Widespread inhibition proportional to excitation controls the gain of a leech behavioral circuit
Widespread inhibition proportional to excitation controls the gain of a leech behavioral circuit
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DOI：
10.1016/j.neuron.2007.11.028
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发表时间：
2008-01-24
期刊：
影响因子：
16.2
通讯作者：
Kristan, William B., Jr.
中科院分区：
文献类型：
--
作者：
Baca, Serapio M.;Marin-Burgin, Antonia;Kristan, William B., Jr.
改变神经元系统的增益具有重要的功能后果，但潜在的机制一直难以捉摸。模型已经提出了各种神经元和系统属性来实现增益控制。在这里，我们表明，在水蛭的局部弯曲行为的神经网络的增益依赖于广泛的抑制。利用行为分析、细胞内记录和电压敏感染料成像，我们比较了仅阻断已知的侧抑制与阻断所有GABA能抑制的效果。这揭示了抑制的另一个来源，这是广泛的，并按比例增加刺激强度。在一个三层局部弯曲网络的输入/输出函数模型中，我们发现，抑制所有的中间神经元与刺激强度成比例，产生实验观察到的增益变化。这种控制行为增益的相对简单的机制可能在脊椎动物和无脊椎动物的神经系统中普遍存在。
Changing gain in a neuronal system has important functional consequences, but the underlying mechanisms have been elusive. Models have suggested a variety of neuronal and systems properties to accomplish gain control. Here, we show that the gain of the neuronal network underlying local bending behavior in leeches depends on widespread inhibition. Using behavioral analysis, intracellular recordings, and voltage-sensitive dye imaging, we compared the effects of blocking just the known lateral inhibition with blocking all GABAergic inhibition. This revealed an additional source of inhibition, which was widespread and increased in proportion to increasing stimulus intensity. In a model of the input/output functions of the three-layered local bending network, we showed that inhibiting all interneurons in proportion to the stimulus strength produces the experimentally observed change in gain. This relatively simple mechanism for controlling behavioral gain could be prevalent in vertebrate as well as invertebrate nervous systems.