Brain-Derived Neurotrophic Factor in the Nucleus Accumbens Mediates Individual Differences in Behavioral Responses to a Natural, Social Reward.

BDNF-oxytocin interactions in the brain are implicated in mammalian maternal behavior. We found that BDNF gene expression is increased in the hippocampus of rat mothers that show increased pup licking/grooming (high LG mothers) compared to low LG mothers. High LG mothers also showed increased BDNF protein levels in the nucleus accumbens (nAcc).

Environmental regulation of the neural epigenome.

Parental effects are a major source of phenotypic plasticity. Moreover, there is evidence from studies with a wide range of species that the relevant parental signals are influenced by the quality of the parental environment. The link between the quality of the environment and the nature of the parental signal is consistent with the idea that parental effects, whether direct or indirect, might serve to influence the phenotype of the offspring in a manner that is consistent with the prevailing environmental demands.

Maternal programming of defensive responses through sustained effects on gene expression.

There are profound maternal effects on individual differences in defensive responses and reproductive strategies in species ranging literally from plants to insects to birds. Maternal effects commonly reflect the quality of the environment and are most likely mediated by the quality of the maternal provision (egg, propagule, etc.), which in turn determines growth rates and adult phenotype.

Long-term consequences of neonatal rearing on central corticotropin-releasing factor systems in adult male rat offspring.

In a series of studies on the long-term consequences of neonatal rearing, we compared hypothalamic and extrahypothalamic central corticotropin-releasing factor (CRF) systems in male rats reared under conditions of animal facility rearing, nonhandling (HMS0), handling with brief maternal separation for 15 min (HMS15), or handling with moderate maternal separation for 180 min (HMS180) daily from postnatal days 2-14. CRF-like immunoreactivity (CRFir) was elevated in lumbar cerebrospinal fluid of adult HMS180 and HMS0 rats relative to the other groups. In the paraventricular nucleus, central nucleus of the amygdala, bed nucleus of the stria terminalis, and locus coeruleus, CRFir and CRF mRNA levels were significantly elevated in HMS0 and HMS180 rats.

Epigenetic programming of stress responses through variations in maternal care.

Early life experiences shape an individual's physical and mental health across the lifespan. Not surprisingly, an upbringing that is associated with adversity can produce detrimental effects on health. A central theme that arises from studies in human and nonhuman species is that the effects of adversity are mediated by the interactions between a mother and her young.