Effects of the mere presence of conspecifics on the motor performance of rats: Higher speed and lower accuracy

A predictive model and a field study on heterogeneous slug distribution in arable fields arising from density dependent movement

Factors and processes determining heterogeneous (‘patchy’) population distributions in natural environments have long been a major focus in ecology. Existing theoretical approaches proved to be successful in explaining vegetation patterns. In the case of animal populations, existing theories are at most conceptual: they may suggest a qualitative explanation but largely fail to explain patchiness quantitatively. We aim to bridge this knowledge gap. We present a new mechanism of self-organized formation of a patchy spatial population distribution. A factor that was under-appreciated by pattern formation theories is animal sociability, which may result in density dependent movement behaviour. Our approach was inspired by a recent project on movement and distribution of slugs in arable fields. The project discovered a strongly heterogeneous slug distribution and a specific density dependent individual movement. In this paper, we bring these two findings together. We develop a model of density dependent animal movement to account for the switch in the movement behaviour when the local population density exceeds a certain threshold. The model is fully parameterized using the field data. We then show that the model produces spatial patterns with properties closely resembling those observed in the field, in particular to exhibit similar values of the aggregation index.

Impaired social facilitation on voluntary exercise of BALB/cCrSlc mice, a proposed as an autism spectrum disorder model

Impaired social facilitation was reported in autism spectrum disorder (ASD) children. However, behavioral analysis methods of social facilitation for ASD model have not been reported. We developed a novel breeding home cage for social facilitation. Voluntary exercise of more social C57BL/6 J mice was significantly increased in the presence of observer mouse compared to that in the absence of observer mouse. In contrast, the presence of observer mouse did not affect voluntary exercise of less social BALB/cCrSlc mice. These suggest that BALB/cCrSlc mice, a mouse model of ASD, exhibited impaired social facilitation. Our method would provide novel clues for ASD pathophysiology.