Changes in masticatory movements and motor neuronal activities after lesioning of the tongue projection area of the first somatosensory cortex in awake cats.

我们研究了清醒猫的口面第一体感皮层（Sl）和运动皮层（MC: M、P和C）咀嚼相关神经元（MRNs）的活动模式和特性。Sl、M、P和C的mrn大多在口腔周围或舌区有共同的感受野。在Sl中，超过90%的mrn显示咀嚼节奏后的活动变化（运动后RB）。超过50%的mrn在咀嚼运动前和咀嚼运动期间显示持续活动（前运动SB）。P中约40%的mrn在下颌和舌头运动前显示活动变化（Pre-movement TB）。C组约50%的mrn为运动后RB。为了研究Sl的口周或舌投影区功能，我们在口腔周或舌投影区（PL和TL-cats）注射了kainic酸（0.1%,2mul），检测了MC损伤后5-6周口腔面部行为和mrn活性的变化。在早期阶段（病变后10天），pl猫咀嚼开始延迟，嘴里有一滴食物。tl猫的摄食时间延长。与正常猫相比，pl猫的口周区接受野的mrn比例在M、P和C中减少了70%。tl -猫的舌部接收区MRNs在p.p未被记录，pl -猫在M的运动前SB率下降，在c的运动后RB率下降，tl -猫在P的运动前TB率下降。这些发现表明，Sl在咀嚼过程中的口周或舌部信息可能将口腔周围持续收缩或食物条件下适当运动的命令传递给M或P。

We have studied activity patterns and properties of mastication-related neurons (MRNs) in the orofacial first somatosensory (Sl) and motor (MC : M,P and C) cortices of awake cats. Most MRNs in Sl, M,P and C Had common receptive fields in perioral or tongue regions. Over 90% of MRNs in Sl showed activity changes following the masticatory rhythm (Post-movement RB). Over 50% of MRNs in M showed sustained activities (Pre-movement SB) before and during masticatory movements. About 40% of MRNs in P showed activity changes before movements of the jaw and tongue (Pre-movement TB). About 50% of MRNs in C were Post-movement RB.To investigated the function of the perioral or tongue projection area of Sl, we examined changes in orofacial behaviors and activities of MRNs in MC for 5-6 weeks after lesioning by a kainic acid injection (0.1%, 2mul) into the perioral or tongue projection area (PL and TL-cats). In the early phase (for 10 days after a lesion), PL-cats showed a delay in the masticatory start and a drop of food from mouth. TL-cats showed prolongations of the ingestion time. The proportion of MRNs with receptive fields in the perioral region of PL-cats was reduced by 70% in M,P and C in comparison with norma cats. MRNs with receprive fields in the tongue of TL-cats were not recorded in P.PL-cats decreased Pre-movement SB rate in M and Post-movement RB rate in C.TL-cats decreased Pre-movement TB rate in P.These findings suggest that perioral or tongue information in Sl during mastication may transfer commands of continuous contractions around the mouth or of appropriate movements following food condition to M or P.