Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 3

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

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

100%
Leszczynska A. N., Cabaj A. M., Slawinska U., Majczynski H.
Acta Neurobiologiae Experimentalis
|
2013
|
tom 73
|
nr Suppl.1
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.
2

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

100%
Leszczynska A., Cabaj A. M., Slawinska U., Majczynski H.
Acta Neurobiologiae Experimentalis
|
2011
|
tom 71
|
nr S
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.
3

Differential effects on locomotor-like movements of paraplegic rats produced by activation of 5-HT2 or 5-HT7 receptors

88%
Slawinska U., Miazga K., Majczynski H., Cabaj A. M., Jordan L. M.
Acta Neurobiologiae Experimentalis
|
2011
|
tom 71
|
nr S
There is considerable evidence from research in neonatal and adult rat and mouse preparations to warrant the conclusion that activation of 5-HT2 and 5-HT7 receptors leads to activation of the spinal cord circuitry for locomotion. Both types of receptors are involved in control of locomotor movements, but it is not clear how they are implicated in the responses to 5-HT agonists observed after spinal cord injury. Here we used different agonists that are known to be efficient in promoting locomotor recovery in paraplegic rats: 8-OHDPAT (acting on 5-HT7) and quipazine (acting on 5-HT2 receptors). Motor performance was tested before and 15 – 30 min after i.p. drug application in spinal rats placed with the forequarters on a platform above a treadmill while the hindlimbs were touching the moving treadmill belt. Tail pinching was used to induce hindlimb movements that were monitored using video recordings synchronized with simultaneous EMG recordings from the soleus and tibialis anterior muscles of both legs. The application of either 5-HT receptor agonist improved hindlimb plantar walking. Analysis of intra- and interlimb coordination confirmed that the motor performance was significantly better, but in slightly different ways, after application of either drug. Interlimb coordination (left-right coordination) was significantly better after 8-OHDPAT, and the activity of antigravity soleus muscle was significantly longer during locomotor-like movement enhanced by quipazine (an improvement in intralimb coordination). Our results suggest that 5-HT2 and 5-HT7 receptors both facilitate activity in the spinal circuitry controlling locomotion, but their effects are likely exerted on different populations of spinal neurons. These agonists also have affinity to other types of receptors (e.g., 8-OHDPAT acts also on 5-HT1a receptors and quipazine also has affinity for 5-HT3 receptors), so further experiments are needed to substantiate the roles of 5-HT2a and 5-HT7 receptors.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.