COMPARATIVE-STUDY OF THE LUTEINIZING-HORMONE RELEASING HORMONE (LHRH) NEURONAL NETWORKS IN MAMMALS

The development of immunocytochemical procedures utilizing antisera to synthetic luteinizing hormone releasing hormone (LHRH) has permitted the identification and description of neurons which synthesize, store and secrete this neurohormone. This paper presents an overview of published studies for several mammalian species in an attempt to characterize and describe interspecies similarities and differences in LHRH distribution. In studies employing a combination of radiofrequency lesions and and immunocytochemical assessments of lesion effects, at least 6 separate LHRH neuronal networks have been identified and traced in the guinea pig brain. In view of this work, this species will be used as the representative mammal against which distribution patterns of immunoreactive LHRH-containing neurons in mouse, hamster and primates will be compared. Finally, the physiological roles of these neuroendocrine networks in the regulation of anterior pituitary function and control of sexual behavior are discussed.