Involvement of the serotonergic, GABAergic and glutamatergic systems of the rostral anterior cingulate cortex in the trait and state anxiety of adult male Wistar rats.

Despite significant advancements to understand of the neural circuitry involved in anxiety, the neurobiology of trait anxiety remains unclear. The rostral anterior cingulate cortex (rACC) and various pathways have been implicated in its regulation, making it a key to trait anxiety. The present study aimed to investigate the role of these neurotransmitter systems in the rACC in trait anxiety.

Effects of a rat model of gestational hypothyroidism on forebrain dopaminergic, GABAergic, and serotonergic systems and related behaviors.

We investigated the effects of maternal hypothyroidism on forebrain dopaminergic, GABAergic, and serotonergic systems and related behavior in adult rat offspring. Experimental gestational hypothyroidism (EGH) was induced by administering 0.02% methimazole (MMI) to pregnant rats from gestational day 9 to delivery.

Excitotoxic lesion of the medial prefrontal cortex in Wistar rats: Effects on trait and state anxiety.

The neural substrate of anxiety response (state anxiety) to a threatening situation is well defined. However, a lot less is known about brain structures implicated in the individual's predisposition to anxiety (trait anxiety). Scientific evidences lead us to suppose that the medial prefrontal cortex (mPFC) is involved in both trait and state anxiety.

Trait vs. state anxiety in different threatening situations.

Objective: Anxiety as a uni- or multidimensional construct has been under discussion. The unidimensional approach assumes that there is a general trait anxiety, which predisposes the individuals to increases in state anxiety in various threatening situations. In this case, there should be a correlation between state and trait anxiety in any situation of threat.

Effect of Lemongrass Aroma on Experimental Anxiety in Humans.

Objectives: The objective of this study was to evaluate the potential anxiolytic effect of lemongrass (Cymbopogon citratus) aroma in healthy volunteers submitted to an anxiogenic situation.

Design: Forty male volunteers were allocated to four different groups for the inhalation of lemongrass essential oil (test aroma: three or six drops), tea tree essential oil (control aroma: three drops), or distilled water (nonaromatic control: three drops). Immediately after inhalation, each volunteer was submitted to an experimental model of anxiety, the video-monitored version of the Stroop Color-Word Test (SCWT).

Pharmacological validation of the free-exploratory paradigm in male Wistar rats: A proposed test of trait anxiety.

The free-exploratory paradigm (FEP) has been proposed as a model of trait anxiety for both mice and rats. However, its pharmacological validation has only been carried out for the mice. Thus, the aim of the present study was to pharmacologically validate FEP for Wistar rats, by testing the effects of clinically established anxiolytic and anxiogenic drugs, in four different experiments.

Environmental enrichment for adult rats: effects on trait and state anxiety.

Experimental evidence indicates that enriched environment (EE) induces neurobiological and behavioural alterations. EE in early life improves learning and memory and reduces trait and state anxiety. However, the effect of EE established in adulthood has rarely been investigated.

The influence of trait anxiety on the elevation of arterial pressure induced by L-NAME in rats.

Due to the high prevalence of anxiety disorders and hypertension comorbidity in the general population, the establishment of anxiety as a risk factor for elevated blood pressure, or the reverse, is of great relevance. In this context, animal models can be of great scientific value, as they permit the control of several variables. Bearing this in mind, the influence of anxiety, not as a state, but as a personality trait (trait anxiety), on blood pressure elevation and vice versa were investigated for the first time in rats, using the free-exploratory paradigm (FEP).

The free-exploratory paradigm as a model of trait anxiety in female rats: test-retest reliability.

The free-exploratory paradigm has been proposed as a model of trait anxiety and as such has been proven stable over time, which is a sine qua non condition for any model proposing to evaluate a personality trait. However this stability has only been shown for male rats. Considering that anxiety disorders are most prevalent in women, it's crucial that females are tested in animal models.

Effect of sweet orange aroma on experimental anxiety in humans.

Objectives: The objective of this study was to evaluate the potential anxiolytic effect of sweet orange (Citrus sinensis) aroma in healthy volunteers submitted to an anxiogenic situation.

Design: Forty (40) male volunteers were allocated to five different groups for the inhalation of sweet orange essential oil (test aroma: 2.5, 5, or 10 drops), tea tree essential oil (control aroma: 2.

Automation of the free-exploratory paradigm.

The free-exploratory paradigm (FEP) is currently the only proposed animal model of trait anxiety, making it highly valuable to behavioural neuroscience. However, FEP has not yet been automated, so its results depend on human scoring, which can be quite imprecise. The aim of this study was, therefore, to validate an automated version of FEP, using a commercially available video-tracking system (ANY-maze(©) - Stoelting Co.

Trait anxiety affects the orofacial nociceptive response in rats.

The aims of the present study were to assess the influence of: a) trait anxiety on orofacial pain; and b) orofacial pain on state anxiety. Forty-four rats were initially exposed to the free-exploratory paradigm for the evaluation of their anxiety profiles. In accordance to the parameter "Percentage of time in the novel side", the animals were considered as presenting high or low levels of trait anxiety when presenting values below the 1st quartile, or above the 3rd quartile, respectively.

Anxiolytic-like effect of sweet orange aroma in Wistar rats.

Aromatherapy is the use of essential oils as an alternative treatment for medical purposes. Despite the lack of sufficient scientific proof, it is considered a holistic complementary therapy employed to enhance comfort and decrease distress. Citrus fragrances have been particularly used by aromatherapists for the treatment of anxiety symptoms.

The free-exploratory paradigm as a model of trait anxiety in rats: test-retest reliability.

The free exploratory paradigm has been proposed as a model of trait anxiety. By definition, trait anxiety does not vary from moment to moment, therefore any model used to evaluate it needs to give the same results in sequential trials. With this in mind, the test-retest reliability of the free-exploratory paradigm in rats was evaluated.

Trait and state anxiety in animal models: Is there correlation?

It is believed that subjects with high trait anxiety levels tend to present state anxiety reactions with greater intensity than individuals with low trait anxiety levels. In order to verify if this premise is valid for animal models of anxiety, the present work investigated the possible correlation between two behavioral tests: the elevated plus-maze, a classic model of state-anxiety, and the free-exploratory paradigm, which has been proposed as a model of trait anxiety. The behavior of 46 drug-naive, adult, Wistar, male rats was measured in these two models on two occasions, 1 week apart.

IAPS includes photographs that elicit low-arousal physiological responses in healthy volunteers.

This article describes pleasant IAPS pictures that elicit low-arousal rather than the high-arousal physiological responses previously reported in the literature. Thirty-two International Affective Picture System (IAPS) photographs were grouped into 4 sets of 8 photographs: highly pleasant-arousing (sexual content and adventures), highly pleasant-relaxing pictures (landscapes, flowers or babies), neutral on both valence/arousal, and highly unpleasant-arousing ones. These stimuli were shown to 24 healthy Brazilian University students (12 males) who had their physiological responses recorded [corrugator and zygomatic facial electromyography activity, skin conductance, heart rate, and peripheral temperature].

The anxiolytic effect of pregnancy in rats is reversed by finasteride.

Several studies have shown the influence of the oestrous cycle on anxiety levels and the important role of progesterone in this effect. The metabolism of this steroid hormone yields neuroactive steroids among them allopregnanolone (alloP) and allotetrahydrodeoxycorticosterone (alloTHDOC), which bind to GABAA receptors and have anxiolytic effects. Considering that during pregnancy there is an increase in levels of both progesterone and its metabolites, the main objectives of this work were: (1) to assess changes in anxiety levels during pregnancy and (2) to verify the role of alloP and alloTHDOC in this process using finasteride, an inhibitor of 5alpha-reductase, the enzyme responsible for their synthesis.

The anxiogenic video-recorded Stroop Color-Word Test: psychological and physiological alterations and effects of diazepam.

From among the few human experimental models that can be used to predict the clinical activity of new anxiolytic drugs, the video-recorded Stroop Color-Word Test (VRSCWT), which uses subjective scales to evaluate anxious states, is notable for its simplicity. However, considering that the choice of treatment for anxiety disorders is heavily dependent on the level of somatic symptomatology, a quantitative evaluation of the physiological alterations elicited by the anxiogenic situation of the VRSCWT would also be of great interest. In the present study, 36 healthy male and female volunteers were submitted to either the VRSCWT or to a nonanxiogenic test.