Responses to Novelty in Two Inbred Strains of Mice and Their F sub(1) Hybrids: Behaviour and Brain Biogenic Amines

Responses to novelty of two inbred strains of mice, C57BL/6JOrl (C) and A/JOrl (A) and their reciprocal F sub(1) hybrids were recorded. The parental strains differed from each other: the C strain showed a preference for a novel environment and neophobic reactions to a novel object introduced into the familiar environment. The A mice were characterized by a preference for the familiar environment and lower neophobia towards the novel object. In addition, the C strain exhibited high and the A strain low locomotor activity. The reciprocal hybrids were identical in their major responses to the C strain. Neurochemical investigations indicated that the parental A strain showed a lower level of dopamine in the striatum and in the olfactory bulbs when compared with the C strain and the hybrid F sub(1) CxA.