ABSTRACT
An intercostal nerve-spinal cord implantation and semitransection of the spinalcord at the point between the origin and insertion of the intercostal nerve was madeon ten adult dogs and two monkeys.One to two weeks after this operation,paraly-tic legs following semitransection of the spinal cord recoverded from the paralysis.The implanted nerves were cut during the different period from 124 to 366 days.The function of the legs of four animals which had recovered paralysed again aftersurgical section of implanted nerve.Histologically,the inserted nerves in the spinalcord were recognized in these animals.Many of the growing fibers extended fromdistal end of the inserted intercostal nerve into the gray and white matter ofthe distal segment of the spinal cord.It is considered that the efficacy of the inter-costal nerve-spinal cord implantation depends upon the choice of the symptomaticindications and the success of the implantation procedure.
ABSTRACT
Twenty eight rabbits were divided into two groups with exception of three used as control. The right monocular enucleation was performed at five and twenty days postnatal respectively in the two experimental groups. The animals were sacrificed at intervals that ranged from 1 to 150 days.The qualitative and quantitative observations showed that the cell changes in the dorsal lateral geniculate nucleus following enucleation were different in the 2 groups, In the first group, the developing cells in the dorsal lateral geniculate nucleus arrested growth immediately following enucleation, but the affected cells continued to differentiate for 1～10 days postoperatively. Subsequently, there were no marked further cell changes until 150 days after enucleation. In the second, the mature neurons in the dorsal lateral geniculate nucleus atrophied rapidly to the maximization during 5～7 days postoperatively. There was no any cell loss to be found in either group. The average decrease in perikaryon size was 30～40％, in nucleus size was 25～30％, and in nucleolus size was 20～25％.The cell changes in the lateral part of the contralateral dorsal lateral geniculate nucleus were compared to the medial part of the ipsilateral dorsal lateral geniculate nucleus after monocular removal. While the cells in the lateral part of the ipsilateral dorsal lateral geniculate nucleus were normal just as in the medial part of the contralateral dorsal lateral geniculate nucleus.The neurons in the ventral lateral geniculate nucleus had no changes to be found in every case.
ABSTRACT
Divergent axon collaterals from forebrain and brainstem to the dorsal hippocampus in the rat were examined by means of HRP method and fluorescent retrograde double labeling method.HRP solution was injected into the left or right dorsal htppocampus of 3 rats. HRP labeled cells were observed in the bilateral medial parts of medial septal areas, vertical limbs of the diagonal band of Broca, supramammillary nuclei, submammillothalamic nuclei, superior central nucleus and locus ceruleus.PI and Bb solution were injected into the left and right hippocampus of 3 rats separately. Many retrograde double labeled cells were found in the nuclei mentioned above.The results indicate that the retrograde double labeled ceils in these nuclei may divergently projected to both the left and right dorsal hippocampi. They play an important role in harmonizing the activity of bilateral hippocampi.
ABSTRACT
The postnatal development of the efferent projections to the lumbosacral spinal cord from the brain stem of rats were studied with HRP retrograde transport method. Fifty per cent solution of HRP was slowly injected into the intumescentia lumbalis on its right side in 18 albino rats from postnatal 1-35 days. The HRP labelled cells were found in the following nuclei:1. Of the midbrain: the nucleus ruber, substantia nigra and nucleus raphe dorsalis.2. Of the pons: the nucleus reticularis pontis oralis, nucleus reticularis pontis caudalis, locus coeruleus, nucleus subcoeruleus, nucleus raphe magnus, nucleus vestibularis lateralis, and nucleus vestibularis medialis.3. Of the medulla oblongata: the nucleus raphe obscurus, nucleus raphe pallidus, nucleus reticularis ventralis, nucleus reticularis gigantocellularis, nucleus reticularis lateralis, nucleus tractus spinalis nervi trigemini, nucleus commissuralis (Cajal), nucleus prepositus hypoglossi, and nucleus gracilis.The number of the labelled cells in the above nuclei increased steadily with age. The results of present study showed that there was a postnatal developmental process in the efferent projections from the brain stem to the lumbosacral cord. The maturity of the projections from ruber nucleus and locus coeruleus were later than those of the vestibulospinal and reticulospinal tracts. The postnatal developmental process of the brain stem projections to the lumbosacral spinal cord were completed by one month after birth.