Department of Prosthodontics, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON M5G 1G6, Canada.
J Dent Res. 2010 Oct;89(10):1142-7. doi: 10.1177/0022034510373767. Epub 2010 Jun 16.
Jaw and tongue motor alterations may occur following changes in food consistency, but whether such changes are associated with re-organization of motor representations within the facial sensorimotor cortex is unclear. We used intracortical microstimulation (ICMS) and recordings of evoked electromyographic responses to determine jaw (anterior digastric) and tongue (genioglossus) motor representations within the histologically defined face primary motor cortex (face-M1) and adjacent somatosensory cortex (face-S1) of rats fed hard (N = 6) or soft (N = 6) diet for 2 to 3 weeks. ICMS evoked jaw and tongue responses from an extensive area within the face-M1 and a smaller area within the face-S1. A significant contralateral predominance was reflected in the number and latency of ICMS-evoked jaw responses (p < 0.05). There were no significant differences between the hard- and soft-diet groups in jaw and tongue motor representations, suggesting that the rat's ability to adapt to changes in diet consistency may not be associated with significant neuroplasticity of sensorimotor cortex motor outputs.
咀嚼和舌运动的改变可能会在食物稠度发生变化后发生，但这些改变是否与面部感觉运动皮层内运动代表区的重新组织有关尚不清楚。我们使用皮层内微刺激（ICMS）和诱发肌电图反应的记录来确定在接受硬食（N=6）或软食（N=6）喂养 2 至 3 周的大鼠的组织学定义的面部初级运动皮层（face-M1）和相邻体感皮层（face-S1）内的咀嚼（前二腹肌）和舌（颏舌肌）运动代表区。ICMS 从 face-M1 内的广泛区域和 face-S1 内的较小区域诱发咀嚼和舌反应。ICMS 诱发的咀嚼反应的数量和潜伏期反映出明显的对侧优势（p<0.05）。在硬食和软食组之间，咀嚼和舌运动代表区没有显著差异，这表明大鼠适应饮食稠度变化的能力可能与感觉运动皮层运动输出的显著神经可塑性无关。
