Long-term depression in freely moving rats is dependent upon strain variation, induction protocol and behavioral state
Long-term depression in freely moving rats is dependent upon strain variation, induction protocol and behavioral state
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DOI：
10.1093/cercor/10.5.482
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发表时间：
2000-05-01
期刊：
影响因子：
3.7
通讯作者：
Manahan-Vaughan, D
中科院分区：
文献类型：
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作者：
Manahan-Vaughan, D
海马长时程抑制（LTD）是由反复低频刺激（LFS）引起的突触传递持续减少。虽然LTD已被广泛证明在CA 1区在体外，很少有积极的报告，LTD在体内发生。在这项研究中，条件下，homosynaptic LTD发生在CA 1区的自由运动大鼠进行了调查。研究了三种大鼠品系：Wistar、Sprague-Dawley和Hooded Lister。Wistar和Sprague-Dawley大鼠在1 Hz LFS后表达最佳LTD，而Hooded Lister大鼠在1 - 10 Hz的LFS范围内测试时未显示LTD。暴露于显著的应激短暂增强了Wistar和Sprague-Dawley大鼠的LTD，但并不促进LTD抗性品系的LTD诱导。高频电刺激可诱导长时程增强，但各品系的LTP表现不同。这些数据表明LTD的表达根据所用大鼠的品系而变化，并且紧密依赖于刺激频率。此外，动物的行为状态可能影响LTD表达。这些数据可以解释，在一定程度上，相互矛盾的报告在体内海马LTD的诱导。
Hippocampal long-term depression (LTD) comprises a persistent decrease in synaptic transmission which is induced by repeated low-frequency stimulation (LFS). Although LTD has been widely demonstrated in the CA1 region in vitro, very few positive reports of LTD in vivo have occurred. In this study, the conditions under which homosynaptic LTD occurs in the CA1 region of freely moving rats was investigated. Three rat strains were studied: Wistar, Sprague-Dawley and Hooded Lister. Whereas Wistar and Sprague-Dawley rats expressed optimal LTD following 1 Hz LFS, Hooded Lister rats showed no LTD when tested in an LFS range of 1-10 Hz. Exposure to marked stress transiently enhanced LTD obtained in Wistar and Sprague-Dawley rats, hut did not facilitate LTD induction in the LTD resistant strain. It was possible to induce long-term potentiation with high-frequency stimulation, although the profile of LTP was different in each strain. These data suggest that the expression of LTD varies according to the strain of rat used and is tightly dependent upon stimulation frequency. In addition the behavioral state of the animal may influence LTD expression. These data may explain, in part, the conflicting reports with regard to the inducibility of hippocampal LTD in vivo.