Stress paradigms in rodent
models have been associated with elevated anxiety and contrasting alterations in neuronal morphology in the hippocampus and amygdala, with dendritic atrophy observed in the hippocampus and increased dendritic arborization in the amygdala.12, 13 Developing rodents deprived
of maternal nurturance show decreased hippocampal volume and
altered stress reactivity.14 An epigenetic mechanism for this effect has been elaborated.15 Importantly, controlled trials that have randomized institutionalized toddlers to early therapeutic foster
care vs institutionalization have documented the deleterious effects
of early relative deprivation on cognitive outcomes.16