Logical Levels of Steroid Hormone Action in the Control of Vertebrate Behavior

SYNOPSIS. Three steroid-sensitive neural systems are reviewed to suggest where hormones actto modify neuroendocrine or behavioral functions: the system controlling the ovulatory surge of luteinizing hormone in laboratory rats, the system controlling male copulatory behavior in the rat, and the system controlling passerine bird vocalizations. In each, steroids act at several levels, including the final common path. This generalization is discussed in light of some earlier conceptualizations of the levels of hormone action in behavioral systems.