Table 1.
Ethogram used for the assessment of maternal care behavior in C57BL/6N and Balb/c dams.
Figure 1.
Effects of strain and genotype on maternal care behavior.
Behavioral strain differences between C57BL/6N and Balb/c mothers with a glucocorticoid receptor wildtype (GR +/+) or a heterozygous deletion (GR +/−) are exemplarily presented for four different behavioral measures: (A) ‘licking/grooming’, (B) ‘passive nursing’, (C) ‘self-grooming out of nest’ and (D) ‘climbing/digging’. While strains were found to differ significantly in all four measures, GR genotype did not affect the behavior. Moreover, a significant strain-by-genotype-interaction was found with respect to ‘licking/grooming’. While C57BL/6N +/+ dams spent more time ‘licking/grooming’ than Balb/c mothers of both GR genotypes, no difference was found between C57BL/6N +/− mothers and Balb/c dams. Data are presented as untransformed means ± standard error of the mean, * p<0.05, ** p<0.01.
Table 2.
Summary of all data generated by behavioral observations and the pup retrieval test.
Figure 2.
Effects of strain and genotype on maternal behavior in the pup retrieval test.
Behavioral strain differences between C57BL/6N and Balb/c mothers with a glucocorticoid receptor wildtype (GR +/+) or a heterozygous deletion (GR +/−) are presented for two out of three behavioral measures: (A) ‘handling’ and (B) ‘crouching over pups’. Strains differed significantly in ‘handling’, but GR genotype did not affect any of the behavioral measures. However, a tendency for a strain-by-genotype-interaction was found with respect to ‘crouching’. Data are presented as untransformed means ± standard error of the mean, T p<0.1, * p<0.05.