Human brain material is part of the Zagreb Neuroembryological Collection (Kostovic et al. 1991 (link)), obtained during regular autopsies after spontaneous or medically indicated abortions at clinical hospitals affiliated with the University of Zagreb, School of Medicine. All specimens were without macroscopic or microscopic central nervous system pathology. A sampling of the tissue was performed following the Declaration of Helsinki (2000) and approved by the Internal Review Board of the Ethical Committee of the School of Medicine, University of Zagreb. After extraction during the autopsy, postmortem human brains were immersion-fixed in 4% paraformaldehyde (PFA) in 0.1 M phosphate-buffered saline (PBS; pH = 7.4). The fetal age was determined based on the pregnancy records and crown-rump length (CRL) in millimeters and expressed in PCWs, instead of gestational weeks (GW). Following fixation, tissue blocks were embedded in paraffin and sectioned in a coronal or semi-horizontal plane on a microtome (Leica, SM2000R, Wetzlar, Germany) at 10 to 20 µm thick sections. In total, seven brain specimens were systematically processed and analyzed in the period from 7.5 to 15 PCW (CRL 28–120 mm). From these seven, three human fetal brain specimens aged 8, 13 and 15 PCW were serially sectioned from the frontal to the occipital pole to follow the anatomy of the whole cingulate gyrus and then processed by immunohistochemistry. The prospective cingulate cortex is located between the folded archicortical dorsal hippocampus ventrally and the isocortex (neocortex) dorsally (Kostović and Krmpotić 1976 ) and we analyzed the medial interhemispheric cortex.
Free full text: Click here
