Naslov
Origin and tangential migration of cortical GABAergic neurons in primates during early fetal period

Autori
Hladnik, Ana ; Esclapez, Monique ; Petanjek, Zdravko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
6th Croatian Neuroscience Congress Book of Abstracts / - , 2017, 49-49

Skup
6th Croatian Neuroscience Congress

Mjesto i datum
Osijek, Hrvatska, 16.09.2017. - 18.09.2017

Vrsta sudjelovanja
Poster

Vrsta recenzije
Domaća recenzija

Ključne riječi
GAD65, GAD67, somatostatin, calretinin, medial telencephalic wall

Sažetak
Although the basic principles of cortical development are conserved across mammals, evolutionary increased complexity of cortical GABAergic network leads to significant variability in origin and migration of GABAergic neurons when primates are compared to rodents. GABAergic cortical network in primates is particularly distinguished by tremendous increase in the proportion of calretinin neurons which contribute to half of GABAergic neuron population and are two times more numerous than other two major subpopulations, parvalbumin and calbindin/somatostatin. Therefore, it could be expected that the evolution is changing developmental rules to enable substantial changes that appear inside primate GABAergic network. To establish place of origin and migratory routes of different GABAergic neuron subpopulations in primates, we examined postmortem human and monkey fetal brain tissue during early fetal period (8-12 postconceptional weeks in human and embryonic day 47-56 in cynomologus monkey) processed immunohistochemicaly for markers of GABAergic neurons (GAD65 and GAD67) as well as for molecular markers of three major subpopulations. Data confirmed that, as in all mammals described so far, the most important source of GABAergic neurons during the early fetal period is the ganglionic eminence. The vast majority of progenitors in the ganglionic eminence express GAD65 (but not GAD67). After leaving the ganglionic eminence tangentially migrating cells continue to express GAD65, emerge laterally on the cortico-striatal border and form main tangential migratory stream in the subventricular/intermediate zone of the lateral telencephalic wall. Intensive GAD67 expression is observed by progenitors in the proliferative zones in rostro- dorsal and ventro-caudal part of the medial telencephalic wall. These so far undescribed proliferative regions are a source of GABAergic neurons which accumulate in the basal telencephalon and continue to migrate through the marginal zone and the layer below the cortical plate (primordial subplate). Part of the GAD67+ migrating cells in this superficial stream originates also from the preoptic area and hypothalamic proliferative zone which are in continuation with GAD67+ proliferative zones of medial telencephalon. Data also showed that already during the early fetal period the majority of GABAergic cells that originate from the ganglionic eminence and migrate via deeper migratory stream express calretinin, while GAD67+ proliferative zones of the medial telencephalic wall are the main source of somatostatin cells that migrate via the superficial stream. Our results suggest that primate specific features of GABAergic neuronal development are present already during the early fetal period. Two main subpopulations of GABAergic cortical neurons, somatostatin and calretinin, have clearly distinguishable origin and migratory routes, and significant production of calretinin subpopulation occurs earlier than in rodents. In addition to their dorsal production later on, this significant early production also accounts for tremendous increase in the proportion of calretinin neurons in primates.

Izvorni jezik
Engleski

Znanstvena područja
Temeljne medicinske znanosti

POVEZANOST RADA