Expression of tenascin C in the subplate zone of human telencephalon during prenatal development

Tenascin C (TNC) jedan je od glikoproteina međustanične tvari (ECM) mozga koji se javlja rano u razvoju središnjeg živčanog sustava. Spoznaja o razvojnom izraţaju TNC u fetalnom mozgu čovjeka gotovo da i nema. Rad obuhvaća 11 postmortalnih humanih telencefalona (čeoni režanj), dobi od 12-40 tjedana gestacije (TG), koji su analizirani imunohistokemijski na TNC, u cilju određivanja raspodjele izražaja TNC, a pomoću Image određivanja intenziteta izražaja TNC u sloju pod pločom. Međustanična imunoreaktivnost TNC je rasprostranjena u uskom sloju duboke subplate zone od 16 TG, proširujući se na veću površinu duboke subplate zone u 18-20 TG. Vrhunac izražaja TNC u 22/23 TG je ograničen na uski sloj srednjeg dijela subplate zone. Nakon 28 TG, imunoreaktivnost TNC u subplate zoni nije prepoznatljiva. Obrat izražaja TNC iz duboke u površnu subplate zonu s napredovanjem gestacije ukazuje na njegovu ulogu u rastu neurita, njihovoj polarizaciji i regionalnom navođenju prema formiranju sinapsi s glavnim kortikalnim krugovima. Prema ovome, poremećaj izražaja TNC tijekom razvoja može biti značajan za poremećaje vezane s oblikovanjem kortikalnih veza.Tenascin C (TNC) is one of the brain extracellular matrix (ECM) glycoproteins, which appears early in central nervous system development. Knowledge about TNC expression pattern in the fetal human brain development is still scanty. The study encompass 11 post mortal human telencephalons (frontal lobe) aged from 12 post conception weeks (PCW) to 40 PCW, which were analyzed immunohistochemically for TNC expression and by ImageJ for the intensity of TNC expression in the subplate zone. Extracellular immunoreactivity of TNC is distributed throughout the subplate zone from 16 PCW, in very narrow layer in the deep subplate zone and becoming wider in 18/20 PCW. The peak of TNC expression at 22/23 PCW, was confined to narrow layer in the superficial portion of the subplate zone. After 28 PCW, TNC immunoreactivity in subplate zone was not detectable. The shift of TNC expression from the deep to the superficial subplate zone with advancing gestational age suggests its role in the growth of neurits, polarization and their regional address selection on the pathway to the synaptic target cell in formation of major cortical connections. Thus, disturbance of TNC developmental expression could be relevant for disorders in genesis of cortical connections