Subplate Zone of the Human Brain: Historical Perspective and New Concepts

Subplate zone (SP) is prominent, transient laminar compartment of the human fetal cerebral wall. The SP develops around 13 and gradually disappears after 32–34 postovulatory weeks. The SP neurons can be found as late as nine postnatal months, while remnants of the SP neurons can be traced until adult age in the form of interstitial neurons of the gyral white matter. SP is composed of postmigratory and migratory neurons, growth cones, loosely arranged axons, dendrites, glial cell and synapses. The remarkable feature of the SP is the presence of large amount of extracellular matrix. This feature can be used for delineation of SP in magnetic resonance images (MRI) of both, in vivo and post mortem brains. The importance of SP as the main synaptic zone of the human fetal cortex is based on the rich input of »waiting« afferents from thalamus and cortex, during the crucial phase of cortical target area selection. SP increases during mammalian evolution and culminates in human brain concomitantly with increase in number and diversity of cortico-cortical fibers. The recent neurobiological evidence shows that SP is important site of spontaneous endogeneous activity, building a framework for development of cortical columnar organization. The SP, which can be readily visualized on conventional and DTI (diffusion-tensor-imaging) MRI in vivo, today is in the focus of interest of pediatric neurology due to the following facts: (1) SP is the site of early neural activity, (2) SP is the major substrate for functional plasticity, and (3) selective vulnerability of SP may lead to cognitive impairment

Citogenetička istraživanja pet populacija vrste Muscari comosum (L.) Mill. (Alliaceae) s područja Dalmacije

The Mediterranean populations of the species Muscari comosum (L.) Mill. are well investigated, and results of these investigations have shown that it is most frequently diploid with 2n=18, and rarely 2n=19, 19+1B, 27 or 36. A literature search showed that the populations from Dalmatia mentioned have not been karyologically explored. In this work we present cytogenetic investigations of the species Muscari comosum (L.) Mill. collected from five localities in central Dalmatia.Mediteranske populacije vrste Muscari comosum (L.) Mill. vrlo dobro su istražene. Rezultati njihovih istraživanja pokazuju da su većinom diploidi s 2n=18, a rjeđe 2n=19, 19+1B, 27 ili 36. Pregledom literaturnih podataka ustanovljeno je da navedena vrsta s područja Dalmacije nije kariološki analizirana. U ovom radu navedeni su rezultati citogenetičkih analiza biljaka vrste Muscari comosum (L.) Mill. sakupljenih na pet lokaliteta središnje Dalmacije

Cytogenetical investigations of Croatian stenoendemic species Fibigia triquetra (Brassicaceae)

This paper concerns the cytogenetic investigation of the Croatian endemic species Fibigia triquetra (DC.) Boiss. (Brassicaceae). The number of chromosomes in all investigated cells from three populations of Fibigia triquetra was 2n=2x=!6. Chromosomes were small and ranged from submetacentrics to acrocentrics. One chromosome pair had a relatively small satellite. Although meiosis was not completely regular, irregularities were not very frequent. Low pollen germination rate was probably due to these irregularities. As the species is perennial, weakness of seed germination seems not to be important for its survival

Primate-Specific Origins and Migration of Cortical GABAergic Neurons

Gamma-aminobutyric-acidergic (GABAergic) cells form a very heterogeneous population of neurons that play a crucial role in the coordination and integration of cortical functions. Their number and diversity increase through mammalian brain evolution. Does evolution use the same or different developmental rules to provide the increased population of cortical GABAergic neurons? In rodents, these neurons are not generated in the pallial proliferative zones as glutamatergic principal neurons. They are produced almost exclusively by the subpallial proliferative zones, the ganglionic eminence (GE) and migrate tangentially to reach their target cortical layers. The GE is organized in molecularly different subdomains that produce different subpopulations of cortical GABAergic neurons. In humans and non-human primates, in addition to the GE, cortical GABAergic neurons are also abundantly generated by the proliferative zones of the dorsal telencephalon. Neurogenesis in ventral and dorsal telencephalon occurs with distinct temporal profiles. These dorsal and ventral lineages give rise to different populations of GABAergic neurons. Early-generated GABAergic neurons originate from the GE and mostly migrate to the marginal zone and the subplate. Later-generated GABAergic neurons, originating from both proliferative sites, populate the cortical plate. Interestingly, the pool of GABAergic progenitors in dorsal telencephalon produces mainly calretinin neurons, a population known to be significantly increased and to display specific features in primates. We conclude that the development of cortical GABAergic neurons have exclusive features in primates that need to be considered in order to understand pathological mechanisms leading to some neurological and psychiatric diseases

The Role of Croatia in the Management of the Humanitarian Crisis in Bosnia and Herzegovina

Croatia played a crucial role in the management and termination of the humanitarian crisis caused by the aggression of the Yugoslav Army and Serbian paramilitary forces in Bosnia and Herzegovina. Between 1992 and 1995, Croatia accepted three waves of refugees and cared for more than 500,000 refugees from B&H; it thus secured the basic precondition for the survival of B&H as a state. Croatia invested more than 1,000,000.000 U.S. dollars from its State budget just for the care of refugees from B&H. Even today about 130,000 Bosnian refugees are still accomodated in Croatia, for most are still unable to return to their homes. The European Community and the UN were unable to protect the lives of civilians or to prevent grave breaches of international humanitarian law. At the some time, the Croatian military operation "Storm" in 1995 saved the lives of thousands of civilians in the Bihać area. A careful analysis of the Croatian contribution to the achievement of the Dayton agreements and the resolution of the humanitarian crisis in B&H clearly reveals that the positive role of Croatia has been seriously underestimated and down-played by the international community