f c A m ( ( G s W Over the past 50 years, a great deal of behavioral ndocrinological research has established a central ole for gonadal steroid hormones in the control of exual behaviors in a wide range of vertebrate taxa. he underlying mechanisms controlling these behavors appear to be well conserved throughout evoluion. Both the neural structures regulating male and emale sexual behaviors and...

17a-hydroxy-4-pregnen-3-one (17aP) hormone is a precursor of other steroid hormones and radioimmunoassay has already been used to measure it, but a simple and rapid "Enzyme Linked Immunosorbant Assay" (ELISA) is described and validated here. A general procedure for prepara-tion of the acetylcholinesterase labelled steroid is described, which is applicable to any steroid. Use of acetyl...