MINISYMPOSIUM IV. MAHESH NEUROENDOCRINE MINISYMPOSIUM. STRESS, BEHAVIOR, AND REPRODUCTION: NEUROENDOCRINE CONTROL OF GONADAL FUNCTION
Monday, August 2, 2004
9:00 AM–10:30 AM
Chair: Matthew P. Hardy (The Population Council, New York, NY); Co-Chair: Jon E. Levine (Northwestern University, Evanston, IL)
(MS12) STRESS AND MATERNAL INFLUENCE: ROLE OF CORTICOTROPIN-RELEASING FACTOR AND RECEPTORS.
Bale, Tracy1, 1 University of Pennsylvania, Philadelphia, PA
ABSTRACT- Studies have well defined the roll of postpartum maternal nurturing and its effects on mood and stress sensitivity of the pups, both during development and as adults. Maternal stress hormone levels have also been implicated in alterations of the anxiety levels of the offspring. Therefore, both the behavioral and endocrine maternal state have dramatic effects on the emotional status of the pups. A great difficulty in studying effects of maternal stress has been modeling increased susceptibility and sensitivity to stress in rodents. A key factor in the response to stress is the neuropeptide corticotropin-releasing factor (CRF). CRF and its receptors (CRFR1 and CRFR2) are important regulators of the hypothalamic pituitary adrenal (HPA) axis. While CRF stimulates the HPA axis in response to stress and plays a key role in activation of anxiety behaviors via activation of CRFR1, other CRF family members act to decelerate the stress response via activation of CRFR2. Mice deficient for CRFR2 show elevated anxiety-like behaviors and a hypersensitive stress response likely due to unimpeded CRFR1 activity. Therefore, the CRFR2-deficient mice provide a good model of increased stress sensitivity in which to better examine the developmental effects of maternal stress. In our studies, we have found a significant correlation between the CRFR2 genotype of the dam and the anxiety-like behaviors detected in their offspring. As we have previously reported that the CRFR2-deficient mice display increased anxiety-like behaviors and a hypersensitivity to stress, it is likely that this phenotype is affecting the behavior of pups reared by mothers sensitive to stress. In order to determine if this effect was due to prenatal or postnatal experience, we have examined maternal behaviors in these dams as well as effects of cross-fostering on the development of stress responses and anxiety-like behaviors in their offspring.
KEY WORDS: maternal, anxiety, stress, CRF