Male Roman high and low avoidance rats show different patterns of copulatory behaviour: comparison with Sprague Dawley rats.
Roman high- (RHA) and low-avoidance (RLA) rats, selectively bred for, respectively, rapid vs. extremely poor acquisition of avoidant behaviour in the shuttle-box, display different coping strategies when exposed to aversive environmental conditions: RLA rats are reactive copers and show hyperemotional behaviour characterized by hypomotility and freezing, while RHA rats show a proactive coping behaviour aimed at gaining control over the stressor. RHA rats also display a robust sensation/novelty seeking profile, high baseline levels of impulsivity, and marked preference for, and intake of, natural and drug rewards. This study shows that the Roman lines also differ in sexual behaviour, a main source of natural reward. Thus, male RHA rats engaged in copulatory activity with a receptive female showing more mounts, intromissions and ejaculations in the first copulation test as compared with their RLA counterparts and Sprague Dawley rats used as an external reference strain. Such differences decreased only partially in subsequent copulation tests, with RHA rats always showing higher levels of sexual motivation and performance than RLA rats. Accordingly, analysis of copulatory parameters of five copulation tests performed at 3-day intervals confirmed that the Roman lines display different patterns of copulatory activity that persist after stabilization of copulatory behaviour by sexual experience. Finally, the weight of the testes, epididymides and seminal vesicles increased to a similar extent in both Roman lines after sexual activity. These results are discussed in terms of the relative contribution of differences in brain neurotransmission (mainly dopamine) and neuroendocrine function to the different patterns of copulatory behaviour of the Roman lines.
Department of Biomedical Sciences, Neuroscience and Clinical Pharmacology Section, University of Cagliari, 09042 Monserrato, Italy. Electronic address: fabrizio.sanna@unica.it.
Fabrizio
F
Sanna
Department of Life and Environmental Sciences, Section of Pharmaceutical, Pharmacological and Nutraceutical Sciences, University of Cagliari, 09124 Cagliari, Italy.
Maria Giuseppa
MG
Corda
Department of Biomedical Sciences, Neuroscience and Clinical Pharmacology Section, University of Cagliari, 09042 Monserrato, Italy; Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, 09042 Monserrato, Italy.
Maria Rosaria
MR
Melis
Department of Life and Environmental Sciences, Section of Pharmaceutical, Pharmacological and Nutraceutical Sciences, University of Cagliari, 09124 Cagliari, Italy.
Maria Antonietta
MA
Piludu
Department of Life and Environmental Sciences, Section of Pharmaceutical, Pharmacological and Nutraceutical Sciences, University of Cagliari, 09124 Cagliari, Italy.
Osvaldo
O
Giorgi
Department of Biomedical Sciences, Neuroscience and Clinical Pharmacology Section, University of Cagliari, 09042 Monserrato, Italy; Centre of Excellence for the Neurobiology of Addictions, University of Cagliari, 09042 Monserrato, Italy; Institute of Neuroscience, National Research Council, Cagliari Section, 09042 Monserrato, Italy.
Antonio
A
Argiolas
D000311:Adrenal Glands / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001362:Avoidance Learning; D001835:Body Weight; D003307:Copulation / Q000502:physiology; D004822:Epididymis / Q000502:physiology; D005260:Female; D008297:Male; D009042:Motivation; D009929:Organ Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D012669:Seminal Vesicles / Q000502:physiology; D013045:Species Specificity; D013737:Testis / Q000502:physiology; D013997:Time Factors
Copulatory behaviour; Roman high avoidance rats; Roman low avoidance rats