Restorative Neurology and Neuroscience

Purpose: The effect of the transplantation of choroid plexus epithelial cells (CPECs) on locomotor improvement and tissue repair including axonal extension in spinal cord lesions was examined in rats with spinal cord injury (SCI).

Methods: CPECs were cultured from the choroid plexus of green fluorescent protein (GFP)-transgenic rats, and transplanted directly into the contusion-injured spinal cord lesions of rats of the same strain. Locomotor behaviors were evaluated based on BBB scores every week after transplantation until 4 weeks after transplantation. Histological and immunohistochemical examinations were performed at 2 days, and every week until 5 weeks after transplantation.

Results: Locomotor behaviors evaluated by the BBB score were significantly improved in cell-transplanted rats. Numerous axons grew, with occasional interactions with CPECs, through the astrocyte-devoid areas. These axons exhibited structural characteristics of peripheral nerves. GAP-43-positive axons were found at the border of the lesion 2 days after transplantation. Cavity formation was more reduced in cell-transplanted than control spinal cords. CPECs were found within the spinal cord lesion, and sometimes in association with astrocytes at the border of the lesion until 2 weeks after transplantation.

Conclusion: The transplantation of CPECs enhanced locomotor improvement and tissue recovery, including axonal regeneration, in rats with SCI.

Purpose: This study investigated whether (–)-epigallocatechin-3-gallate (EGCG) can enhance cognition by a neurorestorative effect in a rat model of bilateral common carotid artery occlusion (BCCAO).

Methods: Forty-eight male, 8-week-old Sprague-Dawley rats were randomly allocated to four groups 6 weeks after BCCAO or sham operation: EGCG-single intravenous injection (25 mg/kg/day; SIV group), EGCG-multiple intraperitoneal injection (50 mg/kg/day for 5 days; MIP group), untreated BCCAO group (untreated group), and sham-operated group (sham group).

Results: Escape latency was significantly shorter in the SIV and MIP groups than in the untreated group. SIV and MIP groups were significantly different from the untreated group in the activity of superoxide dismutase and the content of malondialdehyde (p < 0.05). Protein expression level of brain-derived neurotrophic factor was not significantly different between groups (p > 0.05), while protein expression of vascular endothelial growth factor was significantly lower in the SIV group than in the untreated group (p < 0.05). Protein expression of N-methyl-D-aspartate receptor subunits NR1 and NR2B was significantly higher in the MIP group than in the untreated group (p < 0.05).

Conclusions: EGCG administration at 6 weeks after BCCAO is neurorestorative via an anti-oxidant effect and synaptogenesis, except for angiogenesis.

Purpose: The aim of this study was to assess the proper timing of extradural cortical stimulation (ECS) on the motor relearning in a rat model of subacute photothrombotic stroke.

Methods: Photothrombotic infarction was induced on the dominant sensorimotor cortex in male Sprague-Dawley rats after training in a single-pellet reaching task (SPRT). Rats were randomly divided into three groups after stroke: ECS during the inactive period (Day-ECS group), ECS during the active period (Night-ECS group) and no ECS (Non-stimulated group). Six sham-operated rats were assigned to the control group. The Day- and Night-ECS group received continuous ECS for 12 hours during the day or night for 2 weeks from day 4 after the stroke. Behavioral assessment with SPRT was performed daily.

Results: SPRT showed a significantly faster and greater improvement in the Day and Night-ECS groups than in the Non-stimulated group. In the Day- and Night-ECS groups, the success rate of SPRT differed significantly from Non-stimulated group on day 11 and day 8, respectively. In addition, the Night-ECS group showed a significantly higher SPRT success rate than the Day-ECS group from days 10 to 13.

Conclusion: ECS during the active period might be more effective for motor relearning in the subacute stroke rat model.

Purpose: Cervical injuries are the most common form of spinal cord injury (SCI), and are often complicated by pathological secondary damage. Therefore, cervical SCI is of great clinical importance for understanding pathology and potential therapies. Here we utilize a weight drop cervical hemi-contusion injury model using a NYU/MASCIS impactor that produced graded anatomical and functional deficits.

Methods: Three groups of rats were established: 1) Sham (laminectomy only) (n = 6), 12.5 mm weight drop (n = 10), and 25 mm weight drop (n = 10) SCI groups. Forelimb functional assessments of grooming ability, cereal manipulation, and forepaw adhesive removal were performed weekly after injury. Using transcranial magnetic motor evoked potentials (tcMMEPs), supraspinal motor stimulations were recorded in both forelimbs and hindlimbs at 5 and 28d post-injury. Lesion volume and myelinated tissue area were assessed through histological analysis.

Results: A 12.5 mm weight drop height produced considerable tissue damage compared to Sham animals, while a 25 mm drop induced even greater damage than the 12.5 mm drop (p < 0.05). Forelimb functional assessments showed that increased injury severity and tissue damage was correlated to the degree of forelimb functional deficits. Interestingly, the hindlimbs showed little to no motor function loss. Upon tcMMEP stimulation, surprisingly little motor signal was recorded in the hindlimbs despite outward evidence of hindlimb motor recovery.

Conclusions: Our findings highlight a correlation between anatomical damage and functional outcome in a graded cervical hemi-contusion model, and support a loss of descending motor control from supraspinal inputs and intraspinal plasticity that promote spontaneous hindlimb functional recovery in this model.

Purpose: In aged humans, stroke is a major cause of disability for which no neuroprotective measures are available. In animal studies of focal ischemia, short-term hypothermia often reduces infarct size. Nevertheless, efficient neuroprotection requires long-term, regulated lowering of whole body temperature. Previously, we reported that post-stroke exposure to hydrogen sulfide (H₂S) effectively lowers whole body temperature and confers neuroprotection in aged animals.

Methods: In the present study using behavioral tests, MRI, telemetrical EEG, BP and temperature recordings, RT-PCR and immunofluorescence, we assessed infarct size, vascular density, neurogenesis and as well as the expression of genes coding for proteasomal proteins as well as in post-stroke aged Sprague-Dawley rats exposed to H₂S- induced hypothermia.

Results: Two days exposure to mild hypothermia diminishes the expression of several genes involved in protein degradation, thereby leading to better preservation of infarcted tissue. Further, hypothermia increased the density of newly formed blood vessels in the peri-lesional cortex did not enhance neurogenesis in the infarcted area of aged rats. Likewise, there was improved recovery of fine vestibulomotor function and asymmetric sensorimotor deficit.

Conclusion: Long-term hypothermia may be a viable clinical approach by simultaneously targeting multiple processes including better tissue preservation, enhanced vascular density and improved behavioral performance.

Purpose: The overall objective was to elucidate cellular mechanisms by which G-CSF enhances recovery from traumatic brain injury in a hippocampal-dependent learning task.

Methods: Chimeric mice were prepared by transplanting bone marrow cells that express green fluorescent protein (GFP+) from a transgenic “green” mice into C57BL/6 mice. Two months later, the animals sustained mild controlled cortical impact (CCI) to the right frontal-parietal cortex, followed by G-CSF (100 μg/kg) treatment for 3 consecutive days. The primary behavioral end-point was performance on the radial arm water maze (RAWM) assessed before and after CCI (days 7 and 14). Secondary endpoints included a), motor performance on a rotating cylinder (rotarod), b) measurement of microglial and astroglial response, c) hippocampal neurogenesis, and d) measures of neurotrophic factors (BDNF, GDNF) in brain homogenates.

Results: G-CSF treatment resulted in significantly better performance on the rotorod at one week, and in the RAWM after one and two weeks. The cellular changes found 2 wks after CCI in the G-CSF group included increased numbers of hippocampal newborn neurons as well as astrocytosis and microgliosis in striatum and frontal cortex on both sides of brain. GFP+ cells that co-labeled with Iba1 (microglial marker) comprised a significant proportion of striatal microglia in G-CSF treated animals, indicating the capacity of G-CSF to increase microglial recruitment to the site of injury. Neurotrophic factors GDNF and BDNF, elaborated by activated microglia and astrocytes, were increased in G-CSF treated mice.

Conclusions: G-CSF serves as a neurotrophic factor that increases hippocampal neurogenesis (or enhances survival of new-born neurons), and activates astrocytes and microglia. In turn, these activated glia release a plethora of cytokines and neurotrophic factors that contribute, in a poorly understood cascade, to the brain’s repair response. G-CSF also acts directly on bone marrow-derived cells to enhance recruitment of microglia to the site of CCI from circulating monocytes to the site of CCI.

Purpose: Major depression and related mood disorders are the most common long-term outcomes associated with traumatic brain injury (TBI). Given the potentially debilitating consequences of depression, and the fact that TBI patients are frequently refractory to antidepressant drugs, new therapies are clearly needed. We hypothesized that human bone marrow-derived mesenchymal stem cells (hMSC), delivered intravenously, can effectively treat TBI-induced depression and other behavioral deficits associated with TBI.

Methods: Rats (n = 8 per group) were subjected to experimental TBI or control sham operation. Six hours post TBI, rats were treated with 1×10⁶ hMSC or vehicle control. Immediately after TBI and prior to hMSC or control treatment, rats were subjected to either targeted precision x-ray irradiation to eliminate subventricular zone (SVZ) proliferation or sham irradiation. One week after TBI, SVZ irradiation, and hMSC treatment, rats were evaluated for the depression-like behavior, anhedonia, using the two-bottle saccharin preference paradigm; and for working memory using the novel object recognition test.

Results: TBI resulted in a 54% (p≤0.05) decrease in saccharin preference scores while treatment of TBI with hMSC fully prevented this anhedonic behavior. TBI was also found to produce a 73% (p≤0.05) decrease in novel object interaction time, indicating impaired working memory, and was similarly improved by treatment with hMSC. The ability of hMSC to prevent TBI-associated depression and working memory impairment was eliminated when SVZ proliferation was inhibited by irradiation.

Conclusions: This work has identified a possible role for hMSC in the treatment of TBI-induced depression and other behaviors and suggests a mechanistic role for proliferative cells of the SVZ proliferation in hMSC efficacy.

Purpose: Systemic Lupus Erythematosus (SLE) is an autoimmune disease which is characterised by elevated levels of autoantibodies and cytokines in the body. Via alteration of the regulation of inflammation, damage to different organ systems, including the central nervous system (CNS), was found in SLE patients. Patients diagnosed with SLE were reported to suffer from different kinds of psychiatric signs and symptoms. As neurogenesis has been suggested to be a potential key player of psychiatric symptoms and emotional behavior disturbances, this study aims to investigate whether neurogenesis is altered in an animal model of SLE. Also, neuroinflammation was studied.

Methods: Female NZB/W F1 mice were used as an animal model of SLE. Animals were divided into two groups: 1. pre-diseased mice (lupus-prone NZB/W F1 female mice, age 10–15 weeks, negative for proteinuria and with basal levels of serum anti-dsDNA autoantibodies) and 2. diseased mice (NZB/W F1 female mice, > 25 weeks of age, with elevated serum levels of anti-dsDNA autoantibodies and with persistent proteinuria of > 3 mg/ml for more than 2 weeks). Comparisons of the levels of neurogenesis and neuroinflammtion between two groups of mice were studied by the immunohistochemistry.

Results: After the onset of SLE symptoms, a reduction of neurogenesis in the hippocampus was found, while there was a dramatic increase of doublecortin (DCX+) neuronal precursor cells in the corpus callosum (CC) and in the subventricular zone (SVZ). Meanwhile, exacerbated inflammation was present in the corpus callosum of the diseased mice, which was suggested by the increased number of GFAP+ cells and IBA-1+ cells.

Conclusions: To the best of our knowledge, this is the first study showing an increase of neuronal precursor cells in the corpus callosum of the female NZB/W F1 mice. The present study suggests a coincidence but not a causal relationship between neurogenesis and neuroinflammation. The present results have also provided new insight showing that the altered neurogenesis and neuroinflammation may be a potential neurological mechanism for the cognitive and mood disturbance found in the SLE patients.

Background: Virtual reality (VR) has the potential to provide intensive, repetitive, and task-oriented training, and game-based therapy can enhance patients’ motivation and enjoyment.

Objective: The objective of the present study was to develop a mobile game-based upper extremity VR program for patients who have experienced stroke, and to evaluate the feasibility and effectiveness of the program.

Methods: This randomized, double-blind, controlled trial included 24 patients with ischemic stroke. The intervention group (n = 12) received 30 min of conventional occupational therapy (OT) and 30 min of the mobile upper extremity rehabilitation program using a smartphone and a tablet PC (MoU-Rehab). The controls (n = 12) received conventional OT alone for 1 h per day. Rehabilitation consisted of 10 sessions of therapy, 5 days per week, for 2 weeks. The outcome measures (Fugl−Meyer Assessment of the upper extremity [FMA-UE], Brunnström stage [B-stage] for the arm and the hand, manual muscle testing [MMT], modified Barthel index [MBI], EuroQol-5 Dimension [EQ-5D], and Beck Depression Inventory [BDI]) were assessed at the beginning and end of treatment, and at 1 month. User satisfaction was evaluated by a questionnaire.

Results: A greater improvement in the FMA-UE, B-stage, and MMT was found after treatment with the MoU-Rehab than with conventional therapy. The extent of improvements in the MBI, EQ-5D, and BDI was not significantly different between the two groups. Patients in the experimental group completed the 2-weeks treatment without adverse effects, and they were generally satisfied with MoU-Rehab.

Conclusion: This mobile game-based VR rehabilitation program appears to be feasible and effective for promoting upper limb recovery after ischemic stroke.