Multiple spine boutons are formed after long-lasting LTP in the awake rat
Multiple spine boutons are formed after long-lasting LTP in the awake rat
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DOI：
10.1007/s00429-012-0488-0
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发表时间：
2012
影响因子：
3.1
通讯作者：
N. Medvedev;N. Medvedev;G. Dallérac;G. Dallérac;V. I. Popov;V. I. Popov;J. R. Arellano;J. R. Arellano;J. R. Arellano;H. A. Davies;I. Kraev;V. Doyère;Michael G. Stewart
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作者：
N. Medvedev;N. Medvedev;G. Dallérac;G. Dallérac;V. I. Popov;V. I. Popov;J. R. Arellano;J. R. Arellano;J. R. Arellano;H. A. Davies;I. Kraev;V. Doyère;Michael G. Stewart
多发性脊束核(MSB)的形成与认知能力有关，包括海马依赖的联想学习和记忆。从培养的海马片获得的数据表明，突触可塑性的长期维持需要在现有突触上形成新的突触接触。然而，这一假设从未在清醒的、自由活动的动物身上得到检验。在本研究中，我们在清醒的成年大鼠的齿状回(DG)中诱导了长时程增强(LTP)，并在诱导后24小时对轴突和树突的薄片进行了电子显微镜的三维重建。与诱发长期抑郁(LTD)的动物或用N-甲基-D-天冬氨酸(NMDA)拮抗剂阻断LTP的动物相比，观察到的变化具有特异性。我们的数据表明，虽然Bouton的数量没有变化，但在LTP诱导后24小时，每Bouton的突触数量显著增加。此外，我们证明这种增加是特定于蘑菇刺的，而不是归因于它们的分裂。因此，本研究填补了行为研究和体外研究之间存在的空白，即MSB的形成在突触可塑性和认知能力中的作用。
The formation of multiple spine boutons (MSBs) has been associated with cognitive abilities including hippocampal-dependent associative learning and memory. Data obtained from cultured hippocampal slices suggest that the long-term maintenance of synaptic plasticity requires the formation of new synaptic contacts on pre-existing synapses. This postulate however, has never been tested in the awake, freely moving animals. In the current study, we induced long-term potentiation (LTP) in the dentate gyrus (DG) of awake adult rats and performed 3-D reconstructions of electron micrographs from thin sections of both axonal boutons and dendritic spines, 24 h post-induction. The specificity of the observed changes was demonstrated by comparison with animals in which long-term depression (LTD) had been induced, or with animals in which LTP was blocked by anN-methyl-d-aspartate (NMDA) antagonist. Our data demonstrate that whilst the number of boutons remains unchanged, there is a marked increase in the number of synapses per bouton 24 h after the induction of LTP. Further, we demonstrate that this increase is specific to mushroom spines and not attributable to their division. The present investigation thus fills the gap existing between behavioural and in vitro studies on the role of MSB formation in synaptic plasticity and cognitive abilities.