title: Chronic social isolation enhances reproduction in the monogamous prairie vole (Microtus ochrogaster).
abstract: Chronic stressors are generally considered to disrupt reproduction and inhibit mating. Here we test the hypothesis that a chronic stressor, specifically social isolation, can facilitate adaptive changes that enhance/accelerate reproductive effort. In general, monogamous species display high levels of prosociality, delayed sexual maturation, and greater parental investment in fewer, higher quality offspring compared with closely related polygynous species. We predicted that chronic social isolation would promote behavioral and neurochemical patterns in prairie voles associated with polygyny. Male and female prairie voles were isolated for four weeks and changes in mating behavior, alloparental care, estrogen receptor (ER) α expression and tyrosine hydroxylase (TH) expression in brain regions regulating sociosexual behavior were examined. In males, isolation accelerated copulation, increased ERα in the medial amygdala (MEApd) and bed nucleus of the stria terminalis (BSTpm), and reduced TH expression in the MEApd and BSTpm, but had no effect on alloparental behavior. In females, isolation resulted in more rapid estrus induction and reduced TH expression in the MEApd and BSTpm, but had no effect on estradiol sensitivity or ERα expression. The results support the hypothesis that ERα expression in the MEApd and BSTpm is a critical determinant of male copulatory behavior and/or mating system. The lack of change in alloparental behavior suggests that changes in prosocial behavior are selective and regulated by different mechanisms. The results also suggest that TH in the MEApd and BSTpm may play a critical role in determining mating behavior in both sexes.
authors.affiliation: The Brain-Body Center, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois 60612, United States; Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States. Electronic address: anperry@utep.edu.
authors.forename: Adam N
authors.initials: AN
authors.lastname: Perry
authors.affiliation: The Brain-Body Center, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois 60612, United States; Kinsey Institute and Department of Biology, Indiana University, Bloomington, IN 47405, United States.
authors.forename: C Sue
authors.initials: CS
authors.lastname: Carter
authors.affiliation: The Brain-Body Center, Department of Psychiatry, University of Illinois at Chicago, Chicago, Illinois 60612, United States; Department of Biological Sciences, University of Texas at El Paso, El Paso, TX 79968, United States.
authors.forename: Bruce S
authors.initials: BS
authors.lastname: Cushing
mesh_terms: D000679:Amygdala / Q000378:metabolism; D000818:Animals; D003411:Arvicolinae / Q000378:metabolism / Q000502:physiology* / Q000523:psychology; D066276:Corticomedial Nuclear Complex / Q000378:metabolism; D047628:Estrogen Receptor alpha / Q000378:metabolism; D005260:Female; D008297:Male; D012098:Reproduction / Q000502:physiology*; D012686:Septal Nuclei / Q000378:metabolism; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012919:Social Behavior; D012934:Social Isolation; D013315:Stress, Psychological / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D014446:Tyrosine 3-Monooxygenase
keywords: Estrogen receptor alpha; Isolation; Prairie vole; Prosocial behavior; Reproduction; Tyrosine hydroxylase