Maternal care, hippocampal synaptogenesis and cognitive development in rats

We report that variations in maternal care in the rat promote hippocampal s ynaptogenesis and spatial learning and memory through systems known to medi ate experience-dependent neural development. Thus, the offspring of mothers that show high levels of pup licking and grooming and arched-back nursing showed increased expression of NMDA receptor subunit and brain-derived neur otrophic factor (BDNF) mRNA, increased cholinergic innervation of the hippo campus and enhanced spatial learning and memory. A cross-fostering study pr ovided evidence for a direct relationship between maternal behavior and hip pocampal development, although not all neonates were equally sensitive to v ariations in maternal care.