Dam rats were given Pb (0.58, 1.76, and 5.27 mmol . L(-1)), containing
water ad lib from d 16 of gestation to weaning of the offspring on d
21 postpartum. The pups continued drinking the same water till the pos
tnatal d 30. The neurobehavioral function of pups was tested. The seco
nd step-down latencies (SDL(2)) were shortened and the number of step-
downs in 5 min (NSD) were increased in step-down test. The prolongatio
n of the lapse of time in passing through the whole course (LTPWC) and
the increase in number of entries into the blind alley (NEBA) were me
asured in water maze test. The number of ambulations and rearings were
increased in locomotor activity. The results indicated that Pb exerts
adverse effects on the learning ability and memory function, and indu
ces hyperactivity in young rats.