Evolutionary conserved neural signature of early life stress affects animal social competence

In vertebrates the early social environment can persistently influence behaviour and social competence later in life. However, the molecular mechanisms underlying variation in animal social competence are largely unknown. In rats, high-quality maternal care causes an upregulation of hippocampal glucocorticoid receptors (gr) and reduces offspring stress responsiveness. This identifies gr regulation as a candidate mechanism for maintaining variation in animal social competence. We tested this hypothesis in a highly-social cichlid fish, Neolamprologus pulcher, reared with or without caring parents. We find that the molecular pathway translating early social experience into later-life alterations of the stress axis is homologous across vertebrates: fish reared with parents expressed the glucocorticoid receptor gr1 more in the telencephalon. Furthermore, expression levels of the transcription factor egr-1 (early growth response 1) were associated with gr1 expression in the telencephalon and ...