National Institute of Mental Health, Topolová 748, 250 67, Klecany, Czech Republic.
Faculty of Medicine at Charles University, 116 36, Prague, Czech Republic.
Brain Struct Funct. 2019 Apr;224(3):973-983. doi: 10.1007/s00429-019-01835-7. Epub 2019 Jan 18.
The bulk of brain energy expenditure is allocated for maintenance of perpetual intrinsic activity of neurons and neural circuits. Long-term electrophysiological and neuroimaging studies in anesthetized and behaving animals show, however, that the great majority of nerve cells in the intact brain do not fire action potentials, i.e., are permanently silent. Herein, I review emerging data suggesting massive redundancy of nerve cells in mammalian nervous system, maintained in inhibited state at high energetic costs. Acquired in the course of evolution, these collections of dormant neurons and circuits evade routine functional undertakings, and hence, keep out of the reach of natural selection. Under penetrating stress and disease, however, they occasionally switch in active state and drive a variety of neuro-psychiatric symptoms and behavioral abnormalities. The increasing evidence for widespread occurrence of silent neurons warrants careful revision of functional models of the brain and entails unforeseen reserves for rehabilitation and plasticity.
大脑能量消耗的大部分用于维持神经元和神经回路的持续内在活动。然而，在麻醉和行为动物的长期电生理和神经影像学研究表明，在完整大脑中绝大多数神经细胞不产生动作电位，也就是说，它们是永久性沉默的。在此，我回顾了一些新出现的数据，这些数据表明哺乳动物神经系统中的神经细胞存在大量冗余，它们处于抑制状态，需要高能量成本来维持。这些休眠神经元和回路是在进化过程中获得的，它们逃避常规的功能活动，因此，不受自然选择的影响。然而，在穿透性应激和疾病下，它们偶尔会进入活跃状态，并引发各种神经精神症状和行为异常。越来越多的证据表明沉默神经元的广泛存在，这需要对大脑的功能模型进行仔细的修正，并需要对康复和可塑性进行意想不到的储备。
