Arandia-Romero Iñigo, Tanabe Seiji, Drugowitsch Jan, Kohn Adam, Moreno-Bote Rubén
Department of Information and Communication Technologies, Universidad Pompeu Fabra, Barcelona 08018, Spain; Research Unit, Parc Sanitari Sant Joan de Deu, Esplugues de Llobregat, Barcelona 08950, Spain.
Dominick Purpura Department of Neuroscience and Ophthalmology and Visual Science, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
Neuron. 2016 Mar 16;89(6):1305-1316. doi: 10.1016/j.neuron.2016.01.044. Epub 2016 Feb 25.
Numerous studies have shown that neuronal responses are modulated by stimulus properties and also by the state of the local network. However, little is known about how activity fluctuations of neuronal populations modulate the sensory tuning of cells and affect their encoded information. We found that fluctuations in ongoing and stimulus-evoked population activity in primate visual cortex modulate the tuning of neurons in a multiplicative and additive manner. While distributed on a continuum, neurons with stronger multiplicative effects tended to have less additive modulation and vice versa. The information encoded by multiplicatively modulated neurons increased with greater population activity, while that of additively modulated neurons decreased. These effects offset each other so that population activity had little effect on total information. Our results thus suggest that intrinsic activity fluctuations may act as a "traffic light" that determines which subset of neurons is most informative.
大量研究表明，神经元反应受刺激特性以及局部网络状态的调节。然而，关于神经元群体的活动波动如何调节细胞的感觉调谐并影响其编码信息，我们却知之甚少。我们发现，灵长类动物视觉皮层中持续的和刺激诱发的群体活动波动，以乘法和加法的方式调节神经元的调谐。虽然分布在一个连续体上，但具有较强乘法效应的神经元往往具有较弱的加法调制，反之亦然。乘法调制神经元编码的信息随着群体活动增强而增加，而加法调制神经元编码的信息则减少。这些效应相互抵消，因此群体活动对总信息影响不大。我们的结果因此表明，内在活动波动可能充当一个“交通信号灯”，决定哪些神经元子集最具信息性。
