Progestins and place preference conditioning after paced mating

• Published in: Hormones and behavior 2004-08, Vol.46 (2), p.151-157
• Main Authors: González-Flores, Oscar, Camacho, Francisco J, Domı́nguez-Salazar, Emilio, Ramı́rez-Orduna, Juan M, Beyer, Carlos, Paredes, Raúl G
• Format: Article
• Language: English
• Subjects: 5-alpha-Dihydroprogesterone - physiology; Analysis of Variance; Animal ethology; Animals; Association Learning - physiology; Behavioral psychophysiology; Biological and medical sciences; Conditioned place preference; Conditioning, Classical - physiology; Copulation - physiology; Estradiol - physiology; Female; Fundamental and applied biological sciences. Psychology; Hormones and behavior; Housing; Male; Mammalia; Megestrol Acetate - metabolism; Paced mating; Pregnanes - metabolism; Progesterone - analogs & derivatives; Progesterone - metabolism; Progestins; Progestins - physiology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Random Allocation; Rats; Rats, Wistar; Reward; Vertebrata
• ISSN: 0018-506X; 1095-6867
• DOI: 10.1016/j.yhbeh.2004.02.006

When female rats pace their coital interaction, a reward state evaluated by conditioned place preference is induced. Progesterone (P) is essential for the expression of proceptive behavior and for the induction of CPP. However, the functional significance of ring A reduction of P for the induction of this state during estrous is unsettled. In the present study, we evaluated whether ring A-reduced metabolites of P are involved in the reward state induced when the females are allowed to pace their sexual contacts. Ovariectomized (ovx) female rats treated with estradiol benzoate (EB, 5 μg) and P (13 μg), Megestrol acetate (MA; 13 μg ), 5α-pregnan-20 dione (5αDHP; 3 μg), or 5β-pregnan-3α-ol-20-one (5β,3α-Pgl; 3 μg) were used. Progestins were dissolved in propylene glycol and intravenously (iv) injected through an indwelling jugular catheter before females were tested for pacing behavior. After 15 intromissions or one ejaculation, females were gently placed in the nonpreferred compartment of a CPP box. Paced mating in all groups treated with progestins induced a clear change of preference. The administration of progestins alone did not induce CPP. These results suggest that P and ring A-reduced metabolites facilitate the reward state following pacing.