1985 — 1990 |
Clemens, Lynwood G |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Neural Control of Sexual Behavior @ Michigan State University
The long term goal of this research program is to determine how the brain regulates reproductive behavior. The laboratory rat will be used as the model system for this work because the extensive work that has been done on this species makes it a valuable tool. Reproductive behavior is regulated by gonadal hormones which act within specific brain sites to bring about the behaviors that are required to maximize its reproductive potential. The experiments in this proposal focus on the biochemical and endocrinological events that must occur in these specific brain sites to translate the hormonal message into the program of integrated neural activity. Much of the proposed work is concerned with the effects of estrogen upon processes that regulate acetycholine action in the hypothalamus and midbrain. It would appear that estrogen is capable of modifying cholinergic activity in extensive brain regions, many of which have long been associated with emotionality as well as reproductive behavior. A better understanding of these basic neuroendocrine and biochemical brain processes will provide insight into many areas related to health including reproduction, emotionality and behavioral fluctuations that are associated with variations in gonadal hormones.
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1 |
1991 — 1994 |
Clemens, Lynwood |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Neural Control of Masculine Sexual Responses @ Michigan State University
The goal of Dr. Clemens' research is to understand connections between the brain and the spinal cord of nerve cells that are involved in the control of reproductive behavior. Specific tracer substances will be used to define such pathways at both the light and electron microscopic levels. The neurochemical characteristics of the pathways and the effects of hormonal manipulations on the nerve cells will also be studied. Knowledge about this neural system under normal conditions is a prerequisite to understanding changes that can occur when the system is dysfunctional such as may happen with aging. This research will contribute to basic understanding of the role of the nervous system in reproductive function.
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0.915 |
1995 — 1998 |
Clemens, Lynwood |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Neural and Hormonal Substrates of Reproductive Behavior @ Michigan State University
IBN-9511971 Clemens, Lynwood G. Reproductive success in most species depends on both humoral and neural responses acting coordinately. The majority of studies have focused on the male as the critical component for determining successful outcomes, however, female reproductive tract function is also significant, and yet underinvestigated. In the present work, Dr. Clemens will focus on the effects of hormones on uterine contractions and the role of these contractions in the initiation of pregnancy. By recording electrical activity of uterine muscles, it will be possible to determine what stimuli are important for the induction of uterine activity around the time of ovulation and whether these responses are associated with the release of hormones from the ovary involved in the initiation of pregnancy. The experiments will provide new and exciting information on the role of the female reproductive system in pregnancy initiation and reproductive success in mammals.
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0.915 |
1998 — 2006 |
Clemens, Lynwood |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Neural and Hormonal Substrates of Behavior @ Michigan State University
9728883 Clemens A major biological issue is understanding the nature of sex differences and similarities in the regulation of behavior. One of the problems that arises in comparing males and females is that we often use different measurement scales for males than we use for females. Moreover, scientists tend to focus their attention only on the differences between the sexes. Dr. Clemens notes that when functional units of behavior that are comparable between males and females are used, then general principles emerge that can apply to both genders. Using state-of-the-art neuroanatomical tools to examine neural activity, he will determine whether males and females have evolved forebrain mechanisms that respond similarly to the same contextual features of a situation. On the other hand, Dr. Clemens also notes substantial physiological differences exist in the peripheral nervous system of males and females which emerge as a result of endocrine processes during early development. He will use a variety of biological and behavioral techniques to investigate underlying mechanisms. These experiments will allow him to specify with great precision, exactly which cells in the central nervous system are active during different phases of the physiological and behavioral process in both males and females. The results from these fundamental studies could provide a new framework within which to view sex differences and similarities in the neuroendocrine substrates of behavior. Moreover, the findings could lead to a better understanding of how complex patterns of peripheral neural activity are integrated and controlled by the central nervous system.
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0.915 |
2000 — 2002 |
Clemens, Lynwood G |
P42Activity Code Description: Undocumented code - click on the grant title for more information. |
Environmental Contaminants &Neuroecology of Reproductive Behavior @ Michigan State University
This project is designed to investigate the effects of PCB congeners of PCB congeners 2,4,2',4 tetrachlorobiphenyl and 3,4,3',4' tetrachlorobiphenyl (TCBs) on the maternal and sexual behaviors of laboratory rats. Preliminary observations indicate that treatment of pregnant rats with TCBs produce behavioral effects that interfere with the display of normal maternal behavior. The experiments included in the first part of the proposal test hypothesis about the endocrine and neurochemical causes of these behavioral effects of TCBs. Specifically, the work investigates how the hormones of pregnancy and lactation modulate the toxic effects of TCBs on the dopaminergic pathway from the substantial nigra to the basal ganglia. The second part of the proposal focuses on the effects of prenatal and neonatal exposure to TCBs on the development of female sexual behavior. The central hypothesis tested here is that TCBs prevent the development of normal sexual behavior by affecting the development of dopaminergic systems. These dopaminergic pathways are responsible for the motivational and motoric aspects of female sexual behavior. This work makes use of sensitive behavioral anatomical and neurochemical approaches and the anticipated results will greatly expand our understanding of the effects of environmental contaminants on brain function and behavior. This work also begins to differentiate between developmental effects of TCBs that are due to direct actions on the developing nervous system from those that are the indirect result of change sin the quality of maternal care.
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2005 — 2007 |
Clemens, Lynwood G |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Male Sex Behavior and Development of the Pelvic Ganglia @ Michigan State University
DESCRIPTION (provided by applicant): The objective of the proposed research is to clarify the relationship between the effects maternal care has on development of reproductive neurobiology and behavior in laboratory rats. This goal will be achieved by concurrent evaluation of the changes in behavior and morphology that result from variation in maternal care. The specific aims of the proposal are: 1. Determine the effects of enhanced maternal stimulation on the development of the spinal nucleus of the bulbocavernosus (SNB), the major pelvic ganglion (MPG), and male reproductive behavior in the laboratory rat. 2. Determine the mechanism(s) by which maternal stimulation affects the morphology of the SNB and the MPG. 3. Determine the effects of deprivation of maternal stimulation on the development of the SNB and the MPG, and male reproductive behavior. These objectives will be archived by using two general models to examine the impact of variation in maternal care on the reproductive well being of males. One model takes advantage of the finding that some mother rats engage in high levels of licking and grooming of their neonatal offspring. This enhanced care facilitates the development of greater reproductive efficacy in the male offspring. The second model is one of maternal neglect and provides the opportunity to study the mechanisms by which severe reductions in maternal care lead to deficits in reproductive function in the male. Both models have parallels in the human where enhanced skin-to-skin contact (Kangaroo Care) accelerates autonomic and neurobehavioral maturation in human infants whereas early physical and emotional neglect in the human increase the risk of disease, and compromises growth and development. Whether it is touching and holding infant humans in a nursery or the maternal stimulation of young animals in a laboratory or animal care facility, the importance of early conspecific contact is of fundamental importance to the health and well-being of the offspring as adults.
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