Pierre Deviche - US grants

The neuroendocrine mechanisms that regulate the control of feeding is a fundamentally important problem that is not well understood. It is known that control of food consumption depends on complex interactions between several types of neurochemicals, including neuropeptides and steroidal hormones. Based on extensive neurobiological data, Dr. Deviche hypothesizes that opioids interact with androgens within specific brain cells of the hypothalamus, an important neural structure for regulatory behaviors. To test this theory, he will use a combination of neuroanatomical, biochemical and behavioral approaches. Experiments will identify the specific hypothalamic nuclei that opioid peptides act to influence feeding, and where these peptides interact with respect to testosterone, the major testicular androgen. Moreover, the unique environment at the University of Alaska enables Dr. Deviche to utilize a seasonally breeding, migratory avian species that undergo extreme seasonal changes in testosterone as his model. He will establish the relationship between density of CNS opioid receptors and variations within plasma concentrations of this androgen. It is likely that these data could ultimately have significance for our understanding of human eating disorders. For example, anorexia nervosa is a life-threatening eating disorder for which there is some evidence for opioid and endocrine dysfunctions.

9315307 Deviche It is well established that a wide variety of organisms have internal biological clocks that are instrumental in allowing them to maintain synchrony to both daily (i.e., circadian) and annual cycles of environmental change. Plants and animals routinely experience small adjustments in these rhythms, often triggered by intensity of light, to synchronize their internal clocks with the passing seasons or changes in the environment. Indeed, precisely timed bursts of bright light can stop the daily cycle of the human biological clock. A major question is how photic signals are transduced into physiological responses. Two structures in the brain that have been identified as playing a role in this response are the suprachiasmatic nuclei of the hypothalamus and the pineal gland. These structures receive neural input from the retina of the eye when it is stimulated by light. It has been proposed that some vertebrates also may possess extra-pineal, extra-retinal photoreceptors, referred to as deep brain photoreceptors, which are capable of entraining circadian rhythms. At this time we do not know the location, sensitivity, or most importantly the neural connections of these putative receptors. This project awards Dr. Deviche a small grant for exploratory resesarch to address this important problem. He has found a model system in a species of highly photoperiodic arctic bird that possibly could provide the answers. Using an antibody that identifies rhodopsin-like photopigments in the retina and the pineal, he will locate cell bodies and terminals in the brain. Light conditions will be manipulated to determine whether light exposure stimulates the expression of these photopigments in these brain cells. If successful, this will be the first demonstration that some cells deep within the central nervous system are photosensitive. These results would open new avenues towards understanding the mechanisms by which light stimulation reaches and alters th e nervous system to influence biological timing, and will have impact also beyond neuroscience to arctic biology and ornithology. Understanding the basic neural mechanisms for timing could lead to treatment of problems such as impaired attentiveness that affect human performance during work shifts from day to night, or jet lag, or other factors that make the internal clock out of sync with the environment. ***

9312641 Deviche A symposium has been organized by Dr. Deviche as part of the annual meeting of the American Society of Zoologists. This conference will focus on the endocrine mechanisms involved in the physiological functions of artic birds and mammals. The physiological functions include endocrine control of pre- migratory fattening, hibernation and reproductive endocrinology. The topic, "Endocrinology of Artic Birds and Mammals", is timely and the speakers are considered experts in their respective fields. It is anticipated that the symposium will be of interest to comparative endocrinologists and physiologists as well as behavioral ecologists. ***

9317916 Roby This Equipment Proposal requests funds to purchase (1) total body electrical conductivity (TOBEC) body composition analyzers, (2) a Soxhlet lipid extraction apparatus, (3) a thin-layer chromatography/flame ionization detector (TLC./FID) system, (4) an automated adiabatic bomb calorimeter and (5) support equipment for proximate body tissue analysis (saws, balance, freeze dryer, ovens). This equipment will be used to measure the body composition and energy content of arctic animals, as part of several related research projects on the hysiological ecology of high latitude endotherms (songbirds, microtines, geese, seabirds, ground squirrels, and ruminants). All projects seek to understand the regulatory role of nutrient and energy reserves for either migration, reproduction, or survival. The TOBEC body composition analyzer is a new instrument for noninvasive measurement of body composition in live subjects and provides an opportunity to examine temporal variation in an individual's fat and protein reserves. The Soxhlet apparatus would be used to calibrate the TOBEC technique and extract stored lipids for further analyses. Separation and quantitation of lipid classes would be accomplished with the TLC/FID system, and the energy content of storage compounds will be measured with the isoperibol oxygen bomb calorimeter. Determination of body composition is a fundamental method for evaluating physical condition and nutritional status of animals. Lipid and lean mass are measures of energy and protein reserves and, presumably, of fitness during periods of food shortage, dormancy, or negative energy ba lance. Scientists at the Institute of Arctic Biology are engaged in several research projects that test the adaptive significance of fat reserves for endotherms living in high latitude environments. Procurement of the above pieces of equipment will greatly enhance existing research projects at the Institute that are described in this proposal, and will provide many opportunities for new projects. In addition, the new instrumentation will significantly improve instruction and research of undergraduate, graduate, and post-doctoral students at the University of Alaska Fairbanks. 9 9 ( Times New Roman Symbol & Arial " h E = abstract Deseree King, BIR Deseree King, BIR X1 ~CRD3E17TMP X1 ~CAL1E3FTMP l:L ~CRD1809TMP p:L 9317916 Roby This Equipment Proposal requests funds to purchase (1) total body electrical conductivity (TOBEC) body compositi 9 d 9 ! ! (# ! ! ! F 9 9 ( Times New Roman Symbol & Arial " h E = abstract Deseree King, BIR Deseree King, BIR

PROJECT TITLE: Neuroendocrine Bases and Environmental Regulation of Reproduction in a Flexibly Breeding Songbird

PRINCIPAL INVESTIGATOR: Pierre Deviche, Arizona State University

PROJECT NUMBER: IOS 1026620

This project will combine field studies on free-ranging organisms with experiments in a controlled laboratory setting to investigate the neuroendocrine bases of vertebrate reproductive flexibility. It will use multidisciplinary approaches ranging from molecular techniques to whole animal experiments in order to determine how animals integrate external environmental cues to regulate neuroendocrine and physiological changes associated with seasonal reproduction. The research will contribute to unraveling the role of some brain peptides in the control of seasonality and how the brain expression of these peptides is influenced by specific environmental factors. The findings will be relevant to our understanding of the bases of reproductive resilience and they will enhance our comprehension of the effects of some environmental perturbations, such as those potentially associated with global climate warming, on the reproductive physiology of vertebrate populations. The experimental model for the research will be a songbird. Many birds are conspicuous and birds in general are inherently fascinating to the general public. The studies will, therefore, be used to promote basic and advanced biological concepts related to how animals may adapt to the effects of global climate warming and other anthropogenic perturbations of their natural environments. Experimental data will be made publicly available through the Ask-a-Biologist web site, a wildly popular site that promotes science education at all levels, but in particular in high schools. All aspects of the research will involve the mentoring and active participation of undergraduates and graduate students.