Experimental design to induce prenatal, transgenerational and multigenerational stress. Animals of the parental generation (F0) were assigned to a stress (S) condition. Their pregnant prenatally stressed daughters received either stress (SS) or no stress (SN). Their pregnant grand-daughters received either stress (SSS) or no stress (SNN). Groups of non-stressed controls were bred alongside the stressed generations. In our conceptual framework prenatal stress programs the germ line of F1 progeny, resulting in physiological and behavioural changes in the F2 generation. S, stress; N, non-stress generation.