Biological Substrates of Human Sexuality explores some of the past decade's explosion of research on the neuroscience and endocrinology of sexuality and presents the latest findings in this field. From studies of twins that test a genetic basis for sexual orientation through close examinations of the intertwined roles of the endocrine system and hypothalamus in sexuality, this volume gives a vivid portrait of the state of the art in sexuality research. Among the findings discussed are: women with complete spinal cord injury are nonetheless capable of sexual response, including orgasm; compulsive sexual behavior may have its roots in dysregulation of the limbic system; certain regions of the hypothalamus show marked anatomical differences between males and females across species, and lesions to these regions can eliminate sexual behavior; neurotransmitters in the brain and its periphery are closely linked to sexual response: Viagra targets peripheral mechanisms, but newer drugs target central brain mechanisms as well. Contributors to this volume, all experts in the field of the psychobiology of human sexuality, discuss these topics in depth, providing results from their own studies as well as those of other experts. These exciting discussions are based on cutting edge research founded in the contributors' comprehensive knowledge of their field. In addition to revelations of new findings, authors reflect on practical implications for treating sexual disorders and other sexuality issues, making this a volume for both researchers and practitioners in the field.