BEHAVIORAL CHARACTERIZATION OF STEROIDOGENIC FACTOR-1 KNOCKOUT MICE

Sex differences in the brain are mainly caused by sex steroid hormones. Steroidogenic factor-1 is a key regulator of gonadal and adrenal development, and SF-1 knockout mice (SF-1KO) are born without gonads and adrenal glands and the region of the ventromedial nucleus of the hypothalamus (VMH) is reorganized. Due to the absence of gonadal hormones during embryonic development and alterations of the VMH, SF-1 KO mice provide an important model to study VMH dependent and hormonally independent sex differences in brain and behaviour. Initial studies did not show significant sex differences that could be attributed to sex chromosome effects, but provided interesting differences in aggressive and affiliative behaviours between genotypes, that may be attributable to the disrupted cellular organization of the VMH in SF-1 KO mice. However, further more focused behavioural studies also revealed some sex differences that could be also attributed to the action of sex chromosomes.