CHANGES IN BLOOD FLOW IN THE COMPONENT STRUCTURES OF THE DOG BRAIN DURING POSTNATAL MATURATION

Abstract— Blood flow was measured quantitatively in 35 structures of the brains of dogs of various ages from birth to maturity. In general, values were low at birth and rose to maximal levels between 3 and 7 weeks of postnatal age; declines from the peak levels then followed until values characteristic of maturity were attained by 13 weeks of postnatal age. From relatively uniform perfusion rates throughout the brain at birth there gradually emerged a marked heterogeneity, in parallel with the structural and functional maturation and differentiation known to occur in the brain during this period of life. Our observations may reflect the summation of the changes in energy demands associated on the one hand with biosynthetic processes essential for growth and development and with the support for progressively increasing functional activities on the other.