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The Zagreb Collection of developing and adult human brains consists of approximately 1,300 brains of fetuses, children and adults that were collected following routine autopsies in the period from 1974 to 2014. The collection comprises brains of different normal developmental stages that may serve for investigation of normal human brain development. Previous studies on this material have led to several important contributions on human cortical development, such as the discovery of the transient fetal subplate zone. The Zagreb Collection, however, also contains approximately 100 brains with different anomalies including chromosomal aberrations such as Down syndrome. We have analyzed all the available material from the Zagreb Collection and identified 44 brains of fetuses and children with Down syndrome, 10 with Patau syndrome, 6 with Edwards syndrome as well as 7 holoprosencephalic, 7 hydrocephalic and 4 microcephalic brains. The largest part of the Collection is available for further research using modern genetic, immunocytochemical and imaging methods, especially magnetic resonance imaging. Furthermore, the histological slides from the Zagreb Collection are currently being digitally scanned and made available as virtual slides to general scientific audience. The Zagreb Collection represents unique and versatile resource for the future study of normal and abnormal human brain development.

We quantitatively analyzed the dendritic and dendritic spine development on basal and oblique dendrites of large layer IIIc pyramidal neurons of the prospective prefrontal area 9 in the brains of three infants with Down syndrome (DS) and five age-matched-controls over the period from 32 weeks postconception to the 7th postnatal month. By using Neurolucida 3.1 software on rapid Golgi impregnated slices, 9–10 neurons were three-dimensionally reconstructed. There were no significant differences in the pattern of the dendritic and spine development between the basal and apical oblique dendrites. The DS subjects did not depart significantly from the developmental curve of the control subjects. Our data showed that large and significant segment outgrowth, in parallel with dendritic elongation occurred during a limited period of time, between 36 weeks postconception and the first postnatal month. Dendritic spines appeared at the time of birth and their density continued to increase up to the age of 7 months. During the first postnatal month long thin spines and filopodia-like protrusions predominated, but the spines later changed their morphology to a more mature form. No differences in the spine morphology were qualitatively observed between the DS infants and the age matched controls. This data suggests that intensive formation of cortical circuitry occurs on large layer IIIc pyramidal neurons during perinatal period and is not disturbed in DS infants. Consequently, this could be a biological potential to mitigate psychomotor impairment in DS patient.

We compared weekly quizzes in extended-matching format with multiple-choice questions and oral examinations as means of monitoring students' progress in gross anatomy. Students' performance on 19 weekly oral examinations or 10-question quizzes based on extended-matching or multiple-choice formats were correlated with their success on 3 interim examinations and the final comprehensive examination. The Kuder-Richardson formula 20, an estimate of precision of the test, was 0.64 for extended-matching quizzes. Students' performance on interim examinations did not differ significantly. There was a significant correlation between students' mean scores on weekly quizzes and mean scores on interim examinations in both the extended-matching (r = 0.516) and multiple-choice group (r = 0.823). The mean grades (ranging from 2 to 5) on the final exam, based on understanding of anatomical concepts and their application in clinical practice, were significantly higher in extended-matching group (4.8) than in the multiple-choice (4.1) and orally examined groups (3.9) (p < 0.05). We conclude that extended-matching quizzes were at least as effective as multiple-choice quizzes and oral examinations and may be better for acquiring synthetic understanding of anatomical concepts especially in combination with other means of knowledge assessment. We recommend them as a reliable and objective means of monitoring students' performance during a gross anatomy course.