The hypothesis of this work is that the effects of γ-irradiation on Fe allocation in developing brain requires the interaction of mother-fetus, and that Fe content changes mostly reflect the γ-irradiation effects over neural precursor cells. Two irradiation protocols of cultures were performed: i) direct γ-irradiation of cells after isolation, and ii) γ-irradiation in utero followed by isolation and culture of the cells. In cells irradiated in vitro, no changes neither in the total Fe content nor in the labile Fe pool (LIP) were observed from 1 to 4 h pi, as compared to these parameters in non-irradiated cells. In cells irradiated in utero, an increase (3.3-fold) in the total Fe content of the neural precursor cells was observed at 4 h pi, as compared to the content in non-irradiated cells. Also, the LIP content was decreased after 1 h pi. Thiobarbituric reactive substances (TBARS) content showed an increase at 4 h pi, as compared to control values, and nitric oxide (NO) generation was increased by 2.6-fold at 2 and 4 h pi. The data reported here suggested that the increase in Fe content was associated to γ-irradiation in the developing brain, requiring the mother-fetus interaction, and that NO seems to play a key role.