BEHAVIORAL AND INTESTINAL RESPONSES TO NOVELTY IN RATS SELECTED FOR DIVERGING REACTIVITY IN THE OPEN-FIELD TEST

There are indications that the severity of functional gastrointestinal disturbances in humans is linked to individual coping styles. In rode nts, the open held test can be used to assess individual differences i n behavioural responsivity to novel challenges. Two groups of Wistar r ats were selected for high (HA) and low (LA) locomotor activity in a n ovel open field and fitted with electrodes on the proximal colon. Duri ng subsequent exposure to a novel box, a smaller locomotor activation in LA was accompanied by a greater increase in colonic spike burst act ivity compared to HA rats, even though this novel stressful challenge did not result in a clear defecation response in either group. In cont rast, no marked behavioural differences between HA and LA were seen in the shock prod paradigm. Although detection of divergent behavioural responsivity in HA and LA rats may depend on stimulus quality or inten sity, combined use of behavioural selection and intestinal motility re cording in freely moving rats may offer a model to study individual vu lnerability to stress-related disturbances of intestinal function. (C) 1997 Elsevier Science B.V.