monkeys

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S. Stevens Negus

2012-01-01

Full Text Available Delta opioid agonists enhance antinociceptive effects of mu-opioid agonists in many preclinical assays of acute nociception, but delta/mu interactions in preclinical models of inflammation-associated pain have not been examined. This study examined interactions between the delta agonist SNC80 [(+-4-[(αR-α-((2S,5R-4-allyl-2,5-dimethyl-1-piperazinyl-3-methoxybenzyl]-N,N-diethylbenzamide] and the mu agonist analgesics methadone, morphine, and nalbuphine in an assay of capsaicin-induced thermal allodynia in rhesus monkeys. Thermal allodynia was produced by topical application of capsaicin to the tail. Antiallodynic effects of methadone, morphine, and nalbuphine were evaluated alone or in combination with fixed proportions of SNC80 identical to proportions previously shown to enhance acute thermal antinociceptive effects of these mu agonists in rhesus monkeys (0.9 : 1 SNC80/methadone; 0.29 : 1 SNC80/morphine; 3.6 : 1 SNC80/nalbuphine. Methadone, morphine, and nalbuphine each produced dose-dependent antiallodynia. SNC80 produced partial antiallodynia up to the highest dose tested (5.6 mg/kg. SNC80 produced a modest, enantioselective, and naltrindole-reversible enhancement of methadone-induced antiallodynia. However, SNC80 did not enhance morphine antiallodynia and only weakly enhanced nalbuphine antiallodynia. Overall, SNC80 produced modest or no enhancement of the antiallodynic effects of the three mu agonists evaluated. These results suggest that delta agonist-induced enhancement of mu agonist antiallodynia may be weaker and less reliable than previously demonstrated enhancement of mu agonist acute thermal nociception.

Skinfold thickness affects the isometric knee extension torque evoked by Neuromuscular Electrical Stimulation.

Science.gov (United States)

Medeiros, Flávia V A; Vieira, Amilton; Carregaro, Rodrigo L; Bottaro, Martim; Maffiuletti, Nicola A; Durigan, João L Q

2015-01-01

Subcutaneous adipose tissue may influence the transmission of electrical stimuli through to the skin, thus affecting both evoked torque and comfort perception associated with neuromuscular electrical stimulation (NMES). This could seriously affect the effectiveness of NMES for either rehabilitation or sports purposes. To investigate the effects of skinfold thickness (SFT) on maximal NMES current intensity, NMES-evoked torque, and NMES-induced discomfort. First, we compared NMES current intensity, NMES-induced discomfort, and NMES-evoked torque between two subgroups of subjects with thicker (n=10; 20.7 mm) vs. thinner (n=10; 29.4 mm) SFT. Second, we correlated SFT to NMES current intensity, NMES-induced discomfort, and NMES-evoked knee extension torque in 20 healthy women. The NMES-evoked torque was normalized to the maximal voluntary contraction (MVC) torque. The discomfort induced by NMES was assessed with a visual analog scale (VAS). NMES-evoked torque was 27.5% lower in subjects with thicker SFT (p=0.01) while maximal current intensity was 24.2% lower in subjects with thinner SFT (p=0.01). A positive correlation was found between current intensity and SFT (r=0.540, p=0.017). A negative correlation was found between NMES-evoked torque and SFT (r=-0.563, p=0.012). No significant correlation was observed between discomfort scores and SFT (rs=0.15, p=0.53). These results suggest that the amount of subcutaneous adipose tissue (as reflected by skinfold thickness) affected NMES current intensity and NMES-evoked torque, but had no effect on discomfort perception. Our findings may help physical therapists to better understand the impact of SFT on NMES and to design more rational stimulation strategies.

Pharmacology of Bradykinin-Evoked Coughing in Guinea Pigs.

Science.gov (United States)

Hewitt, Matthew M; Adams, Gregory; Mazzone, Stuart B; Mori, Nanako; Yu, Li; Canning, Brendan J

2016-06-01

Bradykinin has been implicated as a mediator of the acute pathophysiological and inflammatory consequences of respiratory tract infections and in exacerbations of chronic diseases such as asthma. Bradykinin may also be a trigger for the coughing associated with these and other conditions. We have thus set out to evaluate the pharmacology of bradykinin-evoked coughing in guinea pigs. When inhaled, bradykinin induced paroxysmal coughing that was abolished by the bradykinin B2 receptor antagonist HOE 140. These cough responses rapidly desensitized, consistent with reports of B2 receptor desensitization. Bradykinin-evoked cough was potentiated by inhibition of both neutral endopeptidase and angiotensin-converting enzyme (with thiorphan and captopril, respectively), but was largely unaffected by muscarinic or thromboxane receptor blockade (atropine and ICI 192605), cyclooxygenase, or nitric oxide synthase inhibition (meclofenamic acid and N(G)-nitro-L-arginine). Calcium influx studies in bronchopulmonary vagal afferent neurons dissociated from vagal sensory ganglia indicated that the tachykinin-containing C-fibers arising from the jugular ganglia mediate bradykinin-evoked coughing. Also implicating the jugular C-fibers was the observation that simultaneous blockade of neurokinin2 (NK2; SR48968) and NK3 (SR142801 or SB223412) receptors nearly abolished the bradykinin-evoked cough responses. The data suggest that bradykinin induces coughing in guinea pigs by activating B2 receptors on bronchopulmonary C-fibers. We speculate that therapeutics targeting the actions of bradykinin may prove useful in the treatment of cough. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Awareness during anaesthesia for surgery requiring evoked potential monitoring: A pilot study

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Pritish J Korula

2017-01-01

Full Text Available Background: Evoked potential monitoring such as somatosensory-evoked potential (SSEP or motor-evoked potential (MEP monitoring during surgical procedures in proximity to the spinal cord requires minimising the minimum alveolar concentrations (MACs below the anaesthetic concentrations normally required (1 MAC to prevent interference in amplitude and latency of evoked potentials. This could result in awareness. Our primary objective was to determine the incidence of awareness while administering low MAC inhalational anaesthetics for these unique procedures. The secondary objective was to assess the adequacy of our anaesthetic technique from neurophysiologist′s perspective. Methods: In this prospective observational pilot study, 61 American Society of Anesthesiologists 1 and 2 patients undergoing spinal surgery for whom intraoperative evoked potential monitoring was performed were included; during the maintenance phase, 0.7-0.8 MAC of isoflurane was targeted. We evaluated the intraoperative depth of anaesthesia using a bispectral (BIS index monitor as well as the patients response to surgical stimulus (PRST scoring system. Post-operatively, a modified Bruce questionnaire was used to verify awareness. The adequacy of evoked potential readings was also assessed. Results: Of the 61 patients, no patient had explicit awareness. Intraoperatively, 19 of 61 patients had a BIS value of above sixty at least once, during surgery. There was no correlation with PRST scoring and BIS during surgery. Fifty-four out of 61 patient′s evoked potential readings were deemed ′good′ or ′fair′ for the conduct of electrophysiological monitoring. Conclusions: This pilot study demonstrates that administering low MAC inhalational anaesthetics to facilitate evoked potential monitoring does not result in explicit awareness. However, larger studies are needed to verify this. The conduct of SSEP electrophysiological monitoring was satisfactory with the use of this

Non-disruptive tactics of suppression are superior in countering terrorism, insurgency, and financial panics.

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David A Siegel

Full Text Available BACKGROUND: Suppressing damaging aggregate behaviors such as insurgency, terrorism, and financial panics are important tasks of the state. Each outcome of these aggregate behaviors is an emergent property of a system in which each individual's action depends on a subset of others' actions, given by each individual's network of interactions. Yet there are few explicit comparisons of strategies for suppression, and none that fully incorporate the interdependence of individual behavior. METHODS AND FINDINGS: Here I show that suppression tactics that do not require the removal of individuals from networks of interactions are nearly always more effective than those that do. I find using simulation analysis of a general model of interdependent behavior that the degree to which such less disruptive suppression tactics are superior to more disruptive ones increases in the propensity of individuals to engage in the behavior in question. CONCLUSIONS: Thus, hearts-and-minds approaches are generally more effective than force in counterterrorism and counterinsurgency, and partial insurance is usually a better tactic than gag rules in quelling financial panics. Differences between suppression tactics are greater when individual incentives to support terrorist or insurgent groups, or susceptibilities to financial panic, are higher. These conclusions have utility for policy-makers seeking to end bloody conflicts and prevent financial panics. As the model also applies to mass protest, its conclusions provide insight as well into the likely effects of different suppression strategies undertaken by authoritarian regimes seeking to hold on to power in the face of mass movements seeking to end them.

Do Puzzle Pieces and Autism Puzzle Piece Logos Evoke Negative Associations?

Science.gov (United States)

Gernsbacher, Morton Ann; Raimond, Adam R.; Stevenson, Jennifer L.; Boston, Jilana S.; Harp, Bev

2018-01-01

Puzzle pieces have become ubiquitous symbols for autism. However, puzzle-piece imagery stirs debate between those who support and those who object to its use because they believe puzzle-piece imagery evokes negative associations. Our study empirically investigated whether puzzle pieces evoke negative associations in the general public.…

Suppress to feel and remember less: Neural correlates of explicit and implicit emotional suppression on perception and memory.

Science.gov (United States)

Katsumi, Yuta; Dolcos, Sanda

2018-02-09

Available evidence suggests that emotion regulation can modulate both immediate (emotional experience) and long-term (episodic memory) effects of emotion, and that both explicit and implicit forms may be effective. However, neural mechanisms by which explicit and implicit emotional suppression affect these phenomena remain unclear, particularly regarding their effects on memory. In this study, participants rated the emotional content of negative and neutral images, following explicit (verbal instructions) or implicit (priming) induction of emotional suppression goals, during functional magnetic resonance imaging. Participants' memory for the images was tested one week later. Behaviorally, explicit suppression reduced emotional ratings of negative images, whereas both explicit and implicit suppression reduced subsequent memory. At the neural level, the engagement of explicit suppression was uniquely associated with decreased activity in the amygdala (AMY), during emotional ratings, and in the AMY and inferior frontal gyrus (IFG), during successful encoding. Although both explicit and implicit suppression diminished functional connectivity between these regions and the hippocampus (HC) linked to successful encoding, explicit suppression was uniquely associated with interference with AMY-HC interactions, which no longer predicted subsequent memory for the explicitly-suppressed items. Overall, these findings advance our understanding of the common and dissociable mechanisms of explicit and implicit emotional suppression on perception and memory, and suggest their impact on both bottom-up and top-down mechanisms involved in emotion-cognition interactions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Frozen with fear: Conditioned suppression in a virtual reality model of human anxiety.

Science.gov (United States)

Allcoat, Devon; Greville, W James; Newton, Philip M; Dymond, Simon

2015-09-01

Freezing-like topographies of behavior are elicited in conditioned suppression tasks whereby appetitive behavior is reduced by presentations of an aversively conditioned threat cue relative to a safety cue. Conditioned suppression of operant behavior by a Pavlovian threat cue is an established laboratory model of quantifying the response impairment seen in anxiety disorders. Little is known however about how different response topographies indicative of conditioned suppression are elicited in humans. Here, we refined a novel virtual reality (VR) paradigm in which presentations of a threat cue of unpredictable duration occurred while participants performed an operant response of shooting and destroying boxes searching for hidden gold. The VR paradigm detected significant suppression of response topographies (shots, hits and breaks) for a Pavlovian threat cue relative to a safety cue and novel cue presentations. Implications of the present findings for translational research on appetitive and aversive conflict in anxiety disorders are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials,

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Erika Celis-Aguilar

Full Text Available Abstract Introduction: Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. Objective: To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Methods: Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8 mL of gentamicin intratympanic application at a 30 mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Results: Ten patients were included; nine patients with Meniere's disease and one patient with (late onset delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30 dB. Conclusions: Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials.

Mechanical properties of the cuticles of three cockroach species that differ in their wind-evoked escape behavior

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Andrew J. Clark

2014-07-01

Full Text Available The structural and material properties of insect cuticle remain largely unexplored, even though they comprise the majority (approximately 80% of animals. Insect cuticle serves many functions, including protection against predatory attacks, which is especially beneficial to species failing to employ effective running escape responses. Despite recent advances in our understanding of insect escape behaviors and the biomechanics of insect cuticle, there are limited studies on the protective qualities of cuticle to extreme mechanical stresses and strains imposed by predatory attacks, and how these qualities vary between species employing different escape responses. Blattarians (cockroaches provide an appropriate model system for such studies. Wind-evoked running escape responses are strong in Periplaneta americana, weak in Blaberus craniifer and absent in Gromphodorhina portentosa, putting the latter two species at greater risk of being struck by a predator. We hypothesized that the exoskeletons in these two larger species could provide more protection from predatory strikes relative to the exoskeleton of P. americana. We quantified the protective qualities of the exoskeletons by measuring the puncture resistance, tensile strength, strain energy storage, and peak strain in fresh samples of thoracic and abdominal cuticles from these three species. We found a continuum in puncture resistance, tensile strength, and strain energy storage between the three species, which were greatest in G. portentosa, moderate in B. craniifer, and smallest in P. americana. Histological measurements of total cuticle thickness followed this same pattern. However, peak strain followed a different trend between species. The comparisons in the material properties drawn between the cuticles of G. portentosa, B. craniifer, and P. americana demonstrate parallels between cuticular biomechanics and predator running escape responses.

Phantom somatosensory evoked potentials following selective intraneural electrical stimulation in two amputees.

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Granata, Giuseppe; Di Iorio, Riccardo; Romanello, Roberto; Iodice, Francesco; Raspopovic, Stanisa; Petrini, Francesco; Strauss, Ivo; Valle, Giacomo; Stieglitz, Thomas; Čvančara, Paul; Andreu, David; Divoux, Jean-Louis; Guiraud, David; Wauters, Loic; Hiairrassary, Arthur; Jensen, Winnie; Micera, Silvestro; Rossini, Paolo Maria

2018-06-01

The aim of the paper is to objectively demonstrate that amputees implanted with intraneural interfaces are truly able to feel a sensation in the phantom hand by recording "phantom" somatosensory evoked potentials from the corresponding brain areas. We implanted four transverse intrafascicular multichannel electrodes, available with percutaneous connections to a multichannel electrical stimulator, in the median and ulnar nerves of two left trans-radial amputees. Two channels of the implants that were able to elicit sensations during intraneural nerve stimulation were chosen, in both patients, for recording somatosensory evoked potentials. We recorded reproducible evoked responses by stimulating the median and the ulnar nerves in both cases. Latencies were in accordance with the arrival of somatosensory information to the primary somatosensory cortex. Our results provide evidence that sensations generated by intraneural stimulation are truly perceived by amputees and located in the phantom hand. Moreover, our results strongly suggest that sensations perceived in different parts of the phantom hand result in different evoked responses. Somatosensory evoked potentials obtained by selective intraneural electrical stimulation in amputee patients are a useful tool to provide an objective demonstration of somatosensory feedback in new generation bidirectional prostheses. Copyright © 2018. Published by Elsevier B.V.

An inventory and update of jealousy-evoking partner behaviours in modern society.

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Dijkstra, Pieternel; Barelds, Dick P H; Groothof, Hinke A K

2010-01-01

The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's extra-dyadic involvement with someone else by means of modern communication devices, such as the Internet. A second study examined the extent to which undergraduates and a community sample experienced jealousy in response to these partner behaviours. Results showed that explicit unfaithful behaviours evoked most feelings of jealousy, followed by a partner's emotional or romantic involvement with someone else by means of modern communication devices. In general, older individuals responded with less jealousy in response to a partner's unfaithful and suspicious behaviours. Clinical implications are discussed. (c) 2009 John Wiley & Sons, Ltd.

The relation of ongoing brain activity, evoked neural responses, and cognition

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Sepideh Sadaghiani

2010-06-01

Full Text Available Ongoing brain activity has been observed since the earliest neurophysiological recordings and is found over a wide range of temporal and spatial scales. It is characterized by remarkably large spontaneous modulations. Here, we review evidence for the functional role of these ongoing activity fluctuations and argue that they constitute an essential property of the neural architecture underlying cognition. The role of spontaneous activity fluctuations is probably best understood when considering both their spatiotemporal structure and their functional impact on cognition. We first briefly argue against a ‘segregationist’ view on ongoing activity, both in time and space, countering this view with an emphasis on integration within a hierarchical spatiotemporal organization of intrinsic activity. We then highlight the flexibility and context-sensitivity of intrinsic functional connectivity that suggest its involvement in functionally relevant information processing. This role in information processing is pursued by reviewing how ongoing brain activity interacts with afferent and efferent information exchange of the brain with its environment. We focus on the relationship between the variability of ongoing and evoked brain activity, and review recent reports that tie ongoing brain activity fluctuations to variability in human perception and behavior. Finally, these observations are discussed within the framework of the free-energy principle which – applied to human brain function - provides a theoretical account for a non-random, coordinated interaction of ongoing and evoked activity in perception and behaviour.

Enhancement and suppression in the visual field under perceptual load.

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Parks, Nathan A; Beck, Diane M; Kramer, Arthur F

2013-01-01

The perceptual load theory of attention proposes that the degree to which visual distractors are processed is a function of the attentional demands of a task-greater demands increase filtering of irrelevant distractors. The spatial configuration of such filtering is unknown. Here, we used steady-state visual evoked potentials (SSVEPs) in conjunction with time-domain event-related potentials (ERPs) to investigate the distribution of load-induced distractor suppression and task-relevant enhancement in the visual field. Electroencephalogram (EEG) was recorded while subjects performed a foveal go/no-go task that varied in perceptual load. Load-dependent distractor suppression was assessed by presenting a contrast reversing ring at one of three eccentricities (2, 6, or 11°) during performance of the go/no-go task. Rings contrast reversed at 8.3 Hz, allowing load-dependent changes in distractor processing to be tracked in the frequency-domain. ERPs were calculated to the onset of stimuli in the load task to examine load-dependent modulation of task-relevant processing. Results showed that the amplitude of the distractor SSVEP (8.3 Hz) was attenuated under high perceptual load (relative to low load) at the most proximal (2°) eccentricity but not at more eccentric locations (6 or 11°). Task-relevant ERPs revealed a significant increase in N1 amplitude under high load. These results are consistent with a center-surround configuration of load-induced enhancement and suppression in the visual field.

Enhancement and Suppression in the Visual Field under Perceptual Load

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Nathan A Parks

2013-05-01

Full Text Available The perceptual load theory of attention proposes that the degree to which visual distractors are processed is a function of the attentional demands of a task – greater demands increase filtering of irrelevant distractors. The spatial configuration of such filtering is unknown. Here, we used steady-state visual evoked potentials (SSVEPs in conjunction with time-domain event-related potentials (ERPs to investigate the distribution of load-induced distractor suppression and task-relevant enhancement in the visual field. Electroencephalogram (EEG was recorded while subjects performed a foveal go/no-go task that varied in perceptual load. Load-dependent distractor suppression was assessed by presenting a contrast reversing ring at one of three eccentricities (2°, 6°, or 11° during performance of the go/no-go task. Rings contrast reversed at 8.3 Hz, allowing load-dependent changes in distractor processing to be tracked in the frequency-domain. ERPs were calculated to the onset of stimuli in the load task to examine load-dependent modulation of task-relevant processing. Results showed that the amplitude of the distractor SSVEP (8.3Hz was attenuated under high perceptual load (relative to low load at the most proximal (2° eccentricity but not at more eccentric locations (6˚ or 11˚. Task-relevant ERPs revealed a significant increase in N1 amplitude under high load. These results are consistent with a center-surround configuration of load-induced enhancement and suppression in the visual field.

Stimulus-specific suppression preserves information in auditory short-term memory.

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Linke, Annika C; Vicente-Grabovetsky, Alejandro; Cusack, Rhodri

2011-08-02

Philosophers and scientists have puzzled for millennia over how perceptual information is stored in short-term memory. Some have suggested that early sensory representations are involved, but their precise role has remained unclear. The current study asks whether auditory cortex shows sustained frequency-specific activation while sounds are maintained in short-term memory using high-resolution functional MRI (fMRI). Investigating short-term memory representations within regions of human auditory cortex with fMRI has been difficult because of their small size and high anatomical variability between subjects. However, we overcame these constraints by using multivoxel pattern analysis. It clearly revealed frequency-specific activity during the encoding phase of a change detection task, and the degree of this frequency-specific activation was positively related to performance in the task. Although the sounds had to be maintained in memory, activity in auditory cortex was significantly suppressed. Strikingly, patterns of activity in this maintenance period correlated negatively with the patterns evoked by the same frequencies during encoding. Furthermore, individuals who used a rehearsal strategy to remember the sounds showed reduced frequency-specific suppression during the maintenance period. Although negative activations are often disregarded in fMRI research, our findings imply that decreases in blood oxygenation level-dependent response carry important stimulus-specific information and can be related to cognitive processes. We hypothesize that, during auditory change detection, frequency-specific suppression protects short-term memory representations from being overwritten by inhibiting the encoding of interfering sounds.

Chronic restraint stress impairs endocannabinoid mediated suppression of GABAergic signaling in the hippocampus of adult male rats.

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Hu, Wen; Zhang, Mingyue; Czéh, Boldizsár; Zhang, Weiqi; Flügge, Gabriele

2011-07-15

Chronic stress, a risk factor for the development of psychiatric disorders, is known to induce alterations in neuronal networks in many brain areas. Previous studies have shown that chronic stress changes the expression of the cannabinoid receptor 1 (CB1) in the brains of adult rats, but neurophysiological consequences of these changes remained unclear. Here we demonstrate that chronic restraint stress causes a dysfunction in CB1 mediated modulation of GABAergic transmission in the hippocampus. Using an established protocol, adult male Sprague Dawley rats were daily restrained for 21 days and whole-cell voltage clamp was performed at CA1 pyramidal neurons. When recording carbachol-evoked inhibitory postsynaptic currents (IPSCs) which presumably originate from CB1 expressing cholecystokinin (CCK) interneurons, we found that depolarization-induced suppression of inhibition (DSI) was impaired by the stress. DSI is a form of short-term plasticity at GABAergic synapses that is known to be CB1 mediated and has been suggested to be involved in hippocampal information encoding. Chronic stress attenuated the depolarization-induced suppression of the frequency of carbachol-evoked IPSCs. Incubation with a CB1 receptor antagonist prevented this DSI effect in control but not in chronically stressed animals. The stress-induced impairment of CB1-mediated short-term plasticity at GABAergic synapses may underlie cognitive deficits which are commonly observed in animal models of stress as well as in patients with stress-related psychiatric disorders. Copyright © 2011 Elsevier Inc. All rights reserved.

Deconstructing Interocular Suppression: Attention and Divisive Normalization.

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Hsin-Hung Li

2015-10-01

Full Text Available In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression, the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature and divisive normalization contribute to interocular suppression.

Deconstructing Interocular Suppression: Attention and Divisive Normalization.

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Li, Hsin-Hung; Carrasco, Marisa; Heeger, David J

2015-10-01

In interocular suppression, a suprathreshold monocular target can be rendered invisible by a salient competitor stimulus presented in the other eye. Despite decades of research on interocular suppression and related phenomena (e.g., binocular rivalry, flash suppression, continuous flash suppression), the neural processing underlying interocular suppression is still unknown. We developed and tested a computational model of interocular suppression. The model included two processes that contributed to the strength of interocular suppression: divisive normalization and attentional modulation. According to the model, the salient competitor induced a stimulus-driven attentional modulation selective for the location and orientation of the competitor, thereby increasing the gain of neural responses to the competitor and reducing the gain of neural responses to the target. Additional suppression was induced by divisive normalization in the model, similar to other forms of visual masking. To test the model, we conducted psychophysics experiments in which both the size and the eye-of-origin of the competitor were manipulated. For small and medium competitors, behavioral performance was consonant with a change in the response gain of neurons that responded to the target. But large competitors induced a contrast-gain change, even when the competitor was split between the two eyes. The model correctly predicted these results and outperformed an alternative model in which the attentional modulation was eye specific. We conclude that both stimulus-driven attention (selective for location and feature) and divisive normalization contribute to interocular suppression.

Evoked Brain Activity and Personnel Performance

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1987-10-01

Shucard and Horn (1972), Galbraith, Gliddon, and Busk (1970), and Callaway (1975), the latter using Navy recruits. Callaway’s own work was reported at...G.C., Gliddon, J.B., & Busk , J. (1970). Visual evoked responses in mentally retarded and nonretarded subjects. American Journal of Mental Deficiency

Puberty suppression in adolescents with gender identity disorder: a prospective follow-up study.

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de Vries, Annelou L C; Steensma, Thomas D; Doreleijers, Theo A H; Cohen-Kettenis, Peggy T

2011-08-01

Puberty suppression by means of gonadotropin-releasing hormone analogues (GnRHa) is used for young transsexuals between 12 and 16 years of age. The purpose of this intervention is to relieve the suffering caused by the development of secondary sex characteristics and to provide time to make a balanced decision regarding actual gender reassignment. To compare psychological functioning and gender dysphoria before and after puberty suppression in gender dysphoric adolescents. Of the first 70 eligible candidates who received puberty suppression between 2000 and 2008, psychological functioning and gender dysphoria were assessed twice: at T0, when attending the gender identity clinic, before the start of GnRHa; and at T1, shortly before the start of cross-sex hormone treatment. Behavioral and emotional problems (Child Behavior Checklist and the Youth-Self Report), depressive symptoms (Beck Depression Inventory), anxiety and anger (the Spielberger Trait Anxiety and Anger Scales), general functioning (the clinician's rated Children's Global Assessment Scale), gender dysphoria (the Utrecht Gender Dysphoria Scale), and body satisfaction (the Body Image Scale) were assessed. Behavioral and emotional problems and depressive symptoms decreased, while general functioning improved significantly during puberty suppression. Feelings of anxiety and anger did not change between T0 and T1. While changes over time were equal for both sexes, compared with natal males, natal females were older when they started puberty suppression and showed more problem behavior at both T0 and T1. Gender dysphoria and body satisfaction did not change between T0 and T1. No adolescent withdrew from puberty suppression, and all started cross-sex hormone treatment, the first step of actual gender reassignment. Puberty suppression may be considered a valuable contribution in the clinical management of gender dysphoria in adolescents. © 2010 International Society for Sexual Medicine.

Evoked potentials in pediatric cerebral malaria

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Minal Bhanushali

2011-12-01

Full Text Available Cortical evoked potentials (EP provide localized data regarding brain function and may offer prognostic information and insights into the pathologic mechanisms of malariamediated cerebral injury. As part of a prospective cohort study, we obtained somatosensory evoked potentials (SSEPs and brainstem auditory EPs (AEPs within 24 hours of admission on 27 consecutive children admitted with cerebral malaria (CM. Children underwent follow-up for 12 months to determine if they had any long term neurologic sequelae. EPs were obtained in 27 pediatric CM admissions. Two children died. Among survivors followed an average of 514 days, 7/25 (28.0% had at least one adverse neurologic outcome. Only a single subject had absent cortical EPs on admission and this child had a good neurologic outcome. Among pediatric CM survivors, cortical EPs are generally intact and do not predict adverse neurologic outcomes. Further study is needed to determine if alterations in cortical EPs can be used to predict a fatal outcome in CM.

The area postrema (AP) and the parabrachial nucleus (PBN) are important sites for salmon calcitonin (sCT) to decrease evoked phasic dopamine release in the nucleus accumbens (NAc).

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Whiting, Lynda; McCutcheon, James E; Boyle, Christina N; Roitman, Mitchell F; Lutz, Thomas A

2017-07-01

The pancreatic hormone amylin and its agonist salmon calcitonin (sCT) act via the area postrema (AP) and the lateral parabrachial nucleus (PBN) to reduce food intake. Investigations of amylin and sCT signaling in the ventral tegmental area (VTA) and nucleus accumbens (NAc) suggest that the eating inhibitory effect of amylin is, in part, mediated through the mesolimbic 'reward' pathway. Indeed, administration of the sCT directly to the VTA decreased phasic dopamine release (DA) in the NAc. However, it is not known if peripheral amylin modulates the mesolimbic system directly or whether this occurs via the AP and PBN. To determine whether and how peripheral amylin or sCT affect mesolimbic reward circuitry we utilized fast scan cyclic voltammetry under anesthesia to measure phasic DA release in the NAc evoked by electrical stimulation of the VTA in intact, AP lesioned and bilaterally PBN lesioned rats. Amylin (50μg/kg i.p.) did not change phasic DA responses compared to saline control rats. However, sCT (50μg/kg i.p.) decreased evoked DA release to VTA-stimulation over 1h compared to saline treated control rats. Further investigations determined that AP and bilateral PBN lesions abolished the ability of sCT to suppress evoked phasic DA responses to VTA-stimulation. These findings implicate the AP and the PBN as important sites for peripheral sCT to decrease evoked DA release in the NAc and suggest that these nuclei may influence hedonic and motivational processes to modulate food intake. Copyright © 2017 Elsevier Inc. All rights reserved.

Laser-evoked coloration in polymers

International Nuclear Information System (INIS)

Zheng, H.Y.; Rosseinsky, David; Lim, G.C.

2005-01-01

Laser-evoked coloration in polymers has long been a major aim of polymer technology for potential applications in product surface decoration, marking personalised images and logos. However, the coloration results reported so far were mostly attributed to laser-induced thermal-chemical reactions. The laser-irradiated areas are characterized with grooves due to material removal. Furthermore, only single color was laser-induced in any given polymer matrix. To induce multiple colors in a given polymer matrix with no apparent surface material removal is most desirable and challenging and may be achieved through laser-induced photo-chemical reactions. However, little public information is available at present. We report that two colors of red and green have been produced on an initially transparent CPV/PVA samples through UV laser-induced photo-chemical reactions. This is believed the first observation of laser-induced multiple-colors in the given polymer matrix. It is believed that the colorants underwent photo-effected electron transfer with suitable electron donors from the polymers to change from colorless bipyridilium Bipm 2+ to the colored Bipm + species. The discovery may lead to new approaches to the development of laser-evoked multiple coloration in polymers

Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials.

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Celis-Aguilar, Erika; Hinojosa-González, Ramon; Vales-Hidalgo, Olivia; Coutinho-Toledo, Heloisa

Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8mL of gentamicin intratympanic application at a 30mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Ten patients were included; nine patients with Meniere's disease and one patient with (late onset) delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30dB. Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials). Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

β2-Adrenergic Receptor Activation Suppresses the Rat Phenethylamine Hallucinogen-Induced Head Twitch Response: Hallucinogen-Induced Excitatory Post-synaptic Potentials as a Potential Substrate

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Marek, Gerard J.; Ramos, Brian P.

2018-01-01

5-Hydroxytryptamine2A (5-HT2A) receptors are enriched in layers I and Va of the rat prefrontal cortex and neocortex and their activation increases the frequency of glutamatergic excitatory post-synaptic potentials/currents (EPSP/Cs) onto layer V pyramidal cells. A number of other G-protein coupled receptors (GPCRs) are also enriched in cortical layers I and Va and either induce (α1-adrenergic and orexin2) or suppress (metabotropic glutamate2 [mGlu2], adenosine A1, μ-opioid) both 5-HT-induced EPSCs and head twitches or head shakes induced by the phenethylamine hallucinogen 2,5-dimethoxy-4-iodoamphetamine (DOI). Another neurotransmitter receptor also localized to apparent thalamocortical afferents to layers I and Va of the rat prefrontal cortex and neocortex is the β2-adrenergic receptor. Therefore, we conducted preliminary electrophysiological experiments with rat brain slices examining the effects of epinephrine on electrically-evoked EPSPs following bath application of DOI (3 μM). Epinephrine (0.3–10 μM) suppressed the late EPSPs produced by electrical stimulation and DOI. The selective β2-adrenergic receptor antagonist ICI-118,551 (300 nM) resulted in a rightward shift of the epinephrine concentration-response relationship. We also tested the selective β2-adrenergic receptor agonist clenbuterol and the antagonist ICI-118,551 on DOI-induced head twitches. Clenbuterol (0.3–3 mg/kg, i.p.) suppressed DOI (1.25 mg/kg, i.p.)-induced head twitches. This clenbuterol effect appeared to be at least partially reversed by the selective β2-adrenergic receptor antagonist ICI-118,553 (0.01–1 mg/kg, i.p.), with significant reversal at doses of 0.1 and 1 mg/kg. Thus, β2-adrenergic receptor activation reverses the effects of phenethylamine hallucinogens in the rat prefrontal cortex. While Gi/Go-coupled GPCRs have previously been shown to suppress both the electrophysiological and behavioral effects of 5-HT2A receptor activation in the mPFC, the present work appears

Development of Organogel-Derived Capsaicin Nanoemulsion with Improved Bioaccessibility and Reduced Gastric Mucosa Irritation.

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Lu, Muwen; Cao, Yong; Ho, Chi-Tang; Huang, Qingrong

2016-06-15

Capsaicin (CAP) is the major active component in chili peppers with health-promoting benefits. However, the low bioavailability and irritating quality of CAP greatly limit its applications in functional foods. The objective of this study was to develop a food-grade nanoemulsion to increase the dissolution and bioaccessibility of CAP and to alleviate its irritating effects. To achieve this goal, CAP was first dissolved in medium-chain triacylglycerol (MCT), followed by the addition of sucrose stearate S-370 as organogelator to develop CAP-loaded organogel. The oil-in-water (O/W) emulsion was formed using organogel as the oil phase and Tween 80 as the emulsifier. After ultrasonication treatment, droplet sizes of emulsion were decreased to 168 nm with enhanced dissolution rate and bioaccessibility. In vivo study further confirmed the reduced rat gastric mucosa irritation caused by CAP. The organogel-derived nanoemulsion was proved to be an effective delivery system for CAP-based functional food products.

Correspondence between Traditional Models of Functional Analysis and a Functional Analysis of Manding Behavior

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LaRue, Robert H.; Sloman, Kimberly N.; Weiss, Mary Jane; Delmolino, Lara; Hansford, Amy; Szalony, Jill; Madigan, Ryan; Lambright, Nathan M.

2011-01-01

Functional analysis procedures have been effectively used to determine the maintaining variables for challenging behavior and subsequently develop effective interventions. However, fear of evoking dangerous topographies of maladaptive behavior and concerns for reinforcing infrequent maladaptive behavior present challenges for people working in…

A comparison of auditory evoked potentials to acoustic beats and to binaural beats.

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Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

2010-04-01

The purpose of this study was to compare cortical brain responses evoked by amplitude modulated acoustic beats of 3 and 6 Hz in tones of 250 and 1000 Hz with those evoked by their binaural beats counterparts in unmodulated tones to indicate whether the cortical processes involved differ. Event-related potentials (ERPs) were recorded to 3- and 6-Hz acoustic and binaural beats in 2000 ms duration 250 and 1000 Hz tones presented with approximately 1 s intervals. Latency, amplitude and source current density estimates of ERP components to beats-evoked oscillations were determined and compared across beat types, beat frequencies and base (carrier) frequencies. All stimuli evoked tone-onset components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude in response to acoustic than to binaural beats, to 250 than to 1000 Hz base frequency and to 3 Hz than to 6 Hz beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left temporal lobe areas. Differences between estimated sources of potentials to acoustic and binaural beats were not significant. The perceptions of binaural beats involve cortical activity that is not different than acoustic beats in distribution and in the effects of beat- and base frequency, indicating similar cortical processing. Copyright 2010 Elsevier B.V. All rights reserved.

Study on change of multi-modally evoked potentials in nasopharyngeal carcinoma patients after radiotherapy

International Nuclear Information System (INIS)

Qin Ling; Chen Jiaxin; Zhang Lixiang; Wang Tiejian; Han Min; Lu Xiaoling

2001-01-01

Objective: To investigate possible changes of multi-modally evoked potentials in nasopharyngeal carcinoma patients after radiotherapy. Methods: Altogether 48 nasopharyngeal carcinoma patients receiving primary conventional external beam irradiation were examined before and after radiotherapy to determine their brainstem auditory-evoked potential (BAEP), short-latency somatosensory-evoked potential (SLSEP) and pattern reversal visual-evoked potential (PRVEP). Results: In comparison with the conditions before radiotherapy, in different periods after radiotherapy abnormal peak latency and interval latency difference were found in BAEP, SLSEP and PRVEP. Conclusion: Nasopharyngeal carcinoma after radiotherapy may cause abnormal function of nerve conduction in early periods, which can be showed by BAEP, SLSEP, PRVEP, and injury can be timely detected if the three evoked potentials are used together. Thus authors suggest BAEP, SLSEP, PRVEP should be examined in nasopharyngeal carcinoma patients during and after the radiotherapy so as to find early damage in auditory somatosensory and visual conduction pathways

The Effect of Learning Disability on Contralateral Suppression of Otoacoustic Emissions in Primary Students

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Saeid Sarough Farahani

2006-06-01

Full Text Available Background and Aim: One of the most significant complaints of children with learning disability (LD is difficulty in understanding speech in the presence of background noise. Different studies have shown that the medial olivocochlear bundle(MOCB may play a role in hearing in noise. The MOCB function can be evaluated by the contralateral suppression of tone burst evoked otoacoustic emissions (TBEOAEs.The aim of the present study was to evaluate frequency specifications of MOCB by the contralateral suppression of TBEOAEs at 1,2,3 and 4 KHz in response to contralateral white noise in LD students. Materials and Methods: This case-control study was conducted on 34 LD students aged 7-11 years and 31 normal students matched for age.The contralateral suppression of TBEOAEs was evaluated by comparing TBEOAEs amplitudes with and without contralateral white noise. Results: In the absence of noise there was no significant difference between TBEOAEs amplitudes of two groups. In the presence of noise significant decrease was seen in TBEOAEs amplitudes at 1,2,3 and 4 KHz in both groups. In LD students the amount of this decrement at 1,2 and 4 KHz was lower than in the normal students. Conclusion: A significant diminished suppression effect at 1,2 and 4 KHz in LD students indicates that at these frequency regions MOCB function was reduced. Therefore it suggests that the assessment of MOCB by evaluating the suppression effect of TBEOAEs included in the test battery approach used in the diagnostic of LD students.

Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber).

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Park, Thomas J; Lu, Ying; Jüttner, René; Smith, Ewan St J; Hu, Jing; Brand, Antje; Wetzel, Christiane; Milenkovic, Nevena; Erdmann, Bettina; Heppenstall, Paul A; Laurito, Charles E; Wilson, Steven P; Lewin, Gary R

2008-01-01

In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P) in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

Selective inflammatory pain insensitivity in the African naked mole-rat (Heterocephalus glaber.

Directory of Open Access Journals (Sweden)

Thomas J Park

2008-01-01

Full Text Available In all mammals, tissue inflammation leads to pain and behavioral sensitization to thermal and mechanical stimuli called hyperalgesia. We studied pain mechanisms in the African naked mole-rat, an unusual rodent species that lacks pain-related neuropeptides (e.g., substance P in cutaneous sensory fibers. Naked mole-rats show a unique and remarkable lack of pain-related behaviors to two potent algogens, acid and capsaicin. Furthermore, when exposed to inflammatory insults or known mediators, naked mole-rats do not display thermal hyperalgesia. In contrast, naked mole-rats do display nocifensive behaviors in the formalin test and show mechanical hyperalgesia after inflammation. Using electrophysiology, we showed that primary afferent nociceptors in naked mole-rats are insensitive to acid stimuli, consistent with the animal's lack of acid-induced behavior. Acid transduction by sensory neurons is observed in birds, amphibians, and fish, which suggests that this tranduction mechanism has been selectively disabled in the naked mole-rat in the course of its evolution. In contrast, nociceptors do respond vigorously to capsaicin, and we also show that sensory neurons express a transient receptor potential vanilloid channel-1 ion channel that is capsaicin sensitive. Nevertheless, the activation of capsaicin-sensitive sensory neurons in naked mole-rats does not produce pain-related behavior. We show that capsaicin-sensitive nociceptors in the naked mole-rat are functionally connected to superficial dorsal horn neurons as in mice. However, the same nociceptors are also functionally connected to deep dorsal horn neurons, a connectivity that is rare in mice. The pain biology of the naked mole-rat is unique among mammals, thus the study of pain mechanisms in this unusual species can provide major insights into what constitutes "normal" mammalian nociception.

Index finger somatosensory evoked potentials in blind Braille readers.

Science.gov (United States)

Giriyappa, Dayananda; Subrahmanyam, Roopakala Mysore; Rangashetty, Srinivasa; Sharma, Rajeev

2009-01-01

Traditionally, vision has been considered the dominant modality in our multi-sensory perception of the surrounding world. Sensory input via non-visual tracts becomes of greater behavioural relevance in totally blind individuals to enable effective interaction with the world around them. These include audition and tactile perceptions, leading to an augmentation in these perceptions when compared with normal sighted individuals. The objective of the present work was to study the index finger somatosensory evoked potentials (SEPs) in totally blind and normal sighted individuals. SEPs were recorded in 15 Braille reading totally blind females and compared with 15 age-matched normal sighted females. Latency and amplitudes of somatosensory evoked potential waveforms (N9, N13, and N20) were measured. Amplitude of N20 SEP (a cortical somatosensory evoked potential) was significantly larger in the totally blind than in normal sighted individuals (p Braille reading right index finger. Totally blind Braille readers have larger N20 amplitude, suggestive of greater somatosensory cortical representation of the Braille reading index finger.

Cognitive and neural consequences of memory suppression in major depressive disorder.

Science.gov (United States)

Sacchet, Matthew D; Levy, Benjamin J; Hamilton, J Paul; Maksimovskiy, Arkadiy; Hertel, Paula T; Joormann, Jutta; Anderson, Michael C; Wagner, Anthony D; Gotlib, Ian H

2017-02-01

Negative biases in cognition have been documented consistently in major depressive disorder (MDD), including difficulties in the ability to control the processing of negative material. Although negative information-processing biases have been studied using both behavioral and neuroimaging paradigms, relatively little research has been conducted examining the difficulties of depressed persons with inhibiting the retrieval of negative information from long-term memory. In this study, we used the think/no-think paradigm and functional magnetic resonance imaging to assess the cognitive and neural consequences of memory suppression in individuals diagnosed with depression and in healthy controls. The participants showed typical behavioral forgetting effects, but contrary to our hypotheses, there were no differences between the depressed and nondepressed participants or between neutral and negative memories. Relative to controls, depressed individuals exhibited greater activity in right middle frontal gyrus during memory suppression, regardless of the valence of the suppressed stimuli, and differential activity in the amygdala and hippocampus during memory suppression involving negatively valenced stimuli. These findings indicate that depressed individuals are characterized by neural anomalies during the suppression of long-term memories, increasing our understanding of the brain bases of negative cognitive biases in MDD.

Degree of suppression of associations to stages of addiction by the response of "high".

Science.gov (United States)

Haertzen, C A; Ross, F E

1980-05-01

Male heroin or opiate addicts (N = 78) had a great inclination to give the association "to be high" to the names of nine drugs of abuse in a multiple-forced-choice association test irrespective of whether they had weak or strong habits for the drugs used as stimulus words. The tendency to give the "high" response was so great that other responses indicative of stages of addiction, steps in drug-taking, or drug effects were suppressed below the chance level. When scales were scored so that the response of "high" had no effect, the habit status of the sample revealed by associations with a specific set of words became clearer. A pattern of a strong habit for opiates evoked by opiate names became more evident after elimination of the effect of the response to "high," as did the strong habit pattern in response to drug relevant words. However, the pattern of responses characteristic of a nonaddictive status evoked by clean words remained relatively stable even including the effect of the response of "high." The study suggests that more meaningful responses are found when the response options are multiple rather than fixed.

When guilt evokes self-punishment: evidence for the existence of a Dobby Effect.

Science.gov (United States)

Nelissen, Rob M A; Zeelenberg, Marcel

2009-02-01

Feelings of guilt may be resolved in various ways. The scientific literature has mainly highlighted beneficial interpersonal consequences of guilt, showing repeatedly that guilt motivates compensatory pro-social behavior to repair social bonds. The authors reveal that when opportunities for compensation are not present, guilt may evoke self-punishment. Self-punishment was demonstrated through self-denied pleasure in a scenario study, and by self-enforced penalties in an experimental study. The authors call this tendency for self-punishment the Dobby Effect, and discuss it as an explanation for the widely held conviction that atonement absolves sins, its contribution to some types of psychopathology, as well as its possible functional relevance. (c) 2009 APA, all rights reserved

Behavioral and electrophysiological studies of radiation detection in a freshwater crustacean

International Nuclear Information System (INIS)

Rodriguez, A.; Kimeldorf, D.J.

1976-01-01

Behavioral and electrophysiological studies were done on the crayfish (Pacifastacus trowbridgii Stimpson) to determine its ability to detect exposure to 300 kVp x rays. Behavioral arousal responses were observed at exposure rates of 10 to 30 R/sec. Wholebody and partial-body exposures of eye-stalkless (blinded) animals also induced similar responses and indicated a radiation-sensitive receptor in the abdomen. Prolonged exposure under free choice of residence conditions induced an avoidance of the x-ray field. X-ray exposure of the dark-adapted compound eye evoked an electroretinogram (ERG) that was similar to the light-evoked ERG. The ERG amplitude was directly proportional to the total exposure with exposures less than 300 msec duration and related to the logarithm of the exposure rate with exposures greater than 300 msec. X-ray exposure of receptor sites on the medial branch of the antennule and the cheliped of the first walking-leg did not yield any significant chemoreceptor responses as judged by electrophysiological tests. X-irradiation of the sixth abdominal ganglion in both isolated and in vivo preparations elicited significant increases in neural impulse activity. The latency varied inversely with exposure rate. Spike potentials evoked by x rays were similar to those evoked by light; however, a supplemental increase in spikes of lower amplitude occurred that did not occur during light stimulation. It appears likely that the behavioral response in the crayfish, subjected to abdomen-only exposure, may be instigated by x-ray excitation of the sixth ganglion

Protein kinases mediate increment of the phosphorylation of cyclic AMP -responsive element binding protein in spinal cord of rats following capsaicin injection

Directory of Open Access Journals (Sweden)

Li Junfa

2005-09-01

Full Text Available Abstract Background Strong noxious stimuli cause plastic changes in spinal nociceptive neurons. Intracellular signal transduction pathways from cellular membrane to nucleus, which may further regulate gene expression by critical transcription factors, convey peripheral stimulation. Cyclic AMP-responsive element binding protein (CREB is a well-characterized stimulus-induced transcription factor whose activation requires phosphorylation of the Serine-133 residue. Phospho-CREB can further induce gene transcription and strengthen synaptic transmission by the activation of the protein kinase cascades. However, little is known about the mechanisms by which CREB phosphorylation is regulated by protein kinases during nociception. This study was designed to use Western blot analysis to investigate the role of mitogen-activated protein (MAP/extracellular signal-regulated kinase (ERK kinase (MEK 1/2, PKA and PKC in regulating the phosphorylation of CREB in the spinal cord of rats following intraplantar capsaicin injection. Results We found that capsaicin injection significantly increased the phosphorylation level of CREB in the ipsilateral side of the spinal cord. Pharmacological manipulation of MEK 1/2, PKA and PKC with their inhibitors (U0126, H89 and NPC 15473, respectively significantly blocked this increment of CREB phosphorylation. However, the expression of CREB itself showed no change in any group. Conclusion These findings suggest that the activation of intracellular MAP kinase, PKA and PKC cascades may contribute to the regulation of phospho-CREB in central nociceptive neurons following peripheral painful stimuli.

Newborn hearing screening with transient evoked otoacoustic emissions and automatic auditory brainstem response

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Renata Mota Mamede de Carvallo

2008-09-01

Full Text Available Objective: The aim of the present investigation was to check Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests applied together in regular nurseries and Newborn Intensive Care Units (NICU, as well as to describe and compare the results obtained in both groups. Methods: We tested 150 newborns from regular nurseries and 70 from NICU. Rresults: The newborn hearing screening results using Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response tests could be applied to all babies. The “pass” result for the group of babies from the nursery was 94.7% using Transient Evoked Otoacoustic Emissions and 96% using Automatic Auditory Brainstem Response. The newborn intensive care unit group obtained 87.1% on Transient Evoked Otoacoustic Emissions and 80% on the Automatic Auditory Brainstem Response, and there was no statistical difference between the procedures when the groups were evaluated individually. However, comparing the groups, Transient Evoked Otoacoustic Emissions were presented in 94.7% of the nursery babies and in 87.1% in the group from the newborn intensive care unit. Considering the Automatic Auditory Brainstem Response, we found 96 and 87%, respectively. Cconclusions: Transient Evoked Otoacoustic Emissions and Automatic Auditory Brainstem Response had similar “pass” and “fail” results when the procedures were applied to neonates from the regular nursery, and the combined tests were more precise to detect hearing impairment in the newborn intensive care unit babies.

Sex differences in the jealousy-evoking nature of a rival's body build

NARCIS (Netherlands)

Dijkstra, Pieternel; Buunk, Abraham (Bram)

This study among 185 college students showed that potential rivals with a relatively low waist-to-hip ratio (WHR) evoked more jealousy in women than in men. In contrast, rivals with a relatively high shoulder-to-hip ratio (SHR) evoked more jealousy in men than in women, particularly when the rival

Enhanced brainstem and cortical evoked response amplitudes: single-trial covariance analysis.

Science.gov (United States)

Galbraith, G C

2001-06-01

The purpose of the present study was to develop analytic procedures that improve the definition of sensory evoked response components. Such procedures could benefit all recordings but would especially benefit difficult recordings where many trials are contaminated by muscle and movement artifacts. First, cross-correlation and latency adjustment analyses were applied to the human brainstem frequency-following response and cortical auditory evoked response recorded on the same trials. Lagged cross-correlation functions were computed, for each of 17 subjects, between single-trial data and templates consisting of the sinusoid stimulus waveform for the brainstem response and the subject's own smoothed averaged evoked response P2 component for the cortical response. Trials were considered in the analysis only if the maximum correlation-squared (r2) exceeded .5 (negatively correlated trials were thus included). Identical correlation coefficients may be based on signals with quite different amplitudes, but it is possible to assess amplitude by the nonnormalized covariance function. Next, an algorithm is applied in which each trial with negative covariance is matched to a trial with similar, but positive, covariance and these matched-trial pairs are deleted. When an evoked response signal is present in the data, the majority of trials positively correlate with the template. Thus, a residual of positively correlated trials remains after matched covariance trials are deleted. When these residual trials are averaged, the resulting brainstem and cortical responses show greatly enhanced amplitudes. This result supports the utility of this analysis technique in clarifying and assessing evoked response signals.

Intentional suppression can lead to a reduction of memory strength: Behavioral and electrophysiological findings

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Gerd Thomas Waldhauser

2012-10-01

Full Text Available Previous research has shown that the intentional suppression of unwanted memories can lead to forgetting in later memory tests. However, the mechanisms underlying this effect remain unclear. This study employed recognition memory testing and event-related potentials (ERPs to investigate whether intentional suppression leads to the inhibition of memory representations at an item level. In a think/no-think experiment, participants were cued to either suppress (no-think condition or retrieve (think condition previously learned words, 18 or 0 times. Performance in a final recognition test was significantly reduced for repeatedly suppressed no-think items when compared to the baseline, zero-repetition condition. ERPs recorded during the suppression of no-think items were significantly more negative-going in a time-window around 300 ms when compared to ERPs in the think condition. This reduction correlated with later recognition memory impairment. Furthermore, ERPs to no-think items from 225-450 ms were more negative-going in later phases of the experiment, suggesting a gradual reduction of memory strength with repeated suppression attempts. These effects were dissociable from correlates of recollection (500-600 ms and inhibitory control (450-500 ms that did not vary over the time-course of the experiment and appeared to be under strategic control. Our results give strong evidence that the no-think manipulation involves inhibition of memory representations at an item level.

Is Urgent Evoke a Digital Ba?

DEFF Research Database (Denmark)

Wichmand, Mette

2018-01-01

of such a platform, the World Bank’s online game Urgent Evoke, which has been designed with the pur- pose of engaging citizens in developing innovative solutions for sociopolitical problems like poverty. The analysis is based on Nonaka’s concept of Ba, which means “place” and is described as a platform for advancing...

Impact of Genetic Reduction of NMNAT2 on Chemotherapy-Induced Losses in Cell Viability In Vitro and Peripheral Neuropathy In Vivo.

Directory of Open Access Journals (Sweden)

Richard A Slivicki

Full Text Available Nicotinamide mononucleotide adenylyl transferases (NMNATs are essential neuronal maintenance factors postulated to preserve neuronal function and protect against axonal degeneration in various neurodegenerative disease states. We used in vitro and in vivo approaches to assess the impact of NMNAT2 reduction on cellular and physiological functions induced by treatment with a vinca alkaloid (vincristine and a taxane-based (paclitaxel chemotherapeutic agent. NMNAT2 null (NMNAT2-/- mutant mice die at birth and cannot be used to probe functions of NMNAT2 in adult animals. Nonetheless, primary cortical cultures derived from NMNAT2-/- embryos showed reduced cell viability in response to either vincristine or paclitaxel treatment whereas those derived from NMNAT2 heterozygous (NMNAT2+/- mice were preferentially sensitive to vincristine-induced degeneration. Adult NMNAT2+/- mice, which survive to adulthood, exhibited a 50% reduction of NMNAT2 protein levels in dorsal root ganglia relative to wildtype (WT mice with no change in levels of other NMNAT isoforms (NMNAT1 or NMNAT3, NMNAT enzyme activity (i.e. NAD/NADH levels or microtubule associated protein-2 (MAP2 or neurofilament protein levels. We therefore compared the impact of NMNAT2 knockdown on the development and maintenance of chemotherapy-induced peripheral neuropathy induced by vincristine and paclitaxel treatment using NMNAT2+/- and WT mice. NMNAT2+/- did not differ from WT mice in either the development or maintenance of either mechanical or cold allodynia induced by either vincristine or paclitaxel treatment. Intradermal injection of capsaicin, the pungent ingredient in hot chili peppers, produced equivalent hypersensitivity in NMNAT2+/- and WT mice receiving vehicle in lieu of paclitaxel. Capsaicin-evoked hypersensitivity was enhanced by prior paclitaxel treatment but did not differ in either NMNAT2+/- or WT mice. Thus, capsaicin failed to unmask differences in nociceptive behaviors in either

A Pilot Study: Evaluation of the Effects of Treatment with 0.75% Topical Capsaicin in Patients with Reflex Sympathetic Dystrophy Using Three Phase Bone Scintigraphy

Science.gov (United States)

1991-01-28

years topical capsaicin has recieved growing attention in the treatment of specific pain syndromes. Derived primarily from neonatal and adult rat...dorsal roots19󈧚, cornea19, and coeliac ganglion23 . Similar, and generally parallel, depletions have been shown for cholecystokinin.16-23 A review this...stimulation. Therapy of causalgia has its roots in S. Wier Mitchell’s civil war experience beginning at the United States Army Hospital for Diseases on

Electroencephalographic evoked pain response is suppressed by spinal cord stimulation in complex regional pain syndrome: a case report.

Science.gov (United States)

Hylands-White, Nicholas; Duarte, Rui V; Beeson, Paul; Mayhew, Stephen D; Raphael, Jon H

2016-12-01

Pain is a subjective response that limits assessment. The purpose of this case report was to explore how the objectivity of the electroencephalographic response to thermal stimuli would be affected by concurrent spinal cord stimulation. A patient had been implanted with a spinal cord stimulator for the management of complex regional pain syndrome of both hands for 8 years. Following ethical approval and written informed consent we induced thermal stimuli using the Medoc PATHWAY Pain & Sensory Evaluation System on the right hand of the patient with the spinal cord stimulator switched off and with the spinal cord stimulator switched on. The patient reported a clinically significant reduction in thermal induced pain using the numerical rating scale (71.4 % reduction) with spinal cord stimulator switched on. Analysis of electroencephalogram recordings indicated the occurrence of contact heat evoked potentials (N2-P2) with spinal cord stimulator off, but not with spinal cord stimulator on. This case report suggests that thermal pain can be reduced in complex regional pain syndrome patients with the use of spinal cord stimulation and offers objective validation of the reported outcomes with this treatment.

Effect of binasal occlusion (BNO) on the visual-evoked potential (VEP) in mild traumatic brain injury (mTBI).

Science.gov (United States)

Ciuffreda, Kenneth J; Yadav, Naveen K; Ludlam, Diana P

2013-01-01

The purpose of the experiment was to assess the effect of binasal occlusion (BNO) on the visually-evoked potential (VEP) in visually-normal (VN) individuals and in those with mild traumatic brain injury (mTBI) for whom BNO frequently reduces their primary symptoms related to abnormally-increased visual motion sensitivity (VMS). Subjects were comprised of asymptomatic VN adults (n = 10) and individuals with mTBI (n = 10) having the symptom of VMS. Conventional full-field VEP testing was employed under two conditions: without BNO and with opaque BNO which blocked regions on either side of the VEP test stimulus. Subjective impressions were also assessed. In VN, the mean VEP amplitude decreased significantly with BNO in all subjects. In contrast, in mTBI, the mean VEP amplitude increased significantly with BNO in all subjects. Latency was normal and unaffected in all cases. Repeat VEP testing in three subjects from each group revealed similar test-re-test findings. Visuomotor activities improved, with reduced symptoms, with BNO in the mTBI group. It is speculated that individuals with mTBI habitually attempt to suppress visual information in the near retinal periphery to reduce their abnormal VMS, with addition of the BNO negating the suppressive influence and thus producing a widespread disinhibition effect and resultant increase in VEP amplitude.

MRI correlates of interaction between gender and expressive suppression among the Chinese population.

Science.gov (United States)

Wang, Kangcheng; Huang, Hui; Chen, Li; Hou, Xin; Zhang, Yong; Yang, Junyi; Hao, Xin; Qiu, Jiang

2017-04-07

Expressive suppression is a kind of emotion regulation strategies by suppressing behaviors related to emotional responding. Despite the amount of behavioral research on expressive suppression, the structural and functional mechanisms underlying the interaction between gender and expressive suppression in Chinese healthy subjects have remained unknown. In the current study, we assessed the levels of expressive suppression and acquired the structural and functional imaging data from 273 Chinese individuals. A nearly automatic cortical processing technique was used to calculate cortical thickness for each subject. The results from cortical thickness analyses revealed a significant interaction between gender and expressive suppression in the superior frontal gyrus. Then, we conducted the whole-brain functional connectivity analysis with the seed of the superior frontal gyrus to explore the functionally related regions of brain. Subsequent analysis of the interaction between gender and expressive suppression indicated a significant functional connectivity between the superior frontal gyrus and default mode network (DMN) core regions, including the medial prefrontal cortex, precuneus and parahippocampal gyrus. Our results provided the robust empirical evidence illustrating the role of the superior frontal gyrus and DMN in gender difference of expressive suppression among the Chinese population. These findings might have implications for understanding gender difference in emotion processing and regulation. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Evoked Emotions Predict Food Choice

OpenAIRE

Dalenberg, Jelle R.; Gutjar, Swetlana; ter Horst, Gert J.; de Graaf, Kees; Renken, Remco J.; Jager, Gerry

2014-01-01

In the current study we show that non-verbal food-evoked emotion scores significantly improve food choice prediction over merely liking scores. Previous research has shown that liking measures correlate with choice. However, liking is no strong predictor for food choice in real life environments. Therefore, the focus within recent studies shifted towards using emotion-profiling methods that successfully can discriminate between products that are equally liked. However, it is unclear how well ...

The consequences of suppressing affective displays in romantic relationships: A challenge and threat perspective.

Science.gov (United States)

Peters, Brett J; Jamieson, Jeremy P

2016-10-01

Emotion suppression is one of the most studied topics in emotion regulation. However, little is known about how response-focused regulation strategies unfold in romantic relationships from the perspectives of both emotion regulators and their interaction partners. Using the biopsychosocial (BPS) model of challenge and threat as an organizing framework, 2 experiments examined effects of expressive suppression (vs. expression) on affective, cognitive, physiological, and behavioral processes in regulators and their romantic partners. In Experiment 1 a crowd-sourced sample of individuals currently in a romantic relationship simulated scenarios in which the self or partner engaged in response-focused emotion regulation (expression or suppression of affective displays). Suppressors expected worse outcomes compared with expressers. However, individuals on the receiving end of suppression (suppression targets) did not differ from expression targets. Experiment 2 then examined romantic couples' responses to suppression/expression in vivo. Regulators were randomly assigned to suppress/express affective displays and partners (targets) were unaware of the manipulation. Suppressors and suppression targets exhibited more malignant physiological responses (increased vascular resistance and elevated cortisol reactivity) during an emotional conversation and reduced intimacy behavior as measured with a novel touch task. Consequences for relationship processes are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The Relationship of Visual Evoked Potential Asymmetries to the Performance of Sonar Operators

Science.gov (United States)

1981-08-11

also been related to EP variability. Schizophrenic adults and patients with Korsakoff’s Syndrome have shown higher evoked potential variability than...average evoked response in Korsakoff patients. J. Psychiatry Res. 6: 253-260, 1969. Santoro, T. and D. Fender. Rules for the perception of

Interpersonal Complementarity – Self-rated Behavior by Normal and Antisocial Adolescents with a Liked and Disliked Peer

Directory of Open Access Journals (Sweden)

Camilla Hakelind

2007-12-01

Full Text Available The principle of complementarity in interpersonal theory and the SASB model (Structural Analysis of Social Behavior as developed by Benjamin (1974 were used to study how adolescents in a normal group of 60 adolescents and a group of 42 adolescents with severe behavioural problems rated that they usually behaved in relation to a liked and disliked peer. The peer’s behaviour varied in a systematic way on the dimensions of affiliation and dominance. Complementary behavior was defined as the same behaviour from peer and self and anticomplementarity was defined as opposite behaviour from self in relation the peer’s behavior. Consistent over the two groups complementarity and anticomplementarity were influenced by both the peer’s behaviour and type of relationship with the peer. Friendly behaviour from a liked peer evoked much more complementary friendly behaviour compared to a disliked peer who with the same behaviour evoked almost as much anticomplementary hostile behaviour as complementary friendly behaviour. Hostile behaviour from a disliked peer evoked much more complementary hostile behaviour compared to a liked peer with the same kind of behavior. Autonomy granting from a liked peer evoked more complementary autonomous behaviour compared to a disliked peer. Differences between the two groups were small and only in relation with a disliked peer. The results were discussed in terms of interpersonal theory and the principle of complementarity with focus on kind of relationship.

Dynamic interactions of the cortical networks during thought suppression.

Science.gov (United States)

Aso, Toshihiko; Nishimura, Kazuo; Kiyonaka, Takashi; Aoki, Takaaki; Inagawa, Michiyo; Matsuhashi, Masao; Tobinaga, Yoshikazu; Fukuyama, Hidenao

2016-08-01

Thought suppression has spurred extensive research in clinical and preclinical fields, particularly with regard to the paradoxical aspects of this behavior. However, the involvement of the brain's inhibitory system in the dynamics underlying the continuous effort to suppress thoughts has yet to be clarified. This study aims to provide a unified perspective for the volitional suppression of internal events incorporating the current understanding of the brain's inhibitory system. Twenty healthy volunteers underwent functional magnetic resonance imaging while they performed thought suppression blocks alternating with visual imagery blocks. The whole dataset was decomposed by group-independent component analysis into 30 components. After discarding noise components, the 20 valid components were subjected to further analysis of their temporal properties including task-relatedness and between-component residual correlation. Combining a long task period and a data-driven approach, we observed a right-side-dominant, lateral frontoparietal network to be strongly suppression related. This network exhibited increased fluctuation during suppression, which is compatible with the well-known difficulty of suppression maintenance. Between-network correlation provided further insight into the coordinated engagement of the executive control and dorsal attention networks, as well as the reciprocal activation of imagery-related components, thus revealing neural substrates associated with the rivalry between intrusive thoughts and the suppression process.

Mapping social behavior-induced brain activation at cellular resolution in the mouse

Science.gov (United States)

Kim, Yongsoo; Venkataraju, Kannan Umadevi; Pradhan, Kith; Mende, Carolin; Taranda, Julian; Turaga, Srinivas C.; Arganda-Carreras, Ignacio; Ng, Lydia; Hawrylycz, Michael J.; Rockland, Kathleen; Seung, H. Sebastian; Osten, Pavel

2014-01-01

Understanding how brain activation mediates behaviors is a central goal of systems neuroscience. Here we apply an automated method for mapping brain activation in the mouse in order to probe how sex-specific social behaviors are represented in the male brain. Our method uses the immediate early gene c-fos, a marker of neuronal activation, visualized by serial two-photon tomography: the c-fos-GFP-positive neurons are computationally detected, their distribution is registered to a reference brain and a brain atlas, and their numbers are analyzed by statistical tests. Our results reveal distinct and shared female and male interaction-evoked patterns of male brain activation representing sex discrimination and social recognition. We also identify brain regions whose degree of activity correlates to specific features of social behaviors and estimate the total numbers and the densities of activated neurons per brain areas. Our study opens the door to automated screening of behavior-evoked brain activation in the mouse. PMID:25558063

An Idle-State Detection Algorithm for SSVEP-Based Brain-Computer Interfaces Using a Maximum Evoked Response Spatial Filter.

Science.gov (United States)

Zhang, Dan; Huang, Bisheng; Wu, Wei; Li, Siliang

2015-11-01

Although accurate recognition of the idle state is essential for the application of brain-computer interfaces (BCIs) in real-world situations, it remains a challenging task due to the variability of the idle state. In this study, a novel algorithm was proposed for the idle state detection in a steady-state visual evoked potential (SSVEP)-based BCI. The proposed algorithm aims to solve the idle state detection problem by constructing a better model of the control states. For feature extraction, a maximum evoked response (MER) spatial filter was developed to extract neurophysiologically plausible SSVEP responses, by finding the combination of multi-channel electroencephalogram (EEG) signals that maximized the evoked responses while suppressing the unrelated background EEGs. The extracted SSVEP responses at the frequencies of both the attended and the unattended stimuli were then used to form feature vectors and a series of binary classifiers for recognition of each control state and the idle state were constructed. EEG data from nine subjects in a three-target SSVEP BCI experiment with a variety of idle state conditions were used to evaluate the proposed algorithm. Compared to the most popular canonical correlation analysis-based algorithm and the conventional power spectrum-based algorithm, the proposed algorithm outperformed them by achieving an offline control state classification accuracy of 88.0 ± 11.1% and idle state false positive rates (FPRs) ranging from 7.4 ± 5.6% to 14.2 ± 10.1%, depending on the specific idle state conditions. Moreover, the online simulation reported BCI performance close to practical use: 22.0 ± 2.9 out of the 24 control commands were correctly recognized and the FPRs achieved as low as approximately 0.5 event/min in the idle state conditions with eye open and 0.05 event/min in the idle state condition with eye closed. These results demonstrate the potential of the proposed algorithm for implementing practical SSVEP BCI systems.

Conduction velocity of the human spinothalamic tract as assessed by laser evoked potentials

DEFF Research Database (Denmark)

Cruccu, G.; Iannetti, G. D.; Agostino, R.

2000-01-01

To study the conduction velocity of the spinothalamic tract (STT) we delivered CO2 laser pulses, evoking pinprick sensations, to the skin overlying the vertebral spinous processes at different spinal levels from C5 to T10 and recorded evoked potentials (LEPs) in 15 healthy human subjects...

Evidence that 5-hydroxytryptamine3 receptors mediate cytotoxic drug and radiation-evoked emesis

International Nuclear Information System (INIS)

Miner, W.D.; Sanger, G.J.; Turner, D.H.

1987-01-01

The involvement of 5-hydroxytryptamine (5-HT) 5-HT 3 receptors in the mechanisms of severe emesis evoked by cytotoxic drugs or by total body irradiation have been studied in ferrets. Anti-emetic compounds tested were domperidone (a dopamine antagonist), metoclopramide (a gastric motility stimulant and dopamine antagonist at conventional doses, a 5-HT 3 receptor antagonist at higher doses) and BRL 24924 (a potent gastric motility stimulant and a 5-HT 3 receptor antagonist). Domperidone or metoclopramide prevented apomorphine-evoked emesis, whereas BRL 24924 did not. Similar doses of domperidone did not prevent emesis evoked by cis-platin or by total body irradiation, whereas metoclopramide or BRL 24924 greatly reduced or prevented these types of emesis. Metoclopramide and BRL 24924 also prevented emesis evoked by a combination of doxorubicin and cyclophosphamide. These results are discussed in terms of a fundamental role for 5-HT 3 receptors in the mechanisms mediating severely emetogenic cancer treatment therapies. (author)

Interhemispheric Asymmetries in Visual Evoked Potential Amplitude

Science.gov (United States)

1980-06-12

Layne, 1965) and of patients with Korsakoff’s syndrome (Malerstein and Callaway, 1969) . In the schizophrenics, the high variability is related to poor...communication. Malerstein, A. J., Callaway, E. Two-tone average evoked response in Korsakoff patients. J. Psychiatr. Res. 6: 253-260, 1969. Marsh, G

Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

Energy Technology Data Exchange (ETDEWEB)

Nightingale, S. (Royal Victoria Infirmary, Newcastle upon Tyne (UK)); Schofield, I.S.; Dawes, P.J.D.K. (Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

1984-01-01

Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings.

Sexual Behaviors in Autism: Problems of Definition and Management.

Science.gov (United States)

Realmuto, George M.; Ruble, Lisa A.

1999-01-01