1] Neurosciences Program, Stanford University, Stanford, California, USA. [2] Department of Electrical Engineering, Stanford University, Stanford, California, USA. [3] Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA.
1] Department of Neuroscience, Columbia University Medical Center, New York, New York, USA. [2] Grossman Center for the Statistics of Mind, Columbia University Medical Center, New York, New York, USA. [3] David Mahoney Center for Brain and Behavior Research, Columbia University Medical Center, New York, New York, USA. [4] Kavli Institute for Brain Science, Columbia University Medical Center, New York, New York, USA.
Nat Neurosci. 2014 Mar;17(3):440-8. doi: 10.1038/nn.3643. Epub 2014 Feb 2.
Neural circuits must perform computations and then selectively output the results to other circuits. Yet synapses do not change radically at millisecond timescales. A key question then is: how is communication between neural circuits controlled? In motor control, brain areas directly involved in driving movement are active well before movement begins. Muscle activity is some readout of neural activity, yet it remains largely unchanged during preparation. Here we find that during preparation, while the monkey holds still, changes in motor cortical activity cancel out at the level of these population readouts. Motor cortex can thereby prepare the movement without prematurely causing it. Further, we found evidence that this mechanism also operates in dorsal premotor cortex, largely accounting for how preparatory activity is attenuated in primary motor cortex. Selective use of 'output-null' vs. 'output-potent' patterns of activity may thus help control communication to the muscles and between these brain areas.
神经回路必须进行计算，然后有选择地将结果输出到其他回路。然而，在毫秒时间尺度上，突触不会发生根本性的变化。那么，一个关键问题是：神经回路之间的通讯是如何控制的？在运动控制中，直接参与驱动运动的大脑区域在运动开始之前就已经活跃了。肌肉活动是神经活动的一种读出，但在准备过程中，它在很大程度上保持不变。在这里，我们发现，在准备过程中，当猴子保持静止时，运动皮层活动的变化在这些群体读出水平上相互抵消。运动皮层可以在不提前引发运动的情况下准备运动。此外，我们还发现了证据表明，这种机制也存在于背侧运动前皮层中，这在很大程度上解释了为什么在初级运动皮层中，预备活动会减弱。因此，选择性地使用“输出无效”与“输出有效”的活动模式可能有助于控制与肌肉的通讯以及这些大脑区域之间的通讯。
