NEONATAL HANDLING AND ENVIRONMENTAL ENRICHMENT EFFECTS ON EMOTIONALITY, NOVELTY REWARD SEEKING, AND AGE-RELATED COGNITIVE AND HIPPOCAMPAL IMPAIRMENTS - FOCUS ON THE ROMAN RAT LINES/

Roman high- and low-avoidance (RHA/Verh and RLA/Verh) rats are selecte d and bred for extreme divergence in two-way active avoidance acquisit ion. In addition, compared to RLA/Verh rats, RHA/Verh rats are (behavi orally and physiologically) less anxious or reactive to stressors, sho w increased novelty (sensation)-seeking behavior as well as a higher p reference for rewarding substances, and are usually less efficient in learning tasks not involving shock administration. The present article reviews evidence showing that neonatal handling and/or environmental enrichment leads to enduring effects (their magnitude frequently depen ding upon the rat line) on those behaviors. For example, it has been f ound that neonatal handling reduces most of the (behavioral and physio logical) signs of emotionality/anxiety in RLA/Verh rats, while environ mental enrichment increases their novelty seeking (also the case with RHA/Verh rats), saccharin and ethanol intake, and sensitivity to amphe tamine. Finally, initial results (currently being further elaborated u pon) support a preventive action of both environmental treatments on a ge-related impairments in learning a spatial, water maze task as well as on hippocampal neuronal atrophy.