DENDRITIC ARBORIZATION IN THE HUMAN FETUS AND INFANT WITH THE TRISOMY-18-SYNDROME

Dendritic arborization patterns of visual cortical neurons in four cases of trisomy 18 syndrome were compared with those in 8 neurologically asymptomatic age-matched controls. The trisomy cases included a 20-week-old fetus, a term infant, a 3-month-old infant, and 6-month-old infant. Quantitative Golgi analysis showed a decrease in the mean total dendritic length of apical dendrites in layer 5 pyramidal neurons in the term infant with trisomy 18. In layer 3, an attenuated dendritic tree was observed in the earlier age groups with increased dendritic extent at 6 months. Although not conclusive, due to the small number of subjects, this preliminary study showed definitive dendritic abnormalities in the trisomy 18 syndrome. © 1990.