Physiological and neurobehavioral alterations during development in lead exposed rats.

Neonatal rats were exposed to lead (Pb) from parturition to weaning via the milk of dams which consumed 0 (tap water), 0.02% or 0.2% PbAc2 solutions. To determine if this regimen altered physiological and neurobehavioral development, responses to a battery of sensory-motor tests were evaluated during maturation and as adults. The tests were: visual evoked responses (VER), temperature regulation, maximal electroshock seizure patterns, reflex patterns, and neuromuscular performance. Overall results revealed that the Pb-exposed group compared to controls exhibited delayed maturation, altered developmental patterns and long-term CNS disturbances. Additionally, low-level strychnine administration during development caused additive interactions with both Pb groups, uncovering subtle effects of toxicant exposure. These sensitive and quantifiable techniques proved useful for assessing CNS functioning following perinatal insult, and except for the VER, are simple to conduct and cost efficient because they require a minimal amount of personnel training, equipment cost and time invested per animal. These screening tests also suggest further areas of study and may indicate the mechanism(s) responsible for the deficit.