Metabolic and Endocrine Control of Behavior

许多人吃得过多，体重增加太多，而另一些人吃得太少，经历了营养不良和不孕症等严重问题。瘦素是一种新发现的蛋白质，由身体脂肪细胞自然产生和分泌，被认为在调节饮食、体重和生育能力方面发挥作用。这一提议旨在了解瘦素如何影响饮食、体重和生殖。我们将研究叙利亚仓鼠，因为与其他动物不同，它们有可靠的4天排卵（发情）周期，对瘦素治疗非常敏感，禁食时间短，运动量增加。我们将寻找瘦素影响体重、饮食和发情周期的线索。例如，为了找出瘦素在哪里起作用，我们将把瘦素注射到体内的效果与瘦素治疗仅限于大脑一小块区域的效果进行比较。我们将研究的一些影响包括体重、食物摄入量和发情周期的长短。我们还将用瘦素治疗仓鼠，并确定大脑的哪些部分变得活跃。此外，我们将通过检查瘦素对仓鼠的影响来确定大脑的特定部位是否对瘦素的作用至关重要，这些部位的大脑恰好有小的损伤。了解瘦素的作用机制和作用部位可能为了解体重、饮食和生育是如何被调节以及如何治疗肥胖或神经性厌食症提供重要线索。这项工作可能对理解各种涉及代谢对神经系统影响的行为问题具有更普遍的重要性。

PI: Schneider, J. IBN-9723938 Many people overeat and gain too much weight, while other people eat too little and experience serious problems such as malnutrition and infertility. Leptin is a newly discovered protein that is naturally made and secreted by body fat cells, and is thought to play a role in the regulation of eating, body weight and fertility. This proposal is designed to understand how leptin influences eating, body weight and reproduction. We will study Syrian hamsters because, unlike other animals, they have a reliable, 4-day ovulatory (estrous) cycle that is very sensitive to leptin treatment, a short period of fasting, and increased exercise. We will look for clues as to where in the body and by what mechanism leptin affects body weight, eating and estrous cycles. For example, in order to find where leptin acts, we will compare the effects of leptin injected into the body to effects when leptin treatment is restricted to a small area of the brain. Some of the effects we will examine will be body weight, food intake and length of the estrous cycle. We will also treat hamsters with leptin and determine which parts of the brain become active. In addition, we will determine whether particular parts of the brain are critical for leptin's effects by examining the effects of leptin in hamsters with small lesions of these exact brain areas. Knowledge of leptin's mechanism and site of action may provide important clues to how body weight, eating and fertility are regulated as well as how to treat obesity or anorexia nervosa. This work may have more general importance for understanding a variety of behavioral problems that involve effects of metabolism on the nervous system.