Sexual Differentiation in Prairie Voles: The Effects of Corticosterone and Testosterone

• Published in: Physiology & behavior Vol. 62; no. 6; pp. 1379 - 1383
• Main Authors: Roberts, R.Lucille, Zullo, Amy S, Carter, C.Sue
• Format: Journal Article
• Language: English
• Published: Cambridge Elsevier Inc 01-12-1997; New York, NY Elsevier
• Subjects: Animals; Arvicolinae - physiology; Behavioral psychophysiology; Biological and medical sciences; Corticosterone; Corticosterone - pharmacology; Female; Fundamental and applied biological sciences. Psychology; Hormones and behavior; Male; Orchiectomy; Posture - physiology; Prairie voles; Pregnancy; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Sex Differentiation - drug effects; Sexual behavior; Sexual Behavior, Animal - drug effects; Sexual differentiation; Testosterone; Testosterone - pharmacology; Prairie voles; Testosterone; Corticosterone; Sexual differentiation; Sexual behavior; Androgen; Rodentia; Lordosis; Glucocorticoid; Breeding behavior; Reproduction; Vertebrata; Mammalia; Castration; Animal; Adrenal hormone; Virilism; Microtus ochrogaster; Testicular hormone; Sex steroid hormone
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/S0031-9384(97)00365-X

ROBERTS, R. L., A. S. ZULLO AND C. S. CARTER.
Sexual differentiation in prairie voles: The effects of corticosterone and testosterone.
PHYSIOL BEHAV 62(6) 1379–1383, 1997.—Prairie voles (
Microtus ochrogaster) exhibit low levels of physical sexual dimorphism and have endogenous basal corticosterone levels that are 5–10 times higher than those measured in rats; prairie voles also do not show a postnatal period of adrenal hyporesponsivity. On the basis of studies in rats suggesting that adrenal hyperactivity during the perinatal period could reduce masculinization or feminize sexual behavior, we hypothesized that adrenal hormones might influence sexual differentiation in prairie voles. We also examined the hypothesis that the effects of testosterone in prairie voles might differ from those reported in other rodents. Treatments with either corticosterone or testosterone propionate (TP) were given prenatally (gestational Days 12-20), via maternal injection, or postnatally (Days 1-6), by directly injecting the pups. Additional groups of males were castrated or sham-operated on postnatal Day 1, and a subgroup of castrated males received postnatal TP. Male and female sexual behavior was observed in adulthood following gonadectomy and hormone treatments. Corticosterone treatment was associated with high levels of mounting in both sexes and did not inhibit lordosis behavior in females. Postnatal TP treatment inhibited lordosis in females but did not facilitate mounting in either sex. Males that were castrated at birth showed unexpectedly high levels of mounting in response to adult androgens. The results of this study suggest that in prairie voles corticosterone is capable of masculinizing without defeminizing sexual behavior, whereas postnatal testicular secretions are not essential for, and may actually inhibit, masculinization in this species.