The purpose of this grant proposal is to develop novel paradigms, acquire new techniques and apply them to either extensions of current research themes or to new research endeavors related to these themes in order to develop further the career of the PI.
Three Specific Aims are proposed, each with a set of experiments.
Specific Aim I : What is the role of the innervation of adipose tissue in the photoperiodic control of seasonal obesity? Experiments are proposed to extend our recent report of the direct innervation of white adipose tissue (WAT) by the sympathetic nervous system (SNS) and our finding of sensory innervation of WAT (see Preliminary Studies), and the role of each in the photoperiodic control of seasonal obesity in Siberian hamsters. Four questions will be answered: 1) Can the short day-induced decreases in body fat occur independently of the SNS innervation of WAT?, 2) Does the relatively separate SNS innervation of WAT converge in the CNS?, 3) What is the extent of the sensory innervation of WAT?, and 4) What is the functional role of the sensory innervation of WAT in the short day-induced decreases in body fat? Specific Aim II: What is the relationship between the amount of total body fat and level of food hoarding and what role does the sensory innervation of adlpose tissue play in this relationship? Siberian hamsters appear to respond to decreases in body fat by increasing externally stored energy in the form of a food hoard. Naturally occurring and experimentally induced decreases in body fat will be used to test further the inverse relationship between total body fat and the level of food hoarding in Siberian hamsters, and the role of the sensory innervation of WAT in this relationship. Food hoarding will be studied using a simulated burrow system. Three questions will be answered: 1) Do the short day-induced decreases in body fat stimulate food hoarding?, 2) Does partial surgical lipectomy (fat removal) stimulate food hoarding?, and 3)What is the role of the sensory innervation of WAT on the short day-induced increases in food hoarding? Specific Aim III: Can c-Fos activity be used to identify the functional sites of reception/transmission of melatonin signals and thefr efferent projection fields? Experiments are proposed to test the hypothesis that stimulation of the putative sites for the reception/transmission of melatonin signals activates the immediate-early gene c-Fos. This will be accomplished by using the timed infision paradigm for the subcutaneous or intracerebral programmed delivery of physiologically relevant melatonin signals to pinealectomized Siberian hamsters. Three questions will be answered: 1)Do systemic infusions of melatonin activate neurons in the three brain sites that show melatonin binding in Siberian hamsters and what are the neurotransmitter phenotypes of these cells?, 2) Where are the efferent projection fields of the cells that are activated by melatonin and located in the three brain sites that show melatonin binding?, and 3) Can these putative efferent projection fields be verified using retrograde tract tracing combined with c-Fos immunocytochemical techniques?

Agency
National Institute of Health (NIH)
Institute
National Institute of Mental Health (NIMH)
Type
Research Scientist Development Award - Research (K02)
Project #
5K02MH000841-08
Application #
2674337
Study Section
Psychobiology, Behavior, and Neuroscience Review Committee (PBN)
Project Start
1990-04-01
Project End
2001-03-31
Budget Start
1998-04-01
Budget End
1999-03-31
Support Year
8
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Georgia State University
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
837322494
City
Atlanta
State
GA
Country
United States
Zip Code
30302
Day, Diane E; Mintz, Eric M; Bartness, Timothy J (2002) Diet choice exaggerates food hoarding, intake and pup survival across reproduction. Physiol Behav 75:143-57
Demas, Gregory E; Bowers, Robert R; Bartness, Timothy J et al. (2002) Photoperiodic regulation of gene expression in brown and white adipose tissue of Siberian hamsters (Phodopus sungorus). Am J Physiol Regul Integr Comp Physiol 282:R114-21
Demas, G E; Drazen, D L; Jasnow, A M et al. (2002) Sympathoadrenal system differentially affects photoperiodic changes in humoral immunity of Siberian hamsters (Phodopus sungorus). J Neuroendocrinol 14:29-35
Campbell, Patrick K; Waymire, Katrina G; Heier, Robb L et al. (2002) Mutation of a novel gene results in abnormal development of spermatid flagella, loss of intermale aggression and reduced body fat in mice. Genetics 162:307-20
Bartness, Timothy J; Demas, Gregory E; Song, C Kay (2002) Seasonal changes in adiposity: the roles of the photoperiod, melatonin and other hormones, and sympathetic nervous system. Exp Biol Med (Maywood) 227:363-76
Day, D E; Bartness, T J (2001) Effects of foraging effort on body fat and food hoarding in Siberian hamsters. J Exp Zool 289:162-71
Song, C K; Bartness, T J (2001) CNS sympathetic outflow neurons to white fat that express MEL receptors may mediate seasonal adiposity. Am J Physiol Regul Integr Comp Physiol 281:R666-72
Shi, H; Bartness, T J (2001) Neurochemical phenotype of sympathetic nervous system outflow from brain to white fat. Brain Res Bull 54:375-85
Demas, G E; Bartness, T J (2001) Novel method for localized, functional sympathetic nervous system denervation of peripheral tissue using guanethidine. J Neurosci Methods 112:21-8
Bartness, T J; Song, C K; Demas, G E (2001) SCN efferents to peripheral tissues: implications for biological rhythms. J Biol Rhythms 16:196-204

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