Lasley S M, Polan-Curtain J, Armstrong D L
Department of Basic Sciences, University of Illinois College of Medicine, Peoria 61656.
Brain Res. 1993 Jun 18;614(1-2):347-51. doi: 10.1016/0006-8993(93)91054-v.
This study examined the effects of chronic developmental lead (Pb) exposure in rats on hippocampal long-term potentiation (LTP). Male offspring were exposed to 0.2% Pb acetate continuously from birth until testing at 85-105 days. Excitatory postsynaptic potential (EPSP) and population spike amplitudes were measured in the dentate hilar region in response to stimulation applied to the lateral perforant path. LTP was induced in control animals with an average maximal EPSP potentiation of 41%, which was significantly greater than the increase in EPSP amplitudes (2%) in exposed animals after tetanizing stimulation. Current-voltage curves in controls demonstrated significant increases in EPSPs and population spikes after application of pulse trains to induce LTP, while exposed rats exhibited no discernible change in responses. These findings suggest that induction or development of LTP in the dentate hilar region in vivo is impaired by chronic developmental exposure to environmentally relevant levels of Pb.
本研究检测了大鼠慢性发育期铅（Pb）暴露对海马长时程增强（LTP）的影响。雄性后代从出生起持续暴露于0.2%醋酸铅中，直至85 - 105天进行测试。在齿状回门区测量兴奋性突触后电位（EPSP）和群体峰电位幅度，以响应施加于外侧穿通通路的刺激。对照组动物诱导出LTP，平均最大EPSP增强41%，这显著大于强直刺激后暴露组动物EPSP幅度的增加（2%）。对照组的电流 - 电压曲线显示，施加脉冲序列诱导LTP后，EPSP和群体峰电位显著增加，而暴露大鼠的反应未显示出明显变化。这些发现表明，体内齿状回门区LTP的诱导或发育受到与环境相关水平的铅的慢性发育期暴露的损害。
