The parental care test in ICR mice. Schematic representations of the parental care test in a mated pair isolated in an old (b–d) or new (n–p) cage. After cohabiting with their pups as a family unit (a), the parents were separated from the pups for 10min (b–e) and then reunited with five pups (f–i). Subsequent pup retrieval behaviour was then observed (j–m), and the number of family members (new sire or dam) showing retrieval was scored and expressed as a percentage in (z) (one trial per mouse). In (a–m), the pups were placed in a new holding box (e, yellow), and the parents remained in the old box (b–d, grey) during the separation period (n¼35 families each). The number on the right indicates the sires or dams with retrieval out of subjects tested. In (a,n–y), the pups remained in the old cage (q, grey), while the parents (separately or together) were placed in new isolation boxes (n–p, yellow; n¼40 families each). The number on the right indicates sires or dams with retrieval out of subjects tested.
Press Release
Source: Kanagawa University, Japan, Organization of Frontier Science and Innovation
For immediate release: 25 February 2013
Uncovering maternal to paternal communications in mice
(Kanazawa, Japan, 25 February 2013) Researchers at Japan’s Kanazawa University have proven the existence of communicative signalling from female mice that induces male parental behaviour. This research is also described in the February issue of the Kanazawa University Research Bulletin: http://www.kanazawa-u.ac.jp/research_bulletin/index.html
Most mammalian parents use communicative signals between the sexes, but it is uncertain whether such signals affect the levels of parental care in fathers. Scientists have long suspected that female mice play a definite role in encouraging paternal relationships between male mice and their pups.
Now, a research team at Kanazawa University led by Haruhiro Higashida in collaboration with scientists across Japan, Russia and the UK, have proven the existence of auditory and olfactory (smell) signals produced by females which actively trigger paternal activity in males.
Higashida and his team conducted a series of experiments with females and males living in established family groups. Pups were removed from the cage for a short time, while one or both parents remained in the nest. The pups were then returned to the cage, away from the nest. Lone females nearly always brought the pups back to the nest, but lone males were less likely to do so.
Most interestingly, the researchers showed that males were much more likely to retrieve pups when they remained with their mate. This behaviour may be related to ultra-sonic noises emitted by females under stress. These sounds are not emitted by males, pups or non-parental females, and they encouraged the males into parental behaviours. The females also released olfactory signals in the form of pheromones, which triggered the same reaction in the males.
Higashida and his team are keen to expand on their results by analyzing neural signalling in the male brain in response to these female communications.
Further information:
Organization of Frontier Science and Innovation
Kanazawa University
Kakuma, Kanazawa, Ishikawa 920-1192, Japan
E-mail: [email protected]
Website: http://www.kanazawa-u.ac.jp/research_bulletin/index.html
About Kanazawa University
As the leading comprehensive university on the Sea of Japan coast, Kanazawa University has contributed greatly to higher education and academic research in Japan since it was founded in 1949. The University has three colleges and 16 schools offering courses in subjects that include medicine, computer engineering, and humanities.
The University is located on the coast of the Sea of Japan in Kanazawa—a city rich in history and culture. The city of Kanazawa has cultivated a highly respected intellectual profile since the time of the Kaga fiefdom (1598–1867). Kanazawa University is divided into two main campuses: Kakuma and Takaramachi for its approximately 11,000 students including 350 from overseas.
