Bruce Svare, PhD - US grants

Anabolic steroids, the synthetic variants of the primary masculinizing androgen testosterone, are abused by growing numbers of individuals in this country ranging from adolescents seeking to improve their appearance to professional athletes attempting to elevate their performance. The specific aim of the present research is to provide preliminary information on the causes and consequences of such abuse in humans by investigating their effects in laboratory mice. Physical dependence will be studied by exploring behavioral and physiological reactions to both acute and chronic anabolic steroid administration. In addition, we will explore withdrawal symptoms (e.g., the abstinence syndrome) following the termination of chronic treatment as well as the reversal of withdrawal symptoms following readministration of anabolic steroids. Behavioral dependence will be analyzed by studying whether or not and to what extent anabolic steroid hormones can produce pleasurable subjective states with such states having the potential to control behavior. Specifically, Pavlovian conditioning techniques (e.g., context conditioned place preference) will be utilized to explore the issue of behavioral dependence. Finally, because increases in aggressive behavior and violence are some of the most frequently reported side effects of anabolic steroid abuse in humans, we will examine the extent to which anabolic steroid hormones can promote species-typical aggressive behavior in mice. The findings ultimately will aid us in understanding the potential addictive nature and adverse behavioral consequences of these hormones.

Maternal aggression, which has been observed in a variety of mammals in both naturalistic and laboratory settings, functions to protect the home and young as well as to disperse adults and juveniles. While much is known about the physiological determinants of other aspects of parental behavior and other forms of aggressive behavior, comparatively little is known concerning the biological basis of maternal aggression. Yet, females mammals exhibit dramatic changes in their aggressive behavior toward conspecifics during pregnancy, postpartum estrus, and lactation. Dr. Svare has shown that females are aggressive during pregnancy, become docile during postpartum estrus, and then become intensively aggressive during lactation. He will determine the role of steroid hormones in the stimulation and inhibition of these behavioral changes. Dr. Svare will systematically examine aggressive behavior and steroid hormone (estradiol, progesterone, testosterone) concentrations throughout pregnancy and early postpartum period. He will then use this information to construct a schedule of exogenous hormones to reproduce the specific behaviors. The results will enhance our knowledge of the biological basis of female aggressive behavior and may ultimately prove important for understanding the behavioral changes that frequently occur in human peripartum females.

This award will support a workshop organized by Professor Frederick vom Saal and Bruce Svare of the University of Missouri and Professor Stefano Parmigiani of the Institute of Zoology in Parma, Italy. The workshop, to be held at the Center Ettore Majorana in Erice, Italy, aims to bring together scholars from a number of disciplines: biology, psychology, anthropology, history who are examining the causes of abuse of infants, as well as the factors influencing the investment of resources in them. The capacity for parents to protect their offspring is an essential component of reproductive success in species in which there is parental care. Only recently has the phenomenon of infanticide, defined as the killing of preweanling young by members of the same species, been viewed within the context of evolutionary biology. Prior to the late 1970's the killing of infants by conspecifics was generally viewed as an aberrant behavioral response to a breakdown in social structure. A conference on Infanticide in 1982, and the subsequent book, served as the impetus for a considerable amount of research over the last 7 years. This workshop will serve an important function in reviewing the latest findings and discussing future directions.

Anabolic steroids, the synthetic variants of the primary masculinizing androgen testosterone, are abused by growing numbers of individuals in this country ranging from adolescents seeking to improve their appearance to professional athletes attempting to elevate their performance. The specific aim of the present research is to provide preliminary information on the causes and consequences of such abuse in humans by investigating their effects in laboratory mice. Physical dependence will be studied by exploring behavioral and physiological reactions to both acute and chronic anabolic steroid administration. In addition, we will explore withdrawal symptoms (e.g., the abstinence syndrome) following the termination of chronic treatment as well as the reversal of withdrawal symptoms following readministration of anabolic steroids. Behavioral dependence will be analyzed by studying whether or not and to what extent anabolic steroid hormones can produce pleasurable subjective states with such states having the potential to control behavior. Specifically, Pavlovian conditioning techniques (e.g., context conditioned place preference) will be utilized to explore the issue of behavioral dependence. Finally, because increases in aggressive behavior and violence are some of the most frequently reported side effects of anabolic steroid abuse in humans, we will examine the extent to which anabolic steroid hormones can promote species-typical aggressive behavior in mice. The findings ultimately will aid us in understanding the potential addictive nature and adverse behavioral consequences of these hormones.