Pathological Changes In Spinal Cord Research Articles

Obesity Promotes EAE Through IL-6 and CCL-2-Mediated T Cells Infiltration.

Growing evidence suggests that obesity is associated with the susceptibility and disease severity of multiple sclerosis. The chronic inflammation induced by obesity is believed to contribute to this process. However, the immune mechanisms connecting obesity to the prevalence and pathogenesis of MS are poorly defined. In this study, we show that high fat diet (HFD)-induced obese mice developed an exacerbated EAE as indicated by higher clinical scores and more severe pathological changes in spinal cord than the control mice fed with normal diet (ND), following immunization with myelin oligodendrocyte glycoprotein (MOG) 35–55 peptide. The exacerbation of EAE in HFD mice was associated with enhanced microglial activation and increased expansion of Th1 and Th17 cells. The HFD mice also showed aggravated disease in an adoptive T cell transfer EAE model. Mechanistically, HFD augmented the expression level of IL-6 and CCL-2 both in serum and brain, and blockade of IL-6 and CCL-2 signal ameliorated EAE with reduced T cells infiltration in CNS. Taken together, our results suggest that obesity promotes CNS inflammation in EAE through IL-6 and CCL-2 mediated the inflammatory cells infiltration.

Neuroprotective effect of neuregulin-1β on spinal cord ischemia reperfusion injury

Objective: This study was designed to see if neuregulin-1β (NRG-1β) plays a protective role in spinal cord ischemia and reperfusion injury (SCII). Design: Animal research. Setting: China. Participants: NA. Interventions: Forty-eight SD rats were randomly divided into control group (n = 16), SCII model group (n = 16) and NRG-1β-treated group (n = 16). In control group, the abdominal aorta was isolated but not clipped. The rats in NRG-1β-treated group were treated with 10μg/kg NRG-1β during developing SCII model. Outcome Measures: Neurological scores were evaluated. At 3, 6, 12 and 24 h after the reperfusion, rats were killed. Pathological changes of spinal cord were assessed with HE staining, and immunohistochemical staining of matrix metalloproteinases-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1). MMP-9 and TIMP-1 mRNA levels were assessed using real-time PCR. Results: NRG-1β reduced the damage of SCII in the rats. The expression of MMP-9 protein and mRNA in NRG-1β treatment group was significantly lower than the model group (P < 0.05) at 6 h, 12 h and 24 h after the perfusion. The expression of TIMP-1 protein and mRNA in the treatment group was significantly higher than the model group at 12 h and 24 h after the perfusion. Conclusion: NRG-1β reduced the reperfusion damage in rat model of SCII, in which process MMP-9 and TIMP-1 were probably involved.

A longitudinal DTI and histological study of the spinal cord reveals early pathological alterations in G93A-SOD1 mouse model of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by selective motor neuron degeneration in the motor cortex, brainstem and spinal cord. It is generally accepted that ALS is caused by death of motor neurons, however the exact temporal cascade of degenerative processes is not yet completely known. To identify the early pathological changes in spinal cord of G93A-SOD1 ALS mice we performed a comprehensive longitudinal analysis employing diffusion-tensor magnetic resonance imaging alongside histology and electron microscopy, in parallel with peripheral nerve histology. We showed the gradient of degeneration appearance in spinal cord white and gray matter, starting earliest in the ventral white matter, due to a cascade of pathological events including axon dysfunction and mitochondrial changes. Notably, we found that even the main sensory regions are affected by the neurodegenerative process at symptomatic disease phase. Overall our results attest the applicability of DTI in determining disease progression in ALS mice. These findings suggest that DTI could be potentially adapted in humans to aid the assessment of ALS progression and eventually the evaluation of treatment efficacy.

A progressive compression model of thoracic spinal cord injury in mice: function assessment and pathological changes in spinal cord.

Non-traumatic injury accounts for approximately half of clinical spinal cord injury, including chronic spinal cord compression. However, previous rodent spinal cord compression models are mainly designed for rats, few are available for mice. Our aim is to develop a thoracic progressive compression mice model of spinal cord injury. In this study, adult wild-type C57BL/6 mice were divided into two groups: in the surgery group, a screw was inserted at T9 lamina to compress the spinal cord, and the compression was increased by turning it further into the canal (0.2 mm) post-surgery every 2 weeks up to 8 weeks. In the control group, a hole was drilled into the lamina without inserting a screw. The results showed that Basso Mouse Scale scores were lower and gait worsened. In addition, the degree of hindlimb dysfunction in mice was consistent with the degree of spinal cord compression. The number of motor neurons in the anterior horn of the spinal cord was reduced in all groups of mice, whereas astrocytes and microglia were gradually activated and proliferated. In conclusion, this progressive compression of thoracic spinal cord injury in mice is a preferable model for chronic progressive spinal cord compression injury.

Surgical treatment outcomes in children with tethered spinal cord syndrome. A prognosis on the basis of spinal 3T MRI tractography

The study objective was to identify factors affecting surgical treatment outcomes in children with tethered cord syndrome (TCS). The study included 21 TCS patients aged 1 to 14 years who underwent tethered cord release. The preoperative and postoperative data of clinical and neurophysiological examination and high field (3T) MRI tractography of the caudal spinal cord were compared. Regression of the TCS clinical and electrophysiological signs and the lack of pathological changes in the spinal cord tracts were observed in patients with filum terminale abnormalities and caudal lipomas after surgery. In patients with secondary spinal cord tethering caused by scar formation after lumbosacral myelomeningocele repair, a motor deficit was related to the interruption level of the spinal tracts, and surgical treatment did not lead to significant regression of the TCS clinical and electrophysiological signs. We consider the absence of pathological changes in the caudal spinal cord, based on spinal MRI tractography, as a favorable prognostic factor in TCS surgical treatment.

Efficacy of intrathecally administered monosialoganglioside for treatment of bupivacaine spinal anesthesia-induced neurotoxicity to rat spinal cord

Objective To evaluate the efficacy of intrathecally administered monosialoganglioside (GM-1)for treatment of bupivacaine spinal anesthesia-induced neurotoxicity to rat spinal cord.Methods Adult male Sprague-Dawley rats,weighing 280-300 g,in which the intrathecal catheter was successfully inserted into the L3,4 intervertebral space and advanced toward the tail,were randomly divided into 4 groups (n =36 each):sham operation group (group S),GM-1 group,bupivacaine group (group B) and bupivacaine + GM-1 group (group BG).In B and BG groups,the rats received 5％ bupivacaine 20 μl via the intrathecal catheter 3 times at 1.5-hour intervals.GM-1 20 μg was injected intrathecally 24 h later once a day for 7 days in BG and GM-1 groups.Before bupivacaine injection and on days 1,3,5,7,14 and 28 after bupivacaine injection (T0-T6),tail flick latency (TFL) was measured,MPE (percentage of maximal possible effect) was calculated,and the locomotor recovery was evaluated using the Basso,Beattie,Bresnahan (BBB) Locomotor Rating Scale.Then six rats were randomly chosen and sacrificed in each group.Spinal cord was removed for histopathologic examination (with light and electronic microscope) and for determination of caspase-3 protein and mRNA expression (by immuno-histochemistry and RTPCR).The pathological changes of the spinal cord were scored.Results Compared with S and GM-1 groups,MPE,pathological scores,and caspase-3 protein and mRNA expression were significantly increased and BBB score was decreased at T1-6 in group B (P ＜ 0.05),and MPE was increased at T1-5 (P ＜ 0.05) and returned to the baseline value at T6 (P ＞ 0.05) and pathological scores,and caspase-3 protein and mRNA expression were significantly increased and BBB score was decreased at T1-6 in group BG (P ＜ 0.05).There were no significant differences in each parameter at each time point between S and GM-1 groups (P ＞ 0.05).Compared with group B,MPE and caspase-3 protein and mRNA expression were significantly decreased at T2-6,pathological scores were decreased at T3-6,and BBB score was increased at T4-6 in group BG (P ＜ 0.05).The pathological changes of spinal cord tissues were obvious at T1-6 in group B and at T1-3 in group BG,but the changes gradually recovered at T4-6 in group BG.Conclusion Intrathecally administered GM-1 has therapeutic effect against bupivacaine spinal anesthesia-induced neurotoxicity to rat spinal cord,and inhibition of neuronal apoptosis in the spinal cord may be involved in the underlying mechanism. Key words: G(M1) ganglioside ; Bupivacaine ; Neurotoxicity; Injections, spinal

Neurological recovery in diabetic rats following spinal cord injury.

This study was designed to assess the effect of spinal cord injury on neurobehavioral, electrophysiological, structural, and biochemical changes in normal and diabetic rats. Experimental diabetes was induced in Sprague-Dawley male rats (weighing 250-280 g) with streptozotocin (50 mg/kg i.p.). Eight weeks after the treatment with streptozotocin the animals were anaesthetized with chloral hydrate and laminectomy was performed at T 7-8 level leaving the dura intact. A compression plate (2.2 x 5.0 mm) loaded with a weight of 35 g was placed on the exposed spinal cord for 5 min. Postoperative neurological function was assessed using inclined plane test, modified Tarlov score, and vocal and sensory score daily for 10 days. Electrophysiological changes were assessed using somatosensory and corticomotor evoked-potentials. The animals were sacrificed at different time intervals and injured site of the spinal cord was analyzed for changes in vitamin E and glutathione levels (as markers of oxidative stress). Pathological changes in spinal cord were also studied using light microscopy. The data on neurobehavioral study clearly indicated that the compression of spinal cord produced highly significant neurological deficit and poor recovery in diabetic rats as compared to nondiabetic rats. Our histopathological and electrophysiological results also confirmed that diabetic animals are more susceptible to compressive spinal cord injury as compared to nondiabetic animals. A higher depletion of antioxidant defense markers (vitamin E and glutathione) was observed in diabetic rats as compared to nondiabetic rats. These results point toward the role of free radicals in poor recovery in diabetic rats following neurotrauma. Further studies are warranted to assess the neuroprotective potential of antioxidants to retard the secondary pathophysiological events following neurotrauma and to enhance the recovery.