Title:It is all About the Chase: Neurosteroidogenesis in Male Rats is Driven by
Control of Mating Pace
Volume: 21
Issue: 7
Author(s): Amy S. Kohtz*Cheryl A. Frye
Affiliation:
- Department of Psychiatry & Human Behavior, Division of Neurobiology & Behavior Research, University of Mississippi
Medical Center, 2500 N State Street, Jackson, MS 39216, USA
Keywords:
Mating, paced-mating, testosterone, 5α-androstane-3α-17β-diol (3α-diol), estradiol, aging.
Abstract:
Background: Masculine sexual behaviors are dependent on androstane-derived steroids;
however, the modulatory effects of mating, and of mating control, on androstane neurosteroidogenesis
remain largely unknown.
Objective: Herein, we investigated the effects of mating control, prior sexual experience, and age on
brain region specific neurosteroidogenic responses in male rats.
Methods: Effects of acute sexual experience were tested in naïve male rats that either remained sexually-
naïve, were exposed to a standard mating chamber, or were either given control of the mating
pace in a standard mating chamber (male control) or mated wherein the female stimulus rat controlled
the mating pace in a paced-mating chamber (female control). Aged (10-12 months) sexually responsive
male rats were similarly euthanized from the homecage or engaged in male controlled or female
controlled mating. All rats were euthanized immediately following exposure conditions for radioimmunoassay
of steroids in midbrain, hypothalamus, hippocampus and cortex.
Results: Consummatory sexual behavior in male vs. female-controlled mating paradigms was altered
by age and prior sexual experience. Male-controlled mating increased androstane neurosteroid metabolism,
such that complementary increases in the testosterone (T) metabolite 5α-androstane-3α-17β-
diol (3α-diol) in the midbrain and hypothalamus of male rats corresponded to decreases in the prohormone,
T. 3α-diol were increased in the hippocampus in response to the context alone, and to a lesser
degree in response to mating. Mating diminished neurosteroidogenesis in the cortex. Neurosteroidogenesis
was overall reduced in aged male rats compared to naïve controls, however, these effects were
more prominent in sexually non-responsive aged male rats.
Conclusion: Extending previous findings, these results indicate differential production of androstane
neurosteroids in a mating exposure, age and brain region dependent manner.
