Participation of periodontium-sensitive neurons in jaw movements

牙周膜机械敏感（PM）神经元有助于口腔内感觉食物的位置，硬度和质地。他们修改下颌运动，使咀嚼我进行有效和顺利。为探讨牙周信息对咀嚼运动的影响，在麻醉大鼠上研究了初级躯体感觉（SI）皮层的反应特性。PM神经元在SI皮质中的两个区域中表示。在对侧下颌切牙刺激时，前内侧区（RM）的神经元较为敏感，而前外侧区（RL）的神经元则对对侧上颌切牙刺激较为敏感。它们中的大多数是快速适应的神经元。在家兔上，观察了重复电刺激皮层PM神经元记录部位引起的节律性下颌运动（RJMs）。在SI皮质的RM区和RL区也记录到家兔的PM神经元。在RM区域，大多数PM单位（85%）的切牙敏感性较低。电刺激RM区产生斩波型RJMs。在RL区，切牙和磨牙敏感PM单位记录，和磨牙敏感单位位于更rostro-medially比切牙敏感单位。超过一半（66%）的切牙敏感PM单位是上切牙敏感。电刺激RL区的PM单位记录网站诱导研磨型RJM。基于这些发现，下切牙敏感的神经元在RM区的SI皮质可能主要有助于神经网络，控制下颌运动在摄取。磨牙敏感皮层神经元的反应特性可能是有用的，用于区分的大小和方向的咬合力在研磨。

Periodontal mechanosensitive (PM) neurons contribute to intra-oral sensation of the location, hardness and textures of foods. They modifies jaw movements so that mastication I performed effectively and smoothly. To investigate the effect of periodontal information on masticatory jaw movements, the response properties of the primary somatosensory (SI) cortex were studied in the anesthetized rat. PM neurons were represented in two areas in the SI cortex. The neurons in the rostro-medial (RM) area were sensitive to the contralateral mandibular incisor tooth, and those in the rostro-lateral area (RL) area were sensitive to the contralateral maxillary incisor tooth. The majority of them were rapidly adapting neurons. In the rabbit, rhythmical jaw movements (RJMs) induced by repetitive electrical stimulation of the recording sites of cortical PM neurons were observed. PM neurons of the rabbit were also recorded from the RM and RL areas of the SI cortex. In the RM area, most PM units (85 %) were lower incisor-sensitive. Electrical stimulation of the RM area produced the chopping-type RJMs. In the RL area, both incisor- and molar-sensitive PM units were recorded, and molar-sensitive units were located more rostro-medially than incisor-sensitive units. More than half (66 %) of the incisor-sensitive PM units were upper incisor-sensitive. Electrical stimulation of the PM unit-recording sites in the RL area induced grinding-type RJMs. Based on these findings, the lower incisor-sensitive neurons in the RM area of the SI cortex might mainly contribute to a neural network that controls jaw movements during ingestion. The response properties of molar-sensitive cortical neurons might be useful for discriminating the magnitude and direction of the biting force during grinding.