Dopaminergic modulation of inhibitory glutamate receptors in the lobster stomatogastric ganglion
Dopaminergic modulation of inhibitory glutamate receptors in the lobster stomatogastric ganglion
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DOI：
10.1152/jn.1997.78.6.3450
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发表时间：
1997-12-01
影响因子：
2.5
通讯作者：
Selverston, AI
中科院分区：
文献类型：
--
作者：
Cleland, TA;Selverston, AI
多刺龙虾胃神经节（STG）的内在节律性受到神经网络内已识别细胞之间的分级突触强度的强烈影响。这些突触强度可以受到多巴胺和血清素等化学神经调节剂的强烈影响。STG中的大多数神经节内化学突触由突触后抑制性谷氨酸受体（IGluR）介导。为了确定对这些IGluR的直接影响是否有助于突触强度的调节，将未鉴定的STG神经元提取到原代培养物中，并评估这些胺能神经调节剂对谷氨酸诱发的膜电流的影响。多巴胺（100 μ M）可靠地和显著地降低了所有测试的IGluR的全细胞斜率电导。血清素（20 μ M）从来没有影响IGlu的反应，虽然它显然改变了其他细胞膜的性能。虽然所有鉴定的STG神经元可能不符合这些观察结果，但数据揭示了培养的神经元内降低IGluR斜率电导的特异性多巴胺激活的调节途径。IGluR调节和原位净突触调节之间的关系促成了一种新兴的模型，其中突触强度可以在不同的功能位点被多重调节，产生复杂的、分布式的和状态依赖性的调节结构。
The intrinsic rhythmicity of the spiny lobster stomatograstric ganglion (STG) is strongly influenced by the strengths of the graded synapses between identified cells within the neural network. These synaptic strengths can be powerfully influenced by chemical neuromodulators such as dopamine and serotonin. Most of the intraganglionic chemical synapses in the STG are mediated by postsynaptic inhibitory glutamate receptors (IGluRs). To determine whether or not direct effects on these IGluRs contribute to the modulation of synaptic strength, unidentified STG neurons were extracted into primary culture and the effects of these aminergic neuromodulators on the glutamate-evoked membrane current were assessed. Dopamine (100 mu M) reliably and significantly reduced the whole cell slope conductance of all IGluRs tested. Serotonin (20 mu M) never affected the IGlu response, although it clearly altered other cellular membrane properties. Although all identified STG neurons may not conform to these observations, the data reveal a specific dopamine activated modulatory pathway within cultured neurons that reduces IGluR slope conductance. The relationship between IGluR modulation and net synaptic modulation in situ contributes to an emerging model in which synaptic strengths can be multiply modulated at different functional sites, yielding a complex, distributed, and state-dependent regulatory structure.