Copulatory Pattern of Male Rats in a Multiple Partner Choice Arena

Authors

  • Armando Ferreira-Nuño PhD,

    Corresponding author
    1. Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología de la Reproducción México, D.F., México;
      Armando Ferreira-Nuño, PhD, Departamento de Biologia de la Reproducción, Area de Neurociencias, Universidad Autonoma Metropolitana-Unidad Iztapalapa, Av. San Rafael Atlixco #186. Col Vicentina Mexico D. F., 09340, Mexico. Tel: 525 58044600 ext. 2723; Fax: 525 58044930; E-mail: fena@xanum.uam.mx
    Search for more papers by this author
  • Claudia Fernández-Soto Biol. Exp.,

    1. Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología de la Reproducción México, D.F., México;
    Search for more papers by this author
  • Jesús Olayo-Lortia Biol. Exp.,

    1. Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología de la Reproducción México, D.F., México;
    Search for more papers by this author
  • Raúl Ramirez-Carreto Biol. Exp.,

    1. Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología de la Reproducción México, D.F., México;
    Search for more papers by this author
  • Raúl G. Paredes,

    1. Departamento de Neurobiología Conductual y Cognitiva, Instituto de Neurobiología, UNAM-Juriquilla, Qro. (Mexico)
    Search for more papers by this author
  • Javier Velázquez-Moctezuma PhD,

    1. Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología de la Reproducción México, D.F., México;
    Search for more papers by this author
  • Adriana Morales-Otal PhD

    1. Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biología de la Reproducción México, D.F., México;
    Search for more papers by this author

Armando Ferreira-Nuño, PhD, Departamento de Biologia de la Reproducción, Area de Neurociencias, Universidad Autonoma Metropolitana-Unidad Iztapalapa, Av. San Rafael Atlixco #186. Col Vicentina Mexico D. F., 09340, Mexico. Tel: 525 58044600 ext. 2723; Fax: 525 58044930; E-mail: fena@xanum.uam.mx

ABSTRACT

Introduction.  It has been demonstrated that testing conditions may influence sexual performance in many mammals, including male rats. We recently developed a multiple partner choice arena (MPCA) consisting of four acrylic cylinders placed in a cross pattern with one male in each cylinder. A sexually receptive female rat was introduced into the center of the MPCA and was allowed to choose a male to copulate with. The female showed a preference for one of the four males, remaining longer and copulating more times with it.

Aim.  The study aims to evaluate and compare the copulatory pattern of male rats in two arenas: the standard arena (SA) and the MPCA.

Methods.  In Experiment 1, a group of 10 male rats mated in an SA (a closed cylinder) and 2 weeks later they mated in the MPCA, in order to compare different parameters of male sexual behavior. In Experiment 2, the sexual behavior of two different groups of sexually experienced male rats was tested in two conditions: the SA and the MPCA. In the latter, only the behavior of the preferred (P) males and nonpreferred (NP) males that ejaculated was recorded.

Main Outcome Measures.  The main outcome is the number of intromissions preceding ejaculation and the latencies to mount, intromit, and ejaculate.

Results.  In Experiment 1, the number of intromissions was significantly reduced and the intromission and ejaculation latencies were significantly shortened when the males were tested in the MPCA rather than in the SA. In Experiment 2, both groups of males tested in the MPCA (P and NP) showed a significant reduction in the number of intromissions preceding ejaculation and shorter mounting and ejaculation latencies in comparison with rats in the SA. This decrease was more noticeable in NP males.

Conclusions.  The MPCA reduce significantly the ejaculatory pattern in male rats. Ferreira-Nuño A, Fernández-Soto C, Olayo-Lortia J, Ramirez-Carreto R, Paredes RG, Velázquez-Moctezuma J, and Morales-Otal A. Copulatory pattern of male rats in a multiple partner choice arena. J Sex Med 2010;7:3845–3856.

Ancillary