Trigeminal Nuclear Complex Research Articles

Brain Ribosomes

This chapter talks about the differentiation of neurons in subnucleus caudalis of the nucleus of the spinal tract of v in human and rabbit. The mammalian spinal trigeminal nuclear complex that serves as the terminus of fibers of the spinal tract of the trigeminal nerve can be subdivided into three subdivisions. These are subnucleus caudalis, subnucleus interpolaris, and subnucleus rostralis. Subnucleus caudalis in the human adult and older human fetus is composed of three parts: pars marginalis, pars gelatinosa and pars magnocellularis. The morphology of each of these is similar to comparable parts of the dorsal horn gray. The differentiation of the cells of subnucleus caudalis of the spinal trigeminal nuclear complex is studied in human embryos of 6.5 to 8 weeks of menstrual age and in rabbit embryos of 13 to 16 days of copulation age. The human embryos were prepared with cresyl violet and protargol silver methods. The rabbit embryos were sectioned in a cryostat and stained with thionin, by the Feulgen method and for acid phosphatase and succinate dehydrogenase activity.

An Electrophysiologic Study of Ascending Pathways from Nucleus Caudalis of the Spinal Trigeminal Nuclear Complex

O BSERVATIONS originally made by Sjiiqvist al and confirmed by other neurosurgeons10,25,a0,ag,40 indicate tha t nucleus caudalis s,26 of the spinal trigeminal nuclear complex is an essential relay nucleus in the anatomic substrate subserving the conduction and integration of impulses evoked by noxious stimuli. I t follows tha t a thorough knowledge of the routes and terminals of afferent pathways extending from nucleus caudalis is necessary to the understanding of neural mechanisms involved in clinically recognized pat terns of pain. Anatomic studies 7,32,33 indicate tha t the pat tern of axonal trajectories emanating from nucleus caudalis differs from tha t of the more rostral components of the spinal trigeminal nuclear complex (nucleus interpolaris and nucleus oralis) and the main sensory nucleus. Furthermore, the soma of trigeminal fibers which project directly to the midbrain and thalamic centers associated with nociperception are contained only within nucleus caudalis. This report presents the findings of an electrophysiologic s tudy devised to identify midbrain and thalamic loci activated by a trigeminal input relayed primarily through nucleus caudalis and to compare these regions with brain-stem loci act ivated by impulses relayed at all levels of the trigeminal nuclear complex. The results of this investi-

A single neuron analysis of buccal cavity representation in the sensory trigeminal complex of the cat

The receptive fields and modality of stimulus necessary to elicit discharges in neurons of the sensory trigeminal nuclear complex were studied in the decerebrate cat. The buccal cavity representation was found to be in the medial portion of the sensory V complex with the mandibular division represented dorsal to the maxillary. Each portion of the periphery appears to be represented by a rostro-caudal line of cells extending from the principal sensory V nucleus to the caudal portion of the descending root. The relation of the morphology of the trigeminal sensory complex to the characteristics of regional and modality representation is presented. The discharge properties of neurons excited from buccal structures, especially teeth, are characterized for light touch, pressure and cruder physiological stimuli. A reinterpretation of the nature of pain representation is discussed.

A morphological and somatotopic analysis of single unit activity in the trigeminal sensory complex of the cat

The receptive fields of 788 neurons have been studied in order to reconstruct the relation of the spatial projection of the integument of the face onto different portions of the sensory trigeminal nuclear complex. At all rostrocaudal levels extending from the principal sensory nucleus to the upper cervical cord, the face is represented with the mandibular division lying dorsally, the ophthalmic division at the ventral surface and the interior of the buccal cavity in the medial portion. Thus each point on the face is represented by a colum of cells extending from the level of the principal V nucleus to at least the lower medulla or upper cervical cord. For a given zone of innervation, neurons within these columns can be excited by delicate tactile stimuli applied to receptive fields of a relatively narrow size range. The trigeminal tactile region of the brain stem conforms within the limits of the experimental method to the morphologically defined trigeminal sensory complex except for some findings beyond its medial limits, as usually defined, concerned with buccal cavity innervation. A revision of the subdivision of the architectonic units of the trigeminal complex is suggested on the basis of morphological and functional evidence.