A better understanding of the developing neonatal respiratory system has resulted in a better management of the premature infant respiratory problems. Unfortunately, a similar statement cannot be made about the management of neonatal intracerebral damage, or of its devastating clinical sequelae. An obvious reason for this discrepancy lies in the fact that our understanding of the neonatal brain structure and vasculature is inadequate, and in some areas (vulnerability of matrix capillaries) lacking. We all are painfully aware that the number of children with "Minimal Brain Damage: is increasing, as more and more premature infants survive because of improvements in the management of their respiratory problems. The aims of this research are; a. study the structural organization of the developing (normal and abnormal) cerebellar and cerebral cortices and their vasculature, b, acquire a better understanding of the neonatal brain, c. utilize that knowledge to improve the management of neonatal intracerebral damage. The investigative tools are; the Golgi method, computer enhance neuronal morphometry, electron microscopy, and immunohistochemistry. The proposed studies are; A. Neurogenesis of Golgi cells of the developing neonatal cerebellum. B. Structural organization of marginal heterotopias of the cerebral cortex. Cortical heterotopias have been described in epilepsy, dyslexia, cerebral palsy, and mental retardation, however their structure remains poorly understood. C. Study cerebral cortex (frontal, motor, Broca's auditory and visual areas) Down's syndrome. D. Study neonatal development and distribution of short circuit cortical neurons. E. Continuation 'maps' reconstructions neonatal brain at various ages to be used as reference data. F. Continuation of neonatal brains collection for future studies. G. Preliminary light and EM immunohistochemical experimental studies of the embryonic vascularization of the cerebral cortex of 11-12 day old mouse embryos.