Wyniki wyszukiwania - Biblioteka Nauki

1

Evolutionary ancient roles of serotonin: long-lasting regulation of activity and development

100%

Turlejski K.

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1996

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tom 56

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nr 2

619-636

EN

Biogenic monoamines (catecholamines, indoleamines and histamine) are evolutionary old and important modulators of long-lasting changes in the functional state of cells.They are found in many protozoans and in almost all metazoans.Monoamines preserve their evolutionary old functions (first of all being intracellular signals and later hormones and growth factors) even in those animals in which they acquired the function of neurotrasmitter.The older functions of serotonin, an important member of the family of indoleamines, are reviewed here.Described are: presence of serotonin on organisms at various phylogenetic levels; its role in embryonal, foetal and postnatal nervous system.It is concluded that in none of these functions serotonin is the only factor, but it is an ubiquitous and important modulator of a vast array of processes and functions taking part in development and plasticity.

2

Acoustic startle response in the opossum Monodelphis domestica in comparison with the wistar albino rat

63%

Blaszczyk J. W. , Turlejski K.

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nr 2

201-204

EN

The acoustic startle response (ASR) was studied in 20 gray short-tailed opossums (Monodelphis domestica) and its characteristics were compared with those obtained from responses of 20 Wistar albino rats. The animals were exposed to 10 ms, 110 dB white noise acoustic pulses in the Coulbourn apparatus. Amplitude of ASR was normalized to the weight of animals and then analyzed. The results show that probability of a freezing response is much higher in the opossums that generally respond with lower startle amplitudes in comparison to rats. These differences may reflect different emotional characteristics of the two species, different reactions to fear in opossum and/or different ecological specializations of the two species.

3

Reduction of the number of new cells reaching olfactory bulbs impairs olfactory perception in the adult opossum

51%

Grabiec M. , Turlejski K. , Djavadian R.

Acta Neurobiologiae Experimentalis

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2009

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tom 69

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nr 2

168-176

EN

In adult mammals cells generated in the subventricular zone (SVZ) migrate to olfactory bulbs (OB). Functional significance of this continuous neurogenesis is not clear. We injected opossums (Monodelphis domestica) for seven consecutive days with a 5HT1A agonist (8-OH-DPAT or buspirone), or its antagonist WAY100635. One hour after each of these injections bromodeoxyuridine (BrdU), a marker of dividing cells was also injected. Two months later, when newly generated neurons settled in the OB and matured the ability of these opossums to detect hidden food by olfactory cues was tested. Afterwards, numbers of BrdU-labeled cell nuclei in their OB were counted and a phenotype of labeled cells established. In all groups investigated the majority of new cells differentiated into neurons (55-76%) and a lower proportion into astroglia (6-12%). Numbers of BrdU-labeled cells differed depending on the applied treatment: both agonists of the 5HT1A receptor increased these numbers, while its antagonist decreased them. The increased number of new OB interneurons did not change the time required for finding all three food items and therefore did not improve the opossums' performance in this test of the olfactory perception. However, opossums that had the reduced number of new generated OB cells searched longer for each food item and in consequence took three times longer to find all three crickets, than did opossums from other groups. In conclusion, lower numbers of new neurons in the opossums OB correlated with their worse behavioral performance in a test based on olfactory perception.

4

Development and plasticity of the retina in the opossum Monodelphis domestica

45%

Djavadian R. , Bisti S. , Maccarone R. , Bartkowska K. , Turlejski K.

Acta Neurobiologiae Experimentalis

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2006

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tom 66

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nr 3

178-188

EN

We investigated the rate of cell proliferation and death in the retina of the Monodelphis opossum during its postnatal development and the influence of early monocular enucleation on these processes. Our results show that in the opossum, as in other marsupials, the peak of the retinal cells divisions occurs postnatally and that generation of retinal cells continues till the time of eye opening (P34), except of the marginal rim, where it continued till P60. Ganglion and amacrine cells are generated between postnatal days (P) P4 and P9, while bipolar cells and photoreceptors are generated simultaneously between P14 and P25. The peak of ganglion cell death as detected by the TUNEL method occurs around P14?19 in the center of retina. The second peak of apoptosis appears in the inner nuclear layer (INL) at P19?25. Gliogenesis takes place between P25 and P34. We also found that monocular enucleation performed during the early period of retinal development (P0?P7) did not influence proliferation, developmental apoptosis or other developmental processes in the retina of the remaining eye.

5

Distribution of the parvalbumin, calbindin-D28K and calretinin immunoreactivity in globus pallidus of the Brazilian short-tailed opossum (Monodelphis domestica)

38%

Domaradzka-Pytel B. , Majak K. , Spodnik J. , Olkowicz S. , Turlejski K. , Djavadian R. L. , Morys J.

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2007

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tom 67

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nr 4

421-438

EN

This study describes the topography, borders and divisions of the globus pallidus in the Brazilian short-tailed opossum (Monodelphis domestica) and distribution of the three calcium binding proteins, parvalbumin (PV), calbindin D-28k (CB) and calretinin (CR) in that nucleus. The globus pallidus of the opossum consists of medial and lateral parts that are visible with Nissl or Timm's staining and also in PV and CR immunostained sections. Neurons of the globus pallidus expressing these proteins were classified into three types on the basis of size and shape of their soma and dendritic tree. Type 1 neurons had medium-sized fusiform soma with dendrites sprouting from the opposite poles. Neurons of the type 2 had medium-to-large, multipolar soma with scarce, thin dendrites. Cell bodies of type 3 neurons were small and either ovoid or round. Immunostaining showed that the most numerous were neurons expressing PV that belonged to all three types. Density of the PV-immunopositive fibers and puncta correlated with the density of the PV-labeled neurons. Labeling for CB resulted mainly in the light staining of neuropil in both parts of the nucleus, while the CB-expressing cells (mainly of the type 2) were scarce and placed only along the border of the globus pallidus and putamen. Staining for calretinin resulted in labeling almost exclusively the immunoreactive puncta and fibers that were distributed with medium-to-high density throughout the nucleus. Close to the border of globus pallidus with the putamen these fibers (probably dendrites) were long, thin and varicous, while more medially bundles of thick, short and smooth fibers predominated. Single CR-ir neurons (all of the type 3) were scattered through the globus pallidus. Colocalization of two calcium binding proteins in one neuron was. never observed. The CB-ir puncta (probably terminals of axons projecting to the nucleus) frequently formed basket-like structures around the PV-ir neurons. Therefore, the globus pallidus in the opossum, much as that in the rat, consists of a heterogeneous population of neurons, probably playing diversified functions.