|Research in the Jill Schneider Laboratory
Neuroendocrinology, Metabolism, Behavior
Energy Balance and Reproduction
Who We Are
||Jill Schneider, Principle Investigator, Warrior Princess, Ninja, Jedi Master
||Laura Szymanski, Ph.D. candidate, padawan, expert in rapid metabolic effects on luteinizing hormone secretion
||Candice Klingerman - Graduate Student, half dingo, half brumby
||Undergraduates, 2007-2008 padawan younglings: Anand Patel, Kevin Patel, Burton Tabaac, Jessica Fayan, Sara Carlson, Jessica Simberlund, Amy Phillips
|l-r Anand Patel, Kevin Patel, Jill Schneider, Burton Tabaac (rear), Jessica Fayan,Sara Carlson, Jessica Simberlund, Laura Szymanski, Amy Phillips, Candice Klingerman (kneeling)
Schneider Lab Photo Gallery
What We Do
We study the physiological mechanisms that underlie energy balance and reproduction.
The Energy-Reproduction Link
The energy balance system (food intake, fat storage and energy expenditure) influences the reproductive system and vice versa. When energy is plentiful organisms tend to store food internally as fat and externally in their homes for future emergencies. In these times of plenty, reproduction is stimulated. A scarcity of energy triggers hunger, foraging and eating and inhibits sexual desire and fertility. Inhibition of reproduction saves energy for those physiological processes necessary for survival. After a satisfying meal, hunger and eating are inhibited and thoughts turn to reproduction. Thus, hunger and sexual motivation, food ingestion and reproduction are switched on and off according to the energetic conditions.
How do we know how much internal energy is available?
Animals sense fuel oxidation. We have shown that reproduction is sensitive to minute-to-minute changes in the availability of metabolic fuels. Inhibition of fuel oxidation inhibits reproduction even when levels of body fat and hormones such as leptin and insulin are high .
Where are these sensors?
Fuel deficits are sensed in the caudal brain stem, although peripheral sensors might also be important for some aspects of reproduction. When a part of the caudal brain stem, the area postrema, is missing, animals no longer sense a decrease glucose oxidation, and do not show infertility in response to inhibition of glucose oxidation.
How does information get to the reproductive part of the brain?
Work from other laboratories suggest that information about fuel availability is carried from the brain stem through neural networks to GnRH neurons. The relationship is complicated, however, and hormones such as leptin interact with fuel oxidation to control reproduction.
What aspects of reproduction are affected?
The female reproductive system is comprised of the brain, particularly areas of the hypothalamus, pituitary gland and ovaries. Measurement of pituitary luteinizing hormone (LH) secretion provides a means of tracking minute-to-minute changes in this system. We find that LH secretion responds within minutes or hours to energetic status and this allows us to determine which metabolic and hormonal signals change rapidly enough to account for these changes in LH secretion.
Metabolic signals and hormones such as leptin and insulin control the neural mechanisms that govern hunger and sexual motivation as well as the neuroendocrine system that controls fertility, mating and ingestive behavior.
Which metabolic signals are most important for control of reproduction? Are hunger for food and sex governed by the same mechanisms that govern that acts of eating and mating?
These are other questions under investigation in the Schneider laboratory.
|Left to Right: Laura Szymanski, Amanda Barisich, Jill Schneider, Candace Schoengold, Asher Edwards, Carolyn Buckley, Janelle Casper, Evan Grodin
Our research has relevance for understanding nutritional infertility, obesity, diabetes and eating disorders such as anorexia nervosa .
If you would like to know more about our research, please contact Dr. Schneider and examine our graduate program in Integrative Biology and Neuroscience .
Food deprivation and leptin prioritize ingestive and sex behavior without affecting estrous cycles in Syrian hamsters
Metabolic and hormonal control of the desire for food and sex: Implications for obesity and eating disorders