The center of gravity in the supine position was located around the llth-12th thoratic vertebral area slightly on the right side in the newborn period, and moved to the caudal direction as the chronological age increases. The center of gravity in the upright position was located on the right side at one year of age, on the midline around 5 years, and on the left side thereafter. Stability of the center of gravity in the upright position rapidly increased until 5 years and afterward it increased slowly. An analysis with a pedoscope showed that the walking pattern of children developed to that of adults around 5 years of age. During walking with eyes closed on the pedoscope, we noticed that the right handed child deviated to the right side and the left handed child to the left. This deviation was not related to the center of gravity in the supine position. In early childhood between one and 3 years, the supporting foot was on the right side which was the same as preference of the foot. For performing daily activities smoothly such as walking and running, a supporting point is always required which bears the body weight during performance. And then, the supporting foot changed from the right to the left as the child with right-handedness grew older. As the result, preferenceof the foot develops on the opposite side of the supporting foot. Functionally, the right foot is different from the left ; the left foot bears the body weight, and the right foot regulates movements, such as walking, in determination of the direction.

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Many chemical agents cause major anomalies in the central nervous system (CNS) after exposure to high doses during gestation. At lower doses, chemical agents may have a detrimental effect on the behavior affecting CNS development at the histological level. Various types of congenital malformations were induced in the pregnant mouse by the administration of chlorambucil (CA). The administration of CA before neural tube closure caused a high incidence of exencephaly. These malformed fetuses were examined for the evaluation of the pathogenesis of open neural tube defects by light and electron microscopic studies. It was found that the neural tube defects were induced by interaction between the death of some neural epithelial cells caused by the primary effect of CA and the response of the surviving cells of the neural tissue. Open areas of neural tube defects were divided into seven morphologicai patterns on the basis of extent and region in the prosencephalon, mesencephalon and rhombencephalon. It is suggested that a fetus with the wide open area in the mesencephalic region will become the exencephalic newborn in future.
The administration of low dose of CA after neural tube closure caused a reduction in body and brain weights. These small brain newborns were examined with regard to postnatal development by morphological and behavioral studies. It was found that they had a tendency to decrease active avoidance responses. In an open-field situation, one group (pups from mothers treated with CA 4 mg/kg at llth day of gestation) showed high emotionality and slight hyperactivity. This process offers a new experimental system which ex. plores the link between morphology and behavioral teratology. Accordingly the relation may be defined in terms of the degree 0f histological abnormality and severity of behavioral pathology in experimental animals or in man.
Finally, a congenital brain malformation induced by oncogene (c-Ha-ras) in transgenic mouse is described, and an approach to future development of the experimental field was discussed.

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Effects of early undernutrition and subsequent rehabilitation on brain growth and development were investigated in mice. In M_1-20 group (mice nursed in litters of 18 from day 1 to 20) the body and brain weight gains were insufficient. In M1-10 also the brain weight was not completely restored. Although in M_1-5 the brain weight in adulthood was almost the same as in controls, that in M_8-12 was less than in M_1-10. In addition, insufficient dendritic development of cortical neurons and disturbed serotonin system were seen in severely malnourished animals.

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A damage to the CNS of neonatal animals often has less severe consequences than a similar damage occurring in adult animals. This difference is often ascribed to collateral sprouting, because collateral sprouting caused by brain lesion is more prominent in immature animals than in adults. Unilateral lesions of the sensorimotor cortex (SMC) of the kitten, for example, cause aberrant crossed cortico-rubral (CR) projection, which is absent in adults. The present study was performed to explore the possibility that the crossed projection is caused by the arrested retraction of exuberant projection. Plant lectin, Phaseolus vulgaris -leucoagglutinin was injected iontophoretically into SMC of the kitten about 20-40 days after birth and CR fibers were stained immunocytochemically. One to two weeks after injection, abundunt CR fibers with numerous varicosities were observed in the ipsilateral red nucleus (RN). CR fibers were also found in the contralateral RN, although the number was much less. By contrast, many labelled fibers were seen in the contralateral RN of the kitten whose SMC had been ablated 20-40 days after birth. The CR fibers seemed to have more prominent branching in the contralateral RN of the lesioned animals than in the control ones. Furthermore, there were more labelled fibers crossing the midline in lesioned animals than normal ones. The aberrant crossed CR projection may thus resulted from increase of crossed corticorubral projections which were rarely seen in intact kittens.

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Myelin-specific glycoprotein was identified and isolated by using one of lectins, called peanut agglutinin. This myelin-specific glycoprotein showed developmental shift in its expression. It was expressed on the ependymal cells in the fetal brain, disappeared just before the initiation of myelination, and again expressed on myelin structures in the matured brain. Oligodendroglia isolated from rat brain also expressed this glycoprotein. Thus, this glycoprotein is possibly a differentiation marker associated with the process of myelin formation. This glycoprotein showed molecular weights of 130, 000 and 110, 000, and had highly agglutinating nature, which isthe common molecular nature of various adhesive proteins in nervous tissue, such as neural cell adhesive molecule and myelin-associated glycoprotein. These adhesive molecules are considered to be important in the molecular events, such as intercellular interactions and the construction of nervous tissue. Two proteins were found to bind with this glycoprotein in the brain by affinity chromatography. The presence of the specific binding protein suggests that this adhesive myelin-specific glycoprotein is a molecular signal on the surface of myelin membrane.
This myelin glycoprotein was also detected on human cell lines which are derived from T cell leukemia as well as thymocytes. Considering the fact that many other molecules are commonly expressed both in nervous tissue and cells of lymphocyte lineage, these two tissues may be using quite similar set of surface molecules as signals for their histogenesis or functions.

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Krabbe's globoid cell leukodystrophy is characterized by severe demyelination. The cause of this demyelination is obscure. We attempted to study biological effects of psychosine on mouse dorsal root ganglion cells or dissociated brain cell cultures. The results suggested that psychosine effects on the mitochondrial membrane which result in cell dysfunction, possibly leading to demyelination.
The treatment of Krabbe's globoid cell leukodystrophy was explored in twitcher mice by liposomes. Charonia lumpas beta- galactosidase was able to hydrolyze galactocerebroside. Liposomes containing charonia lumpas beta-galactosidase were successfully incorporated into the mouse tissues and could be degraded the accumulated 3H- galactocerebroside in twitcher tissues. Liposomes containing aminophenyl-alpha- mannoside were successfully incorporated into brain, possibly crossing blood brain barrier. The radioactivity from liposomes was recovered in lysosome rich fraction of glial cells, suggesting that this type of liposome could predominantly incorporated into glial cells.

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We used cerebral function monitor (CFM) to know continuously the cerebral function of neonates in the intensive care unit, and studied its usefulness for the early detection of perinatal brain damage.
CFM showed the patterns of active and quiet sleeps and the developmental changes. In term asphyxiated and preterm neonates, the abnormal CFM patterns were judged by comparing with normal ones. The cases with continuously low amplitude, monotonous, high voltage burst, periodic low amplitude, flat or suppression burst patterns showed neurological handicaps such as mental retardation, cerebral palsy, or resulted in death.
CFM is useful to monitor the changing cerebral function of neonates in the intensive care unit.

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