Sensorimotor developmental delays and lower anxiety in rats prenatally exposed to cadmium.

Pregnant rats were treated with 0.3 or 0.6 mg cadmium (CdCl2) kg(-1) injected subcutaneously on a daily basis from gestational day 7 to day 15 (organogenesis period). One control group was not injected and the other received saline. Offspring were tested for ontogeny of sensorimotor development and at 45 or 90 days of age for anxiety behavior. The study of sensorimotor development showed that gestational exposure to 0.6 mg Cd kg(-1) produced a delay in the development of the righting reflex and of the cliff aversion in the pups. No differences were observed in the development of the negative geotaxis, nor in the ages of eye and ear opening. Anxiety studies using an elevated plus maze showed a lower anxiety in all the offspring prenatally exposed to 0.6 mg Cd kg(-1) as these rats spent more time and entered the open arms more times compared with those of the other groups. The results demonstrate that exposure to low levels of Cd during organogenesis may modify some central nervous system functions.