Functional changes of masticatory and swallowing movements by aging and cognitive disorder

在猴进行舌运动、咀嚼和吞咽运动的同时，记录初级运动皮层（MI）、初级躯体感觉皮层（SI）和咀嚼皮层（CMA）的神经元活动。在这些区域记录到足够的神经元活动后，训练猴子执行视觉引导的认知任务。然后，我们记录了这些区域的700个神经元活动。在MI、SI和CMA，舌运动相关活动的阳性率分别为71%、61%和15%，咀嚼相关活动的阳性率分别为81%、83%和88%，吞咽相关活动的阳性率分别为26%、0%和55%。在显示舌运动相关活动的神经元中，我们比较了它们在获得认知任务前后的活动。在获得前，MI、SI和CMA分别有23%、25%和40%的舌运动相关活动。另一方面，在收购后，这些活动在MI、SI和CMA中分别占79%、54%和35%。获得认知任务后，与舌运动相关活动的MI和SI神经元的比例显著增加。研究结果提示，MI、SI和CMA的面部区域可能参与舌运动、咀嚼和吞咽的行为控制。此外，与舌运动相关的MI和SI神经元在获得后也发生了变化，这表明口面运动训练可能促进了神经元的可塑性，并引起了大脑的激活。

While the monkeys performed tongue movement, mastication and swallowing, we recorded the neuronal activity from primary motor cortex (MI), primary somatosensory cortex (SI) and cortical masticatory area (CMA) defined by ICMS. After the sufficient neuronal activities were recorded from these areas, the monkeys were trained to perform the visually guided cognitive task. Then, we recorded the 700 neuronal activities from these areas. The tongue movement related activities were showed in 71%, 61% and 15% neurons, the masticatory related activities were shown in 81%, 83% and 88%, the swallowing related activities were shown in 26%, 0% and 55% neurons at MI, SI and CMA, respectively. In the neurons which showed the tongue movement related activities, we compared their activities before and after acquisition of the cognitive task. Before the acquisition, the tongue movement related activities were shown in 23%, 25% and 40% in MI, SI and CMA, respectively. In the other hand, after the acquisition, these activities were shown in 79%, 54% and 35% in MI, SI and CMA, respectively. The ratio of the MI and SI neuron with tongue movement related activities significantly increased after acquisition of the cognitive task. The findings suggest that the face area in MI, SI and CMA may contribute to the behavioral control of the tongue movement, mastication and swallowing. In addition, the finding that the MI and SI neurons with tongue movement related activities showed the changes after the acquisition suggests that the training of orofacial movements may promote the plasticity of the neuron and elicit the activation of the brain.