Active neural coordination of motor behaviors with internal states

The brain must continuously coordinate skeletomuscular movements with internal physiological states like arousal, but how is this coordination achieved? One possibility is that brain simply reacts to changes in external and/or internal signals. Another possibility is that it is actively coordinating both external and internal activities. We used functional ultrasound imaging to capture a large medial section of the brain, including multiple cortical and subcortical areas, in marmoset monkeys while monitoring their spontaneous movements and cardiac activity. By analyzing the causal ordering of these different time-series, we found that information flowing from the brain to movements and heart rate fluctuations were significantly greater than in the opposite direction. The brain areas involved in this external versus internal coordination were spatially distinct but also extensively interconnected. Temporally, the brain alternated between network states for this regulation. These findings suggest that the brain’s dynamics actively and efficiently coordinate motor behavior with internal physiology.

大脑必须持续协调骨骼肌肉运动与唤醒等内部生理状态，但此类协调究竟如何实现？
一种假说认为大脑仅被动响应外部及/或内部信号的变化；另一种假说则提出大脑会主动协调外部与内部的各项活动。
本研究采用功能超声成像（functional ultrasound imaging）技术，在普通狨猴(marmoset monkeys)身上开展实验：采集其大脑大范围内侧区域的成像数据，该区域涵盖多个皮层与皮层下脑区，同时记录受试动物的自发运动与心脏活动。
通过分析这些不同时间序列的因果顺序，我们发现从大脑流向运动系统以及与心率波动相关的信息流，其规模显著高于反向流动的信息流。
参与此类外部-内部协调的脑区在空间分布上存在差异，但同时也存在广泛的神经连接。在时间维度上，大脑会在用于执行此类调控的不同网络状态间交替切换。
上述研究结果表明，大脑的神经活动会主动且高效地协调运动行为与内部生理状态。