Hormones and Neuroendocrine Factors in Atypical Human Sexual Behavior

Abstract

Exactly 100 years ago, Brown-Sequard reported apparent physiological and behavioral consequences of self-injection of animal testicular extracts (Brown-Sequard, 1889). Such self-experimentation among scientists and physicians was not uncommon during those “frontier days” of endocrinology and medicine. What was unusual was Brown-Sequard’s descriptive report of astonishing and fast-acting (within days) rejuvenating effects of guinea pig and dog testicular fluids on human affect, physiology, and behavior. He claimed that his appetite, energy level, mood, demeanor, intellectual capacities, muscular strength, and digestive and excretory systems were all improved. He also claimed that stopping the injections resulted in a gradual but complete return to his preexperimental condition. Brown-Sequard concluded that some “great dynamogenic power is possessed by some substance or substances which our blood owes to the testicles” (Brown-Sequard, 1889, p. 105).