| 1. |
- Javal, Marion, et al.
(författare)
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A preliminary assessment of the physiological and morphological correlates of beetle aggression in an emerging sugarcane pest, Cacosceles newmannii ( Thomson, 1877) (Coleoptera: Cerambycidae)
- 2022
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Ingår i: African Entomology. - : ENTOMOLOGICAL SOC SOUTHERN AFRICA. - 1021-3589 .- 2224-8854. ; 30
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the morphological and physiological correlates of competitive behaviours can provide important insights into the ecology of competition, home range size and resource consumption. Here we first estimated and defined sexual dimorphism in a poorly studied African cerambycid species, Cacosceles newmannii (Thomson, 1877). We then assessed morphological and physiological attributes of male beetles in relation to their fighting behaviour. Suites of morphological and energetic measurements were carried out on adult males, the latter before and after male-male interactions. Aggressive behaviour and the outcomes of male fighting trials were assessed under controlled conditions. The species is highly sexually dimorphic in relation to mandible size. During male-male interactions, a continuum of behaviours with an increasing risk of injury and metabolic cost was observed. Grasping was prolonged in males with larger fighting apparatus, who also tended to use more energy during the encounter than males displaying other behaviours. Our results indicate that the mandible size in C. newmannii serves as an honest signal of fighting ability in this species. Additionally, energetic assessments in preparation for fighting, costs during a fight, and persistence of metabolic costs postfighting may be useful for understanding the relative fitness costs of competition.
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| 2. |
- Le Moëne, Olivia, et al.
(författare)
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A New Tool for Quantifying Mouse Facial Expressions
- 2023
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Ingår i: eNeuro. - : SOC NEUROSCIENCE. - 2373-2822. ; 10:2
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Tidskriftsartikel (refereegranskat)abstract
- Facial expressions are an increasingly used tool to assess emotional experience and affective state during ex-perimental procedures in animal models. Previous studies have successfully related specific facial features with different positive and negative valence situations, most notably in relation to pain. However, characteriz-ing and interpreting such expressions remains a major challenge. We identified seven easily visualizable facial parameters on mouse profiles, accounting for changes in eye, ear, mouth, snout and face orientation. We monitored their relative position on the face across time and throughout sequences of positive and aversive gustatory and somatosensory stimuli in freely moving mice. Facial parameters successfully captured response profiles to each stimulus and reflected spontaneous movements in response to stimulus valence, as well as contextual elements such as habituation. Notably, eye opening was increased by palatable tastants and innoc-uous touch, while this parameter was reduced by tasting a bitter solution and by painful stimuli. Mouse ear posture appears to convey a large part of emotional information. Facial expressions accurately depicted wel-fare and affective state in a time-sensitive manner, successfully correlating time-dependent stimulation. This study is the first to delineate rodent facial expression features in multiple positive valence situations, including in relation to affective touch. We suggest using this facial expression assay might provide mechanistic insights into emotional expression and improve the translational value of experimental studies in rodents on pain and other states.
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| 3. |
- Le Moene, Olivia, et al.
(författare)
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Male and female immediate fear reaction to white noise in a semi-natural environment: A detailed behavioural analysis of the role of sex and oestrogen receptors
- 2020
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Ingår i: Journal of neuroendocrinology (Print). - : WILEY. - 0953-8194 .- 1365-2826.
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Tidskriftsartikel (refereegranskat)abstract
- In classical rodent anxiety models, females usually display lower anxiety than males, whereas anxiety disorders are more prevalent in women. Perhaps this contradiction is caused by the use of behavioural models with low external validity. Therefore, we analysed immediate reactions to a sudden 90-dB white noise in a semi-natural environment. We observed mixed-sex groups of rats for the 60 seconds preceding noise onset and the first 60 seconds of exposure. White noise elicited fear-specific behaviours hiding alone and huddling. It also increased exploratory and ambulatory behaviours, although only in the burrow zone farthest from the open area. Thus, in a semi-natural environment, white noise enhanced motor activity as a product of fear-induced general arousal. Then, we compared male and female sexual, social, exploratory and anxiety-related behaviour, and found little sex difference. This absence of behavioural effect, also observed in other studies, might be a result of our study design, a familiar environment with an ecologically relevant social context. Fear and anxiety responses are modulated by oestrogens through the activation of oestrogen receptors alpha and beta. Thus, in a third part of out study, we analysed how treatment with either oil, oestradiol benzoate (EB), an agonist to the oestrogen receptor alpha (propylpyrazoletriol [PPT]) or beta (diarylpropionitrile [DPN]) influenced female behaviour. The effect of treatment was limited, both EB and PPT stimulated motor activity in the open area before white noise, probably because of sexual activity. PPT increased the probability of fleeing from the noise, and decreased the latency to do so, which is consistent with a pattern of anxiogenic properties found in previous studies. Contrary to reports in classical procedures, we failed to detect any effect of DPN on immediate fear reactions in a semi-natural environment.
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