Tuning synaptic transmission in the hippocampus by stress: the CRH system.
Tuning synaptic transmission in the hippocampus by stress: the CRH system.
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DOI：
10.3389/fncel.2012.00013
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发表时间：
2012
影响因子：
5.3
通讯作者：
Baram TZ
中科院分区：
文献类型：
--
作者：
Chen Y;Andres AL;Frotscher M;Baram TZ
为了提高生存能力，有机体需要记住并从威胁或压力事件中学习。这一事实使得压力可以影响大脑区域（如海马体）中有助于学习和记忆的突触传递的机制的存在成为必要。这一系列专著的主要重点是肾上腺源性激素、皮质类固醇和脑源性神经递质对应激海马突触功能的作用和作用。在这里，我们专注于海马内的，应激激活的CRH-CRH受体信号传导的海马突触的功能和结构的贡献。促肾上腺皮质激素释放激素（CRH）在成年海马的中间神经元中表达，并在应激时从轴突终末释放。该肽通过调节突触功能和可塑性对学习和记忆发挥时间和剂量依赖性作用。而CRH的生理水平，在几秒钟到几分钟内起作用，增强记忆过程，暴露于假定的严重应激水平的肽导致脊柱回缩和突触丢失在更长的时间内。树突棘（以及因此的突触）的丧失通过位于棘头上的兴奋性突触内的CRHR 1受体下游的肌动蛋白细胞骨架崩溃而发生。慢性暴露于应激水平的CRH可能会促进携带棘突的树突的回退（萎缩）。因此，CRH的急性效应可能有助于应激诱导的适应机制，而长期或过度暴露于肽可能会促进学习问题和过早的认知能力下降。
To enhance survival, an organism needs to remember—and learn from—threatening or stressful events. This fact necessitates the presence of mechanisms by which stress can influence synaptic transmission in brain regions, such as hippocampus, that subserve learning and memory. A major focus of this series of monographs is on the role and actions of adrenal-derived hormones, corticosteroids, and of brain-derived neurotransmitters, on synaptic function in the stressed hippocampus. Here we focus on the contribution of hippocampus-intrinsic, stress-activated CRH-CRH receptor signaling to the function and structure of hippocampal synapses. Corticotropin-releasing hormone (CRH) is expressed in interneurons of adult hippocampus, and is released from axon terminals during stress. The peptide exerts time- and dose-dependent effects on learning and memory via modulation of synaptic function and plasticity. Whereas physiological levels of CRH, acting over seconds to minutes, augment memory processes, exposure to presumed severe-stress levels of the peptide results in spine retraction and loss of synapses over more protracted time-frames. Loss of dendritic spines (and hence of synapses) takes place through actin cytoskeleton collapse downstream of CRHR1 receptors that reside within excitatory synapses on spine heads. Chronic exposure to stress levels of CRH may promote dying-back (atrophy) of spine-carrying dendrites. Thus, the acute effects of CRH may contribute to stress-induced adaptive mechanisms, whereas chronic or excessive exposure to the peptide may promote learning problems and premature cognitive decline.
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DOI：
10.1073/pnas.1003825107
发表时间：
2010-07-20
影响因子：
11.1
作者：
Chen, Yuncai;Rex, Christopher S.;Baram, Tallie Z.
通讯作者：
Baram, Tallie Z.
DOI：
10.1016/0006-291x(74)90539-7
发表时间：
1974-01-01
影响因子：
3.1
作者：
KOCH, Y;BARAM, T;FRIDKIN, M
通讯作者：
FRIDKIN, M
影响因子：
2.9
作者：
Contarino, A;Dellu, F;Gold, LH
通讯作者：
Gold, LH
影响因子：
5.3
作者：
Brunson, KL;Kramár, E;Baram, TZ
通讯作者：
Baram, TZ
影响因子：
11
作者：
Chen, Y.;Kramar, E. A.;Chen, L. Y.;Babayan, A. H.;Andres, A. L.;Gall, C. M.;Lynch, G.;Baram, T. Z.
通讯作者：
Baram, T. Z.