Effects of low lead exposure on neuro-behavioral function in the rat.

Small doses (45-180 micrograms/g) of lead acetate were administered to male rats by gavage every day during the first 3 wk of life. A blood concentration of approximately 59 micrograms/100 ml blood produced signs of disturbances in reflex development and some changes in emotional behavior. Larger doses resulted in subtle changes in the neuromotor coordination function. The effect of low levels of lead exposure on the cognitive function in operant conditioning could not clearly be observed. Brain lead concentration tended to be higher than in other tissues examined. At approximately 10 months following cessation of lead acetate administration, the brain lead concentration had decreased to almost the same level found in control rats, and no distinguishable differences were observed between the lead-treated rats and controls in emotional behavior and neuromotor coordination.