Wyniki wyszukiwania

1

Molecular mechanisms of organizational plasticity in the sensory neocortex of mammals

100%

Arckens L.

Acta Neurobiologiae Experimentalis

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2007

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tom 67

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nr 3

2

BDNF expression in cat striate cortex is regulated by binocular pattern deprivation

51%

Laskowska-Macios K., Arckens L., Kossut M., Burnat K.

Acta Neurobiologiae Experimentalis

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2017

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tom 77

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nr 3

Deprivation of patterned visual information, as in early onset congenital cataract patients, results in a severe impairment in global motion perception. Previously we reported a delayed maturation of the peripheral visual field representation in primary visual area 17, based on a 2‑D DIGE screen for protein expression changes and in situ hybridization for the activity reporter gene ZIF268. To corroborate these findings we here explore the binocular pattern deprivation (BD)‑regulated expression of brain‑derived neurotrophic factor (BDNF), a well‑described neurotrophin precipitously regulated by early visual experience. To assess the timing of maturation‑related BDNF expression we compared the central and the peripheral visual field representations of area 17 of 1, 2, 4 and 6‑month‑old and adult cats reared under normal visual conditions. To scrutinize the outcome of BD, four different deprivation strategies were compared, including early onset BD from birth and lasting for 2, 4 or 6 months (2BD, 4BD, 6BD), and late onset BD for 2 months upon 2 months of normal vision (2N2BD), as animal models of congenital and delayed onset cataract. During normal cortical development the BDNF transcript levels, measured by quantitative RT‑PCR, remained stable. Higher BDNF mRNA levels were found in central area 17 of 2BD and 6BD animals compared to age‑matched controls. In central area 17, the high BDNF mRNA levels at the end of the BD period may activate a mechanism by which plastic processes, halted by deprivation, may begin. We here confirm that the peripheral visual field representation of area 17 matures slower than its central counterpart. Only in central area 17 normal visual input upon BD could upregulate BDNF mRNA which may lead to a fast activation of local plastic adaptations.

3

Binocular deprivation alters the stratification pattern and the morphology of the axons of large ganglion cells in cat retina

51%

Burnat K., Waleszczyk W. J., Van der Gucht E., Arckens L.

Acta Neurobiologiae Experimentalis

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2005

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tom 65

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nr 3

4

Qualitative and quantitative analysis of NMDA receptor subunit distribution in adult cat visual area 17

51%

Theuwissen T., Yermeulen N., Van der Gucht E., Arckens L.

Acta Neurobiologiae Experimentalis

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2005

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tom 65

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nr 5

5

Evidence for cross-modal plasticity in adult mouse visual system

51%

Van Brussel L., Gerits A., Arckens L.

Acta Neurobiologiae Experimentalis

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2009

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tom 69

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nr 3

Since the pioneering work of Hubel and Wiesel in the ’60, research in cat, monkey and humans has led to a central dogma that beyond the critical period the brain only retains a reduced capacity for reorganization. Current work in rodents however challenges this view since specifi c treatments are capable of reinstating cortical plasticity in the adult. The goal of our work was to study this adult cortical reorganization in detail. A combination of deprivation of one eye and stimulation of the remaining eye previously led to the identifi cation of input-specifi c subdivisions (Van Brussel et al. 2009). Using this information as a reference map, we established to what extent each of these functional subdivisions take part in cortical reorganization upon enucleation. Briefl y, there seemed to be two waves of recovery, the fi rst characterized by the expansion of the supragranular binocular zone of V1 and V2L and the second affecting the infragranular layers, initiated at the outer border of the visual cortex with neighboring non-visual cortex and accompanied by hyper-activity of this adjacent cortex. To test a possible non-visual nature of this recovery, we combined monocular enucleation with the inactivation of the remaining eye or a second sensory modality. Both lack of complete visual cortex deactivation upon enucleation of the remaining eye, and strong effects of auditory and somatosensory deprivation on infragranular visual cortex suggest cross-modal plasticity in adult mice.

6

Monocular enucleation induces prominent thymosin beta4 expression in microglia and neurons of the superior colliculus of adult mice

51%

Paulussen M., Verleden S., Arckens L.

Acta Neurobiologiae Experimentalis

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2009

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tom 69

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nr 3

Thymosin beta 4 (Tβ4) is a peptide of 43 amino acids, mainly recognized as a regulator of actin polymerisation by sequestering Gactin. The peptide has been implicated in apoptosis, angiogenesis and lesion-induced neuroplasticity. Tβ4 is widely distributed in the brain, in neurons as well as in microglia. In this study we examined possible changes in Tβ4 expression in the visual system of the mouse after surgical removal of one eye. Adult mice were deprived of vision and sacrifi ced 1, 3 and 5 days and 1, 2 and 7 weeks after enucleation of the right eye. After 3 days of monocular deprivation, a substantial up-regulation of Tβ4-positive microglia was visible in the left superior colliculus, which faded with post-lesion survival time. The Tβ4-positive microglia appeared activated for clearance of debris of degenerating axons and myelin. Apart from this microglial activation, a remarkable neuronal response was observed. In the deeper layers of the left and right superior colliculus Tβ4- positive neurons with very long Tβ4-positive neurites became apparent. These cells were visible within 1 week but became more obvious 7 weeks post-lesion. Tβ4 may therefore participate in growth or remodeling of neuronal processes in deep layers of the superior colliculus possibly to induce some form of recovery of the visual system upon sensory deprivation.

7

Characterization of creatine kinase, brain type, as a new and valuable areal marker in mammalian neocortex

45%

Jacobs S., Speleman S., Van den Bergh G., Clerens S., Arckens L.

Acta Neurobiologiae Experimentalis

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2005

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tom 65

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nr 5

8

Central retinal lesions induce time-dependent protein expression changes throughout area 17

45%

Hu T., Van den Bergh G., Eysel U., Heylen K., Arckens L.

Acta Neurobiologiae Experimentalis

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2009

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tom 69

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nr 3

Central retinal lesions lead to loss of visual input in the central part of area 17 of the adult cat. Eventually this results in topographic map reorganization within the sensory-deprived cortical lesion projection zone (LPZ) as measured by electrophysiology. This recovery coincides with changes in gene/protein expression. We therefore investigated these alterations as a function of post-lesion survival time in three regions of primary visual area 17: the center of the LPZ, the border of the LPZ and far peripheral area 17. We analysed the differential protein expression patterns between control and experimental animals with 2-dimensional differential gel electrophoresis. We have traced 74 differential spots for the three regions in area 17. Central retinal lesions clearly induced region-specifi c and time-dependent protein expression changes. Even the protein expression in far peripheral area 17 spared from a direct impact of the central retinal lesions differed from the corresponding region in normal subjects. We succeeded in identifying 93% of the differential spots by means of mass spectrometry and software processing helped functional grouping within the list of proteins. This analysis allowed us to select two plasticity-related proteins for further validation experiments.

9

Neurolasticity in the hippocampus and the striatum of the mouse during visuo-motor learning: analyses of immediate early gene expression patterns

45%

Laeremans H., Nys J., Gantois I., Arckens L., D'Hooge R.

Acta Neurobiologiae Experimentalis

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2009

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tom 69

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nr 3

Visuo-motor learning, a dynamic process in which visual stimuli are associated with certain motor responses, leads to goaldirected, complex behaviours. Literature states that the striatum and the hippocampus are two important brain areas for this type of learning since neural mechanisms and changing activation patterns within these areas are involved in the processing of visual stimuli and the subsequent motor act. The neural activity of mice trained in the Morris water maze was molecularly chaacterized by in situ hybridization for the immediate early gene activity markers arc and homer1a and this in two timeframes, namely the early learning and the late learning (overtrained/automatisation) phase. First results show that in the early learning phase arc mRNA expression appears to be upregulated in the ventrolateral striatum, while in the overtrained phase a higher expression is noticeable in the dorsal striatum. Arc and homer1a mRNA expression levels in the hippocampus indicate that this structure is more active in the early learning phase compared to the overtrained phase. Subregional analysis of hippocampal homer1a mRNA expression patterns implies an opposite dynamic of CA1/DG and CA3 in response to learning. While CA1/DG activity decreases when mice become overtrained, CA3 activity seems to slightly increase. Further analysis will reveal how differential molecular activity in the subregions of hippocampus and striatum relates to both phases of the visuo-motor learning process.

10

Effects of pattern deprivation on the development of the motion-sensitive posterior medial lateral suprasylvian (PMLS) visual area of the cat as revealed by zif268 gene expression

39%

Zapasnik M., Laskowska-Macios K., Hu T. T., Kossut M., Arckens L., Burnat K.

Acta Neurobiologiae Experimentalis

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2011

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tom 71

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nr S

Long-term binocular pattern deprivation (BD) from eye opening results in severe global motion perception impairment in children and cats. We recently showed in cat that late onset deprivation (month 3 and 4 following 2 months of normal vision; 2N2BD), also leads to global motion perception impairments. Interestingly, 2 months of BD from eye opening facilitates motion perception, while a continuous 4 month BD period from birth (4BD) does not result in significant impairment. To test how these BD outcomes are reflected at the level of neuronal activity we compared the expression profile of the activity reporter gene zif268 in PMLS in three separate BD conditions. Adult and juvenile 4BD, 6BD and 2N2BD cats and age-matched controls were used. Cats were exposed to overnight darkness prior to 1-hour light stimulation and then sacrificed; kittens at the end of the BD period, adults after 2 years of visual training upon BD. In situ hybridization was applied using an oligonucleotide probe complementary to the nucleotides encoding amino acids 2-16 of the rat zif268 gene. For 4BD and 2N2BD kittens the zif268 mRNA level in PMLS was significantly elevated by 50%, as compared to age-matched controls. 6BD kittens also had elevated zif268 signals, but by 21%. Interestingly, zif268 expression in PMLS increases with age as in control kittens higher levels were observed after 6 than 4 months of age. In adult cats zif268 signals were highest in the 4BD group, while 2N2BD cats did not differ from controls. We infer that the developmental pattern of the motionsensitive area PMLS is affected by early BD. BD most likely prolongs the processes of cortical development, as zif268 mRNA levels in 4BD and 2N2BD kittens are equally high. Surprisingly, restoration of normal visual input in adult 2N2BD cats leads to normalization of activity levels in PMLS, while in the 4BD group it remains high. These results link high zif268 gene expression to behavioral performance.

11

Binocular deprivation reveals early plasticity-dependent region- and layer- specific zif268 expression profiles in cat primary visual cortex (area 17)

39%

Laskowska-Macios K., Zapasnik M., Hu T. T., Kossut M., Arckens L., Burnat K.

Acta Neurobiologiae Experimentalis

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2011

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tom 71

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nr S

Binocular pattern deprivation (BD) alters visual cortex circuitry development, here for the first time studied via analysis of regionand layer-specific expression of the activity reporter gene zif268. We describe its profile in cat area 17 after BD in comparison to age-matched controls. Three BD conditions were applied; the first four (4BD) or six (6BD) months from eye-opening, and a late onset BD in the 3rd and 4th month of age, preceded by 2 months of normal vision (2N2BD). Cats were exposed to overnight darkness prior to 1-hour light stimulation and then sacrificed; kittens at the end of the BD period, adults after 2 years of visual training upon BD. Radioactive in situ hybridization was applied to analyze zif268 mRNA levels. Juvenile and adult BD cats showed elevated zif268 mRNA levels in peripheral area 17 compared to central area 17, while in controls the signal was similar throughout area 17. 2N2BD kittens had such a BD pattern only in layer IV. All juvenile control and BD kittens, except 4BD, showed a similar inter-laminar zif268 expression profile for central area 17. The least active was layer IV and the most active layer V/VI. Adult control and BD cats displayed such a pattern throughout area 17. Furthermore in BD kittens, layers IV and II/III had a higher level of zif268 mRNA than in control area 17. 4BD resulted in a distinctive elevation of the zif268 mRNA level: in adults in all peripheral area 17 layers as compared to controls; in juveniles in layer IV throughout area 17 and in central layer II/III compared to controls and other BD kittens. We conclude that the quality of visual input during the initial 4 months of life plays a crucial role in establishing the inter-laminar circuitry within primary visual cortex in cat. We suggest that early BD arrests the developmental processes in central and peripheral representations leading to a continued differential zif268 gene expression ratio in central versus peripheral area 17 into adulthood. Project co-financed by the European Union from the European Regional Development Fund within the frame of International PhD Projects Programme (MPD4-504).

Ograniczanie wyników

Molecular mechanisms of organizational plasticity in the sensory neocortex of mammals

BDNF expression in cat striate cortex is regulated by binocular pattern deprivation

Binocular deprivation alters the stratification pattern and the morphology of the axons of large ganglion cells in cat retina

Qualitative and quantitative analysis of NMDA receptor subunit distribution in adult cat visual area 17

Evidence for cross-modal plasticity in adult mouse visual system

Monocular enucleation induces prominent thymosin beta4 expression in microglia and neurons of the superior colliculus of adult mice

Characterization of creatine kinase, brain type, as a new and valuable areal marker in mammalian neocortex

Central retinal lesions induce time-dependent protein expression changes throughout area 17

Neurolasticity in the hippocampus and the striatum of the mouse during visuo-motor learning: analyses of immediate early gene expression patterns

Effects of pattern deprivation on the development of the motion-sensitive posterior medial lateral suprasylvian (PMLS) visual area of the cat as revealed by zif268 gene expression

Binocular deprivation reveals early plasticity-dependent region- and layer- specific zif268 expression profiles in cat primary visual cortex (area 17)