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Rationale: Spasticity develops in 80% of spinal cord injury cases and negatively affects the patents' quality of life. The most common method of surgical treatment for severe spasticity is a long-term intrathecal baclofen therapy (ITB). Long-term spinal cord stimulation is another possible treatment technique. This paper aims to evaluate the changes in quality of life for patients with spasticity who have been treated with neuromodulation (SCS or ITB) in 12 months after the surgery, as well to compare the changes in quality of life for patients who have been treated with spinal cord stimulation and those who received long-term intrathecal baclofen therapy., Materials and Methods: The influence of spasticity, experienced by the patients with a spinal cord injury, on their quality of life was analyzed before the surgery and 12 months after it. The severity of the spinal cord damage was determined with the scale of the American Spinal Injury Association (ASIA); spasticity was evaluated with the modified Ashworth scale, Penn Spasm Frequency Scale; pain levels were determined with visual analogue scale (VAS), anxiety and depression levels - with HADS. Functional activity of the patients was evaluated with the help of the Functional Independence Measure (FIM)., Results: The treatment results for 33 patients (25 men and 8 women), aged from 18 to 62, are presented. After the trial stimulation, the patients were randomly assigned to either SCS or ITB group (18 and 15 people respectively). The decrease of spasticity in both experimental groups caused lower levels of pain, less functional dependency on other people, lower stress and depression rates and, as a consequence, better quality of life and social adaptation. The obtained results for SCS and ITB groups are statistically similar., (Copyright © 2023. Published by Elsevier Inc.)

Military personnel during combat or peacekeeping operations are exposed to extreme climates of hot or cold environments for longer durations. Spinal cord injury is quite common in military personnel following central nervous system (CNS) trauma indicating a possibility of altered pathophysiological responses at different ambient temperatures. Our previous studies show that the pathophysiology of brain injury is exacerbated in animals acclimated to cold (5 °C) or hot (30 °C) environments. In these diverse ambient temperature zones, trauma exacerbated oxidative stress generation inducing greater blood-brain barrier (BBB) permeability and cell damage. Extracts of Ginkgo biloba EGb-761 and BN-52021 treatment reduces brain pathology following heat stress. This effect is further improved following TiO 2 nanowired delivery in heat stress in animal models. Several studies indicate the role of EGb-761 in attenuating spinal cord induced neuronal damages and improved functional deficit. This is quite likely that these effects are further improved following nanowired delivery of EGb-761 and BN-52021 with cerebrolysin-a balanced composition of several neurotrophic factors and peptide fragments in spinal cord trauma. In this review, TiO 2 nanowired delivery of EGb-761 and BN-52021 with nanowired cerebrolysin is examined in a rat model of spinal cord injury at cold environment. Our results show that spinal cord injury aggravates cord pathology in cold-acclimated rats and nanowired delivery of EGb-761 and BN-52021 with cerebrolysin significantly induced superior neuroprotection, not reported earlier., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

Military personnel are often victims of spinal cord injury resulting in lifetime disability and decrease in quality of life. However, no suitable therapeutic measures are still available to restore functional disability or arresting the pathophysiological progression of disease in victims for leading a better quality of life. Thus, further research in spinal cord injury using novel strategies or combination of available neuroprotective drugs is urgently needed for superior neuroprotection. In this regard, our laboratory is engaged in developing TiO 2 nanowired delivery of drugs, antibodies and enzymes in combination to attenuate spinal cord injury induced pathophysiology and functional disability in experimental rodent model. Previous observations show that histamine antagonists or antioxidant compounds when given alone in spinal cord injury are able to induce neuroprotection for short periods after trauma. In this investigation we used a combination of histaminergic drugs with antioxidant compound H-290/51 using their nanowired delivery for neuroprotection in spinal cord injury of longer duration. Our observations show that a combination of H3 receptor inverse agonist BF-2549 with H3 receptor antagonist and H4 receptor agonist clobenpropit induced neuroprotection is potentiated by antioxidant compound H-290/51 in spinal cord injury. These observations suggests that histamine receptors are involved in the pathophysiology of spinal cord injury and induce superior neuroprotection in combination with an inhibitor of lipid peroxidation H-290/51, not reported earlier. The possible mechanisms and significance of our findings in relation to future clinical approaches in spinal cord injury is discussed., Competing Interests: Conflict of interest There is no conflict of interest between any entity and/or organization mentioned here., (Copyright © 2023. Published by Elsevier Inc.)

Military personnel are often exposed to silica dust during combat operations across the globe. Exposure to silica dust in US military or service personnel could cause Desert Strom Pneumonitis also referred to as Al Eskan disease causing several organs damage and precipitate autoimmune dysfunction. However, the effects of microfine particles of sand inhalation-induced brain damage on the pathophysiology of traumatic brain or spinal cord injury are not explored. Previously intoxication of silica nanoparticles (50-60 nm size) is shown to exacerbates spinal cord injury induces blood-spinal cord barrier breakdown, edema formation and cellular changes. However, the mechanism of silica nanoparticles-induced cord pathology is still not well known. Spinal cord injury is well known to alter serotonin (5-hydroxytryptamine) metabolism and induce oxidative stress including upregulation of nitric oxide synthase and tumor necrosis factor alpha. This suggests that these agents are involved in the pathophysiology of spinal cord injury. In this review, we examined the effects of combined nanowired delivery of monoclonal antibodies to neuronal nitric oxide synthase (nNOS) together with tumor necrosis factor alpha (TNF-α) antibodies and a potent antioxidant H-290/51 to induce neuroprotection in spinal cord injury associated with silica nanoparticles intoxication. Our results for the first time show that co-administration of nanowired delivery of antibodies to nNOS and TNF-α with H-290/51 significantly attenuated silica nanoparticles-induced exacerbation of spinal cord pathology, not reported earlier., (© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG.)

Hallmark of Alzheimer's disease include amyloid beta peptide and phosphorylated tau deposition in brain that could be aggravated following traumatic of concussive head injury. However, amyloid beta peptide or p-tau in spinal cord following injury is not well known. In this investigation we measured amyloid beta peptide and p-tau together with tumor necrosis factor-alpha (TNF-α) in spinal cord and brain following 48 h after spinal cord injury in relation to the blood-spinal cord and blood-brain barrier, edema formation, blood flow changes and cell injury in perifocal regions of the spinal cord and brain areas. A focal spinal cord injury was inflicted over the right dorsal horn of the T10-11 segment (4 mm long and 2 mm deep) and amyloid beta peptide and p-tau was measured in perifocal rostral (T9) and caudal (T12) spinal cord segments as well as in the brain areas. Our observations showed a significant increase in amyloid beta peptide in the T9 and T12 segments as well as in remote areas of brain and spinal cord after 24 and 48 h injury. This is associated with breakdown of the blood-spinal cord (BSCB) and brain barriers (BBB), edema formation, reduction in blood flow and cell injury. After 48 h of spinal cord injury elevation of amyloid beta peptide, phosphorylated tau (p-tau) and tumor necrosis factor-alpha (TNF-α) was seen in T9 and T12 segments of spinal cord in cerebral cortex, hippocampus and brain stem regions associated with microglial activation as seen by upregulation of Iba1 and CD86. Repeated nanowired delivery of cerebrolysin topically over the traumatized segment repeatedly together with monoclonal antibodies (mAb) to amyloid beta peptide (AβP), p-tau and TNF-α significantly attenuated amyloid beta peptide, p-tau deposition and reduces Iba1, CD68 and TNF-α levels in the brain and spinal cord along with blockade of BBB and BSCB, reduction in blood flow, edema formation and cell injury. These observations are the first to show that spinal cord injury induces Alzheimer's disease like symptoms in the CNS, not reported earlier., (Copyright © 2023. Published by Elsevier Inc.)

Spinal cord injury (SCI) is one of the most challenging medical issues. Spasticity is a major complication of SCI. A combination of spinal cord stimulation, new methods of neuroprotection and biomedical cellular products provides fundamentally new options for SCI treatment and rehabilitation. The paper attempts to critically analyze the effectiveness of using these procedures for patients with SCI, suggesting a protocol for a step-by-step personalized treatment of SCI, based on continuity of modern conservative and surgical methods. The study argues the possibility of using neuromodulation as a basis for rehabilitating patients with SCI., Competing Interests: Competing interests The authors declare that they have no competing interests., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Spinal cord injury (SCI) is one of the leading causes of disability in Military personnel for which no suitable therapeutic strategies are available till today. Thus, exploration of novel therapeutic measures is highly needed to enhance the quality of life of SCI victims. Previously, topical application of BDNF and GDNF in combination over the injured spinal cord after 90min induced marked neuroprotection. In present investigation, we added CNTF in combination with BDNF and/or GDNF treatment to examine weather the triple combination applied over the traumatic cord after 90 or 120min could thwart cord pathology. Since neurotrophins attenuate nitric oxide (NO) production in SCI, the role of carbon monoxide (CO) production that is similar to NO in inducing cell injury was explored using immunohistochemistry of the constitutive isoform of enzyme hemeoxygenase-2 (HO-2). SCI inflicted over the right dorsal horn of the T10-11 segments by making an incision of 2mm deep and 5mm long upregulated the HO-2 immunostaining in the T9 and T12 segments after 5h injury. These perifocal segments are associated with breakdown of the blood-spinal cord barrier (BSCB), edema development and cell injuries. Topical application of CNTF with BDNF and GDNF in combination (10ng each) after 90 and 120min over the injured spinal cord significantly attenuated the BSCB breakdown, edema formation, cell injury and overexpression of HO-2. These observations are the first to show that CNTF with BDNF and GDNF induced superior neuroprotection in SCI probably by downregulation of CO production, not reported earlier., Competing Interests: Conflict of interest There is no conflict of interest between any entity and organization mentioned here., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Spinal cord evoked potentials (SCEP) are good indicators of spinal cord function in health and disease. Disturbances in SCEP amplitudes and latencies during spinal cord monitoring predict spinal cord pathology following trauma. Treatment with neuroprotective agents preserves SCEP and reduces cord pathology after injury. The possibility that cerebrolysin, a balanced composition of neurotrophic factors improves spinal cord conduction, attenuates blood-spinal cord barrier (BSCB) disruption, edema formation, and cord pathology was examined in spinal cord injury (SCI). SCEP is recorded from epidural space over rat spinal cord T9 and T12 segments after peripheral nerves stimulation. SCEP consists of a small positive peak (MPP), followed by a prominent negative peak (MNP) that is stable before SCI. A longitudinal incision (2mm deep and 5mm long) into the right dorsal horn (T10 and T11 segments) resulted in an immediate long-lasting depression of the rostral MNP with an increase in the latencies. Pretreatment with either cerebrolysin (CBL 5mL/kg, i.v. 30min before) alone or TiO 2 nanowired delivery of cerebrolysin (NWCBL 2.5mL/kg, i.v.) prevented the loss of MNP amplitude and even enhanced further from the pre-injury level after SCI without affecting latencies. At 5h, SCI induced edema, BSCB breakdown, and cell injuries were significantly reduced by CBL and NWCBL pretreatment. Interestingly this effect on SCEP and cord pathology was still prominent when the NWCBL was delivered 2min after SCI. Moreover, expressions of c-fos and c-jun genes that are prominent at 5h in untreated SCI are also considerably reduced by CBL and NWCBL treatment. These results are the first to show that CBL and NWCBL enhanced SCEP activity and thwarted the development of cord pathology after SCI. Furthermore, NWCBL in low doses has superior neuroprotective effects on SCEP and cord pathology, not reported earlier. The functional significance and future clinical potential of CBL and NWCBL in SCI are discussed., Competing Interests: Conflict of Interests The authors have no conflict of interests with any funding agency or entity reported here., (© 2020 Elsevier B.V. All rights reserved.)

Rationale: Spasticity is one of the main complications after the spinal cord injury (SCI). Most commonly, severe cases of spasticity are treated surgically with intrathecal baclofen therapy (ITB). Spinal cord stimulation for chronic pains (SCS) serves as an alternative for ITB. Both methods have their benefits and limitations. This study is aimed at development of a personalized SCS and ITB treatment algorithm for patients with severe cases of spasticity after SCI., Materials and Methods: The paper analyzes the treatment results of 66 patients with severe spasticity after SCI (50 men and 16 women, age ranging from 18 to 62), average age is 36.03±12.29 y.o. Patients who chose surgery as a spasticity treatment option, received experimental stimulation, and after muscle tone reduction to a comfort level they were surgically implanted with a SCS system for chronic pain management. Patients with negative response to experimental stimulation were tested for baclofen and, based on the results, had a baclofen pump implanted. The patients were examined after 1, 3, 6 and 12 months., Results: Surgical implantation of a SCS system was performed for 18 patients, ITB was used for 15 patients. After first 3 months of observation both groups demonstrated a significant improvement of spasticity index, but the SCS patients had better results. However, 6 months later the MAS scores, frequency of spasms and reflexes in both groups were the same. After 12 months of observation the ITB group exhibited a significant improvement of the MAS scores, compared with the control group, and reached the results, similar to the SCS group., Conclusions: Surgical treatment of patients with severe spasticity after SCI should start with experimental spinal cord stimulation, and, in case of a positive response, be followed by SCS system implantation. Patients with positive response to the experimental stimulation exhibit a significantly prolonged response to treatment, without substantial differences from ITB patients., (© 2020 Elsevier B.V. All rights reserved.)

Spinal cord injury (SCI) is a devastating disease inflicting lifetime disability to the victims. Military personnel are quite often victims of SCI for which no suitable therapeutic strategies have been developed so far. The main reason for SCI induced disability is loss of neural connections below and above the lesion site causing motor paralysis and somatosensory disturbances Loss of neuronal connections thwart spinal cord conduction resulting in motor function disability. To enhance spinal cord conduction grafting of peripheral nerves, implant of hydrogels filled with neuroprotective drugs is used but so far, no satisfactory results re achieved. In this regards implants of microelectrode for enhancing tissue connectivity is suggested that is still under experimental state. We have used titanium implant with or without TiO 2 nanowires in a focal spinal cord injury and studies spinal cord pathology and motor function. In addition, we also combined with nanowired delivery of a potential neuroprotective drug DL-3-n-butylphthalide (DL-NBP) to the spinal cord in a rat model. Our observations show that a combination of titanium implant with nanowired delivery of DL-NBP induces superior neuroprotection and enhance motor functions after SCI. This treatment also restored blood-spinal cord barrier (BSCB) function and reduces edema formation and cell injury after SCI, not reports earlier., (© 2019 Elsevier Inc. All rights reserved.)

Bradykinin is a mediator of vasogenic brain edema formation. Recent reports suggest that bradykinin interacts with nitric oxide synthase (NOS) system in the central nervous system (CNS). However, role of bradykinin in spinal cord injury (SCI) induced alterations in the blood-spinal cord barrier (BSCB), spinal cord blood flow (SCBF), edema formation and cell changes are still not well known. Our previous reports showed that SCI induces marked upregulation of neuronal NOS (nNOS) in the cord associated with BSCB disruption, edema formation and cell injury. Thus, a possibility exists that bradykinin participates in SCI induced nNOS upregulation and cord pathology. To explore this idea a potent bradykinin B2 receptor antagonist HOE-140 was used in our rat model of SCI and cord pathology. SCI was inflicted in Equithesin anesthetized rats by making a longitudinal incision (2mm deep and 5mm long) into the right dorsal horn of the T10-11 segment. The animals were allowed to survive 5h after injury. A focal SCI significantly disrupted BSCB to Evans blue and [131] I-sodium in the traumatized and adjacent segments. Interestingly, far remote spinal cord segments C4 and T5 segments also affected within 5h. These spinal cord segments also exhibited pronounced reductions in the SCBF (mean-30%), increased edematous swelling and profound neuronal damages. Upregulation of nNOS expression is seen in both the dorsal and ventral horns of the spinal cord exhibiting cord pathology. At the ultrastructural level, exudation of lanthanum is seen within the endothelial cell cytoplasm and occasionally in the basal lamina. Pretreatment with low doses of HOE-140 (0. 1mg to 1mg/kg, i.v.) 30min prior to SCI significantly enhanced the SCBF and reduced the BSCB disruption, edema formation, nNOS upregulation and cell injury. However, HOE-140 in doses ranging from 2mg to 5mg/kg, i.v. did not induce significant neuroprotection. These observations are the first to suggest that bradykinin B2 receptors play an important role in BSCB permeability, SCBF, edema formation, nNOS upregulation and cell injury following acute SCI, not reported earlier., (© 2019 Elsevier Inc. All rights reserved.)

Influence of iron oxide magnetic nanoparticles (IOMNPs, 10nm in diameter, 0.25 or 0.50mg/mL in 100μL, i.v.) on the blood-brain barrier (BBB) permeability, edema formation, and neuronal or glial changes within 4-24h after administration was examined in normal rats and after a focal spinal cord injury (SCI). Furthermore, effect of cerebrolysin, a balanced composition of several neurotrophic factors, and active peptide fragments was also evaluated on IOMNP-induced changes in central nervous system (CNS) pathology. The SCI was inflicted in rats by making a longitudinal incision into the right dorsal horn of the T10-11 segments and allowed to survive 4 or 24h after trauma. Cerebrolysin (2.5mL/kg, i.v.) was given either 30min before IOMNP injection in the 4-h SCI group or 4h after injury in the 24-h survival groups. Control group received cerebrolysin in identical situation following IOMNP administration. In all groups, leakage of serum albumin in the CNS as a marker of BBB breakdown and activation of astrocytes using glial fibrillary acidic protein was evaluated by immunohistochemistry. The neuronal injury was examined by Nissl staining. The IOMNPs alone in either low or high doses did not induce CNS pathology either following 4 or 24h after administration. However, administration of IOMNPs in SCI group slightly enhanced the pathological changes in the CNS after 24h but not 4h after trauma. Cerebrolysin treatment markedly attenuated IOMNP-induced aggravation of SCI-induced cord pathology and induced significant neuroprotection. These observations are the first to show that IOMNPs are safe for the CNS and cerebrolysin treatment prevented CNS pathology following a combination of trauma and IOMNP injection. This indicated that cerebrolysin might be used as adjunct therapy during IOMNP administration in disease conditions, not reported earlier., (© 2017 Elsevier Inc. All rights reserved.)

The possibility that histamine influences the spinal cord pathophysiology following trauma through specific receptor-mediated upregulation of neuronal nitric oxide synthase (nNOS) was examined in a rat model. A focal spinal cord injury (SCI) was inflicted by a longitudinal incision into the right dorsal horn of the T10-11 segments. The animals were allowed to survive 5h. The SCI significantly induced breakdown of the blood-spinal cord barrier to protein tracers, reduced the spinal cord blood flow at 5h, and increased the edema formation and massive upregulation of nNOS expression. Pretreatment with histamine H1 receptor antagonist mepyramine (1mg, 5mg, and 10mg/kg, i.p., 30min before injury) failed to attenuate nNOS expression and spinal cord pathology following SCI. On the other hand, blockade of histamine H2 receptors with cimetidine or ranitidine (1mg, 5mg, or 10mg/kg) significantly reduced these early pathophysiological events and attenuated nNOS expression in a dose-dependent manner. Interestingly, TiO 2 -naowire delivery of cimetidine or ranitidine (5mg doses) exerted superior neuroprotective effects on SCI-induced nNOS expression and cord pathology. It appears that effects of ranitidine were far superior than cimetidine at identical doses in SCI. On the other hand, pretreatment with histamine H3 receptor agonist α-methylhistamine (1mg, 2mg, or 5mg/kg, i.p.) that inhibits histamine synthesis and release in the central nervous system thwarted the spinal cord pathophysiology and nNOS expression when used in lower doses. Interestingly, histamine H3 receptor antagonist thioperamide (1mg, 2mg, or 5mg/kg, i.p.) exacerbated nNOS expression and cord pathology after SCI. These novel observations suggest that blockade of histamine H2 receptors or stimulation of histamine H3 receptors attenuates nNOS expression and induces neuroprotection in SCI. Taken together, our results are the first to demonstrate that histamine-induced pathophysiology of SCI is mediated via nNOS expression involving specific histamine receptors., (© 2017 Elsevier Inc. All rights reserved.)

Previous studies from our laboratory showed that topical application of growth hormone (GH) induced neuroprotection 5 h after spinal cord injury (SCI) in a rat model. Since nanodelivery of drugs exerts superior neuroprotective effects, a possibility exists that nanodelivery of GH will induce long-term neuroprotection after a focal SCI. SCI induces GH deficiency that is coupled with insulin-like growth factor-1 (IGF-1) reduction in the plasma. Thus, an exogenous supplement of GH in SCI may enhance the IGF-1 levels in the cord and induce neuroprotection. In the present investigation, we delivered TiO2-nanowired growth hormone (NWGH) after a longitudinal incision of the right dorsal horn at the T10-11 segments in anesthetized rats and compared the results with normal GH therapy on IGF-1 and GH contents in the plasma and in the cord in relation to blood-spinal cord barrier (BSCB) disruption, edema formation, and neuronal injuries. Our results showed a progressive decline in IGF-1 and GH contents in the plasma and the T9 and T12 segments of the cord 12 and 24 h after SCI. Marked increase in the BSCB breakdown, as revealed by extravasation of Evans blue and radioiodine, was seen at these time points after SCI in association with edema and neuronal injuries. Administration of NWGH markedly enhanced the IGF-1 levels and GH contents in plasma and cord after SCI, whereas normal GH was unable to enhance IGF-1 or GH levels 12 or 24 h after SCI. Interestingly, NWGH was also able to reduce BSCB disruption, edema formation, and neuronal injuries after trauma. On the other hand, normal GH was ineffective on these parameters at all time points examined. Taken together, our results are the first to demonstrate that NWGH is quite effective in enhancing IGF-1 and GH levels in the cord and plasma that may be crucial in reducing pathophysiology of SCI.

Increased levels of ubiquitin and heat shock protein (HSP) 72 kD are often seen in spinal cord injury (SCI). However, their roles in cell injury or survival are not well known. Thus, we have investigated the possible relationship between ubiquitin and HSP expressions in relation to cell injury in healthy animals, or following nanoparticle (NP) intoxication in SCI animals. A focal SCI was inflicted on the T10-11 segments over the right dorsal horn; animals were allowed to survive from 5 to 8 h after trauma. Separate groups of rats were exposed to SiO2, Ag, or Cu NPs for 7 days and subjected to SCI on the eighth day. A marked increase in ubiquitin or HSP immunoreactive cells occurred in the T9 to T12 segments 5 h after the injury, which further extended to the T4 and L5 after 8 h of survival. At this time, a marked increase in blood-spinal cord barrier (BSCB) permeability to Evans blue and radioiodine, accompanied by an intense edema formation, was observed. Changes were further exacerbated in NP-treated traumatized rats. The most marked expressions of ubiquitin and HSP in SCI were seen in rats treated with SiO2, followed by Ag, and Cu NPs. Treatment with H-290/51 (50 mg/kg p.o., 30 to 60 min after injury) or carfilzomib (1 mg/kg, i.v., 30 to 60 min after trauma) significantly reduced the ubiquitin or HSP expressions, as well as the BSCB breakdown, the edema formation, and the cell injury in the cord both 5 and 8 h after the injury, in normal animals. However, a double dose of H-290/51 (100 mg/kg) or carfilzomib (2 mg/kg) is needed to reduce cord pathology or ubiquitin and HSP expressions in traumatized animals treated with NPs. H-290/51 showed superior beneficial effects in reducing cord pathology in SCI than carfilzomib. These observations are the first to demonstrate that (i) NP-treated traumatized animals induce a widespread BSCB leakage, edema formation, and cord pathology as well as an overexpression of ubiquitin and HSP, (ii) high doses of antioxidant compounds or proteasome inhibitors are required for neuroprotection in the NP-exposed traumatized group, and (iii) ubiquitin and HSP expressions play a key role in neuronal injury in SCI, not reported earlier.

Currently, there is a lack of effective therapeutic methods to restore neurological function for chronic complete spinal cord injury (SCI) by conventional treatment. Neurorestorative strategies with positive preclinical results have been translated to the clinic, and some patients have gotten benefits and their quality of life has improved. These strategies include cell therapy, neurostimulation or neuromodulation, neuroprosthesis, neurotization or nerve bridging, and neurorehabilitation. The aim of this consensus by 31 experts from 20 countries is to show the objective evidence of clinical neurorestoration for chronic complete SCI by the mentioned neurorestorative strategies. Complete chronic SCI patients are no longer told, "nothing can be done." The clinical translation of more effective preclinical neurorestorative strategies should be encouraged as fast as possible in order to benefit patients with incurable CNS diseases. This manuscript is published as part of the International Association of Neurorestoratology (IANR) special issue of Cell Transplantation.

The 10th Global College of Neuroprotection and Neuroregeneration Annual Conference in collaboration with the 6th International Association of Neurorestoratology VI Intercontinental Hotel, Bucharest, Romania, 4-7 April 2013 The 10th Global College of Neuroproetction and Neuroregeneration Annual Conference together with the International Association of Neurorestoratology VI was held in Bucharest under the auspicious of the Society for the Study of Neuroprotection and Neuroplasticity during 4-7 April 2013. The focus of these unified societies meeting was on neurorestoration, neuroprotection and neuroregeneration in various clinical neurodegenerative diseases; for example, Alzheimer's, Parkinson's, Huntington's disease, stroke and brain or spinal cord injuries. The main aim to enhance healthcare was suggested by the use of stem cells, nanodrug delivery of drugs and stem cells, use of multimodal drugs as well as a combination of different approaches. The meeting was attended by more than 500 delegates including researches, policy makers and healthcare professionals along with several representatives from drug industries from Europe and USA. It appears that future of neuroprotection could be achieved by the use of stem cells and nanodrug delivery in chronic neurological disorders.

Spinal cord injury (SCI) is a serious clinical situation for which no suitable drug therapy exists. SCI often results in paraplegia or quadriplegia and, apart from the personal trauma leads to huge costs to society for rehabilitation or day-to-day life support. Sensory motor dysfunction following SCI is mainly a consequence of the slowly progressing cord pathology after primary injury that worsens over tine. Thus, almost all sensory and motor nerve control and pathways passing through spinal cord and reflexes are compromised in SCI patients. As a result their peripheral nervous system, autonomic nervous function and central nervous system regulations are adversely affected. Experiments carried out in our laboratory show that various therapeutic agents, if given within 10 to 30 minutes after primary SCI could correct morphological changes to a certain extent. In these rat models of SCI reduction in cord pathology, e.g., bloodspinal cord barrier (BSCB) breakdown, edema formation and cell injury by the neuroprotective agents that also limited sensory motor dysfunction and improved functional behavior. However, these drugs if given beyond 30 minutes after SCI showed a markedly reduced neuroprotective efficacy. Thus, new strategies are needed to enhance neuroprotection in SCI to prevent structural and functional changes over longer periods of time. To that end our laboratory has initiated a series of investigations in which nanowired delivery of various neurotherapeutic agents are applied after different time periods of SCI, that resulted in a much better outcome than with the parent compounds under identical conditions. The superior neuroprotective activity of nanowired compound delivery could be due to a reduced metabolism of active compounds in the central nervous system (CNS) or by sustained release of the drug for longer times. In addition, nanowired drugs may penetrate the CNS faster and could reach widespread areas once entering the spinal cord. Thus, nanowired drug delivery to treat SCI may have potential therapeutic value. These aspects of nanowired drug delivery to enhance neuroprotection in SCI are discussed in this review based on our own investigations.

Central nervous system (CNS) injury is a complex in which numerous neurochemicals and other vasoactive agents actively contribute towards the development of posttraumatic brain pathology and/or repair mechanisms. A focal trauma to the brain or spinal cord releases several endogenous neurodestructive agents within the CNS, resulting in adverse cellular reactions. Our laboratory is engaged in identifying these endogenous neurodestructive signals in the CNS following injury caused by trauma or hyperthermia. Our observations show that serotonin (5-HT), dynorphin A (Dyn A 1-17), nitric oxide synthase (NOS), and tumor necrosis factor-α (TNF-α) could be potential neurodestructive signals in the CNS injury. Thus, neutralization of these agents using monoclonal antibodies directed against 5-HT, NOS, Dyn A (1-17), and TNF-α in vivo will result in marked neuroprotection and enhance neurorepair after trauma. In addition, a suitable combination of monoclonal antibodies, for example, NOS and TNF-α, when applied 60-90 min after trauma, is capable to enhance neuroprotective ability and thwart cell and tissue injury after spinal cord insult. Taken together, our novel observations suggest a potential use of monoclonal antibodies as suitable therapeutic agents in CNS injuries to achieve neuroprotection and/or neurorepair., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Spinal cord injury (SCI) is a serious clinical problem that causes lifetime disabilities to victims and inflicting huge social burden on our society. One of the main lacunae in developing potential therapeutic measures in SCI is a lack of suitable animal models that could be comparable to clinical situations. Thus, development of new animal models of SCI is highly needed to expand our knowledge on cell injury and repair process in order to reduce cord pathology, and in translating advanced therapies in patients of SCI to improve therapeutic strategies. Keeping these views in mind, a suitable animal model is developed in our laboratory that can be used to explore new therapeutic tools in SCI. The details of our methods used to induce SCI in rodents and neuroprotection achieved by use of selected neurotrophic factors are described in this chapter.

Spinal cord injury (SCI) is a devastating disease that leads to permanent disability of victims for which no suitable therapeutic intervention has been achieved so far. Thus, exploration of novel therapeutic agents and nano-drug delivery to enhance neuroprotection after SCI is the need of the hour. Previous research on SCI is largely focused to improve neurological manifestations of the disease while ignoring spinal cord pathological changes. Recent studies from our laboratory have shown that pathological recovery of SCI appears to be well correlated with the improvement of sensory motor functions. Thus, efforts should be made to reduce or minimize spinal cord cell pathology to achieve functional and cellular recovery to enhance the quality of lives of the victims. While treating spinal cord disease, recovery of both neuronal and non-neuronal cells, e.g., endothelia and glial cells are also necessary to maintain a healthy spinal cord function after trauma. This review focuses effects of novel therapeutic strategies on the role of spinal cord microvascular reactions and endothelia cell functions, i.e., blood-spinal cord barrier (BSCB) in SCI and repair mechanisms. Thus, new therapeutic approach to minimize spinal cord pathology after trauma using antibodies to various neurotransmitters and/or drug delivery to the cord directly by topical application to maintain strong localized effects on the injured cells are discussed. In addition, the use of nanowired drugs to affect remote areas of the cord after their application on the injured spinal cord in thwarting the injury process rapidly and to enhance the neuroprotective effects of the parent compounds are also described in the light of current knowledge and our own investigations. It appears that local treatment with new therapeutic agents and nanowired drugs after SCI are needed to enhance neurorepair leading to improved spinal cord cellular functions and the sensory motor performances.

The possibility that neutralization of nitric oxide synthase and tumor necrosis factor alpha (TNF-alpha) in the cord using their antiserum will induce neuroprotection and improve functional outcome following spinal cord injury (SCI) was examined in a rat model. The SCI was induced in rats by a unilateral incision of the right dorsal horn at the T10-11 segments under equithesin anesthesia. TNF-alpha and/or neuronal nitric oxide synthase (nNOS) antibodies were applied over the traumatized spinal cord at 10-90 minutes after injury and functional recovery and cord pathophysiology were examined at five hours. Topical application of TNF-alpha antiserum at 10 min followed by NOS antiserum at 20 min after SCI significantly improved functional recovery and attenuated blood-spinal cord barrier (BSCB) disturbances, edema formation, and cord pathology. These neuroprotective effects were also seen when the NOS antiserum was applied 10 min after injury followed by TNF-alpha antiserum at 30 min after trauma. However, when TNF-alpha antiserum was applied 1 h after injury and NOS antiserum was given either before or after TNF-alpha antiserum, no neuroprotective effects were observed. Interestingly, neuronal injury was tightly correlated with nNOS expression in the cord in antibody treated groups. These novel observations suggest that early blockade of TNF-alpha and nNOS expression within 20-30 min after SCI is beneficial in nature. This indicates that TNF-alpha and nitric oxide play synergistic roles in the pathophysiology of SCI and combined antibodies therapy has added neuroprotective values in spinal trauma.

The possibility that drugs attached to nanowires enhance their therapeutic efficacy was examined in a rat model of spinal cord injury (SCI). Three Acure compounds AP-173, AP-713 and AP-364 were tagged with TiO(2)-based nanowires (50-60 nm) and applied over the traumatized cord either 5 or 60 min after SCI in rats produced by a longitudinal incision into the right dorsal horn of the T10-11 segments under equithesin anaesthesia. Normal compounds were used for comparison. After 5 h SCI, behavioral outcome, blood-spinal cord barrier (BSCB) permeability, edema formation and cell injury were examined. Topical application of nanowired compound AP-713 (10 microg in 20 microL) when applied either 5 or 60 min after injury markedly attenuated behavioral dysfunction at 2-3 h after SCI and reduces BSCB disruption, edema formation and cord pathology at 5 h compared to other compounds. Whereas normal compounds applied at 5 min after injury (but not after 60 min) had some significant but less beneficial effects compared to their nanowired combinations. On the other hand, nanowires alone did not influence spinal cord pathology or motor function after SCI. Taken together, our results indicate that the nanowired-drug-delivery enhances the neuroprotective efficacy of drugs in SCI and reduces functional outcome compared to normal compounds even applied at a later stage following trauma, not reported earlier.

The possibility that a combination of neurotrophins induces long-lasting neuroprotection of the cord following spinal cord injury (SCI) was examined in a rat model. The SCI was performed by making a unilateral incision into the right dorsal horn of the T10-11 segments and the animals were allowed to survive 5 h after trauma. Different combination of neurotrophins, i.e., BDNF in combination with GDNF, NT-3, or NGF was applied topically over the traumatized spinal cord and motor dysfunction, blood-spinal cord barrier (BSCB) breakdown, edema formation, and cell injury were examined. Topical application of BDNF in combination with GDNF and NGF 30 min (but not 60 or 90 min) at high concentrations (0.5 microg each) after SCI significantly improved motor function and reduced BSCB breakdown, edema formation, and cell injury at 5 h. However, concurrent application of BDNF, IGF-1, and GDNF (but not with NT-3 or NGF) even 60 or 90 min after trauma induced a significant reduction in motor dysfunction and spinal cord pathology. These observations suggest that a combination of neurotrophins may have added therapeutic value in the treatment of SCI, not reported earlier.

Silicon (SiO2) nanoparticles or silica dust is quite common form of exposure to soldiers engaged in gulf war that may influence their health and brain function. It is quite likely that traumatic injuries to the CNS may be influenced by exposure to these nanoparticles. However, the details of silicon nanoparticles on human health functions are still unknown. In this investigation we examined the effects of chronic silicon dioxide nanoparticles (SiO2, 40-50 nm) exposure on spinal cord injury (SCI) induced alterations on the functional outcome and the cord pathology in a rat model. Since nanoparticles induce oxidative stress, the influence of an antioxidant compound H-290/51 was also examined in these nanoparticles treated injured rats as well. Rats treated with SiO2 for 7 days did not show any significant alteration in behaviour on rota rod performances or on capacity angle tests. However, subjection of these nanoparticles exposed rats to SCI resulted in a profound deterioration in motor functions compared to normal rats with SCI. The magnitude of blood-spinal cord barrier (BSCB) disruption to Evans blue and radioiodine tracers and edema formation was much more aggravated following SCI in nanoparticles treated animals compared to untreated traumatized rats. Pretreatment with H-290/51 (50 mg/kg, p.o.) 30 min before SCI in nanoparticle treated rats did not alter spinal cord pathology or functional outcome, however, this dose of the compound was very effective in reducing pathophysiology of SCI in normal animals. These observations are the first to suggest that exposure of nanoparticles enhances the sensitivity of CNS to injuries and alter the effect of neuroprotective drugs.

Recently nano-drug delivery to the central nervous system (CNS) has been shown to be more effective than the parent compound by itself. An increased availability of the drug for longer periods to the brain or spinal cord and/or a decrease in the drug metabolism altogether could lead to potentiation of the pharmacological activity of the nano-delivered compounds. However, it is still unclear whether the nanocarriers used to deliver the drugs may itself has any potential neurotoxic activity. Although, nanodrug-delivery appears to be a quite promising therapeutic tool for the future clinical therapy, its advantages and limitations for the routine use of patients still needs to be elucidated. Our laboratory is engaged to study a plethora of potential neuroprotective novel compounds delivered to the CNS using nanowiring techniques following brain or spinal cord trauma. Our investigations show that nanowired drugs, if delivered locally following spinal cord injury achieve better neuroprotection than the parent compounds. This effect of nano-drug delivery appears to be very selective in nature. Thus, a clear differentiation based on the compounds used for nano-drug delivery can be seen on various pathological parameters in spinal cord injury. These observations suggest that nanowiring may itself do not induce neuroprotection, but enhance the neuroprotective ability of compounds after trauma. This review describes some recent advances in nano-drug delivery to the CNS in relation to novel neuroprotective strategies with special emphasis on spinal cord trauma based on our own observations and recent findings from our laboratory investigations.

Spinal cord injury (SCI) is a serious clinical problem for which no suitable therapeutic strategies have been worked out so far. Recent studies suggest that the SCI and its pathophysiological responses could be altered by systemic exposure to nanoparticles. Thus, SCI when made in animals intoxicated with engineered nanoparticles from metals or silica dust worsened the outcome. On the other hand, drugs tagged with titanium (TiO(2)) nanoparticles or encapsulated in liposomes could enhance their neuroprotective efficacy following SCI. Thus, to expand our knowledge on nanoparticle-induced alterations in the spinal cord pathophysiology further research is needed. These investigations will help to develop new strategies to achieve neuroprotection in SCI, for example, using nanodrug delivery. New results from our laboratory showed that nanoparticle-induced exacerbation of cord pathology following trauma can be reduced when the suitable drugs tagged with TiO(2) nanowires were administered into the spinal cord as compared to those drugs given alone. This indicates that nanoparticles depending on the exposure and its usage could induce both neurotoxicity and neuroprotection. This review discusses the potential adverse or therapeutic utilities of nanoparticles in SCI largely based on our own investigations. In addition, possible mechanisms of nanoparticle-induced exacerbation of cord pathology or enhanced neuroprotection following nanodrug delivery is described in light of recently available data in this rapidly emerging field of nanoneurosciences., (Copyright 2009 Elsevier B.V. All rights reserved.)

Spinal cord injury (SCI) is a serious clinical disorder that leads to lifetime disability for which no suitable therapeutic agents are available so far. Further research is needed to understand the basic mechanisms of spinal cord pathology that results in permanent disability and poses a heavy burden on our society. In the past, a lot of effort was placed on improving functional outcome with the help of various therapeutic agents, however less attention has been paid on the development and propagation of spinal cord pathology over time. Thus, it is still unclear whether improvement of functional outcome is related to spinal cord pathology or vice versa. Few drugs are able to influence functional outcome without having any improvement on cord pathology. Some drugs, however, can lessen cord pathology but fail to influence the functional outcome. The goal of future treatment options for SCI is therefore to find suitable new drugs or a combination of existing drugs and to use various cellular transplants, neurotrophic factors, myelin-inhibiting factors, tissue engineering and nano-drug delivery to improve both the functional and the pathological outcome in the inured patient. This review deals with the key aspects of the latest treatments for SCI and suggests some possible future therapeutic measures to enhance healthcare in clinical situations.

Previously, we have shown that topical application of brain-derived neurotrophic factor (BDNF) or insulin-like growth factor 1 (IGF-1) given within 5 to 30 min after a focal trauma to the rat spinal cord attenuates spinal cord injury (SCI)-induced breakdown of the blood-spinal cord barrier (BSCB), edema formation, motor dysfunction, and cell injury. This investigation was undertaken to find out whether a combination of select neurotrophins (BDNF, glial cell line-derived neurotrophic factor [GDNF], neurotrophin 3 [NT-3], or nerve growth factor [NGF]) will further enhance the neuroprotective efficacy of growth factors in SCI. The neurotrophins (0.1-1 microg/10 microL in phosphate-buffered saline) were applied 30, 60, or 90 min after injury topically over the traumatized spinal cord either alone or in combination. The SCI was performed by making a unilateral incision into the right dorsal horn of the T10-T11 segment under Equithesin anesthesia. The rats were allowed to survive 5 h after trauma. Topical application of BDNF, GDNF, or NGF 30 min after SCI in high concentration (0.5 microg and 1 microg) significantly improved the motor functions and reduced the BSCB breakdown, edema formation, and cell injury seen at 5 h. These beneficial effects of neurotropins were absent when administered separately either 60 or 90 min after SCI. However, a combination of BDNF and GDNF (but not with NT-3 or NGF) given either 60 or 90 min after SCI significantly reduced the motor dysfunction and spinal cord pathology at 5 h. These novel observations suggest that a select group of neurotrophins in combination have potential therapeutic value for the treatment of SCI in clinical situations.

The possibility that drugs attached to innocuous nanowires enhance their delivery within the central nervous system (CNS) and thereby increase their therapeutic efficacy was examined in a rat model of spinal cord injury (SCI). Three compounds--AP173 (SCI-1), AP713 (SCI-2), and AP364 (SCI-5) (Acure Pharma, Uppsala, Sweden)--were tagged with TiO(2)-based nanowires using standard procedure. Normal compounds were used for comparison. SCI was produced by making a longitudinal incision into the right dorsal horn of the T10-T11 segments under Equithesin anesthesia. The compounds, either alone or tagged with nanowires, were applied topically within 5 to 10 min after SCI. In these rats, behavioral outcome, blood-spinal cord barrier (BSCB) permeability, edema formation, and cell injury were examined at 5 h after injury. Topical application of normal compounds in high quantity (10 microg in 20 microL) attenuated behavioral dysfunction (3 h after trauma), edema formation, and cell injury, as well as reducing BSCB permeability to Evans blue albumin and (131)I. These beneficial effects are most pronounced with AP713 (SCI-2) treatment. Interestingly, when these compounds were administered in identical conditions after tagging with nanowires, their beneficial effects on functional recovery and spinal cord pathology were further enhanced. However, topical administration of nanowires alone did not influence trauma-induced spinal cord pathology or motor functions. Taken together, our results, probably for the first time, indicate that drug delivery and therapeutic efficacy are enhanced when the compounds are administered with nanowires.

New compounds having affinity to various melanocortin receptors have recently been identified as possible neuroprotective agents. This review is focused on the role of neuroprotective effects of melanocortins in CNS injury and repair mechanisms. Using selective non-peptidic compounds with varying affinity to melanocortin receptors, our laboratory has shown their anti-edematous effects in the spinal cord injury. This effect of the compounds is related with their ability to attenuate blood-spinal cord barrier permeability. The functional significance and possible therapeutic strategies of these compounds in CNS injury are discussed.

Several neurotrophic factors are known to induce neuroprotection in traumatic injuries to the central nervous system (CNS). However, many neurotrophins are unable to attenuate cell death following CNS injuries. New data generated in our laboratory show that a suitable combination of neurotrophic factors may enhance the neuroprotective efficacy of neurotrophins on cell and tissue injury and improve sensory motor functions. This novel aspect of neurotrophins treatment in combination in spinal cord injury (SCI) induced behavioral dysfunctions and spinal cord pathology is examined in a rat model. Our investigations suggest that a suitable combination of neurotrophins will attenuate both neural and non-neural (glial cells and endothelial cells) damage in SCI leading to enhanced neuroprotection. The possible cellular and molecular mechanisms of synergistic effects of some neurotrophins in combination are still speculative and require further investigation.

Alterations in the spinal cord microenvironment in a neuropathic pain model in rats comprising right L-4 spinal nerve lesion were examined following 1, 2, 4 and 10 weeks using albumin and glial fibrillary acidic protein (GFAP) immunoreactivity. Rats subjected to nerve lesion showed pronounced activation of GFAP indicating astrocyte activation, and exhibited marked leakage of albumin, suggesting defects of the blood-spinal cord barrier (BSCB) function in the corresponding spinal cord segment. The intensities of these changes were most prominent in the gray matter of the lesioned side compared to the contralateral cord in both the dorsal and ventral horns. The most marked changes in albumin and GFAP immunoreaction were seen after 2 weeks and persisted with mild intensities even after 10 weeks. Distortion of nerve cells, loss of neurons and general sponginess were evident in the gray matter of the spinal cord corresponding to the lesion side. These nerve cell and glial cell changes was mainly evident in the areas showing leakage of endogenous albumin in the spinal cord. These novel observations indicate that chronic nerve lesion has the capacity to induce a selective increase in local BSCB permeability that could be instrumental in nerve cell and glial cell activation. These findings may be relevant to our current understanding on the pathophysiology of neuropathic pain.

The possibility that local administration of low molecular weight non-peptide compounds with varying affinities at melanocortin receptors in the spinal cord will influence pathophysiological outcome of spinal cord injury (SCI) was examined in a rat model. Five new Melacure compounds ME10092, ME10354, ME10393, ME10431 and ME10501 were used in this investigation. Each compound was dissolved in saline and tested at 3 different doses, i.e. 1 microg, 5 microg and 10 microg total dose in 10 microl applied topically 5 min after SCI. The animals were allowed to survive 5 h and trauma induced edema formation, breakdown of the blood-spinal cord barrier (BSCB) and cell injuries were examined and compared with untreated injured rats. A focal SCI inflicted by an incision into the right dorsal horn of the T10-11 segments resulted in marked edema formation, breakdown of the BSCB to Evans blue albumin and caused profound nerve cell injury in the T9 and the T12 segments. Topical application of ME10501 (a compound with high affinity at melanocortin, MC-4 receptors) in high doses (10 microg) resulted in most marked neuroprotection in the perifocal spinal cord (T9 and T12) segments. On the other hand, only a mild or no effect on spinal cord pathology was observed in the traumatized animals that received ME10092, ME10354, ME10393 and ME10431 at 3 different doses. These observations suggest that non-peptide compounds with varying affinity to melanocortin receptors are able to influence the pathophysiology of SCI. Furthermore, compounds acting at melanocortin, MCR4 receptors are capable to induce neuroprotection in spinal cord following trauma.

The possibility that oxidative stress participates in heat shock protein 72 kD (HSP 72) expression following a focal trauma to the spinal cord was examined using a potent antioxidant compound H-290/51 in a rat model. A focal spinal cord injury (SCI) inflicted by making a longitudinal incision on the right dorsal horn of the T10-T11 segment under equithesin anaesthesia resulted in profound upregulation of HSP 72 expression in the adjacent spinal cord segments T9 and T12. This expression of HSP was most marked in the ipsilateral cord at 5 h after SCI. Pretreatment with H-290/51 (50 mg/kg, p.o.) 30 min before SCI markedly attenuated HSP expression in the spinal cord seen at 5 h. The motor functions of traumatized rats were also improved in the drug treated group. At this time, structural changes in the spinal cord and edema formation were considerable reduced compared to the untreated traumatized rats. Taken together, these observations suggest that (i) oxidative stress participates in HSP response following trauma, and (ii) the antioxidant compound H-290/51 attenuates cellularstress, improves motor functions and induces considerable neuroprotection in the early phase of SCI. Further studies using post-injury treatment with H-290/51 is needed to explore its therapeutic potentials in clinical settings.

We examined the potential efficacy of brain-derived neurotrophic factor (BDNF) and glial-derived neurotrophic factor (GDNF) applied over traumatized spinal cord, alone or in combination, for attenuating motor dysfunction, blood-spinal cord barrier (BSCB) breakdown, edema formation, and cell injury in a rat model. Under Equithesin anesthesia, spinal cord injury (SCI) was performed by making a unilateral incision into the right dorsal horn of the T10-11 segment. The rats were allowed to survive 5 hours after trauma. The BDNF or GDNF was applied (0.1 to 1 microg/10 microl in phosphate buffer saline) 30, 60, or 90 minutes after SCI. Topical application of BDNF or GDNF 30 minutes after SCI in high concentration (0.5 microg and 1 microg) significantly improved motor function and reduced BSCB breakdown, edema formation, and cell injury at 5 hours. These beneficial effects of neurotrophins were markedly absent when administered separately either 60 or 90 minutes after injury. However, combined application of BDNF and GDNF at 60 or 90 minutes after SCI resulted in a significant reduction in motor dysfunction and spinal cord pathology. These novel observations suggest that neurotrophins in combination have potential therapeutic value for the treatment of SCI in clinical situations.

The possibility that a chronic nerve ligation impairs the spinal cord cellular microenvironment was examined using leakage of endogenous albumin, reaction of astrocytes, and structural changes in a rat model. Rats subjected to 8 weeks of unilateral L4/L5 nerve ligation (a model of neuropathic pain) showed leakage of albumin, up-regulation of glial fibrillary acidic protein (GFAP) immunoreaction, and abnormal cell reaction. Distortion and loss of nerve cells as well as general sponginess of the gray matter was clearly evident. Cell changes were present in both dorsal and ventral horns and were most marked on the ipsilateral side compared to the contralateral cord. Nerve cell and glial cell changes are normally present in the regions showing intense albumin immunoreactivity, indicating disruption of the blood-spinal cord barrier (BSCB). Our observations indicate that a chronic nerve lesion has the capacity to induce selective breakdown of the BSCB that could be responsible for activation of astrocytes and abnormal cell reaction. These findings enhance our understanding of the pathophysiology of neuropathic pain and/or other spinal cord disorders.

The role of histamine in edema formation, blood-spinal cord barrier (BSCB) permeability, and spinal cord blood flow (SCBF) following spinal cord injury (SCI) was examined using modulation of histamine H1, H2, and H3 receptors in the rat. Focal trauma to the spinal cord at the T10-11 level significantly increased spinal cord edema formation, BSCB permeability to protein tracers and SCBF reduction in the T9 and T12 segments. Pretreatment with histamine H1 receptor antagonist mepyramine (1 mg, 5 mg, and 10 mg/kg, i.p.) did not attenuate spinal pathophysiology following SCI. Blockade of histamine H2 receptors with cimetidine or ranitidine (1 mg, 5 mg, or 10 mg/kg 30 minutes before injury) significantly reduced early pathophysiological events in a dose dependent manner. The effects of ranitidine were far superior to cimetidine in identical doses. Pretreatment with a histamine H3 receptor agonist alpha-methylhistamine (1 mg and 2 mg/kg/i.p.), that inhibits histamine synthesis and release in the CNS, thwarted edema formation, BSCB breakdown, and SCBF disturbances after SCI. The lowest dose of histamine H3 agonist was most effective. Blockade of histamine H3 receptors with thioperamide (1 mg, 5 mg/kg, i.p.) exacerbated spinal cord pathology. These observations suggest that stimulation of histamine H3 receptors and blockade of histamine H2 receptors is neuroprotective in SCI.

The neuroprotective efficacy of post-injury treatment with the antioxidant compound H-290/51 (10, 30, and 60 minutes after trauma) on immediate early gene expression (c-fos), blood-spinal cord barrier (BSCB) permeability, edema formation, and motor dysfunction was examined in a rat model of spinal cord injury (SCI). SCI was produced by a longitudinal incision into the right dorsal horn of the T10-11 segment under Equithesin anesthesia. Focal SCI in control rats resulted in profound up-regulation of c-fos expression, BSCB dysfunction, edema formation, and cell damage in the adjacent T9 and T12 segments at 5 hours. Pronounced motor dysfunction was present at this time as assessed using the Tarlov scale and the inclined plane test. Treatment with H-290/51 (50 mg/kg, p.o.) 10 and 30 minutes after SCI (but not after 60 minutes) markedly attenuated c-fos expression and motor dysfunction. In these groups, BSCB permeability, edema formation, and cell injuries were mildly but significantly reduced. These observations suggest that (i) antioxidants are capable of attenuating cellular and molecular events following trauma, and (ii) have the capacity to induce neuroprotection and improve motor function if administered during the early phase of SCI, a novel finding.

Previous investigations from our laboratory show that up-regulation of neuronal nitric oxide synthase (NOS) following spinal cord injury (SCI) is injurious to the cord. Antiserum to dynorphin A (1-17) induces marked neuroprotection in our model of SCI, indicating an interaction between dynorphin and NOS regulation. The present investigation was undertaken to find out whether topical application of dynorphin A (1-17) antiserum has some influence on neuronal NOS up-regulation in the traumatized spinal cord. SCI was produced in anesthetized animals by making a unilateral incision into the right dorsal horn of the T10-11 segments. The antiserum to dynorphin A (1-17) was applied (1 : 20, 20 microL in 10 seconds) 5 minutes after trauma over the injured spinal cord and the rats were allowed to survive 5 hours after SCI. Topical application of dynorphin A (1-17) antiserum significantly attenuated neuronal NOS up-regulation in the adjacent T9 and T12 segments. In the antiserum-treated group, spinal cord edema and cell injury were also less marked. These observations provide new evidence that the opioid active peptide dynorphin A may be involved in the mechanisms underlying NOS regulation in the spinal cord after injury, and confirms our hypothesis that up-regulation of neuronal NOS is injurious to the cord.

The role of nitric oxide (NO) in spinal cord injury (SCI)-induced motor dysfunction, breakdown of the blood-spinal cord barrier (BSCB), edema formation, and cell injury was examined using a pharmacological approach. We used three types of nitric oxide synthase (NOS) inhibitors: a nonselective blocker, L-NAME; an irreversible inhibitor of all isoforms of NOS, L-NMMA; and a long-term competitive inhibitor of neuronal NOS with equal potency to inhibit endothelial NOS, L-NNA. The compounds were administered once daily in separate groups of rats for 7 days. On the 8th day, SCI was performed by making a longitudinal incision into the right dorsal horn of the T10-11 segments, and the rats were allowed to survive 5 h after injury. Long-term treatment with L-NNA attenuated SCI-induced NOS upregulation, BSCB breakdown, edema formation, and cell injury, whereas comparatively less neuroprotection is offered by L-NMMA. The magnitude of neuroprotection is much less evident in injured animals that received L-NAME. Interestingly, SCI-induced motor dysfunction measured according to the Tarlov scale showed close correlation with the magnitude of neuroprotection. Thus, an improvement in motor function was seen in animals pretreated with L-NNA, whereas rats treated with L-NAME or L-NMMA did not show any influence on motor dysfunction after SCI. This observation suggests that inhibition of neuronal NOS is important for neuroprotection, and the disturbances in motor function following SCI are associated with the state of spinal cord pathology.

Spinal cord injury (SCI) induces lifetime disability, and no suitable therapy is available to treat victims or to minimze their sufferings. Recently, neurotrophins and compounds acting at melanocortin receptors have been been identified as potential neuroprotective agents. In this investigation, the neuroprotective effects of neurotrophins and melanocortins on the pathophysiology of SCI were examined in a rat model. The SCI was produced by making a longitudinal incision into the right dorsal horn of the T10-11 segments under equithesin anesthesia. In separate groups, neurotrophins [BDNF or IGF-1 (0.1-1 microg/10 microL in saline)] or melanocortins (ME10092, ME10354, ME10393, ME10431, and ME10501, having affinities to melanocortin receptors; 1-10 mug in saline) were applied topically over the traumatized cord segment within 5-10 min after SCI and the rats were allowed to survive for 5 h. A focal SCI resulted in widespread disruption of the blood-spinal cord barrier (BSCB) to Evans blue albumin (EBA), ([131])iodine, or lanthanum tracers and exhibited profound edema formation and cell or tissue destruction. Topical application of BDNF, IGF-1, or ME10501 (having high affinity to melanocortin-4 receptor, MCR-4) in high quantity markedly attenuated BSCB disruption, edema formation, and nerve cell, glial cell, and axonal injuries. On the other hand, low doses of neurotrophins or melanocortins were not effective in attenuating pathophysiology of SCI. These observations suggest that neurotrophins (BDNF and IGF-1) and melanocortins (with high affinity to MCR-4) are capable of inducing neuroprotection if applied shortly after trauma in high doses. Taken together, the results indicate that neurotrophins and melanocortins participate in the pathophysiology of spinal cord cell and tissue injury following trauma.

Blood-spinal cord barrier (BSCB) plays an important role in the regulation of the fluid microenvironment of the spinal cord. Trauma to the spinal cord impairs the BSCB permeability to proteins leading to vasogenic edema formation. Several endogenous neurochemical mediators and growth factors contribute to trauma induced BSCB disruption. Studies carried out in our laboratory suggest that those drugs and neurotrophic factors capable to attenuate the BSCB dysfunction following trauma are neuroprotective in nature. Whereas, agents that do not exert any influence on the BSCB disruption failed to reduce cell injury. These observations are in line with the idea that BSCB disruption plays an important role in the pathophysiology of spinal cord injuries. The probable mechanism(s) of trauma induced BSCB dysfunction and its contribution to cell injuries are discussed.

The possibility that five new low molecular weight compounds with varying affinity and selectivity to the melanocortin receptors will exert neuroprotective effects in the spinal cord injury (SCI) induced edema formation and cell damage was examined in a rat model. A focal trauma of the rat spinal cord made by an incision into the right dorsal horn (T10-11) resulted in profound edema formation, leakage of Evans blue albumin and cell injury of the T9 segment at 5 h. Topical application of the Melacure compound ME10501 in high doses (10 microg in 10 microl) given 5 min after SCI resulted in most significant neuroprotection of the T9 segment of the cord compared to other compounds. Thus, marked reduction in water content, leakage of Evans blue albumin, and cell injury were observed in ME10501 treated traumatised rats. These observations suggest that the non-peptide compound ME10501 with affinity to the melanocortin receptor MC4 is capable to induce neuroprotection in the spinal cord following trauma not reported earlier.

The possibility that the upregulation of hemeoxygenase (HO) enzyme responsible for carbon monoxide (CO) formation in the spinal cord following trauma is involved in edema formation and cell damage was examined in a rat model. A focal trauma to the rat spinal cord by making an incision into the right dorsal horn of the T10-11 segment resulted in profound upregulation of HO-2 (the constitutive isoform of the enzyme) expression in the T9 and T12 segments 5 h after injury. In these segments a marked increase in edema formation, nerve cell damage, and expression of heat shock protein (HSP 72) were observed. Pretreatment with p-chlorophenylalanine (p-CPA, a serotonin synthesis inhibitor) significantly attenuated the trauma induced edema formation, cell injury, and HSP expression. Upregulation of HO-2 in p-CPA treated traumatised rats was considerably reduced. These observations suggest that (i) spinal cord injury has the capacity to induce an upregulation of HO-2 and HSP expression, (ii) abnormal production of CO as reflected by HO-2 expression is injurious to the cord, and (iii) that endogenous serotonin is involved in HO-2 expression in the cord.

The possibility that antiserum to tumour necrosis factor-alpha (TNF-alpha) is neuroprotective in spinal cord injury (SCI) was examined in a rat model. SCI was produced by making an incision into the right dorsal horn at the T10-11 segments. Top TNF-alpha antiserum at three concentrations (1:10; 1:50 and 1:100) given 30 min before or 2 min, 5 min or 10 min after trauma resulted in marked reduction in visible swelling, edema formation, and leakage of radiolabelled iodine tracer within the T9 and T12 segments at 5 h in a dose dependent manner. This neuroprotective effect was most pronounced when the antiserum at the highest dose level (1:10) was applied 10 min after SCI. The TNF-alpha antiserum also reduced the SCI induced upregulation of neuronal nitric oxide synthase (nNOS) immunoreactivity in a concentration dependent manner. Taken together, these results suggest that local application of TNF-alpha antiserum is neuroprotective in SCI and that this effect is mediated through NOS regulation.

The influence of the potent L-type Ca[2+] channel antagonist Nimodipine on spinal cord evoked potentials (SCEP) and axonal injury following trauma to the spinal cord was examined in a rat model. Spinal cord injury (SCI) was produced by an incision into the right dorsal horn of the T10-11 segments under urethane anaesthesia (1.5 g/kg, i.p.). SCEPs were recorded by epidural electrodes placed over the T9 (rostral) and T12 (caudal) segments after stimulation of the right tibial and sural nerves. SCI induced a pronounced decrease of the SCEP negative amplitude in the rostral (T9) recordings immediately after trauma. Axonal injury seen as degradation of myelin basic protein (MBP) immunostaining and myelin vesiculation at the ultrastructural level was most pronounced at 5 h. Continuous administration of Nimodipine (2 microg/kg/min, i.v.) from 30 min prior to injury until sacrifice markedly attenuated the changes in SCEP amplitude and latency. Axonal damage, loss of MBP, and myelin vesiculation were much less evident in the nimodipine treated traumatised rats. These observations suggest that Ca[2+] channels play an important role in the trauma induced alterations in SCEP and axonal injury, and indicate a therapeutic value of Ca[2+] blockers in SCI.

Alterations of the blood-spinal cord barrier (BSCB) following spinal cord injury (SCI) and leakage of serum proteins induce vasogenic edema and cell damage. The possibility that two members of the neurotrophin family, BDNF or IGF-1 induce neuroprotection by attenuating the BSCB permeability following trauma was examined in a rat model. Repeated topical application of BDNF or IGF-1 (0.1 1microg, 0.5 microg or 1 microg in 10 microl) onto the spinal cord 30 min before SCI or 2, 5, 10 or 30 min thereafter significantly attenuated BSCB permeability to Evans blue and iodine. In the neurotrophin treated rats. edema formation, degradation of MBP, and myelin vesiculation were much less frequent compared to the untreated traumatised rats. The protective effect of BDNF and IGF-1 was most pronounced at the high dose (1 microg in 10 microl) given either 30 min before or within 10 min after SCI. The observations suggest that early intervention with neurotrophins in high doses following trauma (within 10 min) attenuates disturbances of the fluid microenvironment of the spinal cord. This indicates that BSCB opening plays an important role in SCI induced myelin vesiculation and cord pathology.

The role of oxidative stress in spinal cord injury (SCI) induced upregulation of constitutive or inducible isoforms of nitric oxide synthase (cNOS or iNOS) is not well known. The present investigation was undertaken to examine the influence of an antioxidant compound H-290/51 (Astra-Zeneca, Mölndal, Sweden) on SCI induced cNOS and iNOS upregulation in a rat model. SCI induced by incision into the right dorsal horn of the T10-11 segment resulted in marked NOS upregulation. Upregulation of cNOS was most prominent in the uninjured T9 and T12 segments. On the other hand, iNOS expression was most marked in the injured T10-11 segments. These NOS immunoreactivities were mainly confined to the injured cells located in the edematous regions of the cord exhibiting profound leakage of Evans blue and [131]Iodine-sodium tracers. Pre-treatment with H-290/51 markedly attenuated the trauma-induced cNOS and iNOS expression along with the microvascular permeability disturbances, edema formation and cell injury. These results suggest that (i) oxidative stress is involved in SCI induced induction of cNOS and iNOS, (ii) NO plays an important role in the cord pathology, and (iii) that the compound H-290/51 has a potential therapeutic value in SCI.