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Avoidance Test (avoidance + test)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Kinds of Avoidance Test

passive avoidance test

Selected Abstracts

Retraining automatic action-tendencies to approach alcohol in hazardous drinkers

ADDICTION, Issue 2 2010
Reinout W. Wiers
ABSTRACT Aims The main aim of this study was to test whether automatic action-tendencies to approach alcohol can be modified, and whether this affects drinking behaviour. Design and participants Forty-two hazardous drinkers were assigned randomly to a condition in which they were implicitly trained to avoid or to approach alcohol, using a training variety of the alcohol Approach Avoidance Test (AAT). Participants pushed or pulled a joystick in response to picture-format (landscape or portrait). The pictures depicted alcoholic or non-alcoholic drinks. Participants in the avoid-alcohol condition pushed most alcoholic and pulled most non-alcoholic drinks. For participants in the approach-alcohol condition these contingencies were reversed. After the implicit training, participants performed a taste test, including beers and soft drinks. Automatic action tendencies at post-test were assessed with the AAT, including both trained and untrained pictures, and with a different test (Implicit Association Test, IAT). We further tested effects on subjective craving. Results Action tendencies for alcohol changed in accordance with training condition, with the largest effects in the clinically relevant avoid-alcohol condition. These effects occurred outside subjective awareness and generalized to new pictures in the AAT and to an entirely different test using words, rather than pictures (IAT). In relatively heavy drinking participants who demonstrated changed action tendencies in accordance with their training condition, effects were found on drinking behaviour, with participants in the approach-alcohol condition drinking more alcohol than participants in the avoid-alcohol condition. No effect was found on subjective craving. Conclusions Retraining automatic processes may help to regain control over addictive impulses, which points to new treatment possibilities. [source]

Avoidance tests in site-specific risk assessment,influence of soil properties on the avoidance response of collembola and earthworms,

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2008
Tiago Natal-da-Luz
Abstract The ability of organisms to avoid contaminated soils can act as an indicator of toxic potential in a particular soil. Based on the escape response of earthworms and Collembola, avoidance tests with these soil organisms have great potential as early screening tools in site-specific assessment. These tests are becoming more common in soil ecotoxicology, because they are ecologically relevant and have a shorter duration time compared with standardized soil toxicity tests. The avoidance response of soil invertebrates, however, can be influenced by the soil properties (e.g., organic matter content and texture) that affect behavior of the test species in the exposure matrix. Such an influence could mask a possible effect of the contaminant. Therefore, the effects of soil properties on performance of test species in the exposure media should be considered during risk assessment of contaminated soils. Avoidance tests with earthworms (Eisenia andrei) and springtails (Folsomia candida) were performed to identify the influence of both organic matter content and texture on the avoidance response of representative soil organisms. Distinct artificial soils were prepared by modifying quantities of the standard artificial soil components described by the Organization for Economic Co-operation and Development to achieve different organic matter and texture classes. Several combinations of each factor were tested. Results showed that both properties influenced the avoidance response of organisms, which avoided soils with low organic matter content and fine texture. Springtails were less sensitive to changes in these soil constituents compared with earthworms, indicating springtails can be used for site-specific assessments of contaminated soils with a wider range of respective soil properties. [source]

Phobia of self-injecting and self-testing in insulin-treated diabetes patients: opportunities for screening

DIABETIC MEDICINE, Issue 8 2001
E. D. Mollema
Abstract Aims To define clinically relevant cut-off points for severe fear of self-injecting (FSI) and self-testing (FST) (phobia) in insulin-treated patients with diabetes, and to estimate the magnitude of these phobias in our research population. Methods, FSI and FST were assessed in a cross-sectional survey using the Diabetes Fear of Injecting and Self-testing Questionnaire (D-FISQ). A sample of 24 insulin-treated adult diabetic patients was selected from the high-scorers on FSI and/or FST (, 95th percentile). FSI and FST were re-assessed, after which patients participated in a behavioural avoidance test (BAT), thereby determining the current level of avoidance of either self-injecting or self-testing. FSI and FST scores were linked to the outcome of the BATs. Cut-off scores for severe FSI/FST were determined and extrapolated to the total study population (n = 1275). Results, Seven patients participated in the self-injecting BAT: two patients refused to perform an extra injection. In the self-testing BAT (n = 17) four patients declined to perform the extra blood glucose self-test. Extrapolation of FSI and FST cut-off scores to the total research population showed that 0.2,1.3% of the population scored in the severe FSI range. In FST, 0.6,0.8% of the total study population obtained scores in the cut-off range. Conclusions, Severe FSI and FST, characterized by emotional distress and avoidance behaviour, seems to occur in a small group of insulin-treated patients with diabetes. The D-FISQ can be of use to health care professionals (physicians, nurse specialists) in quickly providing valuable information on levels of FSI and FST in diabetes patients. Diabet. Med. 18, 671,674 (2001) [source]

Enhancement of learning behaviour by a potent nitric oxide-guanylate cyclase activator YC-1

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2005
Wei-Lin Chien
Abstract Memory is one of the most fundamental mental processes, and various approaches have been used to understand the mechanisms underlying this process. Nitric oxide (NO), cGMP and protein kinase G (PKG) are involved in the modulation of synaptic plasticity in various brain regions. YC-1, which is a benzylindazole derivative, greatly potentiated the response of soluble guanylate cyclase to NO (up to several hundreds fold). We have previously shown that YC-1 markedly enhances long-term potentiation in hippocampal and amygdala slices via NO-cGMP-PKG-dependent pathway. We here further investigated whether YC-1 promotes learning behaviour in Morris water maze and avoidance tests. It was found that YC-1 shortened the escape latency in the task of water maze, increased and decreased the retention scores in passive and active avoidance task, respectively. Administration of YC-1 30 min after foot-shock stimulation did not significantly affect retention scores in response to passive avoidance test. Administration of scopolamine, a muscarinic antagonist, markedly impaired the memory acquisition. Pretreatment of YC-1 inhibited the scopolamine-induced learning deficit. The enhancement of learning behaviour by YC-1 was antagonized by intracerebroventricular injection of NOS inhibitor L-NAME and PKG inhibitors of KT5823 and Rp-8-Br-PET-cGMPS, indicating that NO-cGMP-PKG pathway is also involved in the learning enhancement action of YC-1. YC-1 is thus a good drug candidate for the improvement of learning and memory. [source]

Strain differences in ,1 receptor-mediated behaviours are related to neurosteroid levels

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2002
Vân-Ly Phan
Abstract The sigma1 (,1) receptor exerts a potent neuromodulatory role in the brain with relevant consequences in memory processes, response to stress, depression and pharmacodependence. Its precise endogenous ligand is not yet identified but the ,1 receptor appears to be one target for the nongenomic rapid effects of neuroactive steroids in the brain. The aim of the present study was to establish whether differences in ,1 receptor-mediated behaviours could be observed among mouse strains, in relation with differences in either ,1 receptor expression or steroid levels. The ,1 -receptor immunohistochemical distribution appeared similar between Swiss and C57BL/6 strains in all the brain structures examined. The levels of in vivo[3H](+)-SKF-10 047 binding to ,1 receptors were lower in Swiss than in C57BL/6. Adrenalectomy/castration significantly increased [3H](+)-SKF-10 047 binding only in Swiss. The behavioural efficacy of the selective ,1 agonists igmesine and PRE-084 , reversion of the scopolamine-induced amnesia in the passive avoidance test; diminution of the immobility duration in the forced swimming test , were significantly higher in C57BL/6 than in Swiss. Steroid levels were measured in the brain in basal conditions and after stress. C57BL/6 mice presented in both conditions, the lowest progesterone levels, this steroid acting as an endogenous ,1 antagonist. Collectively, the results suggested that strain differences in neuroactive steroid and particularly, progesterone, biosynthesis and sensitivity may contribute to the differential behavioural efficacy of ,1 -receptor ligands. Noteworthy, these observations are coherent with strain differences observed in the intensity of cocaine-induced reward properties, known to critically involve the ,1 receptor. [source]

The NMDA receptor antagonist memantine as a symptomatological and neuroprotective treatment for Alzheimer's disease: preclinical evidence

INTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue S1 2003
Wojciech Danysz
Abstract There is increasing evidence for the involvement of glutamate-mediated neurotoxicity in the pathogenesis of Alzheimer's disease (AD). We suggest that glutamate receptors of the N-methyl-D-aspartate (NMDA) type are overactivated in a tonic rather than a phasic manner in this disorder. This continuous mild activation may lead to neuronal damage and impairment of synaptic plasticity (learning). It is likely that under such conditions Mg2+ ions, which block NMDA receptors under normal resting conditions, can no longer do so. We found that overactivation of NMDA receptors using a direct agonist or a decrease in Mg2+ concentration produced deficits in synaptic plasticity (in vivo: passive avoidance test and/or in vitro: LTP in the CA1 region). In both cases, memantine,an uncompetitive NMDA receptor antagonists with features of an ,improved' Mg2+ (voltage-dependency, kinetics, affinity),attenuated this deficit. Synaptic plasticity was restored by therapeutically-relevant concentrations of memantine (1,,M). Moreover, doses leading to similar brain/serum levels provided neuroprotection in animal models relevant for neurodegeneration in AD such as neurotoxicity produced by inflammation in the NBM or ,-amyloid injection to the hippocampus. As such, if overactivation of NMDA receptors is present in AD, memantine would be expected to improve both symptoms (cognition) and to slow down disease progression because it takes over the physiological function of magnesium. Copyright © 2003 John Wiley & Sons, Ltd. [source]

Procyanidins extracted from the lotus seedpod ameliorate scopolamine-induced memory impairment in mice

PHYTOTHERAPY RESEARCH, Issue 12 2009
Jiqu Xu
Abstract The major purpose of this study was to determine the effect of procyanidins extracted from the lotus seedpod (LSPC) on the learning and memory impairments induced by scopolamine (1 mg/kg, i.p.) in mice. The capacities of memory and learning were evaluated by the Morris water maze and the step-down avoidance test. LSPC (50, 100, 150 mg/kg BW, p.o.) significantly reversed scopolamine-induced learning and memory impairments in the Morris water maze test, as evaluated by shortened escape latency and swimming distance. In the step-down avoidance test, LSPC (50, 100, 150 mg/kg BW, p.o.) treatment significantly reduced the number of errors and shortened latency compared with that of scopolamine. In addition, LSPC was also found to inhibit acetyl cholinesterase (AChE) activity. These results of this study suggest that LSPC may play a useful role in the treatment of cognitive impairment caused by AD and aging. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Pharmacological effects of carcinine on histaminergic neurons in the brain

BRITISH JOURNAL OF PHARMACOLOGY, Issue 5 2004
Zhong Chen
Carcinine (, -alanyl histamine) is an imidazole dipeptide. The present study was designed to characterize the pharmacological effects of carcinine on histaminergic activity in the brain and on certain neurobehavior. Carcinine was highly selective for the histamine H3 receptor over H1 or H2 receptor (Ki (,M)=0.2939±0.2188 vs 3621.2±583.9 or 365.3±232.8 ,M, respectively). Carcinine at a dose of 20 mg kg,1 slightly increased histidine decarboxylase (HDC) activity in the cortex (from 0.186±0.069 to 0.227±0.009 pmol mg protein,1 min,1). In addition, carcinine (10, 20, and 50 mg kg,1) significantly decreased histamine levels in mice brain. Like thioperamide, a histamine H3 receptor antagonist, carcinine (20, 50 ,M) significantly increased 5-HT release from mice cortex slices, but had no apparent effect on dopamine release. Carcinine (20 mg kg,1) significantly inhibited pentylenetetrazole-induced kindling. This inhibition was completedly reversed by (R)- , -methylhistamine, a representative H3 receptor agonist, and , -fluromethylhistidine, a selective HDC inhibitor. Carcinine (20 mg kg,1) ameliorated the learning deficit induced by scopolamine. This amelioration was reversed by (R)- , -methylhistamine as evaluated by the passive avoidance test in mice. Like thioperamide, carcinine dose-dependently increased mice locomotor activity in the open-field test. The results of this study provide first and direct evidence that carcinine, as a novel histamine H3 receptor antagonist, plays an important role in histaminergic neurons activation and might be useful in the treatment of certain diseases, such as epilepsy, and locomotor or cognitive deficit. British Journal of Pharmacology (2004) 143, 573,580. doi:10.1038/sj.bjp.0705978 [source]

Avoidance tests in site-specific risk assessment,influence of soil properties on the avoidance response of collembola and earthworms,

Enhancement of learning behaviour by a potent nitric oxide-guanylate cyclase activator YC-1

Effect of Evolvulus alsinoides Linn. on learning behavior and memory enhancement activity in rodents

PHYTOTHERAPY RESEARCH, Issue 4 2010
Alok Nahata
Abstract In the Ayurvedic system of medicine, the whole herb of ,Shankhpushpi' has been employed clinically for centuries for its memory potentiating, anxiolytic and tranquilizing properties. The present study was undertaken to investigate the effects of Evolvulus alsinoides (EA), considered as Shankhpushpi on learning and memory in rodents. Nootropic activity using Cook and Weidley's pole climbing apparatus, passive avoidance paradigms and active avoidance tests were used to test learning and memory. The ethanol extract of EA and its ethyl acetate and aqueous fractions were evaluated for their memory enhancing properties. Two doses (100 and 200 mg/kg p.o.) of the ethanol extract and ethyl acetate and aqueous fractions were administered in separate groups of animals. Both doses of all the extracts of EA significantly improved learning and memory in rats. Furthermore, these doses significantly reversed the amnesia induced by scopolamine (0.3 mg/kg i.p.). Nootropic activity was compared using piracetam as the standard. EA also exhibited potent memory enhancing effects in the step-down and shuttle-box avoidance paradigms. Copyright © 2009 John Wiley & Sons, Ltd. [source]