Blocking polysynaptic inhibition via opioid receptor activation isolates excitatory synaptic currents without triggering epileptiform activity in organotypic hippocampal slices.
Blocking polysynaptic inhibition via opioid receptor activation isolates excitatory synaptic currents without triggering epileptiform activity in organotypic hippocampal slices.
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通过阿片受体激活阻断多突触抑制可隔离兴奋性突触电流，而不触发器官型海马切片中的癫痫样活动。
DOI：
10.1016/j.jneumeth.2005.04.022
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Madison,DanielV
中科院分区：
文献类型：
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作者：
Hanson,JesseE;Emond,MichelleR;Madison,DanielV
在培养的海马切片制备的突触连接的丰度允许使用同时突触前和突触后细胞内记录的锥体神经元对之间的单一兴奋性连接的测量。然而，这些记录的有用的产量可以大大减少的存在下，多突触抑制，阻塞测量的单突触兴奋性突触后电流（EPSC）。我们已经发现，传统的方法消除污染的GABA受体拮抗剂的突触抑制是有限的有用性，因为经常性的兴奋性连接在器官型切片引起癫痫样爆发的抑制功能的情况下。这种爆发甚至比正常发生的多突触抑制性传递更大程度地掩盖了EPSC。在这里，我们报告了一种新的方法，用于隔离单突触EPSC使用μ阿片激动剂肽DAMGO，以减少在这些记录过程中的多突触抑制。μ-阿片受体的激活已知是高血压抑制性神经元。我们发现DAMGO应用降低了多突触抑制的幅度和频率，允许隔离被记录的两个神经元之间的兴奋性连接。此外，由于DAMGO应用不能完全消除抑制功能，因此很少发生癫痫样爆发。因此，使用DAMGO来防止多突触抑制而不引起癫痫样爆发提供了一种有用的工具，以显著增加测量培养的海马切片制备物中锥体神经元之间的单一兴奋性连接的实验的产率。
The abundance of synaptic connectivity in the cultured hippocampal slice preparation allows measurements of the unitary excitatory connection between pairs of pyramidal neurons using simultaneous presynaptic and postysynaptic intracellular recordings. However, the useful yield of these recordings can be greatly reduced by the presence of polysynaptic inhibition that occludes the measurement of the monosynaptic excitatory postsynaptic current (EPSC). We have found that the traditional method of eliminating contaminating synaptic inhibition with GABA receptor antagonists is of limited usefulness because the recurrent excitatory connections in organotypic slices cause epileptiform bursting in the absence of inhibitory function. This bursting obscures EPSCs to an even greater extent than the normally occurring polysynaptic inhibitory transmission. Here, we report a new method for isolating monosynaptic EPSCs using the mu-opioid agonist peptide DAMGO to reduce polysynaptic inhibition during these recordings. Activation of mu-opioid receptors is known to hyperpolarize inhibitory neurons. We found that DAMGO application reduces the amplitude and frequency of polysynaptic inhibition, allowing isolation of the excitatory connection between the two neurons being recorded. Furthermore, because inhibitory function is not completely eliminated by DAMGO application, epileptiform bursting very rarely develops. Therefore, the use of DAMGO to prevent polysynaptic inhibition without causing epileptiform bursting provides a useful tool to substantially increase the yield of experiments measuring the unitary excitatory connection between pyramidal neurons in the cultured hippocampal slice preparation.