THE PUPILLOCONSTRICTOR AND PUPILLODILATATOR RESPONSE AREA IN RABBITS‘ PRETECTAL REGION, IN THE CENTRAL GRAY MATTER OF MIDBRAIN AND ITSPERIPHERY

摘要: Summary Using 61 rabbits, we made an observation on the papillary reaction. After exposing surface of cerebral cortex or dorsal midbrain, concentric electrodes were inserted, and alternative current 0.5-5 volt 60 cycle was given pretectal region, central gray matter its periphery, stimulated points amounting to 3,500 in total. The pupillary responses areas histologically determined afterwards by means Nissl stain myelin series tracing rabbit's reflex afferent pathway. result thereof is as follows: 1. minimum voltage cause constrictor response dilatator with stimulation needle electrode 0.5 volt. In certain portions, mere insertion produced responses. Pupillo-constriction concurred many cases blephalo-ptosis pupillo-dilstation reopening eyelids. 2. Wheress pupillo-constrictor area founs localized posterior commissure, descending peduncle commirsure matter, pupillo-dilatator lesser delimited, widely distributed over whole midbrain covering. radiatio optical, commissure peduncle, tectum, tegmentum matter. 3. dorsolateral archiform fiber system connection optic tract tractus sublentifomis (Kuhlenbeck) caused contralateral pupillo-constricticn same lateral medial geniculate body, latter represen ting pathway these two systems also arza (Nucl. praetectalis, Nucl. lentifonnis mesencephali, sublentiformis), locus termination pathway, whereas Area praetectalis lying just adjacent yielded both bilateral constriction. 4. Bilateral constriction producible from median commissure; bilateral, homolateral lastly, respectively. 5. Regarding interstitial nuclei, there obtained constrictions interstitialis principalis com-missurae posterioris supra-commissuralis commis-surae posteroris, while only obtainable nuclei located part commissure. 6. So far could roughly determine scope nucleus a small-cell group found between fasciculus longitudinalis dorsalis faxiculus medialis Darkschewitsch about 200 μ anterior main oculomotor constriction. It runs farther 1,200 along dorso-oral side downward middle same. 7. Homolateral fibers. 8. Besides dilatation medialie. 9. Dilatation optica, ventromedial descendens (Kuhlenbeck). Also, body which serve those systems. 10. nuclei. 11. be olivaris colliculi supe-rioris (Fuse). 12. tends occur periventricular (Kuhlenbeck). 13. Our assumption iegarding light rabbits basis experiment makes complete decussation at chiasma enters region scatterringly running through sublentiformis Kuhlen beck. fibers change neuron ragion; secondary starting hers undergoes cornpletc again comrnissure, then turns ventrocaudal direction joins commissure. Then, around way hereof, it reacheo small-celled dorso-lateral ventral midbrain. course differs according different animal species. Therefore, not right apply findings concerning species general.