An Experimental Study on the Accessory Optic System in the Rabbit

• Ban T.

  Department of Anatomy, Osaka University Medical School, Japan

• Ôki T.

  Department of Anatomy, Osaka University Medical School, Japan

• Zyo K.

  Department of Anatomy, Osaka University Medical School, Japan

抄録

1. The accessory optic system in the rabbit was studied by means of Marcia technique.<BR>2. Four group s of retinal fibers were recognized to terminate in the hypothalamus or in the ventral tegmental area of the midbrain, i. e.1) preoptic component,2) supraoptic component,3) anterior accessory optic tract,4) posterior accessory optic tract.<BR>3. The preoptic component is composed of a s m all number of uncrossed retinal fibers, leaving the optic nerve at its mediodorsal corner just rostral to the chiasm to descend dorsolaterad almost in parallel with the dorsal surface of the chiasm to finish its course partly in the lamina terminalis and partly further caudally in medial preoptic area. Fibers show no sign of crossing.<BR>4. The supraoptic component is com p osed of a small number of crossed retinal fibers diverging from the dorsal surface of the chiasm to terminate directly in the pars dorsolateralis of the supraoptic nucleus.<BR>5. The anterior accessory optic tract is composed of the retinal fibers which cross in the chiasm most posteriorly. It appears first medial to the main optic tract on the ventral surface of the diencephalon and then more caudally is divided into a lateral and a medial groups by the medial end of the cerebral peduncle. The lateral group penetrates dorsad through the interfibular spaces of the cerebral peduncle to terminate in the subthalamic nucleus and some of them diverge more caudally into the substantia nigra. The medial group finds its termination in the lateral hypothalamic nucleus and in the pars ventromedialis of the supraoptic nucleus. Sparse fibers are seen to enter the subthalamic nucleus by swinging around the lateral margin of the cerebral peduncle from the lateral group and by swinging around the medial margin from the medial group.<BR>6. The posterior accessory optic tract is composed of the crossed retinal fibers first diverging from the superior quadrigeminal brachium to travel along the lateral surface of the diencephalon and then obliquely along the ventral surface of the cerebral peduncle to arrive at the medial end of this where it turns dorsolaterad along the medial margin of the cerebral peduncle to enter the nucleus opticus tegmenti of Tsai ('25). From the terminal part of this tract in the midbrain tegmentum some fibers are given anterolaterad into the substantia nigra (pars reticularis), a few of which pass into the subthalamic nucleus.<BR>7. It is shown that both the anterior and posterior accessory optic tracts find termination in the subthalamic nucleus and in the substantia nigra, thus establishing the connection between them.<BR>8. The retino-hypothalamic connection is not unitary. The hypothalamus (anatomically and functionally referred to as the SPH-system, Ban '62, '64) receives optic fibers by way of the preoptic component (uncrossed fibers), supraoptic component (crossed fibers) and anterior accessory optic tract (crossed fibers). This is summerized as follows; the retinal fibers terminate in the medial preoptic area and nucleus supraopticus (of the area sympathica-B, )and in the lateral hypothalamic nucleus (of the area parasympathica-C of the SPH-system of B a n, '62, '64).<BR>9. Each retinal quadrant has a share in the composition of the accessory optic system almost in equal quantity and distribution of fibers except in the case of the preoptic component, so far as observed in the series of our frontal sections. For the preoptic component, fibers from the medial or lateral quadrant were observed a little more in number than those from the superior or inferior quadrant.<BR>10. Marchi findings in rabbit were compared with Nauta findings of previous authors in the same animal with consideration of merits and demerits of Marchi technique itself.

収録刊行物

• Okajimas Folia Anatomica Japonica

  Okajimas Folia Anatomica Japonica 40 (4-6), 625-645, 1965

  Editorial Board of Okajimas Folia Anatomica Japonica

キーワード

• Anatomy

詳細情報

• CRID: 1390282680438133120
• NII論文ID: 130004649827
• DOI: 10.2535/ofaj1936.40.4-6_625
• ISSN: 0030154X
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可