Chronic marginal iron intakes during early development in mice alter brainiron concentrations and behavior despite postnatal iron supplementation

The objective of this study was to investigate the behavioral and cognitive outcomes associated with chronic marginal iron (Fe) intakes during early d evelopment. Offspring (3 males and 3 females/litter) of Swiss-Webster femal e mice who had been fed a control Fe diet (75 mu g Fe/g diet) or marginal F e diet (14 mu g Fe/g diet) for 9 wk before mating were weaned on postnatal (PND) 21. Offspring of marginal Fe dams were fed either the marginal Fe die t (marginal group) or a control diet (replete group) from PND 21 throughout the duration of the study, whereas offspring of control dams consumed the control diet ad libitum (control group). On PND 30, 45 and 60, one male and female per litter underwent grip strength and auditory startle testing. A Morris maze was used to assess cognitive function in males starting at PND 50. Marginal Fe mice consistently demonstrated significantly lower grip str ength, which was independent of differences in body weight. In addition, ma rginal Fe males demonstrated attenuated startle responsiveness, as well as altered performance in the Morris water maze. These differences in performa nce were found in association with lower brain Fe concentrations. Postnatal Fe supplementation did not reverse all of these disturbances because diffe rences in brain Fe concentrations and maze learning persisted. This study d emonstrates that chronic marginal Fe intakes during early development can r esult in persistent biochemical and behavioral changes in mice.