The transmission of traits across generations has typically been attributed to the inheritance by offspring of genomic information from parental generations. However, recent evidence suggests that epigenetic mechanisms are capable of mediating this type of transmission. In the case of maternal care, there is evidence for the behavioral transmission of postpartum behavior from mothers to female offspring. The neuroendocrine and molecular mediators of this transmission have been explored in rats and implicate estrogen-oxytocin interactions and the differential methylation of hypothalamic estrogen receptors. These maternal effects can influence multiple aspects of neurobiology and behavior of offspring and this particular mode of inheritance is dynamic in response to environmental variation. In this review, evidence for the generational transmission of maternal care and the mechanisms underlying this transmission will be discussed as will the implications of this inheritance system for offspring development and for the transmission of environmental information from parents to offspring. Keywords maternal; epigenetic; DNA methylation; estrogen receptor Ī±; oxytocin; environment; cross-fostering Maternal effects have been demonstrated across many species and serve as an important cue to offspring development. In mammals, the lengthy period of prenatal and postnatal motherinfant interaction provides an opportunity for mothers to influence offspring through a variety of mechanisms. During gestation, interactions between mother and fetus are critical for growth and development and variations in these interactions can have long-term consequences for offspring physiological and psychological health. These effects have best been demonstrated through study of prenatal stress [1] and maternal malnutrition [2;3] in which changes to the mother's neuroendocrine system and physiology produces a shift in fetal neurodevelopment. Likewise, the care received by an infant early in life can produce changes in the development of neural systems regulating response to novelty and social behavior [4]. Thus, the maternal environment experienced by a developing organism can play a critical role in shaping adult patterns of behavior. Moreover, there can be transmission of these effects to subsequent generations through alterations in the reproductive behavior of offspring. Thus maternal care can be transmitted from mothers to daughters and grand-daughters. The mechanisms mediating Correspondence should be addressed to: Dr. Frances A. Champagne, Department of Psychology, Columbia University, Room 406 Schermerhorn Hall, 1190 Amsterdam Avenue, New York, NY 10017, Phone: (212) 854-2589, Fax: (212) 854-3609, Email: E-mail: fac2105@columbia.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is ...