Sex differences in Mongolian gerbils in four tests of anxiety

Abstract

Animal models or test paradigms for predominantly female disorders, such as anxiety, often use only male animals, with little or no investigation of sex differences. Thus, this study was conducted to compare the behaviour of males and females in four widely used tests of anxiety. The behaviour of male and female Mongolian gerbils was assessed in the elevated plus maze (EPM), black-white box (BWB), open-field and social interaction tests. In the elevated plus maze, females spent proportionally less time in the centre square and greater time in the closed arms compared with males. In the black-white box, they showed significantly greater entries into the black compartment, whilst in the open field, females spent less time sniffing the arena compared with males. Thus, in these three models, there are no conclusive sex differences in anxiety-like behaviour. However, in the social interaction test, females showed more exploratory/cage-orientated behaviour and less active social and aggressive behaviour. In addition, females terminated social contact more frequently. These results can be interpreted as true sex differences, as behaviour in the open-field and social interaction tests did not differ across the oestrous cycle. In conclusion, the results show that sex differences in anxiety-like behaviour in gerbils are best detected using the social interaction test, which suggests that females show a more anxious profile. It also further highlights the need for sex differences to be investigated in tests of anxiety.

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

“…Data from gerbils which had seizures were excluded from the main analysis (Bridges and Starkey, 2004). Seizure data were analysed separately for association between seizure occurrence and experimental condition.…”

“…They were handled daily throughout the study to habituate them to handling and to reduce the likelihood of seizure (Bridges and Starkey, 2004). Cages and racks were rotated daily, so that position in the room and rack was randomised.…”

“…Recent research has shown that the Mongolian gerbil (Meriones unguiculatus), shares greater neuro-endocrinological similarities to humans. For example, the gerbil neurokinnin receptor is more similar to the human neurokinin receptor than that of rats or mice (Varty et al, 2002a,b;Bridges and Starkey, 2004). In the search for drugs to treat anxiety which do not have the wide ranging and debilitating side effects of the benzodiazepines, neurokinin receptors have been implicated in the aetiology of anxiety (Walsh et al, 1995;Gerlai et al, 2002).…”

Vomeronasal organ ablation elicits chemosensory dysfunction and abnormal behavior in mice

“…The behavior of the mouse was videotaped for analysis. We scored locomotion (number of floor grids crossed), frequencies of standing on the hind legs, upright, time spent resting (standing on four feet and showing no movement), time spent in the three center grids and other periphery grids, and latency to initially leave the corner grids (Arakawa 2003;Bridges and Starkey 2004).…”

“…We recorded the latency to first leave (escape) from the light chamber, time spent in the light and dark chambers, and the frequency of crossing between the two chambers with a stopwatch. A mouse was considered to be inside or outside the light chamber when all its four feet were within the light chamber or the tunnel (Bridges and Starkey 2004). Between trials, the box was washed thoroughly with alcohol solution (75%).…”