Kiss1 kisspeptin of bony fish and mammalian kisspeptin analogs enhance the communicative behavior of <i>Danio rerio</i> induced by social isolation

Abstract

Relevance. Rodents are often used as model of social isolation. In the present study, we investigated the effects of social isolation in Danio rerio. Danio rerio form groups, form social hierarchies and exhibit complex of social interactions similar to rodents. The expression of a number of brain genes of fish reared in isolation was found to be different from individuals reared in a group. The aim of the study was to investigate the effect of kisspeptins on the social behaviour of Danio rerio exposed to social isolation. Materials and Methods. Fish were placed in 200 ml individual measuring cups for 48 hours. After the social isolation period, bony fish kisspeptins and mammalian kisspeptin analogues were tested. The animal was placed in the 1L individual tank for 15 min and then placed in the tank with a glass partition, behind which there was a group of congeners. Fish were allowed to approach or swim away from the partition. Two patterns were used to assess behaviour: latent time and number of swims to the partition. The results of the research. When comparing the control group with fish kept in social isolation, reliable differences were observed: The number of swims to the aquarium partition after isolation was 1,3 times higher compared to the control group (p 0,05). Against the background of Kiss1 and Kiss2 bony fish Kisspeptin administration, no significant changes in the number of swims to the aquarium partition were observed. At the same time, after administration of KS6 and KS10, increases in the number of swims to the aquarium partition were observed in 1,6 times (p 0,01) and 1,8 times (p 0,001), respectively. After administration of the comparison drug oxytocin, a 1,6 times (p 0.01) increase in the number of swims to the aquarium partition was observed compared to isolates without administration of the drug. The latent time of swimming to the partition increased 2,4 times in isolates without drug administration compared to the control group (p 0,001). Against the background of oxytocin administration, latent time decreased 2,3 times compared to isolates without drug administration (p 0,001). After Kiss1 administration, latent time decreased respectively 2 times (p 0,001) compared to isolates without drug administration. The latent time was decreased 5 times (p 0,001) after KS10 administration and 3,4 times (p 0,001) after KS6 administration compared to isolates without drug administration. Conclusion. Thus, social isolation in Danio rerio fish reduces communicative behaviour. Analogues of mammalian kisspeptin, Kiss1 kisspeptin of bony fish and oxytocin normalise the communicative behaviour of fish after a period of social isolation to the level of the control group.