Neonatal novelty exposure modulates hippocampal volumetric asymmetry in the rat

Early life environmental manipulations have been shown to affect hippocampa l-dependent learning, hippocampal volume and cerebral lateralization. In th is study, we investigated the effects of neonatal stimulation on hippocampa l volumetric asymmetry. Long-Evans hooded rats were exposed to a novel non- home environment 3 min daily for the first 3 weeks of life. Histological me asures of the left and right hippocampus were made at 8 months of age. We f ound that neonatal novelty exposure resulted in a long-lasting change in hi ppocampal volumetric asymmetry. Specifically, this brief and transient earl y life stimulation increased the right hippocampal volumetric dominance at mid-adulthood. NeuroReport 12:3019-3022 (C) 2001 Lippincott Williams & Wilk ins.