SPATIO-TEMPORAL PATTERNS OF HORMONE AND HORMONE TRANSCRIPTION FACTOR GENE EXPRESSION DURING THE DEVELOPMENT AND MATURE FUNCTION OF THE NEUROENDOCRINE SYSTEM

Abstract

The core of the neuroendocrine system consists of the hypothalamus and pituitary, and the mechanisms that interrelate these two organs. We have used this system as a model for studying the spatio-temporal patterns of gene expression that may be involved in establishing a functional system during the development of the rat embryo, as well as in the modulation of gene expression during different functional states of the adult organism. In the embryo, we have examined the spatio-temporal pattern of expression for the various genes that are involved in the synthesis of the classical anterior pituitary hormones, and it, was found that there is an interesting compartmental pattern of expression which is also characterized by distinct temporal patterns of expression. In addition, we have correlated these patterns with the pattern of expression of two putative transcription factors that are thought to be involved in regulating the expression of growth hormone, thyrotropin releasing hormone, and prolactin. In the adult rat, it is now becoming clear that individual hypothalamic neurosecretory neurons can not only synthesize multiple neuropeptides, but that the genes regulating the synthesis of these neuropeptides may be differentially regulated by different physiological and behavioral factors that fall under the broad category of stress.