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Total Activity (total + activity)
Selected AbstractsPhotic and non-photic entrainment on daily rhythm of locomotor activity in goatsANIMAL SCIENCE JOURNAL, Issue 1 2010Claudia GIANNETTO ABSTRACT We studied the photic (L/D cycle) and non-photic (restricted feeding) entrainment on the patterns of daily rhythm of total locomotor activity in goats. Six female Maltese goats were subjected to three different artificial L/D cycles: 12/12 L/D, 12/12 D/L and constant light. During the 12/12 L/D and 12/12 D/L, food and water were available ad libitum. During constant light, animals were subjected to a restricted feeding treatment. Total activity was recorded by means of an actigraphy-based data logger (Actiwatch-Mini®). Our results showed that goats exhibited clear daily rhythms of activity in 12/12 L/D cycle, 12/12 D/L cycle and constant light, although they showed FAA prior the feeding time during the restricted feeding treatment. Goats were diurnal, with activity consistently beginning promptly following the onset of light. Even when the L/D cycle was delayed by 12 h on some days, to the daily rhythm was re-established. During the constant light period, the onset of activity was linked to the time of food administration. Our study evidences two factors for the rhythm of total locomotor activity in goats: light stimuli (photic) and food access (non photic), strongly coupled to permit organisms the adaptive temporal coordination of behaviour with stable and unstable environmental periodicities. [source] Children's physical activity and psychological health: the relevance of intensityACTA PAEDIATRICA, Issue 6 2009Gaynor Parfitt Abstract Aim: To examine the relevance of physical activity intensity when assessing the relationship between activity and psychological health in 9,10-year-old children. Methods: Activity was assessed by accelerometry in 57 boys (n = 23) and girls (n = 34). Total activity and time spent in very light (,1.9 METs) through to vigorous activity (,6 METs) were recorded. Psychological health inventories to assess anxiety, depression and aspects of self-worth were completed. Results: Time accumulated in very light activity had positive correlations with anxiety and depression (r > 0.30, p < 0.05) and negative correlations with aspects of physical self-worth (r > ,0.29, p < 0.05). Time accumulated in vigorous activity had negative correlations with anxiety and behavioural conduct (r > ,0.30, p < 0.05) and positive correlation with aspects of physical self-worth (r > 0.28, p < 0.05). Children spending over 4 h in very light intensity activity had more negative psychological profiles than children spending under 4 h at this intensity. Conclusion: Aspects of psychological health were negatively correlated with very light intensity activity and positively correlated with vigorous intensity activity. Further research should investigate whether reducing time spent in very light intensity activity and increasing time spent in vigorous intensity activity improves psychological health in children. [source] Human salivary immunoglobulin and antigen-specific antibody activity after tonsillectomyMOLECULAR ORAL MICROBIOLOGY, Issue 5 2001N. K. Childers The importance of the lymphoid tissue collectively known as Waldeyer's ring, which includes the palatine, lingual and nasopharyngeal tonsils, in the induction and contribution of specific antibody responses in human saliva is not clear. The purpose of this study was to determine whether salivary immunoglobulin A (IgA) levels differ in quantity and quality between subjects who have had a tonsillectomy and age, sex and race-matched controls. Parotid saliva, whole saliva, and blood serum samples were collected from 25 volunteer children who had undergone tonsillectomy (T,) within 6,14 months of sampling and from 25 age, sex and race-matched controls. The levels of total IgA (and subclasses) in saliva, and of antigen-specific salivary IgA and serum IgA and IgG antibodies to 4,9 relevant antigens were analyzed by ELISA. No significant difference was observed in the mean total IgA and IgA subclass levels in parotid and whole saliva, although the mean levels for children with a T, were slightly lower. Children with a T, had significantly higher parotid salivary IgA and IgA1 specific/total activity than controls. The total and specific whole saliva IgA and the specific serum IgA or IgG activities were not significantly different from controls. These results indicate an association between the removal of tonsils and increased levels of specific IgA activity in parotid saliva within the first year after a T,. [source] The effect of oral splint devices on sleep bruxism: a 6-week observation with an ambulatory electromyographic recording deviceJOURNAL OF ORAL REHABILITATION, Issue 7 2006T. HARADA summary, This study investigated the effect of stabilization splint (SS) and palatal splint (PS), which had the same design as SS except for the elimination of the occlusal coverage, on sleep bruxism (SB) using a portable electromyographic (EMG) recording system. Sixteen bruxers participated in this study. The EMG activities of the right masseter muscle during sleep were recorded for three nights each in the following five recording periods: before, immediately after, and 2, 4 and 6 weeks after the insertion of the splint. The crossover design, in which each splint was applied to each subject for 6 weeks with an interval of 2 months for a washout period, was employed in this randomized-controlled study. The number of SB events, duration and total activities of SB were analysed. The number of SB events before the insertion of splints (baseline) was 2·98 ± 1·61 times h,1. Both splints significantly reduced SB immediately after the insertion of devices (P < 0·05, one-way repeated-measures anova followed by Dunnett); however, no reduction was observed in 2, 4 or 6 weeks (P > 0·05). There was no statistical difference in the effect on SB between the SS and PS (P > 0·05, two-way repeated-measures anova). Both splints reduced the masseter EMG activities associated with SB; however, the effect was transient. [source] Relationship between intensity of physical activity and health-related quality of life in Portuguese institutionalized elderlyGERIATRICS & GERONTOLOGY INTERNATIONAL, Issue 4 2008Alexandrina Lobo Aims: Health-related quality of life (HRQOL) is considered to be the key goal for health promotion in older people. This study explores the relationship between HRQOL and objectively measured intensity of physical activity (PA) in institutionalized older adults. The analysis of the PA patterns of the subjects in relation to recommended levels of PA was also performed. Methods: One hundred and eighty-five residents of long-term care homes aged 65 years or more, volunteered for this study. The Medical Outcome Study Short Form 36-Item health survey (MOS SF-36) questionnaires and the uni-axial MTI Actigraph were used to assess HRQOL and PA, respectively. Participants were classified as less active, reasonably active and more active by tertile of moderated physical activity (MPA). Results: (i) The men represented a greater number of counts/h and min of MPA in all the tertile groups; (ii) men from the less active group had a significantly higher body mass index; (iii) women came third and exhibited less total activity even though they used this time in more intense activities; (iv) there was a higher significant correlation between MPA, physical function and negative association with body pain in relation to the time of institutionalization in both sexes but was more strongly visible in men; and (v) only men presented a significant positive association with physical health, mental health and vitality. Conclusion: Any intensity of PA seems to be better than no activity for HRQOL, but MPA confers greater benefits for the perception of physical function and body pain in the case of institutionalized elderly persons. [source] Characterization of human sperm N -acetylglucosaminidaseINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2008S. L. Perez Martinez Summary N -acetylglucosaminidase (NAG) is particularly active in mammalian spermatozoa and appears to be involved in fertilization. Although it is assumed that this enzyme is acrosomal, previous results from our laboratory suggest the presence of NAG at the sperm plasma membrane level. The present study attempted to analyse the subcellular distribution of this enzyme in human spermatozoa. Sperm were incubated under different conditions and NAG activity measured in the soluble extracts and cell pellets using a specific fluorometric substrate. A significant proportion of NAG activity was released when sperm were incubated in culture medium, suggesting a weak association with the plasma membrane. This location was confirmed by western blot analysis of plasma membrane fractions and immunofluorescence on non-permeabilized sperm, which showed a positive signal mainly on the acrosomal domain. The distribution of NAG activity between plasma membrane and acrosome was analysed after cell disruption by freezing and thawing. Triton X-100 stimulated sperm and epididymal NAG activity but not the enzyme obtained from other sources. In addition, biotinylated human recombinant NAG was able to bind to human sperm. Finally, after sperm incubation under capacitating conditions, NAG total activity increased and the sperm enzyme lost its ability to be stimulated by Triton X-100. The possible connection of these results with sperm maturation, capacitation and NAG participation in primary binding to the zona pellucida, was discussed. [source] Can physical activity modulate pancreatic cancer risk? a systematic review and meta-analysisINTERNATIONAL JOURNAL OF CANCER, Issue 12 2010Michael A. O'Rorke Abstract Numerous epidemiological studies have examined the association between physical activity and pancreatic cancer; however, findings from individual cohorts have largely not corroborated a protective effect. Among other plausible mechanisms, physical activity may reduce abdominal fat depots inducing metabolic improvements in glucose tolerance and insulin sensitivity, thereby potentially attenuating pancreatic cancer risk. We performed a systematic review to examine associations between physical activity and pancreatic cancer. Six electronic databases were searched from their inception through July 2009, including MEDLINE and EMBASE, seeking observational studies examining any physical activity measure with pancreatic cancer incidence/mortality as an outcome. A random effects model was used to pool individual effect estimates evaluating highest vs. lowest categories of activity. Twenty-eight studies were included. Pooled estimates indicated a reduction in pancreatic cancer risk with higher levels of total (five prospective studies, RR: 0.72, 95% CI: 0.52,0.99) and occupational activity (four prospective studies, RR: 0.75, 95% CI: 0.59,0.96). Nonsignificant inverse associations were seen between risks and recreational and transport physical activity. When examining exercise intensity, moderate activity appeared more protective (RR: 0.79, 95% CI: 0.52,1.20) than vigorous activity (RR: 0.97, 95% CI: 0.85,1.11), but results were not statistically significant and the former activity variable incorporated marked heterogeneity. Despite indications of an inverse relationship with higher levels of work and total activity, there was little evidence of such associations with recreational and other activity exposures. [source] Effect of Antipsychotic Withdrawal on Behavior and Sleep/Wake Activity in Nursing Home Residents with Dementia: A Randomized, Placebo-Controlled, Double-Blinded Study The Bergen District Nursing Home StudyJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 10 2004Sabine Ruths MD Objectives: To explore the effect on sleep/wake activity and on behavioral and psychological symptoms of the withdrawal of antipsychotic medications from nursing home (NH) patients with dementia. Design: Randomized, placebo-controlled, double-blind trial. Setting: NHs in Bergen, Norway. Participants: Thirty patients (mean age 83.5) taking haloperidol, risperidone, or olanzapine for nonpsychotic symptoms. Intervention: Study participants were randomly assigned to withdrawal (intervention group) or continued treatment with antipsychotic medications (reference group) for 4 consecutive weeks. Measurements: Behavioral rating using the Neuropsychiatric Inventory Questionnaire (NPI-Q) and actigraphy. Results: After antipsychotic withdrawal, behavioral scores remained stable or improved in 11 of 15 patients, whereas four had worsening scores. Actigraphy revealed decreased sleep efficiency after drug discontinuation and increased 24-hour and night activity in both groups. Actigraphy records of nighttime and daytime activity indicated sleep problems and restlessness, in terms of the NPI-Q. One patient was restarted on antipsychotics. Conclusion: Antipsychotic drug withdrawal affected activity and sleep efficiency over the short term. Increases in total activity and impaired sleep quality after drug discontinuation should be monitored, because the long-term effect of these changes is not known. The NPI-Q and actigraphy are feasible tools that disclose relevant changes occurring during antipsychotic withdrawal in NH patients with dementia. Their use in clinical practice should be substantiated by larger studies. [source] Affinity and catalytic heterogeneity of polyclonal myelin basic protein-hydrolyzing IgGs from sera of patients with multiple sclerosisJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 3 2010Galina A. Legostaeva Abstract Human myelin basic protein (hMBP)-hydrolyzing activity was recently shown to be an intrinsic property of antibodies (Abs) from multiple sclerosis (MS) patients. Here, we present the first evidence demonstrating a significant diversity of different fractions of polyclonal IgGs (pIgGs) from MS patients in their affinity for hMBP and in the ability of pIgGs to hydrolyze hBMP at different optimal pHs (3,10.5). IgGs containing ,- and ,-types of light chains demonstrated comparable relative activities in the hydrolysis of hMBP. IgGs of IgG1,IgG4 sub-classes were analyzed for catalytic activity. IgGs of all four sub-classes were catalytically active, with their contribution to the total activity of Abzs in the hydrolysis of hMBP and its 19-mer oligopeptide increasing in the order: IgG1 (1.5,2.1%) < IgG2 (4.9,12.8%) < IgG3 (14.7,25.0%) < IgG4 (71,78%). Our findings suggest that the immune systems of individual MS patients generate a variety of anti-hMBP abzymes with different catalytic properties, which can attack hMBP of myelin-proteolipid shell of axons, playing an important role in MS pathogenesis. [source] Antioxidant Activity of Crude Extract, Alkaloid Fraction, and Flavonoid Fraction from Boldo (Peumus boldus Molina) LeavesJOURNAL OF FOOD SCIENCE, Issue 5 2004N. Quezada ABSTRACT: Boldo is an endemic plant from Chile widely used in folk medicine, whose biological (mainly antioxidant) activity has been attributed to the presence of the alkaloid boldine. The aim of this study was to determine the contribution of the flavonoid and other crude fractions from boldo leaves to the antioxidant activity of extracts. The main constituent in the flavonoid fraction was also isolated. The antioxidant activity and reducing power of crude boldo extract and fractions were measured and compared with natural and synthetic antioxidants. The antioxidant activity of boldo leaf extracts came mainly from the flavonoid fraction (44.1%) followed by the alkaloid fraction (15.6%), with catechin and boldine being the main contributors of the antioxidant activity of these 2 fractions (60.9% and 35.6% of the total activity, respectively). On the basis of these results, we propose to use catechin and boldine as markers for the antioxidant activity of boldo leaves. Tailor-made antioxidants to be used in foods can be prepared by enriching these 2 fractions. [source] Purification and some properties of a cysteine proteinase from sorghum malt variety SK5912JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 2 2004Augustine C Ogbonna Abstract A cysteine proteinase from sorghum malt variety SK5912 was purified by a combination of 4 M sucrose fractionation, ion-exchange chromatography on Q- and S-Sepharose (fast flow), gel filtration chromatography on Sephadex G-100 and hydrophobic interaction chromatography on Phenyl Sepharose CL-4B. The enzyme was purified 8.4-fold to give a 13.4% yield relative to the total activity in the crude extract and a final specific activity of 2057.1 U mg,1 protein. SDS,PAGE revealed two migrating protein bands corresponding to apparent relative molecular masses of 55 and 62 kDa, respectively. The enzyme was optimally active at pH 6.0 and 50 °C, not influenced across a relatively broad pH range of 5.0,8.0 and retained over 60% activity at 70 °C after 30-min incubation. It was highly significantly (P < 0.001) inhibited by Hg2+, appreciably (P < 0.01) inhibited by Ag+, Ba2+ and Pb2+ but highly significantly (P < 0.001) activated by Co2+, Mn2+ and Sr2+. The proteinase was equally highly significantly (P < 0.001) inhibited by both iodoacetate and p -chloromercuribenzoate and hydrolysed casein to give the following kinetic constants: Km = 0.33 mg ml,1; Vmax = 0.08 µmol ml,1 min,1. Copyright © 2004 Society of Chemical Industry [source] Rubisco expression in rice leaves is related to genotypic variation of photosynthesis under elevated growth CO2 and temperaturePLANT CELL & ENVIRONMENT, Issue 12 2003R. W. GESCH ABSTRACT Genetic modifications of agronomic crops will likely be necessary to cope with global climate change. This study tested the hypotheses that genotypic differences in rice (Oryza sativa L.) leaf photosynthesis at elevated [CO2] and temperature are related to protein and gene expression of Rubisco, and that high growth temperatures under elevated [CO2] negatively affect photosystem II (PSII) photochemical efficiency. Two rice cultivars representing an indica (cv. IR72) and japonica type (cv. M103) were grown in 350 (ambient) and 700 (elevated) µmol CO2 mol,1 at 28/18, 34/24 and 40/30 °C sinusoidal maximum/minimum, day/night temperatures in outdoor, sunlit, environment-controlled chambers. Leaf photosynthesis of IR72 favoured higher growth temperatures more than M103. Rubisco total activity and protein content were negatively affected in both genotypes by high temperatures and elevated CO2. However, at moderate to high growth temperatures, IR72 leaves averaged 71 and 39% more rbcS transcripts than M103 under ambient and elevated CO2, respectively, and likewise had greater Rubisco activity and protein content. Expression of psbA (D1 protein of PSII) in IR72 leaves increased with temperature, whereas it remained constant for M103, except for a 20% decline at 40/30 °C under elevated CO2. Even at the highest growth temperatures, PSII photochemical efficiency was not impaired in either genotype grown under either ambient or elevated CO2. Genotypic differences exist in rice for carboxylation responses to elevated CO2 and high temperatures, which may be useful in developing genotypes suited to cope with global climate changes. [source] Expression and activity of isoenzymes of superoxide dismutase in wheat roots in response to hypoxia and anoxiaPLANT CELL & ENVIRONMENT, Issue 2 2000S. Biemelt ABSTRACT We investigated the effects of hypoxia, anoxia and reaeration on enzymatic activity and expression of superoxide dismutase (SOD) isoforms in wheat roots (Triticum aestivum L.). Neither hypoxia nor subsequent re-aeration caused significant changes in SOD isoenzyme pattern compared with aerated controls. However, anoxia led to the appearance of additional activity bands of SOD in native gels resulting in an increase in total activity. Additional isoformic bands remained also apparent in the following recovery period. Re-aeration following both hypoxia and anoxia resulted in an increased content of hydrogen peroxide in roots. SOD transcript and protein levels were only slightly altered in response to hypoxia. Although SOD mRNA levels were diminished, protein content of different SOD isoforms increased with duration of anoxia. Incubation of roots with cycloheximide revealed that the additional activity bands and higher SOD protein content under anoxia were not due to de novo synthesis. Crude subcellular fractionation experiments implied that the anoxia-responsive SOD isoforms might be plastid-associated. We suggest that SOD is a very stable enzyme which, under anoxia, accumulates relative to total protein content and remains active even after protein modification under severe environmental stress conditions. [source] A quick method for the assessment of activity and inhibition of fish amylasesAQUACULTURE NUTRITION, Issue 1 2001I. Fernández A sensitive and quick method was developed to determine the presence of ,-amylase in the gut of aquatic organisms, as well as its sensitivity to inhibitors. The assay is based on the utilization of Petri dishes filled with starch,agarose gel as a substrate for the enzyme solution, which is placed in small wells punched in the surface. Circular zones produced by the action of amylase remain colourless after staining with lugol. Pure commercial porcine amylase was used to fit the better conditions for developing the assay (1 g L,1 starch in the gels, 4 h of incubation). The diameter of the cleared zones were related to the activity of enzyme and the method detected linearly amylase activity in a range of 2,20 U well,1, so it was used to reveal the presence of amylase in digestive extracts obtained from different sparid fish. The method was also used to evaluate the effect produced by a specific inhibitor on fish amylases, showing a linear response when the ratio inhibitor:enzyme (in units) changed from 20:1 to 2:1. Comparison of the cleared zones produced by amylases of sparid fish in the presence or absence of inhibitor, revealed differences in their sensitivity to inhibition, which ranged from 15 to 50% of total activity. The assay is proposed for a preliminary evaluation of possible inhibitors contained in feedstuffs used in fish feeding. [source] Cloning and expression of a Melanocarpus albomyces steryl esterase gene in Pichia pastoris and Trichoderma reeseiBIOTECHNOLOGY & BIOENGINEERING, Issue 3 2006Hanna Kontkanen Abstract The ste1 gene encoding a steryl esterase was isolated from the thermophilic fungus Melanocarpus albomyces. The gene has one intron, and it encodes a protein consisting of 576 amino acids. The deduced amino acid sequence of the steryl esterase was shown to be related to lipases and other esterases such as carboxylesterases. Formation of mature protein requires post-translational removal of a putative 18-amino-acid signal sequence and a 13-residue propeptide at the N-terminus. The intronless version of the Melanocarpus albomyces ste1 gene was expressed in Pichia pastoris under the inducible AOX1 promoter. The production level was low, and a large proportion of the total activity yield was found to be present intracellularly. However, the fact that steryl esterase activity was produced by P. pastoris cells carrying the expression cassette confirmed that the correct gene had been cloned. The ste1 gene was subsequently expressed in T. reesei under the inducible cbh1 promoter, and a clearly higher production level was obtained. About 60% of the total activity was bound to the fungal mycelium or to solid components of the culture medium, or existed as aggregates. Triton X-100 was successfully used to recover this activity. The heterologous production system in T. reesei provides a means of producing M. albomyces steryl esterase STE1 reliably in large scale for future studies. © 2006 Wiley Periodicals, Inc. [source] Expression of Secreted His-Tagged S -adenosylmethionine Synthetase in the Methylotrophic Yeast Pichia pastoris and Its Characterization, One-Step Purification, and ImmobilizationBIOTECHNOLOGY PROGRESS, Issue 1 2008Yunxing Luo S -Adenosylmethionine synthetase (SAM synthetase) catalyzes the synthesis of S -adenosylmethionine (SAM), which plays an important role in cellular functions such as methylation, sulfuration, and polyamine synthesis. To develop a simple and effective way to enzymatically synthesize and produce SAM, a soluble form of SAM synthetase encoded by SAM2 from Saccharomycescerevisiae was successfully produced at high level (,200 mg/L) by the recombinant methylotrophic yeast Pichiapastoris. The secreted His6 -tagged SAM synthetase was purified in a single chromatography step with a yield of approximately 82% for the total activity. The specific activity of the purified synthetase was 23.84 U/mg. The recombinant SAM synthetase could be a kind of allosteric enzyme with negative regulation. The enzyme functioned optimally at a temperature of 35 °C and pH 8.5. The stability of the recombinant synthetase and the effectiveness of different factors in preventing the enzyme from inactivation were also studied. Additional experiments were performed in which the recombinant SAM synthetase was purified and immobilized in one step using immobilized metal-chelate affinity chromatography. The immobilized synthetase was found to be 40.4% of the free enzyme activity in catalyzing the synthesis of SAM from dl -Met and ATP. [source] Production of a Polyester Degrading Extracellular Hydrolase from Thermomonospora fuscaBIOTECHNOLOGY PROGRESS, Issue 5 2002Mona K. Gouda The production of a polyester-degrading hydrolase from the thermophilic actinomycete Thermomonospora fusca was investigated with regard to its potential technical application. Only in the presence of a polyester (random aliphatic-aromatic copolyester from 1,4-butanediol, terephthalic acid, and adipic acid with around 40,50 mol % terephthalic acid in the acid component), the excretion of the extracellular enzyme could be achieved with an optimized synthetic medium using pectin and NH4Cl as nitrogen source. Compared to complex media, a significantly higher specific activity at comparable volumetric yields could be obtained, thus reducing the expenditure for purification. The activity profile in the medium is controlled by a complex process involving (1) induction of enzyme excretion, (2) enzyme adsorption on the hydrophobic polyester surface, (3) inhibition of enzyme generation by monomers produced by polyester cleavage, and (4) enzyme denaturation. Diafiltration with cellulose acetate membranes as the sole downstream processing step led to a product of high purity and with sufficient yield (60% of total activity). Scaling-up from shaking flasks to a fermentor scale of 100 L revealed no specific problems. However, the excretion of the hydrolase by the actinomycete turned out to be inhibited by the degradation products (monomers) of the aliphatic-aromatic copolyester used as inductor for the enzyme production. The crude enzyme exhibited generally similar properties (temperature and pH optimum) as the highly purified hydrolase described previously; however, the storage capability and thermal stability is improved when the crude enzyme solution is diafiltrated. [source] Topographic pharmaco-EEG mapping of the effects of the South American psychoactive beverage ayahuasca in healthy volunteersBRITISH JOURNAL OF CLINICAL PHARMACOLOGY, Issue 6 2002Jordi Riba Aims,Ayahuasca is a traditional South American psychoactive beverage used in Amazonian shamanism, and in the religious ceremonies of Brazilian-based syncretic religious groups with followers in the US and several European countries. This tea contains measurable amounts of the psychotropic indole N,N -dimethyltryptamine (DMT), and ,-carboline alkaloids with MAO-inhibiting properties. In a previous report we described a profile of stimulant and psychedelic effects for ayahuasca as measured by subjective report self-assessment instruments. In the present study the cerebral bioavailability and time-course of effects of ayahuasca were assessed in humans by means of topographic quantitative-electroencephalography (q-EEG), a noninvasive method measuring drug-induced variations in brain electrical activity. Methods, Two doses (one low and one high) of encapsulated freeze-dried ayahuasca, equivalent to 0.6 and 0.85 mg DMT kg,1 body weight, were administered to 18 healthy volunteers with previous experience in psychedelic drug use in a double-blind crossover placebo-controlled clinical trial. Nineteen-lead recordings were undertaken from baseline to 8 h after administration. Subjective effects were measured by means of the Hallucinogen Rating Scale (HRS). Results,Ayahuasca induced a pattern of psychoactive effects which resulted in significant dose-dependent increases in all subscales of the HRS, and in significant and dose-dependent modifications of brain electrical activity. Absolute power decreased in all frequency bands, most prominently in the theta band. Mean absolute power decreases (95% CI) at a representative lead (P3) 90 min after the high dose were ,20.20±15.23 µV2 and ,2.70±2.21 µV2 for total power and theta power, respectively. Relative power decreased in the delta (,1.20±1.31% after 120 min at P3) and theta (,3.30±2.59% after 120 min at P3) bands, and increased in the beta band, most prominently in the faster beta-3 (1.00±0.88% after 90 min at P3) and beta-4 (0.30±0.24% after 90 min at P3) subbands. Finally, an increase was also seen for the centroid of the total activity and its deviation. EEG modifications began as early as 15,30 min, reached a peak between 45 and 120 min and decreased thereafter to return to baseline levels at 4,6 h after administration. Conclusions, The central effects of ayahuasca could be objectively measured by means of q-EEG, showing a time pattern which closely paralleled that of previously reported subjective effects. The modifications seen for the individual q-EEG variables were in line with those previously described for other serotonergic psychedelics and share some features with the profile of effects shown by pro-serotonergic and pro-dopaminergic drugs. The q-EEG profile supports the role of 5-HT2 and dopamine D2 -receptor agonism in mediating the effects of ayahuasca on the central nervous system. [source] | ||||||||||||||||