Abstract
The brain is deeply involved in individual- and species-conservation via regulating visceral functions, behaviors, and higher cognitive functions. The energy monitoring network in the brain cooperatively controls not only energy metabolism and feeding behavior but also other physiological functions such as reproduction, thermoregulation and learning and memory processes. Glucose monitoring cells such as glucose-sensitive neurons and glucoreceptor neurons play pivotal roles in this energy monitoring neural network. The energy-monitoring system in the brain is highly sensitive to not only appetite-regulating substances but also many other chemicals related to reproductive functions, thermo-regulation and immune functions. Even environmental chemicals influence this system. These multi-sensing systems provide a model of sophisticated system which accelerate the energy saving and environmental preservation in the individuals, species and environment. Although the brain has such a sophisticated system to maintain energy homeostasis to maximize the adaptive function, recent drastic changes in chemical environments affect this process and disturb the homeostatic functions conduced by the brain. These unexpected changes may concern our increasing problems of obesity, eating disorders, reproductive problems, immune dysfunction and emotional disorders. Physiological and pathophysiological significance of cooperative mechanisms of feeding and other homeostatic functions in various environments will be discussed. [J Physiol Sci. 2007;57 Suppl:S32]
