Huang Yan-You, Kandel Eric R
Center for Neurobiology and Behavior, College of Physicians and Surgeons of Columbia University, New York State Psychiatric Institute, 1051 Riverside Drive, New York, NY 10032, USA.
Proc Natl Acad Sci U S A. 2005 Jan 4;102(1):232-7. doi: 10.1073/pnas.0408368102. Epub 2004 Dec 27.
The subiculum (SB) is the principal target of the axons of the CA1 pyramidal cells and serves as the final relay in the trisynaptic loop between the entorhinal cortex and the hippocampus. We have examined synaptic plasticity in the synaptic pathway between the CA1 pyramidal cells and the SB in hippocampal slices and compared it under the same experimental condition with the synaptic plasticity in Shaffer collateral pathway (CA3-CA1). We find that the frequency response curve of synaptic strength induced by prolonged low-frequency stimulation (1-5 Hz) is systematically up-shifted from Shaffer collateral to the CA1-SB pathway. The up-regulation of synaptic strength is mediated by the activity-dependent modulation by beta-adrenergic transmission. Because the CA3-CA1 and the CA1-SB synaptic pathways are in series and the beta-adrenergic modulation is region-specific, this modulation seems to be involved in the selective control of signal transmission between the different regions of hippocampus.
海马下脚(SB)是CA1锥体细胞轴突的主要靶标,并且在内嗅皮质与海马体之间的三突触回路中充当最终中继站。我们已经研究了海马切片中CA1锥体细胞与SB之间突触通路中的突触可塑性,并在相同实验条件下将其与谢弗侧支通路(CA3-CA1)中的突触可塑性进行了比较。我们发现,由长时间低频刺激(1-5赫兹)诱导的突触强度频率响应曲线从谢弗侧支向CA1-SB通路系统性地上移。突触强度的上调是由β-肾上腺素能传递的活动依赖性调节介导的。由于CA3-CA1和CA1-SB突触通路是串联的,并且β-肾上腺素能调节具有区域特异性,这种调节似乎参与了海马体不同区域之间信号传递的选择性控制。