Prolonged HPA axis dysregulation in postpartum depression associated with adverse early life experiences: A cross-species translational study.

Childhood and adolescent stress increase the risk of postpartum depression (PPD), often providing an increased probability of treatment refractoriness. Nevertheless, the mechanisms linking childhood/adolescent stress to PPD remain unclear. Our study investigated the longitudinal effects of adolescent stress on the hypothalamic-pituitary-adrenal (HPA) axis and postpartum behaviors in mice and humans. Adolescent social isolation prolonged glucocorticoid elevation, leading to long-lasting postpartum behavioral changes in female mice. These changes were unresponsive to current PPD treatments but improved with post-delivery glucocorticoid receptor antagonist treatment. Childhood/adolescent stress significantly impacted HPA axis dysregulation and PPD in human females. Repurposing glucocorticoid receptor antagonists for some cases of treatment-resistant PPD may be considered.

[Initial Medical Care for Spinal Injury].

Neurosurgeons who treat head traumas often encounter cervical spinal injuries. They should be aware of the neurological symptoms, the severity of the symptoms, and the imaging features of cervical injuries. When surgery is required, fixation is often performed.

Targeting Neurogenesis in Seeking Novel Treatments for Ischemic Stroke.

The interruption of cerebral blood flow leads to ischemic cell death and results in ischemic stroke. Although ischemic stroke is one of the most important causes of long-term disability and mortality, limited treatments are available for functional recovery. Therefore, extensive research has been conducted to identify novel treatments. Neurogenesis is regarded as a fundamental mechanism of neural plasticity. Therefore, therapeutic strategies targeting neurogenesis are thought to be promising. Basic research has found that therapeutic intervention including cell therapy, rehabilitation, and pharmacotherapy increased neurogenesis and was accompanied by functional recovery after ischemic stroke. In this review, we consolidated the current knowledge of the relationship between neurogenesis and treatment for ischemic stroke. It revealed that many treatments for ischemic stroke, including clinical and preclinical ones, have enhanced brain repair and functional recovery post-stroke along with neurogenesis. However, the intricate mechanisms of neurogenesis and its impact on stroke recovery remain areas of extensive research, with numerous factors and pathways involved. Understanding neurogenesis will lead to more effective stroke treatments, benefiting not only stroke patients but also those with other neurological disorders. Further research is essential to bridge the gap between preclinical discoveries and clinical implementation.

Adolescent stress impairs postpartum social behavior via anterior insula-prelimbic pathway in mice.

Adolescent stress can be a risk factor for abnormal social behavior in the postpartum period, which critically affects an individual social functioning. Nonetheless, the underlying mechanisms remain unclear. Using a mouse model with optogenetics and in vivo calcium imaging, we found that adolescent psychosocial stress, combined with pregnancy and delivery, caused hypofunction of the glutamatergic pathway from the anterior insula to prelimbic cortex (AI-PrL pathway), which altered PrL neuronal activity, and in turn led to abnormal social behavior. Specifically, the AI-PrL pathway played a crucial role during recognizing the novelty of other mice by modulating "stable neurons" in PrL, which were constantly activated or inhibited by novel mice. We also observed that glucocorticoid receptor signaling in the AI-PrL pathway had a causal role in stress-induced postpartum changes. Our findings provide functional insights into a cortico-cortical pathway underlying adolescent stress-induced postpartum social behavioral deficits.

Adolescent stress impairs postpartum social behavior via anterior insula-prelimbic pathway.

Adolescent stress can be a risk factor for abnormal social behavior in the postpartum period, which critically affects the safety of mothers and children. Nonetheless, the underlying mechanisms remain unclear. Using a newly established mouse model with optogenetics and in vivo calcium imaging, we found that adolescent psychosocial stress, combined with pregnancy and delivery, caused hypofunction of the glutamatergic pathway from the anterior insula to prelimbic cortex (AI-PrL pathway), which altered PrL neuronal activity, and in turn led to abnormal social behavior. Specifically, the AI-PrL pathway played a crucial role during recognizing the novelty of other mice by modulating ″stable neurons″ in PrL, which were constantly activated or inhibited by novel mice. We also observed that glucocorticoid receptor signaling in the AI-PrL pathway had a causal role in stress-induced postpartum changes. Our findings provide novel and functional insights into a cortico-cortical pathway underlying adolescent stress-induced postpartum social behavioral deficits.

Transplantation of modified human bone marrow-derived stromal cells affords therapeutic effects on cerebral ischemia in rats.

AIMS: SB623 cells are human bone marrow stromal cells transfected with Notch1 intracellular domain. In this study, we examined potential regenerative mechanisms underlying stereotaxic transplantation of SB623 cells in rats with experimental acute ischemic stroke. METHODS: We prepared control group, empty capsule (EC) group, SB623 cell group (SB623), and encapsulated SB623 cell (eSB623) group. Transient middle cerebral artery occlusion (MCAO) was performed on day 0, and 24 h after MCAO, stroke rats received transplantation into the envisioned ischemic penumbra. Modified neurological severity score (mNSS) was evaluated, and histological evaluations were performed. RESULTS: In the mNSS, SB623 and eSB623 groups showed significant improvement compared to the other groups. Histological analysis revealed that the infarction area in SB623 and eSB623 groups was reduced. In the eSB623 group, robust cell viability and neurogenesis were detected in the subventricular zone that increased significantly compared to all other groups. CONCLUSION: SB623 cells with or without encapsulation showed therapeutic effects on ischemic stroke. Encapsulated SB623 cells showed enhanced neurogenesis and increased viability inside the capsules. This study reveals the mechanism of secretory function of transplanted SB623 cells, but not cell-cell interaction as primarily mediating the cells' functional benefits in ischemic stroke.

Spinal Surgery after Bilateral Subthalamic Stimulation for Patients with Parkinson's Disease: A Retrospective Outcome Analysis of Pain and Functional Control.

Parkinson's disease (PD) patients often suffer from spinal diseases requiring surgeries, although the risk of complications is high. There are few reports on outcomes after spinal surgery for PD patients with deep brain stimulation (DBS). The objective of this study was to explore the data on spinal surgery for PD patients with precedent DBS. We evaluated 24 consecutive PD patients with 28 spinal surgeries from 2007 to 2017 who received at least a 2-year follow-up. The characteristics and outcomes of PD patients after spinal surgery were compared to those of 156 non-PD patients with degenerative spinal diseases treated in 2013-2017. Then, the characteristics, outcomes, and spinal alignment of PD patients receiving DBS were analyzed in degenerative spinal/lumbar diseases. The mean age at the time of spinal surgery was 68 years. The Hoehn and Yahr score regarding PD was stage 1 for 8 patients, stage 2 for 2 patients, stage 3 for 8 patients, stage 4 for 10 patients, and stage 5 for 0 patient. The median preoperative L-DOPA equivalent daily dose was 410 mg. Thirteen patients (46%) received precedent subthalamic nucleus (STN) DBS. Lumbar lesions with pain were common, and operation and anesthesia times were long in PD patients. Pain and functional improvement of PD patients persisted for 2 years after surgery with a higher complication rate than for non-PD patients. PD patients with STN DBS maintained better lumbar lordosis for 2 years after spinal surgery. STN DBS significantly maintained spinal alignment with subsequent pain and functional amelioration 2 years after surgery. The outcomes of spinal surgery for PD patients might be favorably affected by thorough treatment for PD including DBS.

Vagus Nerve Stimulation with Mild Stimulation Intensity Exerts Anti-Inflammatory and Neuroprotective Effects in Parkinson's Disease Model Rats.

BACKGROUND: The major surgical treatment for Parkinson's disease (PD) is deep brain stimulation (DBS), but a less invasive treatment is desired. Vagus nerve stimulation (VNS) is a relatively safe treatment without cerebral invasiveness. In this study, we developed a wireless controllable electrical stimulator to examine the efficacy of VNS on PD model rats. METHODS: Adult female Sprague-Dawley rats underwent placement of a cuff-type electrode and stimulator on the vagus nerve. Following which, 6-hydroxydopamine (6-OHDA) was administered into the left striatum to prepare a PD model. VNS was started immediately after 6-OHDA administration and continued for 14 days. We evaluated the therapeutic effects of VNS with behavioral and immunohistochemical outcome assays under different stimulation intensity (0.1, 0.25, 0.5 and 1 mA). RESULTS: VNS with 0.25-0.5 mA intensity remarkably improved behavioral impairment, preserved dopamine neurons, reduced inflammatory glial cells, and increased noradrenergic neurons. On the other hand, VNS with 0.1 mA and 1 mA intensity did not display significant therapeutic efficacy. CONCLUSIONS: VNS with 0.25-0.5 mA intensity has anti-inflammatory and neuroprotective effects on PD model rats induced by 6-OHDA administration. In addition, we were able to confirm the practicality and effectiveness of the new experimental device.

Syringo-peritoneal Shunt for Syringomyelia Due to Extensive Adhesive Arachnoiditis: A Case Report.

Adhesive arachnoiditis (AA) is a chronic inflammation inside the dura and remains one of the most challenging diseases. We describe a case of treatment-resistant extensive AA that offers insight into surgical treatment selection. The patient had a 2-year history of progressive spastic gait and was diagnosed with syringomyelia caused by extensive AA. Although syringe-subarachnoid and subarachnoid-subarachnoid shunting resulted in recurrence within a short period, syringo- peritoneal shunting improved the symptoms and there was no recurrence. This case suggests that syringo-peritoneal cerebrospinal fluid (CSF) shunt drainage, which has previously been considered a further step, may be a first-surgery option for extensive AA.

Encapsulation of Mesenchymal Stem Cells: Dissecting the Underlying Mechanism of Mesenchymal Stem Cell Transplantation Therapy.

Mesenchymal stem cells (MSCs) are widely considered good candidates for cell transplantation therapy. Various central nervous system disorders have been suggested as suitable targets for MSC transplantation therapy. In this context, a great deal of basic and clinical research has been conducted to explore its clinical uses. Although depression is one of the most common diseases in the world, the response rate to the currently available treatment is insufficient and new treatments are much needed. Despite the fact that MSC transplantation therapy has the potential to elicit an antidepressant effect, few studies have been conducted on this topic to date and the underlying mechanism remains poorly understood. To address the development of a new treatment for depression, we evaluated the effect of MSCs using the encapsulation technique and Wistar-Kyoto rats. Encapsulation enables dissection of the complicated underlying mechanism of MSC transplantation therapy. Wistar-Kyoto rats that exhibit treatment-resistant depressive-like behaviors allow us to compare the effect of MSCs with that of conventional antidepressant treatment. In this commentary, we briefly summarize our recent published results and discuss future research prospects.

Long-Term Continuous Cervical Spinal Cord Stimulation Exerts Neuroprotective Effects in Experimental Parkinson's Disease.

BACKGROUND: Spinal cord stimulation (SCS) exerts neuroprotective effects in animal models of Parkinson's disease (PD). Conventional stimulation techniques entail limited stimulation time and restricted movement of animals, warranting the need for optimizing the SCS regimen to address the progressive nature of the disease and to improve its clinical translation to PD patients. OBJECTIVE: Recognizing the limitations of conventional stimulation, we now investigated the effects of continuous SCS in freely moving parkinsonian rats. METHODS: We developed a small device that could deliver continuous SCS. At the start of the experiment, thirty female Sprague-Dawley rats received the dopamine (DA)-depleting neurotoxin, 6-hydroxydopamine, into the right striatum. The SCS device was fixed below the shoulder area of the back of the animal, and a line from this device was passed under the skin to an electrode that was then implanted epidurally over the dorsal column. The rats were divided into three groups: control, 8-h stimulation, and 24-h stimulation, and behaviorally tested then euthanized for immunohistochemical analysis. RESULTS: The 8- and 24-h stimulation groups displayed significant behavioral improvement compared to the control group. Both SCS-stimulated groups exhibited significantly preserved tyrosine hydroxylase (TH)-positive fibers and neurons in the striatum and substantia nigra pars compacta (SNc), respectively, compared to the control group. Notably, the 24-h stimulation group showed significantly pronounced preservation of the striatal TH-positive fibers compared to the 8-h stimulation group. Moreover, the 24-h group demonstrated significantly reduced number of microglia in the striatum and SNc and increased laminin-positive area of the cerebral cortex compared to the control group. CONCLUSIONS: This study demonstrated the behavioral and histological benefits of continuous SCS in a time-dependent manner in freely moving PD animals, possibly mediated by anti-inflammatory and angiogenic mechanisms.

Cerebellar Blood Flow and Gene Expression in Crossed Cerebellar Diaschisis after Transient Middle Cerebral Artery Occlusion in Rats.

Crossed cerebellar diaschisis (CCD) is a state of hypoperfusion and hypometabolism in the contralesional cerebellar hemisphere caused by a supratentorial lesion, but its pathophysiology is not fully understood. We evaluated chronological changes in cerebellar blood flow (CbBF) and gene expressions in the cerebellum using a rat model of transient middle cerebral artery occlusion (MCAO). CbBF was analyzed at two and seven days after MCAO using single photon emission computed tomography (SPECT). DNA microarray analysis and western blotting of the cerebellar cortex were performed and apoptotic cells in the cerebellar cortex were stained. CbBF in the contralesional hemisphere was significantly decreased and this lateral imbalance recovered over one week. Gene set enrichment analysis revealed that a gene set for "oxidative phosphorylation" was significantly upregulated while fourteen other gene sets including "apoptosis", "hypoxia" and "reactive oxygen species" showed a tendency toward upregulation in the contralesional cerebellum. MCAO upregulated the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the contralesional cerebellar cortex. The number of apoptotic cells increased in the molecular layer of the contralesional cerebellum. Focal cerebral ischemia in our rat MCAO model caused CCD along with enhanced expression of genes related to oxidative stress and apoptosis.

Cell encapsulation enhances antidepressant effect of the mesenchymal stem cells and counteracts depressive-like behavior of treatment-resistant depressed rats.

Despite the advances in pharmacological therapies, only the half of depressed patients respond to currently available treatment. Thus, the need for further investigation and development of effective therapies, especially those designed for treatment-resistant depression, has been sorely needed. Although antidepressant effects of mesenchymal stem cells (MSCs) have been reported, the potential benefit of this cell therapy on treatment-resistant depression is unknown. Cell encapsulation may enhance the survival rate of grafted cells, but the therapeutic effects and mechanisms mediating encapsulation of MSCs remain unexplored. Here, we showed that encapsulation enhanced the antidepressant effects of MSCs by attenuating depressive-like behavior of Wistar Kyoto (WKY) rats, which are considered as a promising animal model of treatment-resistant depression. The implantation of encapsulated MSCs (eMSCs) into the lateral ventricle counteracted depressive-like behavior and enhanced the endogenous neurogenesis in the subventricular zone (SVZ) and the dentate gyrus (DG) of the hippocampus, whereas the implantation of MSCs without encapsulation or the implantation of eMSCs into the striatum did not show such ameliorative effects. eMSCs displayed robust and stable secretion of vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor, fibroblast growth factor-2, and ciliary neurotrophic factor (CNTF), and the implantation of eMSCs into the lateral ventricle activated relevant pathways associated with these growth factors. Additionally, eMSCs upregulated intrinsic expression of VEGF and CNTF and their receptors. This study suggests that the implantation of eMSCs into the lateral ventricle exerted antidepressant effects likely acting via neurogenic pathways, supporting their utility for depression treatment.

Cell therapy for central nervous system disorders: Current obstacles to progress.

Cell therapy for disorders of the central nervous system has progressed to a new level of clinical application. Various clinical studies are underway for Parkinson's disease, stroke, traumatic brain injury, and various other neurological diseases. Recent biotechnological developments in cell therapy have taken advantage of the technology of induced pluripotent stem (iPS) cells. The advent of iPS cells has provided a robust stem cell donor source for neurorestoration via transplantation. Additionally, iPS cells have served as a platform for the discovery of therapeutics drugs, allowing breakthroughs in our understanding of the pathology and treatment of neurological diseases. Despite these recent advances in iPS, adult tissue-derived mesenchymal stem cells remain the widely used donor for cell transplantation. Mesenchymal stem cells are easily isolated and amplified toward the cells' unique trophic factor-secretion property. In this review article, the milestone achievements of cell therapy for central nervous system disorders, with equal consideration on the present translational obstacles for clinic application, are described.

Animal Models for Parkinson's Disease Research: Trends in the 2000s.

Parkinson's disease (PD) is a chronic and progressive movement disorder and the second most common neurodegenerative disease. Although many studies have been conducted, there is an unmet clinical need to develop new treatments because, currently, only symptomatic therapies are available. To achieve this goal, clarification of the pathology is required. Attempts have been made to emulate human PD and various animal models have been developed over the decades. Neurotoxin models have been commonly used for PD research. Recently, advances in transgenic technology have enabled the development of genetic models that help to identify new approaches in PD research. However, PD animal model trends have not been investigated. Revealing the trends for PD research will be valuable for increasing our understanding of the positive and negative aspects of each model. In this article, we clarified the trends for animal models that were used to research PD in the 2000s, and we discussed each model based on these trends.

Lithium counteracts depressive behavior and augments the treatment effect of selective serotonin reuptake inhibitor in treatment-resistant depressed rats.

Wistar Kyoto (WKY) rats are a useful animal model of treatment-resistant depression. Lithium is effective for treating recurrent mood disorders or treatment-resistant depression, and lithium augmentation treatment is also useful for treatment-resistant depression. However, the treatment effect of lithium on the depressive behavior of WKY rats remains poorly understood, and whether lithium augments the treatment effect of antidepressants in WKY rats is also unknown. In this study, we evaluated the treatment effect of lithium in WKY rats. We also sought to determine if lithium treatment augments the treatment effect of fluoxetine. Lithium was administered for 15 consecutive days and fluoxetine was administered 23.5, 5, and 1 h before the forced swim test (FST) day 2, based on previous studies. Lithium treatment counteracted depressive behavior in the FST and increased hippocampal neurogenesis. Additionally, co-administration of lithium and fluoxetine augmented the treatment effect observed in the FST and in hippocampal neurogenesis in WKY rats, although fluoxetine monotherapy showed no treatment effect. Lithium prevented an increase in body weight, similar to its effect in human patients. These results are consistent with those of lithium augmentation treatment for human patients with treatment-resistant depression. They suggest that WKY rats are a promising animal model for treatment-resistant depression. However, lithium treatment has various side effects. A new treatment with the same anti-depressive effect as fluoxetine + lithium treatment and fewer side effects compared with lithium would be desirable for patients with treatment-resistant depression.

SF-36 scores predict postoperative delirium after surgery for cervical spondylotic myelopathy.

OBJECTIVECervical spondylotic myelopathy (CSM) is one of the most common causes of spinal cord dysfunction. Surgery for CSM is generally effective, but postoperative delirium is a potential complication. Although there have been some studies that investigated postoperative delirium after spine surgery, no useful tool for identifying high-risk patients has been established, and it is unknown if 36-Item Short Form Health Survey (SF-36) scores can predict postoperative delirium. The objective of this study was to evaluate the correlation between preoperative SF-36 scores and postoperative delirium after surgery for CSM.METHODSSixty-seven patients who underwent surgery for CSM at the authors' institution were enrolled in this study. Medical records of these patients were retrospectively reviewed. Patient background, preoperative laboratory data, preoperative SF-36 scores, the preoperative Japanese Orthopaedic Association (JOA) score for the evaluation of cervical myelopathy, and perioperative factors were selected as potential risk factors for postoperative delirium. These factors were evaluated using univariable and multivariable logistic regression analysis.RESULTSTen patients were diagnosed with postoperative delirium. Univariable analysis revealed that the physical functioning score (p = 0.01), general health perception score (p < 0.01), and vitality score (p < 0.01) of the SF-36 were significantly lower in patients with postoperative delirium than in those without. The total number of medications was significantly higher in the delirium group compared with the no-delirium group (p = 0.02). In contrast, there were no significant differences between the delirium group and the no-delirium group in cervical JOA scores (p = 0.20). Multivariable analysis revealed that a low general health perception score was an independent risk factor for postoperative delirium (p = 0.02; odds ratio 0.810, 95% confidence interval 0.684-0.960).CONCLUSIONSSome of the SF-36 scores were significantly lower in patients with postoperative delirium than in those without. In particular, the general health perception score was independently correlated with postoperative delirium. SF-36 scores could help identify patients at high risk for postoperative delirium and aid in the development of prevention strategies.

Encapsulated stem cells ameliorate depressive-like behavior via growth factor secretion.

As prevalence of depression continues to rise around the world, there remains a stagnation of available treatments as the affected population grows. The subset of treatment-resistant depression also is on the rise highlighting the need for innovative treatments to address this issue. Mesenchymal stem cells (MSCs) have been reported to attenuate depression-like behaviors, however, the effects of encapsulation of MSCs have yet to be investigated. Encapsulation of MSCs exhibited prolonged survival of exogenous cell injection accompanied with increased secretion of neurotrophic factors including vascular endothelial growth factor, ciliary neurotrophic factor, and others. The enhanced expression of these factors highlights the ability of encapsulated MSCs to upregulate the respective signaling pathways, which are associated with depression pathology and activation of neurogenesis. This treatment identifies a promising therapeutic option for depression, specifically treatment-resistant depression. Further, evaluation of long-term effects of the treatment is warranted. This paper is a review article. Referred literature in this paper has been listed in the references section. The datasets supporting the conclusions of this article are available online by searching various databases including PubMed. Some original themes in this article come from the laboratory practice in our research center and the authors' experiences.

Characteristics and prognostic factors of Parkinson's disease patients with abnormal postures subjected to subthalamic nucleus deep brain stimulation.

OBJECTIVE: In Parkinson's disease (PD), abnormal postures are often accompanied, which interfere with rehabilitation and subsequent functional recovery. This study investigated the relationship between clinical characteristics and improvement in abnormal postures of PD patients who received subthalamic nucleus deep brain stimulation (STN-DBS). METHODS: Seventy-four PD patients were included in this study. Clinical data were analyzed using the patients' functional status at pre- and post-STN-DBS, including anteflexion vs. non-anteflexion, scoliosis vs. non-scoliosis, improved anteflexion vs. non-improved anteflexion, and improved scoliosis vs. non-improved scoliosis. RESULTS: In patients with anteflexion, UPDRS III motor score at off medication was worse than that of patients with non-anteflexion. Patients with scoliosis presented with more comorbid spinal deformity and longer disease duration than those without scoliosis. Cobb angle of patients with asymmetrical psoas major and erector spinal muscles was more than that of patients without the asymmetry. Patients with improved anteflexion after STN-DBS had thicker abdominal oblique muscle and transverse abdominal muscle than those of patients without improved anteflexion. Patients with improved scoliosis were significantly younger at PD onset than those without improvement. CONCLUSIONS: There were only a few prognostic factors recognized in patients with improved postures. The thick abdominal muscle for anteflexion and younger PD onset for scoliosis were significant factors for improvement by STN-DBS. Rehabilitation designed to maintain muscle for correct postures may contribute to the amelioration of abnormal postures by STN-DBS, although multicenter trials are needed.

Long-Term Potentiation Enhances Neuronal Differentiation in the Chronic Hypoperfusion Model of Rats.

Several reports have shown that long-term potentiation (LTP) per se effectively enhances neurogenesis in the hippocampus of intact animals. If LTP can enhance neurogenesis in chronic hypoperfusion, this approach could potentially become a new therapeutic strategy for the restoration of cognitive function and for prevention from deterioration of mild cognitive impairment (MCI). Using an in vivo LTP model of rats, we examined whether LTP per se can enhance neurogenesis in hypoperfusion rats that underwent permanent bilateral common carotid artery occlusion (permanent 2-vessel occlusion, P2VO). High frequency stimulation (HFS) in the subacute phase after P2VO enhanced hippocampal cell proliferation and neurogenesis. However, most enhanced cell proliferation and neurogenesis was seen in the hypoperfusion rats that received HFS and for which LTP could finally be induced. In contrast, the same effect was not seen in the LTP induction in the chronic phase. The present findings, which reveal that most enhanced neurogenesis was seen in hypoperfusion rats for which LTP could be finally induced, could explain the ability of LTP-like activities such as learning paradigms and environmental stimuli to increase the rate of neurogenesis in the hippocampus even under hypoperfusion conditions. Moreover, the present findings, which reveal that LTP induction in the chronic phase after P2VO could not effectively enhance neurogenesis in the hypoperfusion rats, could indicate that patients with MCI and even middle-aged healthy control individuals should start LTP-like activities as early as possible and continue with these activities to prevent age-related deterioration of hippocampal function.