ABSTRACT
Usual housing conditions lead to dominance hierarchy forming between male mice. The situation produces physiological and behavioural differences between dominants and subordinates. The goal of the present study was to assess stress responses, and possible changes in prepulse inhibition (PPI) of the startle reflex in dominant and subordinate male mice. Three weeks of daily social interactions led to stable aggressive dominance in 11 pairs of male NMRI mice. Stress levels were assessed by measuring faecal corticosterone metabolites (FCM), a non-invasive technique for monitoring hormonal changes in response to specific situations, with repeated sampling of each animal. The analysis of FCM levels showed greater stress in subordinate males at the beginning of the experiment, as the hierarchy was being established, but by the end of the experiment, FCM levels were reduced and similar in both dominants and subordinates. No significant differences were found in the startle response or PPI.
Subject(s)
Behavior, Animal/physiology , Corticosterone/metabolism , Dominance-Subordination , Social Dominance , Social Environment , Animals , Male , Mice , Stress, PsychologicalABSTRACT
Space perception was investigated in two groups of participants with severe visual deficiencies performing a tactile bisection task: the participants in the first group (Archers) regularly practised a high-precision sport, whereas those in the second group (Non-Archers) had never practised this activity. Experiments were carried out to determine whether practising this sport might affect the pseudoneglect (resulting in a deviation to the left of the perceived midpoint with respect to the actual physical midpoint) occurring in sighted persons (Bowers & Heilman, 1980) as well as in completely blind children (Sampaio, Gouarir, & Mvondo Mvondo, 1995). No particular deviation was observed in the group of Non-Archers, whereas pseudoneglect was present in the Archers' group. A significant hand effect (left/right), and a significant effect of starting point of tactile exploration were observed across groups. This confirms the existence of a relationship between hemisphere-hands and hemisphere-hemispace mechanisms. The results obtained here show that practising archery affects pseudoneglect.
Subject(s)
Psychomotor Performance/physiology , Space Perception/physiology , Sports , Touch/physiology , Vision Disorders/physiopathology , Adult , Female , Humans , Male , Middle Aged , Perceptual Disorders/complications , Perceptual Disorders/diagnosis , Perceptual Disorders/physiopathology , Vision Disorders/complicationsABSTRACT
Motor and cognitive phenotypes were assessed in mice deficient for the close homologue of the L1 adhesion molecule (CHL1). The CHL1-deficient mice displayed signs of decreased stress and a modification of exploratory behaviour. The mice also showed motor impairments on the Rotarod, but they were able to move as fast as controls in the alleys of a T-maze. The observed changes were assumed to be related to a deficit in attention. In addition, gender differences in CHL1 deficits were found and are discussed in view of a possible interaction with other cell adhesion molecules (CAMs) during development. The results are discussed in relation with motor and cognitive deficits in the human, caused by mutations of the distal part of the chromosome 3 which contains the CHL1 orthologue.
Subject(s)
Emotions/physiology , Mice, Knockout/physiology , Proteins/metabolism , Psychomotor Performance/physiology , Animals , Body Constitution/genetics , Body Weight/genetics , Cell Adhesion Molecules , Exploratory Behavior , Female , Male , Maze Learning/physiology , Membrane Proteins , Mice , Mice, Inbred C57BL , Proteins/genetics , Reaction Time , Running , Sex Factors , Time FactorsABSTRACT
In this study, the effects of changes in brood composition on the activities of the associated females are investigated in three-foundress nests during the pre-emergence period. Partial correlation coefficients were computed between four variables describing the brood composition (number of eggs, small larvae, large larvae, and pupae) and the duration of nineteen behavioural items performed by the foundresses. Alpha females were found to frequent the face of the comb when there was a large number of eggs. Once the larvae had hatched, these females participated only in activities taking place on the nest. Apart from periods of cell initiation, Alpha females left the nest only in order to rest. Beta females were generally very active, and their activity level was not sensitive to changes in the brood composition. Gamma females showed a lower activity level which was easily stimulated by changes in the brood. These females seem to start working when Beta activity no longer suffices to meet the needs of the colony.
