Hippocampal long-term depression as an index of spatial working memory
Hippocampal long-term depression as an index of spatial working memory
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DOI：
10.1046/j.1460-9568.2002.02159.x
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发表时间：
2002-09-01
影响因子：
3.4
通讯作者：
Matsuki, N
中科院分区：
文献类型：
--
作者：
Nakao, K;Ikegaya, Y;Matsuki, N
长时程增强 (LTP) 是海马突触可塑性的一种形式，是学习和记忆的神经基础的细胞模型，但很少有研究调查长期抑制 (LTD)（LTP 的对应物）的贡献。为了解决海马LTD和空间表现之间可能的关系，在自发交替测试中评估了大鼠的空间认知能力，然后在麻醉下监测同一只大鼠的齿状回对低频突发刺激（LFBS）的LTD反应。为了增强空间表现能力的差异，一些动物在实验前 14 天接受了穹窿伞 (FF) 横断术。通过将 LFBS 应用于完整大鼠的内侧穿通路径，可以可靠地诱导 LTD，而在 FF 损伤的大鼠中没有引发明显的 LTD。空间记忆的行为参数与LTD的大小呈显着相关。我们没有发现任何证据表明认知能力与其他电生理参数相关，例如基础突触反应、产生半最大反应的刺激强度、配对脉冲促进或配对脉冲抑制。这些结果表明，齿状回中 LTD 的大小可以作为空间认知能力的可靠指标，为了解海马 LTD 的功能意义提供见解。
Long-term potentiation (LTP), a form of synaptic plasticity in the hippocampus, is a cellular model for the neural basis of learning and memory, but few studies have investigated the contribution of long-term depression (LTD), a counterpart of LTP. To address the possible relationship between hippocampal LTD and spatial performance, the spatial cognitive ability of a rat was assessed in a spontaneous alternation test and, thereafter, LTD in response to low-frequency burst stimulation (LFBS) was monitored in the dentate gyrus of the same rat under anaesthesia. To enhance a divergence in the ability for spatial performance, some of the animals received fimbria-fornix (FF) transection 14 days before the experiments. LTD was reliably induced by application of LFBS to the medial perforant path of intact rats, while no apparent LTD was elicited in rats with FF lesions. The behavioural parameters of spatial memory showed a significant correlation with the magnitude of LTD. We found no evidence that the cognitive ability correlated with other electrophysiological parameters, e.g. basal synaptic responses, stimulus intensity to produce half-maximal responses, paired-pulse facilitation or paired-pulse depression. These results suggest that the magnitude of LTD in the dentate gyrus serves as a reliable index of spatial cognitive ability, providing insights into the functional significance of hippocampal LTD.