USE OF BULLFROG TADPOLES (RANA CATESBEIANA) TO EXAMINE THE MECHANISMS OF LEAD NEUROTOXICITY

摘要: SYNOPSIS. Sublethal exposure to lead elicits changes in behavior, particularly learning. Previously, we had shown that bullfrog tadpoles exposed 1 mg Pb/liter for 7 days exhibit learning deficits a discriminate avoidance assay. The precise mechanisms involved these lead-induced are not understood, but CNS monoamine neurotransmitter systems have been implicated the process. In present study, 1.7 ± 0.2 and then compared concentrations of neurotransmitters from whole brain samples with those controls. Serotonin or 5-hydroxytryptamine (5-HT) was significantly decreased group while serotonin metabolite, 5-hydroxyindoleacetic acid, (5-HIAA) similar No were observed catecholamines epinephrine norepinephijine following exposure. ratio 5-HIAA/5-HT increased animals as result decrease 5-HT, suggesting 5-HT biosynthesis rather than an increase metabolism. These findings first suggest affects results conjunction previous evidence exposure, offer possibility correlating alterations tadpoles. use this tadpole model shows promise means examine understand neurotoxicity.