The Morphological Findings Of The Proprioceptive Pathways Of The Fifth Nerve In The Central Nervous System And Regulating Mechanisms On The Activity Of The Masticatory Muscles

The trigeminal mesencephalic nucleus (Vme) is the unique group of primary afferent cell bodies that is located within the mammalian central nervous system (CNS) and innervate muscle spindles of jaw-closing muscles and periodontal mechanoreceptors. However, no striking progress has been achieved in the studies of the Vme and proprioceptive pathways for a long time owing to the limitation of research methods and to the special position, cytoarchitecture and featuresa of Vme in CNS. Following are studies (Chapter Ⅰ—Ⅵ) made around the above mentioned aspects.Ⅰ. It is still in dispute about the shape and classification of Vm neurons, and diverse and discrepant results have been reported about the distribution and course of the central processes of the Vme neurons. In the present study, 63 masseteric neurons of Vme in the rat were stained by intracellular injection of horseradish peroxidase (HRP). Labeled neurons were divided into three types, type A ( uni- or pseudounipolar), type B ( bipolar ), and type C (multipolar cells). Each type was further divided into two subtypes according to the largest diameter of the perikarya (subtype a≥30um, subtype b<30um ). These cells are called types Aa, Ab, Ba, Bb, Ca and Cb. The distrbution and course of the central processes of the type Aa Vme neurons was confirmed by this reliable method. The central processes of type Aa neurons projected to target nuclei of three different function, the nuclei of interneurons, motor nuclei...