The quality of parental care has a broad impact on mental health, including the risk for psychopathology [1], [2], [3], [4], [5]. Studies in the rat directly link the maternal care environment to long-term effects on neural systems that regulate stress [6], [7] emotional function[8], [9], learning and memory [10], [11], [12] and neuroplasticity [10], [13], [14], [15]. Naturally occurring variations in maternal care in the first week of life in rats are associated with changes in brain and behavior that persist until adulthood [16]. These effects are reversed by cross-fostering, [7], [9] demonstrating a causal link between maternal care and gene expression programming.
