Etsuro Kawana

On the neuronal origin of the afferents to the ciliary ganglion in cat.

Abstract The histological constitution of the oculomotor nuclear complex and the surrounding structures of cat was re-examined, and it was found that the so-called Edinger-Westphal (EW) nucleus and the anteromedian nuclei consisted of oval cells of small sizes and polygonal cells of medium sizes. The latter cells were scattered in the peripheral portions of the EW and the anteromedian nuclei, and were frequently intermingled with cells of the same type scattered in the central gray and the medial portion of the ventral tegmental area (VTA). Horseradish peroxidase (HRP) was injected into the ciliary ganglion, in order to locate the cells of origin of afferents to this ganglion. The cells labeled by an injection into the ganglion were these polygonal cells of medium sizes scattered in the injected side of midbrain. They weremainly distributed in the VTA, the central gray, and the caudal half of the anteromedian nucleus. The peripheral portion of the EW and the anteromedian nuclei also contained some labeled cells, but these were considered to be cells which had migrated from the central gray and the VTA. Most of the cells in the EW and the anteromedian nuclei were labeled by the injection into the spinal cord. Hence, it was concludedthat the main sources of the afferents to the ciliary ganglion were polygonal cells of medium sizes scattered in the VTA and the central gray, and some of these intermingled with the cells of peripheral boundaries of the EW and the anteromedian nuclei. By contrast, the greater part of the EW and the anteromedian nuclei had a connection with the spinal cord, but not with ciliary ganglion.

A horseradish peroxidase study on the mammillothalamic tract in the rat

The mammillary projections to the anterior thalamic nuclei were investigated in the rat, using the horseradish peroxidase (HRP) method. Pars centralis of the medial mammillary nucleus projects to the medial portion of the ateromedial nucleus (AM). Pars medialis (Mm) of the medial mammillary nucleus sends fibers to the ipsilateral AM and sparsely to the medial portion of the contralateral side. The ventral and dorsal portions of Mm project to the anterior and posterior portions of AM, respectively. The pars latralis (Ml) and pars posterior (Mp) of the medial mammillary nucleus send fibers predominantly to the ipsilateral anteroventral nucleus and sparsely to the contralateral side. A slight difference between Ml and Mp projections was observed. The lateral mammillary nucleus projects bilaterally to the anterodorsal nucleus.

Selective retrograde transport of tritiated D-aspartate from the olfactory bulb to the anterior olfactory nucleus, pyriform cortex and nucleus of the lateral olfactory tract in the rat.

After an injection of [3H]D-aspartate into the olfactory bulb of the rat, retrogradely labeled cells were detected bilaterally in the anterior olfactory nucleus (AON), and ipsilaterally in the pyriform cortex (PC) and nucleus of the lateral olfactory tract (NLOT). These results suggest a certain selective retrograde transport of this amino acid, and are discussed in relation to transmitter candidates in the olfactory bulb.

The mesencephalic root fibers of the trigeminal nerve in the dog.

The trigeminal nerve has motor, intermediate and sensory roots in the dog. The motor root is composed of two bundles: the medial and ventral. The ventral motor root emerges from the pons, forming the common root with the sensory, and then is separated from it to run along with the medial motor root which separately exits from the pons as the ordinary motor root. The mesencephalic root fibers of the trigeminal nerve are investigated in the dog, using the myelin sheath degeneration technique. Degenerated fibers are observed numerously in the ventral motor root and moderately in the medial motor root, and are traced to the mandibular branch of the trigeminal nerve. Some degenerated fibers are observed in the sensory root and they seem to pass through the Gasserian ganglion to enter the ophthalmic and maxillary branches. No degenerated fibers are found in the intermediate root.

Mesencephalic root fibers of the trigeminal nerve in the cat

The trigeminal nerve has three motor roots and one sensory root in the cat. One of the motor roots can be divided into two bundles: the larger and the smaller. These motor roots form the common root with the sensory root at the exit from the pons, sometimes being separated partially by the subarachnoidal space between the medial and the ventral part of the common root. The mesencephalic root fibers are observed numerously in all the motor roots. Some degenerated fibers are observed in the sensory root. The transitional zone of the trigeminal nerve root between central and peripheral nervous system is occupied by interlocking processes of the fibrous astrocyte.