S E File

..The use of this test has, thus, played a crucial role in unravelling the neural basis of anxiety. It is hoped that in the next 25 years, the test will play a crucial role in determining the genetic basis of anxiety disorders...

..It is unlikely that either nicotine withdrawal or differences in cognitive performance could account for the greater anxiety, discontent and aggressive mood that was found in smokers...

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..Evidence is starting to accumulate that NK1 receptor antagonists might have anxiolytic effects in animal tests and in patients...

..On trial 2 in the elevated plus-maze (a model of specific phobia), nicotine (1 microg) has anxiolytic effects when administered to the dorsal hippocampus, but is ineffective (4 and 8 microg) in the lateral septum...

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..It may also benefit the impaired retrieval shown in patients with schizophrenia, Parkinson's disease, and Huntington's disease...

..It is important to control for possible changes in social investigation, neophobia, olfactory sensitivity, anxiety and exploration, before it is concluded that a changed performance in this task is due to changes in learning...

..Soya foods are rich in isoflavone phytoestrogens with weak agonist activity at oestrogen receptors. Oestrogen treatment has been found to improve memory in men awaiting gender reassignment and in post-menopausal women...

..There is some evidence that with long-term treatment the benefits decline, or reverse...

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..Thus, both alpha7 and alpha4beta2 nAChRs might have a role in mediating the anxiogenic effects of nicotine...

..This suggests that tolerance to the anxiogenic effect of nicotine administered into the dorsal hippocampus could be mediated by a reduction in the nicotine enhancement of 5-HT release in this area...

..A low dose of nicotine (5 ng) injected into the dorsal hippocampus was without effect in vehicle pretreated rats, but it was able to reverse the anxiogenic effect found after 24 h of withdrawal from 6 days of nicotine treatment...

..This sex difference in sensitivity to nicotine's anxiolytic effects suggests there may be sex differences in the factors initiating and maintaining teenage smoking...

..Because of the pharmacological profile of DH beta E, our results suggest that the anxiolytic effect of nicotine in the DRN is mediated by the alpha 4 beta 2 nicotinic receptor subtype...

..Thus, an oppositional mechanism may underlie tolerance to the anxiolytic effects, whereas there is as yet no evidence for this type of mechanism mediating tolerance to the anxiogenic effects...

..Our results show that the dorsal hippocampus is one area that can mediate anxiogenic effects in the social interaction test, but the brain region mediating anxiolytic effects remains to be identified...

..These results suggest that the compound may prove to be a useful anxiolytic and that substance P may play a role in mediating states of anxiety...

..These findings provide further evidence for the role of the lateral septum in the modulation of anxiety and suggest that cholinergic projections to this brain area facilitate anxiety through nicotinic receptors...

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..There was no evidence that the treatment regimen affected the rate of development of tolerance, despite very different peak plasma nicotine concentrations...

..Thus the anxiolytic and anxiogenic effects of nicotine can be distinguished both by brain region and by nicotinic receptor subtype...

..7. These results provide further evidence that the two animal tests model distinct states of anxiety, and show how social isolation powerfully modifies both anxiolytic and anxiogenic effects of nicotine...

..These results demonstrate that both the intracerebral location of the injection and test experience profoundly influence the effects of 5-HT1A ligands on behaviour of rats in the elevated plus-maze test of anxiety...

..Thus, after chronic administration, Gincosan appeared to have no beneficial effects in post-menopausal women...

..In the PASAT, both the lorazepam (2.5 mg) group and the middle-aged women were more impaired than the middle-aged men. These results raise the important possibility of gender differences in age-related decline of attentional processes...

..It is hoped comparative studies such as this will enable better understanding of anxiety states in the rat which could parallel the different classes of anxiety recognised in the clinic..

..Thus, the mechanism underlying this behavioural tolerance was not oppositional in nature. It is suggested that a situation-independent learned behavioural strategy is the most likely mechanism for the observed tolerance...

..The results indicated that some of the reduced anxiety could be attributed to the presence of an endogenous anxiolytic ligand...

..The importance of the timing of the nicotine-associated cues was demonstrated by the failure to obtain conditioned anxiogenic effects when rats were exposed to the plus-maze on day 1, 30 min after nicotine (0.45 or 0.1 mg/kg)...

..Both nicotine and a cannabinoid receptor agonist have been reported to change anxiety and both have actions on the reward process, but their effects on SNC have not been investigated...

..The rapid regulation of expression of 5-HT(1A) receptor mRNA leads to the hypothesis that nicotine-induced 5-HT release may alter the postsynaptic sensitivity to 5-HT...

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..The association of histological abnormalities with an acute, fatal syndrome clinically resembling malignant hyperthermia provides a strong basis for a new and extremely useful animal model to study this fatal disorder...

..Analysis of Thy-1 null mice has shown the presence of excessive GABAergic inhibition of neurotransmission in the dentate gyrus of the hippocampal formation selectively, without any neurological or behavioural effects being apparent...

..In addition, only one study has investigated the effects of chronic treatment in young volunteers...

..Thus, this study found limited evidence of cognitive-enhancing properties of modafinil in healthy middle-aged volunteers...

..The aim of the present analysis was to determine the nature of cognitive decline across a range of functions within a period of 5 years from early to late postmenopausal stage...

..Thus, compared with a group of teetotallers, the binge drinkers had lower trait anxiety and depression and poorer performance in tests of sustained attention, episodic memory and planning ability...

..Thus, the middle-aged women responded much more than did the men with negative mood changes to the psychological stress of cognitive testing, although their cognitive performance was not worse...

..In conclusion, there was no evidence that the group drinking moderate levels of alcohol had any cognitive impairment and the teetotal group responded to the cognitive tests with the greatest increases in negative mood...

..It is discussed whether the limited and mixed cognitive effects that we observed could have occurred by chance, or whether a subgroup of CFS patients with daytime sleepiness would have shown greater benefits...

..The beneficial effects of ginkgo were limited to the test of mental flexibility and to those with poorer performance...

..Significant improvements in the same three measures of frontal lobe function were previously found after 12 weeks of soy supplements in postmenopausal women. The effects of soy on memory seem less robust...

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..Thus, significant cognitive improvements in postmenopausal women can be gained from 12 weeks of consumption of a supplement containing soya isoflavones that are independent of any changes in menopausal symptoms, mood or sleepiness...

..Our results suggest that the effects of HRT on cognition may be influenced by the type of HRT, the duration of treatment, the nature of the tests, and the brain region controlling the cognitive function...

..CONCLUSIONS: The present findings suggest that anxiety can be conditioned following exposure to an anxiogenic dose of nicotine, and that this anxiety is specific to the contextual cues associated with the SI test...

..No changes in glutamic acid decarboxylase-67 or glial fibrillary acidic protein mRNA were found. This suggests a role for oestrogen-beta receptors in regulating BDNF mRNA expression...

..It is therefore possible that the soya content of diet could have significant effects on brain and behaviour and be an important source of between-laboratory variability...

..Conditioned anxiety has also been observed 24 h after testing in the SI with a high dose of nicotine...

..Further changes in mood were revealed after the stress of cognitive testing, with the 100 mg group showing greater increases in the 'psychological anxiety' and the 'aggressive mood' factors (as measured from the Bond and Lader scales)...

..The benefits of Ginkgo on memory and frontal lobe function found in this study are modest but are unlikely to be secondary to major mood changes...

..The protocols are described in terms of drug screening tests, but can be modified easily for other purposes...

..In both tests there were age-associated differences in the female rats, with the adolescent females being less anxious (higher percentage of open arm entries and increased social interaction) than the adults...

..Circulating female hormones reduce this effect, but in adult females the combination of dietary restriction and nicotine may have important anxiolytic effects that impact on the initiation of regular smoking...

..Further study with additional tests of anxiety are needed to confirm this intriguing relationship...

..We provide the first evidence for unconditioned and conditioned anxiogenic-like responses to a cannabinoid agonist in the social interaction test...

..Furthermore, the results indicate that high IQ may limit detection of modafinil's positive effects...

..There is also evidence for nicotinic--serotonergic interactions in the acquisition of the water maze, passive avoidance, and impulsivity in the five-choice serial reaction task...

..The two drugs also have opposite effects on cognition and the possibility of long-lasting cognitive impairments resulting from adolescent consumption of cannabis is of particular concern...

..Thus, the endocannabinoid system appears to play a pivotal role in the regulation of emotional states and may constitute a novel pharmacological target for anti-anxiety therapy...