Energy substrates that fuel fast neuronal network oscillations.
Energy substrates that fuel fast neuronal network oscillations.
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DOI：
10.3389/fnins.2014.00398
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发表时间：
2014
影响因子：
4.3
通讯作者：
Kann O
中科院分区：
文献类型：
--
作者：
Galow LV;Schneider J;Lewen A;Ta TT;Papageorgiou IE;Kann O
在伽马频率带（30-− 100 Hz）的快速神经元网络振荡提供了哺乳动物海马和新皮层中复杂神经元信息处理的基本机制。伽马振荡与大脑的高级功能有关，如感官知觉、运动活动和记忆形成。这些振荡来自兴奋性主神经元（如锥体细胞）和抑制性GABA能中间神经元之间的精确突触相互作用，并且它们与高能量消耗相关。然而，能量底物和代谢途径，能够功率皮质伽马振荡已较少定义。在这里，我们调查了能源燃料持续的伽马振荡在CA3子字段的大鼠的器官型海马切片文化。该制剂允许在局部场电位的细胞外记录期间提供上级氧气供应以及快速应用葡萄糖、糖酵解代谢物或药物如糖原磷酸化酶抑制剂。我们的发现是：（i）在切片培养物中，在葡萄糖（10 mmol/L）存在下γ振荡持续超过60 min，而（ii）降低葡萄糖水平（2.5 mmol/L）显著降低振荡幅度。(iii)在低浓度乳酸（2 mmol/L）下不存在γ振荡。(iv)γ振荡持续在高浓度（20 mmol/L）的乳酸或丙酮酸，虽然显示出显着的幅度减少。(v)在葡萄糖剥夺期间，糖原的分解显著延迟了伽马振荡的衰减。然而，当葡萄糖存在时，糖原的周转对于维持γ振荡不是必需的。我们的研究表明，快速的神经元网络振荡可以由不同的富含能量的底物来驱动，其中葡萄糖是最有效的。
Fast neuronal network oscillations in the gamma-frequency band (30–−100 Hz) provide a fundamental mechanism of complex neuronal information processing in the hippocampus and neocortex of mammals. Gamma oscillations have been implicated in higher brain functions such as sensory perception, motor activity, and memory formation. The oscillations emerge from precise synapse interactions between excitatory principal neurons such as pyramidal cells and inhibitory GABAergic interneurons, and they are associated with high energy expenditure. However, both energy substrates and metabolic pathways that are capable to power cortical gamma oscillations have been less defined. Here, we investigated the energy sources fueling persistent gamma oscillations in the CA3 subfield of organotypic hippocampal slice cultures of the rat. This preparation permits superior oxygen supply as well as fast application of glucose, glycolytic metabolites or drugs such as glycogen phosphorylase inhibitor during extracellular recordings of the local field potential. Our findings are: (i) gamma oscillations persist in the presence of glucose (10 mmol/L) for greater than 60 min in slice cultures while (ii) lowering glucose levels (2.5 mmol/L) significantly reduces the amplitude of the oscillation. (iii) Gamma oscillations are absent at low concentration of lactate (2 mmol/L). (iv) Gamma oscillations persist at high concentration (20 mmol/L) of either lactate or pyruvate, albeit showing significant reductions in the amplitude. (v) The breakdown of glycogen significantly delays the decay of gamma oscillations during glucose deprivation. However, when glucose is present, the turnover of glycogen is not essential to sustain gamma oscillations. Our study shows that fast neuronal network oscillations can be fueled by different energy-rich substrates, with glucose being most effective.