title: Maternal care influences neuronal survival in the hippocampus of the rat.
abstract: Maternal care during the first week of postnatal life influences hippocampal development and function (Liu et al., 2000; Nature Neurosci., 3, 799-806). Offspring reared by mothers who exhibit increased levels of pup licking/grooming (LG) show increased hippocampal synaptic density and enhanced spatial learning and memory. Using 5-bromo-2'-deoxyuridine (BrdU), a thymidine analogue incorporated into cells during DNA synthesis, we examined the effects of early maternal care on hippocampal cell proliferation and neuronal survival in the rat. Twenty-four hours following injection on day 7 of life (P7) there were no differences in BrdU labelling in the offspring of high- compared with low-LG mothers, suggesting no maternal effect on the rate of proliferation at this age. However, 14 and 83 days following injection (P21 and P90), the offspring of high-LG mothers had significantly more surviving BrdU-labelled cells and BrdU-NeuN+-colabelled neurons in the dentate gyrus subgranular zone and granule cell layer. At P21, the offspring of high-LG mothers showed increased protein expression of basic fibroblast growth factor and significantly decreased levels of pyknosis. These findings suggest an influence of maternal care on neuronal survival in the hippocampus. Conversely, at the same time point there was a significantly higher level of hippocampal glial fibrillary acidic protein expression in the offspring of low-LG mothers. These findings emphasize the importance of early maternal care for hippocampal development.
authors.affiliation: Developmental Neuroendocrinology Laboratory and McGill Program for the Study of Behaviour, Genes and Environment, Douglas Hospital Research Centre, 6875 Boul. LaSalle Blvd, Montréal, Canada, H4H 1R3.
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Bredy
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Grant
authors.forename: Danielle L
authors.initials: DL
authors.lastname: Champagne
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Meaney
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001522:Behavior, Animal; D015153:Blotting, Western; D001973:Bromodeoxyuridine / Q000378:metabolism; D002232:Carbocyanines / Q000378:metabolism; D002452:Cell Count; D002470:Cell Survival; D005260:Female; D005346:Fibroblast Growth Factors / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D008425:Maternal Behavior / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D010078:Oxazines / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D013997:Time Factors
chemical_list: D002232:Carbocyanines; D005904:Glial Fibrillary Acidic Protein; D010078:Oxazines; C089187:cyanine dye 3; C008619:Nile Blue; D005346:Fibroblast Growth Factors; D010751:Phosphopyruvate Hydratase; D001973:Bromodeoxyuridine