Consequences of lead exposure of rats during pregnancy, lactation, and postweaning. A combined behavioural and neurotoxicological study

Behavioural and electrophysiological changes caused by inorganic lead treatment at different phases of the ontogenesis were investigated in Wistar rats. They were treated by gavage with 80.0, 160.0, and 320.0 mg/ kg lead during the 5th-15th days of pregnancy, or the 5th-15th days of pregnancy + 4 weeks of lactation (females of P generation), or the 5th-15th days of pregnancy + 4 weeks of lactation (females of P generation) + 8 weeks after weaning (males of F1 generation). The behavioural (open field) and electrophysiological (electrocorticogram, cortical evoked potentials, etc.) parameters of F1 male rats in the above groups were investigated at the age of 12 weeks. Only rats exposed to lead during pregnancy exhibited a significant hyperactivity in the OF test expressed as a higher ambulation rate in the first minute in the OF and as longer running distances. Grooming was also increased. The spontaneous and evoked electrophysiological functions showed dose- and treatment-dependent changes (e.g. decreased mean amplitude and increased frequency of the electrocorticogram, lengthened latency and duration of the evoked potentials, etc.). The results indicate that the low-level pre- and postnatal inorganic lead exposure considerably affects both the behaviour and the function of the nervous system.

Keywords:

• Conduction Velocity
• Cortical Evoked Potential
• Electrocorticogram
• Lead
• Open Field Behaviour
• Pre- And Postnatal Exposure
• Rat
• Refractory Period