Wyniki wyszukiwania - Biblioteka Nauki

1

Szanse dla sparalizowanych w swietle wspolczesnej nauki

100%

Slawinska U.

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nr 01-03

9-13

2

The role of peripheral afferent inputs and their interactions with serotonin in the control of motoneuron activity

100%

Slawinska U.

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nr Suppl.1

EN

It is known that neural circuitry in the spinal cord below a total transection is almost totally devoid of serotonin. As a consequence of spinal injury rats do not walk spontaneously. However, chronic spinal rats can be induced to perform proper plantar stepping by tail stimulation in the upright posture. Such plantarstepping is altered by removal of afferent feedback from the paws showing that sensory feedback from the foot facilitates the spinal central pattern generator (CPG) for locomotion when serotonergic innervation is missing. Although spinal rats can be induced to walk in the upright posture, they do not display recovery of quadrupedal locomotion in the horizontal posture typical for progression in rodents. Our data show that activation of 5-HT2A and 5-HT7/1A receptors using their agonists facilitates plantar stepping in the horizontal posture but interferes with upright stepping in paraplegic rats. In our next investigations we found that in intact adult freely moving rats intrathecal application of the selective 5-HT7 antagonist SB269970 induces hindlimb paralysis. This occurs without a direct effect on motoneurons as revealed by an investigation of reflex activity. The antagonist disrupted intra- and inter-limb coordination during locomotion in intact rats but not during fictive locomotion induced by stimulation of the mesencephalic locomotor region (MLR) in adult rat decerebrate preparations. During the recovery period, after transient blocking of MLR evoked fictive locomotion, the amplitude and frequency of rhythmic activity was reduced. The lack of effects on coordination by SB269970 application in paralyzed decerebrate rats with no afferent feedback indicates a critical role of 5-HT7 receptor mediated control of sensory pathways during locomotor activity. Our data show that for optimal coordinated locomotor movements in adult rats, in addition to activation of the serotonergic system, a potent afferent feedback from the foot seems to be necessary FINANCIAL SUPPORT: This work has been supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska‑Curie grant agreement no 665735 (Bio4Med) and by the funding from Polish Ministry of Science and Higher Education within 2016–2020 funds for the implementation of international projects (agreement no 3548/H2020/COFUND/2016/2).

3

Partial restoration of hindlimb function in adult spinal rats after transplantation of embryonic raphe nucleus into the spinal cord below the transection

63%

Slawinska U. , Majczynski H.

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1997

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tom 57

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nr 5

4

Dordzeniowe transplanty tkanki nerwowej jako metoda badania plastycznosci ukladu nerwowego

63%

Slawinska U. , Majczynski H.

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nr 3

461-470

5

Grafted serotonergic neurons can reverse changes in gene expression in motoneurons produced by spinal cord injury in rats

51%

Miazga K. , Joachimiak E. , Fabczak H. , Slawinska U.

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tom 75

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nr Supl.

EN

BACKGROUND AND AIMS: Serotonin, which is supplied to the spinal cord by serotoninergic cells localized in the raphe nuclei and parapiramidal areas of the medulla, plays a very important role in control of the spinal locomotor central pattern generator (CPG). In our previous study we showed that intraperitoneal application of: 8-OH-DPAT (5-HT1A and 5-HT7 serotonin receptor agonist) and quipazine (mainly 5-HT2A serotonin receptor agonist), or intraspinal transplantation of serotonergic cells isolated from 14-day old rat embryo brain stem, facilitates locomotor-like hindlimb movements in spinal rats (spinal cord total transection between Th9 and Th10). 5-HT7 and 5-HT2 serotonin receptor antagonists blocked the locomotor-like hindlimb movements that had been restored in spinal rats grafted with embryonic serotoninergic cells. The aim of the present study was to examine the influence of spinal cord total transection and transplantation of serotonin neurons isolated from the 14-day old rat embryo brain stem on changes in expression of genes encoding 5-HT2A, 5-HT2C and 5-HT7 serotonin receptors in populations of motoneurons innervating tibialis anterior, gastrocnemius lateralis, and extensor caudae medialis muscles. METHODS: For motoneurons labeling a method of retrograde staining using intra muscle injection with cholera toxin B subunit conjugated with Alexa Fluor 555 was used. Motoneurons were then collected by using the laser capture micro-dissection method, and changes in expression of genes encoding serotonin receptors were analyzed by Real-time PCR. RESULTS: The results show that total spinal cord transection changed expression of genes encoding 5-HT2A, 5-HT2C and 5-HT7 serotonin receptors in ankle flexor and ankle and tail extensor muscles. Grafting of serotonin neurons reverses the effects of spinal cord injury on expression of these genes. CONCLUSION: This is the first demonstration that grafts of serotonergic neurons can reverse changes in gene expression in motoneurons produced by spinal cord injury.

6

Intra- and inter-limb coordination after low thoracic lateral hemisection in rats

51%

Leszczynska A. , Cabaj A. M. , Slawinska U. , Majczynski H.

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nr S

EN

Lateral thoracic hemisection of the spinal cord in adult rats results in initial severe impairment of hindlimb movements followed by a relatively fast improvement of locomotor functions. There are data showing substantial or even complete recovery of locomotor performance within 21 – 30 days after spinal cord injury. In our previous study we showed that improvement of locomotor performance reached plateau about four weeks after the injury but animals did not show the full locomotor recovery. The aim of present study was to analyze the time course of relationships between activity of flexors and extensors of each of four limbs during locomotion after lateral hemisection of the spinal cord in rats. The locomotion was tested in freely moving animals walking at speed 0.4 – 1.0 m/s. Bipolar EMG electrodes for the chronic recordings were implanted in soleus and tibialis muscles of hindlimbs and biceps and triceps of forelimbs. The EMG recordings were performed once a week up to six weeks after spinal cord injury. Our results showed that 7 days after the lateral hemisection of the spinal cord the relationship between flexor and extensor muscle (intralimb coordination) of hindlimbs was severely impaired. Moreover, analysis of interlimb coordination revealed that relationships between forelimbs and hindlimbs and hindlimbs themselves were also impaired. Two weeks after surgery the relationships between flexor and extensor muscle of right as well as left hindlimb returned to normal. Diagonal coordination between left forelimb and right hindlimb was also similar to that before the lesion. Only coordination between left hindlimb and remaining three limbs was impaired through the whole period of the study (six weeks after surgery). This results confirmed hypothesis, that after lateral thoracic hemisection of the spinal cord rats did not show the full locomotor recovery.

7

Komórki macierzyste w naprawie urazów rdzenia kręgowego - aktualny stan wiedzy

51%

Zawadzka M. , Kwasniewska A. , Miazga K. , Slawinska U.

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tom 121

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nr 01-03

8

Limited recovery of locomotor functions after lateral hemisection of the spinal cord in rats

51%

Leszczynska A. N. , Cabaj A. M. , Slawinska U. , Majczynski H.

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nr Suppl.1

EN

Lateral hemisection of the spinal cord at the low thoracic level in rats causes severe deterioration of hindlimb locomotor movements followed by the substantial improvements of locomotor functions. However the rate and the level of this improvement remain disputable. In this study we investigated the time course of locomotor recovery analyzing spatial indices of locomotion obtained with CatWalk Gait Analysis System. The animals started to be tested in the CatWalk System two weeks after the injury, when hindlimb plantar stepping recovered. Within first 2 weeks hindlimb locomotor function recovered substantially, and the analyzed locomotor indices reached plateau about one month after injury. Nevertheless, most of the indices, like speed of locomotion, hindlimb base of support, hindlimb abduction did not reached the level obtained before the injury. Within next few months some of them remained at the same level, but 5 months after the hemisection locomotion again started to deteriorate, as was manifested by decrease of locomotor velocity and increase of hindlimb base of support. This study shows that after lateral hemisection of the spinal cord at the low thoracic level the recovery of locomotor functions is limited and that 5 months after the injury the secondary deterioration of locomotion is observed.

9

Noradrenergic contribution in control of hindlimb motor function in adult spinal rats

51%

Maleszak K. , Cabaj A. , Majczynski H. , Slawinska U.

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nr 3

10

Danger and safety signals differentiate hippocampal theta activity in classical conditioning in rats

51%

Jelen P. , Slawinska U. , Kasicki S.

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nr 3

11

Different effects of Riluzole treatment on survival of motor units of fast and slow muscles

51%

Cabaj A. , Lapinska I. , Majczynski H. , Slawinska U.

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tom 65

|

nr 3

12

Graft-induced restoration of hindlimb functions is mediated by 5HT2 receptors

51%

Maleszak K. , Cabaj A. , Majczynski H. , Slawinska U.

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tom 65

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nr 3

13

The age dependent effect of partial denervation of rat fast muscles on their activity

51%

Tyc F. , Slawinska U. , Vrbova G.

Acta Neurobiologiae Experimentalis

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1999

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tom 59

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nr 2

14

Functional and structural changes in rat medial gastrocnemius muscle after spinal cord transection

38%

Kedziorek-Pietryka A. , Lapinska I. , Majczynski H. , Karczewska E. , Redowicz M. J. , Krutki P. , Slawinska U.

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nr 3

15

Subcellular localization of gelatinase activity in skeletal muscle of control and trained rats

38%

Yeghiazaryan M. , Zybura-Broda K. , Rylski M. , Slawinska U. , Kaczmarek L. , Wilczynski G.

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nr S

EN

Matrix metalloproteinases (MMPs) are key regulatory molecules in the formation, remodeling, and degradation of extracellular matrix components in both physiological and pathological processes. However their intracellular presence and activity was also reported. The purpose of this study was to examine the expression and subcellular localization of the gelatinases MMP-2 and MMP-9 in skeletal muscle fibers of normal and physically trained rats. In control hindlimb muscle, the activity and expression of the gelatinases were barely detectable in muscle fibers. In contrast, 5 days after physical training, there was significant upregulation of gelatinolytic activity in myofibers, mainly in their nuclei, and to a lesser extent in sarcoplasm and sarcolemma, as assessed by high resolution in situ zymography. The nuclei of satellite cells did not contained the activity. Within the myonuclei, the gelatinolytic activity was distributed throughout the nuclear interchromatin area. Subcellular fractionation followed by gel zymography revealed that MMP-2, but not MMP-9, is the myonuclear gelatinase whose activation occurs upon training. Training activated and upregulated MMP-9 in the cytoplasm. By RT-PCR, there was significant increase in MMP-9 mRNA only. We conclude that training activates nuclear MMP-2, it also increases both the expression and activity of cytoplasmic/sarcolemmal MMP-9. We suggest that the gelatinases play roles in muscle adaptation to training; MMP-2 may be involved in the processes of nuclear gene expression.

16

CD44-ErbB receptor interaction studied by fluorescence resonance energy transfer analysis using fluorescence lifetime imaging microscopy

26%

Wlodarczyk J. , Gorlewicz A. , Wilczek E. , Gawlak M. , Cabaj A. , Majczynski H. , Nestarowicz K. , Herbik M. , Grieb P. , Slawinska U. , Kaczmarek L. , Wilczynski G.

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nr 3

EN

CD44 is a multifunctional cell surface glycoprotein which regulates cell-cell and cell-matrix interactions in a variety of tissues. CD44 was implicated in the development of peripheral nerves, functioning as a coreceptor for ErbB class of growth factor receptors. However, it is not known whether CD44-ErbB interaction may occur at the adult peripheral synapses. Here we studied, using Fluorescence Lifetime Imaging Microscopy, the proximity between CD44 and ErbB3 at the rat neuromuscular junction (NMJ). This was performed in muscle sections co-immunostained for CD44 and ErbB3, using secondary antibodies coupled to Alexa488 and Alexa647 respectively. Neuromuscular junctions were visualized using Alexa555-bound α-BT. The FRET between Alexa488 (donor) and Alexa647 (acceptor) was judged by measuring an accompanying changes in the donor fl uorescence lifetime. We found that the mean fl uorescence lifetime of the donor fl uorophore labeling CD44 protein was considerably shorter over the NMJ than in nonsynaptic sites. Then we compared normal rat muscle to the muscle affected by denervation in the transgenic model of amyotrophic lateral sclerosis (ALS). Importantly, ALS-like neurodegeneration resulted in signifi cant increase in molecular proximity of CD44 and ErbB3 at the NMJ. The specifi c complex formation between the two proteins was confi rmed using immunoprecipitation analysis. Our study provides novel data on the molecular architecture of the neuromuscular synapse in both health and disease.