Dopamine-sensitive alternation and collateral behaviour in a Y-maze: effects of d-amphetamine and haloperidol

Introduction: The frequency of spontaneous alternation in a Y-maze (visiting each arm in turn at p>50%) depends on the influence of the attention given to intra- and extra-maze cues. We examined the observing responses shown by rats (collateral rearing and head-turning behaviour), the habituation to the novelty and alternation responses over 15 minutes/day, four days in a row - in a Y-maze under enhanced and reduced dopamine (DA) activity (amphetamine- and haloperidol treatment). Methods: Prior to placement in a Y-maze for 15 minutes observation on 4 successive days animals were treated with either amphetamine (0.5 or 2.5 mg/kg) or pre-treated with a low dose of haloperidol (0.08 mg/kg, ip). Results: 1/ Amphetamine treated animals chose the arms at random on day 1, but after the higher dose on day 2-4 they perseverated their choice. The controls maintained their alternation over this period. 2/ The amphetamine-induced effects on alternation were prevented by prior treatment with the neuroleptic haloperidol. 3/ Amphetamine treatment increased the frequency of rearing in the middle at the choice point of the Y-maze. Haloperidol pre-treatment blocked this increase at the midpoint on day 1, and blocked the rearing behavior at the end of an arm on day 2. 4/ Amphetamine also increased the frequency of head turning and "looking", - an effect that was also prevented by haloperidol. (day 2 onwards). 5/ Haloperidol increased the duration of" looking" and of rearing at the end of an arm later in testing.. Conclusions: Two effects are postulated to have occurred. a) a conflict on day 1 between the novelty-controlled sensory or attentional effects, that leads to an alternation of arm-choice, and amphetamine-induced DA activity that facilitates an alternation of behavioural responses: -- the result was random choice and increased rearing at the choice point. b) On days 2-4 the drug-induced effects on switching motor responses came to control behaviou

Locomotor activity in relation to dopamine and noradrenaline in the nucleus accumbens, septal and frontalk areas: a 6-hydroxydopamine study

The Study and the Method: The locomotor activity of adult male Sprague-Dawley was automatically recorded in a circular corridor - circadian changes are described as well as the response to the novel situation and its habituation over three hours. Four groups of animals were compared, - those with sham/vehicle operations and those with 6-OHDA dopamine (DA) depleting lesions in - the frontal cortex, the limbic septum, and the ventral tegmental area (VTA - A10). Results: 1/ Lesions of the VTA resulted in increased dark-phase activity, - and a large response to an apomorphine challenge in comparison to other lesion and control groups: 2/ Septal 6-OHDA lesions did not alter locomotion: 3/ After frontal DA depletion there was a small increase of locomotion after the apomorphine challenge, that might reflect increased receptor sensitivity in cortical or sub-cortical areas: (Table 1: HPLC measures of NA, DA and DOPAC for each group in the prefrontal cortex, septum and N. accumbens) Figure 1 illustrates the cumulative photocell counts per hour over 24 hours for the 4 groups:. Figure 2 illustrates the cumulative photocell counts every 10 minutes over 90 minutes post-apomorphine treatment - maximal at 20-30 minutes and habituating over 60 minutes (90 minutes for the VTA group): overall activity VTA >> Frontal > Septal > Controls. Conclusions: Along with correlations found for motor activity with cortical levels of DA and NA, these results are interpreted to support a role for DA, NA and the region of the frontal cortex in modulating locomotion that is primarily mediated by mesolimbic VTA - accumbens - DA activity

Limbic System, Basal Ganglia, and Dopaminergic Neurons

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Modulation of dopaminergic activity in the nucleus accumbens following facilitation or blockade of the dopaminergic transmission in the amygdala: a study by in vivo differential pulse voltammetry

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Dopamine and behavior: functional and theoretical considerations

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Alternation behavior, spatial discrimination, and reversal disturbances following 6-hydroxydopamine lesions in the nucleus accumbens of the rat

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Behavioral study after local injection of 6-hydroxydopamine into the nucleus accumbens in the rat

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Lesion of dopaminergic terminals in the amygdala produces enhanced locomotor response to d-amphetamine and opposite changes in dopaminergic activity in prefrontal cortex and nucleus accumbens

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Toxicity and Anxiolytic Property of Nettle in Mice in Light/Dark Test

Background: Anxiety is an unpleasant state of inner turmoil often accompanied by cognitive, somatic, emotional, and behavioral components. There is some evidence in traditional medicine for the effectiveness of Urtica urens in the treatment of anxiety in humans. The present study was designed to study anxiolytic property of aqueous extracts of Urtica urens; an important and commonly used for its medicinal properties belongs to urticaceae family. Methods: The anxiolytic activity was evaluated with the adult mice by hole board test, and the light-dark box test, and motor coordination with the rota rod test. The efficacy of the plant extract (100–400 mg/kg) was compared with the standard anxiolytic drug diazepam (1 mg/kg i.p.). Results: The extract increased the time spent in the brightly-lit chamber of the light/dark box, as well as in the number of times the animal crossed from one compartment to the other. Performance on the rota rod was unaffected. In the hole board test, the extract significantly increased both head-dip counts and head-dip duration. Urtica urens, in contrast to diazepam, had no effect on locomotion. Conclusions: These results provides support for anxiolytic activity of Urtica urens, in line with its medicinal traditional use, and may also suggest a better side-effect profile of Urtica urens relative to diazepam

Severe Preeclampsia and Maternal Self-Report of Oral Health, Hygiene, and Dental Care

BACKGROUND: Maternal periodontal disease diagnosed by a detailed oral health examination is associated with preeclampsia. Our objective was to measure the association between maternal self-report of oral symptoms/problems, oral hygiene practices, and/or dental service utilization prior to or during pregnancy and severe preeclampsia. METHODS: A written questionnaire was administered to pregnant women at the time of prenatal ultrasound, and outcomes ascertained by chart abstraction. Chi square test compared maternal oral symptoms/problems, hygiene practices, and dental service utilization between women with severe preeclampsia versus normotensive women. Multivariable logistic regression was used to calculate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for severe preeclampsia. Results: 48 (10%) of 470 women reported ≥ 2 oral symptoms/problems in the 6 months prior to pregnancy and 77 (16%) since pregnancy. 51(11%) reported prior periodontal treatment. 28 (6%) of 470 developed severe preeclampsia. Women with a history of periodontal treatment were more likely to develop severe preeclampsia (aOR, 95%CI: 3.71, 1.40-9.83) than women without a prior history of periodontal treatment. Self-reported oral health symptoms/problems, oral hygiene practices, or dental service utilization prior to or during pregnancy were not associated with severe preeclampsia when considered in the context of other maternal risk factors. Conclusion: Maternal self report of previous periodontal treatment prior to pregnancy is associated with severe preeclampsia