Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat.
Low level postnatal methylmercury exposure in vivo alters developmental forms of short-term synaptic plasticity in the visual cortex of rat.
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DOI：
10.1016/j.taap.2009.07.037
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发表时间：
2009-11-01
影响因子：
3.8
通讯作者：
Yuan Y
中科院分区：
文献类型：
--
作者：
Dasari S;Yuan Y
甲基汞（MeHg）以前曾被证明会影响神经递质的释放。短期突触可塑性（STP）主要与神经递质释放概率的变化有关。为了确定甲基汞是否影响STP的发展，我们研究了STP的形式在大鼠的视觉皮层在体内甲基汞暴露。新生大鼠接受0（0.9%氯化钠），0.75或1.5毫克/公斤/天的甲基汞皮下注射15或30天，出生后第5天开始，之后视觉皮层切片准备场电位记录。在从用载体处理的大鼠制备的切片中，通过以20 - 200 ms刺激间间隔的成对脉冲刺激诱发的场兴奋性突触后电位（fEPSP）显示第二fEPSP（fEPSP 2）的抑制（PPD）。用0.75或1.5 mg/kg/天甲基汞处理大鼠15天后制备的切片中也观察到PPD。然而，较长的持续时间治疗（30天）与任何剂量的甲基汞导致成对脉冲促进（PPF）的fEPSP 2在大多数切片检查。在最初30天的甲基汞处理完成后，甲基汞暴露已终止30天的动物制备的切片中仍可观察到PPF，而对照动物的切片仍显示PPD。甲基汞对STP没有任何频率或区域偏好效应。操纵[Ca 2 +]e或应用GABAA受体拮抗剂荷包牡丹碱可以改变甲基汞诱导的STP变化的强度和极性。因此，这些数据表明，出生后低水平的甲基汞暴露干扰了视皮层中STP的发育转化，这是一个长期的影响。
Methylmercury (MeHg) has been previously shown to affect neurotransmitter release. Short-term synaptic plasticity (STP) is primarily related to changes in the probability of neurotransmitter release. To determine if MeHg affects STP development, we examined STP forms in the visual cortex of rat following in vivo MeHg exposure. Neonatal rats received 0 (0.9% NaCl), 0.75 or 1.5 mg/kg/day MeHg subcutaneously for 15 or 30 days beginning on postnatal day 5, after which visual cortical slices were prepared for field potential recordings. In slices prepared from rats treated with vehicle, field excitatory postsynaptic potentials (fEPSPs) evoked by paired-pulse stimulation at 20 - 200 ms inter-stimulus intervals showed a depression (PPD) of the second fEPSP (fEPSP2). PPD was also seen in slices prepared from rats after 15 day treatment with 0.75 or 1.5 mg/kg/day MeHg. However, longer duration treatment (30 days) with either dose of MeHg resulted in paired-pulse facilitation (PPF) of fEPSP2 in the majority of slices examined. PPF remained observable in slices prepared from animals in which MeHg exposure had been terminated for 30 days after completion of the initial 30 day MeHg treatment, whereas slices from control animals still showed PPD. MeHg did not cause any frequency- or region-preferential effect on STP. Manipulations of [Ca2+]e or application of the GABAA receptor antagonist bicuculline could alter the strength and polarity of MeHg-induced changes in STP. Thus, these data suggest that low level postnatal MeHg exposure interferes with the developmental transformation of STP in the visual cortex, which is a long-lasting effect.
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影响因子：
3.8
作者：
Edwards, JR;Marty, MS;Atchison, WD
通讯作者：
Atchison, WD
影响因子：
1.8
作者：
Daw, N;Yan, R;Yang, YP
通讯作者：
Yang, YP
影响因子：
2.9
作者：
Jia, F;Xie, XQ;Zhou, YF
通讯作者：
Zhou, YF
影响因子：
64.8
作者：
Fagiolini, M;Hensch, TK
通讯作者：
Hensch, TK
影响因子：
5.3
作者：
Buonomano, DV
通讯作者：
Buonomano, DV