Hormones strongly influence and even -drive- certain primitive behaviors. In Central Neural States Relating Sex and Pain, Richard J. Bodnar, Kathryn Commons, and Donald W. Pfaff examine hormonal, neural, and genetic mechanisms of reproductive, pain-sensing, and pain-inhibitory systems. The authors show that there are remarkable neuroanatomical, biochemical, and functional overlaps among these systems. They consider sensory inputs triggering both classes of behaviors and focus on the role of sex hormones in modulating both forms of behavior. Sex hormones acting in different regions...