A comparative study with two types of elevated plus-maze (transparent vs. opaque walls) on the anxiolytic effects of midazolam, one-trial tolerance and fear-induced analgesia

Albrechet‐Souza, Lucas; Oliveira, Amanda Ribeiro de; Luca, Maria Cecı́lia Zanoto de; Tomazini, Fernanda Mariana; Santos, Nelson Ribeiro dos; Brandão, Marcus Lira

doi:10.1016/j.pnpbp.2005.01.010

Cited by 31 publications

(14 citation statements)

References 34 publications

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“…Thus, the effect of MDZ cannot be ascribed to the nonspecific action of the drug. The anxiolytic-like actions of MDZtreated animals in the EPM generally observed in this study replicate the results reported in the literature by authors using the standard test [36][37][38] . Since previous results in our lab showed that MDZ (1.00 mg/kg) did not alter EPM behavior in control rats or AlloP-treated animals under particular experimental conditions (bright light) [18] , the present data suggest that the level of illumination used in the test can alter the sensitivity of the test for detecting the anxiolytic effect of MDZ.…”

Section: Discussionsupporting

confidence: 92%

Effects of Early Postnatal Allopregnanolone Administration on Elevated Plus Maze Anxiety Scores in Adult Male Wistar Rats

Darbra

Pallarès²

2011

Neuropsychobiology

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Background/Aims: Recent findings suggest that neurosteroids are involved in brain development. The present study focused on the long-term effects of developmentally altered allopregnanolone (AlloP) levels on anxiety-like behavior in adulthood. Method: We administered AlloP (10 mg/kg) to rat pups once a day from the 5th to the 9th day after birth. A dose-response study on midazolam in the elevated plus maze test was carried out in adulthood (experiment 1) in order to screen GABAA-benzodiazepine function alterations. Given that the anxiety-like responses were not affected by AlloP, we doubled the initial AlloP dose (experiment 2). One group of pups was left undisturbed with their dams in order to control the effects of daily handling. Only males were behaviorally tested. Results: Neonatal AlloP administration (10 mg/kg) did not alter the behavioral response to midazolam in adulthood at the doses tested. Neonatal AlloP administration at the higher dose (20 mg/kg) induced an anxiolytic-like profile in adulthood (increased entries into and time spent in the open arms), without affecting motor activity. The behavioral effects of neonatal AlloP administration were both selective and independent of daily handling. Conclusion: Alterations in AlloP levels during maturation could partly explain the interindividual differences shown by adult subjects in response to environmental stress.

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Section: Discussionsupporting

confidence: 92%

Effects of Early Postnatal Allopregnanolone Administration on Elevated Plus Maze Anxiety Scores in Adult Male Wistar Rats

Darbra

Pallarès²

2011

Neuropsychobiology

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“…The animals were tested 15 min after the injections. Selection of midazolam dose and time for testing were based on previous studies from this laboratory (9,19,20). In these studies an ethopharmacological analysis was conducted to characterize the one-trial tolerance to midazolam in terms of a thorough dose-response relationship.…”

Section: Methodsmentioning

confidence: 99%

Changes in the biogenic amine content of the prefrontal cortex, amygdala, dorsal hippocampus, and nucleus accumbens of rats submitted to single and repeated sessions of the elevated plus-maze test

Carvalho

Albrechet‐Souza

Masson

et al. 2005

Braz J Med Biol Res

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It has been demonstrated that exposure to a variety of stressful experiences enhances fearful reactions when behavior is tested in current animal models of anxiety. Until now, no study has examined the neurochemical changes during the test and retest sessions of rats submitted to the elevated plus maze (EPM). The present study uses a new approach (HPLC) by looking at the changes in dopamine and serotonin levels in the prefrontal cortex, amygdala, dorsal hippocampus, and nucleus accumbens in animals upon single or double exposure to the EPM (one-trial tolerance). The study involved two experiments: i) saline or midazolam (0.5 mg/kg) before the first trial, and ii) saline or midazolam before the second trial. For the biochemical analysis a control group injected with saline and not tested in the EPM was included. Stressful stimuli in the EPM were able to elicit one-trial tolerance to midazolam on re-exposure (61.01%). Significant decreases in serotonin contents occurred in the prefrontal cortex (38.74%), amygdala (78.96%), dorsal hippocampus (70.33%), and nucleus accumbens (73.58%) of the animals tested in the EPM (P < 0.05 in all cases in relation to controls not exposed to the EPM). A significant decrease in dopamine content was also observed in the amygdala (54.74%, P < 0.05). These changes were maintained across trials. There was no change in the turnover rates of these monoamines. We suggest that exposure to the EPM causes reduced monoaminergic neurotransmission activity in limbic structures, which appears to underlie the "one-trial tolerance" phenomenon.

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“…The maze provides free access to either a protected dark and enclosed environment or an unprotected brightly lit, open and elevated environment (Albrechet-Souza et al, 2005). The EPM used in this study was made of Perspex, formed in a plus shape, with four perpendicular arms set around a centre square and elevated 50 cm above the ground on a podium.…”

Section: Behavioural Testing Apparatusmentioning

confidence: 99%

Anxiolytic effects of Lavandula angustifolia odour on the Mongolian gerbil elevated plus maze

Bradley

Starkey

Brown

et al. 2007

Journal of Ethnopharmacology

114

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A comparative study with two types of elevated plus-maze (transparent vs. opaque walls) on the anxiolytic effects of midazolam, one-trial tolerance and fear-induced analgesia

Cited by 31 publications

References 34 publications

Effects of Early Postnatal Allopregnanolone Administration on Elevated Plus Maze Anxiety Scores in Adult Male Wistar Rats

Effects of Early Postnatal Allopregnanolone Administration on Elevated Plus Maze Anxiety Scores in Adult Male Wistar Rats

Changes in the biogenic amine content of the prefrontal cortex, amygdala, dorsal hippocampus, and nucleus accumbens of rats submitted to single and repeated sessions of the elevated plus-maze test

Anxiolytic effects of Lavandula angustifolia odour on the Mongolian gerbil elevated plus maze

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