Schradin Carsten, Pillay Neville
Ecophysiological Studies Research Group, School of Animal, Plant and Environmental Sciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa.
Physiol Behav. 2004 Mar;81(1):43-50. doi: 10.1016/j.physbeh.2003.12.013.
Paternal behavior is associated with an increase in prolactin levels in fish, birds and mammals, including rodents. The striped mouse (Rhabdomys pumilio) from southern Africa shows highly developed paternal care. We investigated whether striped mouse fathers have higher prolactin levels than nonfathers, and whether there is a relationship between tactile stimulation with pups and prolactin secretion in fathers. We measured serum prolactin in 42 male striped mice assigned to one of four different experimental groups (single males, paired males, fathers housed with mother and pups, and fathers separated from their family by a wire-mesh partition). Our results revealed no increases in prolactin levels in fathers, and fathers with tactile contact with pups did not have higher prolactin levels than the fathers that were prevented from making tactile contact with pups. In contrast, experienced males had higher prolactin levels than inexperienced males. Male striped mice are polygynous in nature, living in groups, with three breeding females, and are permanently associated with pups during the breeding season. In a field study, males had higher prolactin levels during the breeding season than during the nonbreeding season. Thus, prolactin secretion in the polygynous striped mouse might be regulated by environmental stimuli, whereas social stimuli might be important for monogamous species. This is the first study to demonstrate seasonal changes in prolactin levels in a free-living male mammal.
在鱼类、鸟类和包括啮齿动物在内的哺乳动物中，父性行为与催乳素水平的升高有关。来自非洲南部的条纹小鼠（Rhabdomys pumilio）表现出高度发达的父性关怀。我们调查了条纹小鼠父亲的催乳素水平是否高于非父亲，以及父亲与幼崽的触觉刺激和催乳素分泌之间是否存在关系。我们测量了42只雄性条纹小鼠的血清催乳素水平，这些小鼠被分配到四个不同的实验组之一（单只雄性、配对雄性、与母亲和幼崽一起饲养的父亲，以及通过铁丝网隔板与家人分开的父亲）。我们的结果显示，父亲的催乳素水平没有升高，与幼崽有触觉接触的父亲的催乳素水平并不高于被阻止与幼崽进行触觉接触的父亲。相比之下，有经验的雄性的催乳素水平高于没有经验的雄性。雄性条纹小鼠本质上是一夫多妻制，群居，有三只繁殖雌性，并且在繁殖季节与幼崽长期在一起。在一项野外研究中，雄性在繁殖季节的催乳素水平高于非繁殖季节。因此，一夫多妻制条纹小鼠的催乳素分泌可能受环境刺激调节，而社会刺激可能对一夫一妻制物种很重要。这是第一项证明自由生活的雄性哺乳动物催乳素水平存在季节性变化的研究。
