Histone deacetylase 3 expression correlates with vasculogenic mimicry through the phosphoinositide3-kinase / ERK-MMP-laminin5γ2 signaling pathway.

Vasculogenic mimicry (VM) refers to the process by which highly aggressive tumor cells mimic endothelial cells to form vessel-like structures that aid in supplying enough nutrients to rapidly growing tumors. Histone deacetylases (HDACs) regulate the expression and activity of numerous molecules involved in cancer initiation and progression. Notably, HDAC3 is overexpressed in the majority of carcinomas. However, thus far, no data are available to support the role of HDAC3 in VM. In this study, we subjected glioma specimens to immunohistochemical and histochemical double-staining methods and found that VM and HDAC3 expression were related to the pathological grade of gliomas. The presence of VM correlated with HDAC3 expression in glioma tissues. The formation of tubular structures, as determined by the tube formation assay to evaluate VM, was impaired in U87MG cells when transfected by siRNA or treated with an HDAC3 inhibitor. Importantly, the expression of VM-related molecules such as MMP-2/14 and laminin5γ2 was also affected when HDAC3 expression was altered. Furthermore, U87MG cells were treated with a phosphoinositide 3-kinase (PI3K) inhibitor or/and ERK inhibitor and found that the PI3K and ERK signaling pathways play key roles in VM; whereas, in VM, the two signaling pathways did not act upstream or downstream from each other. Taken together, our findings showed that HDAC3 contributed to VM in gliomas, possibly through the PI3K/ERK-MMPs-laminin5γ2 signaling pathway, which could potentially be a novel therapeutic target for gliomas.

Vasculogenic mimicry is a prognostic factor for postoperative survival in patients with glioblastoma.

A previous report has confirmed the existence and clinical significance of vasculogenic mimicry (VM) in glioma. However, its conclusions about the negative clinical significance of VM in glioblastoma are based on a small group of patients and, thus, might be unconvincing. The aim of the present study was to reevaluate the clinical significance of VM in glioblastoma. Patients were classified as VM-positive or VM-negative according to CD34 and periodic acid-Schiff staining. The association between VM and the clinical characteristics of the patients was analyzed. Univariate and multivariate analyses were carried out to identify the independent prognostic factors for overall survival using the Cox regression hazard model. Survival times were estimated using the Kaplan-Meier method and compared using the log-rank test. Of all 86 glioblastomas, 23 were found to have VM. The presence of VM in glioblastoma was not associated with gender, age, Karnofsky performance status, hydrocephalus, tumor burden, microvessel density, tumor relapse, or the extent of tumor resection. The univariate and multivariate analyses revealed that VM is an independent prognostic factor for overall survival. The median survival time for patients with VM was 11.17 months compared with 16.10 months for those without VM (P = 0.017). In addition to VM, an age of 65 years or older, a KPS of 60 or less, a large tumor burden are significant prognostic factors for patient survival. Our data suggest that VM might be an independent adverse prognostic factor in newly diagnosed GBM, further prospective studies are needed to answer this question.

Surgical cannulation of the superior ophthalmic vein for the treatment of previously embolized cavernous sinus dural arteriovenous fistulas: serial studies and angiographic follow-up.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of transorbital puncture for the retreatment of previously embolized cavernous sinus dural arteriovenous fistulas (DAVFs) via a superior ophthalmic vein (SOV) approach. MATERIALS AND METHODS: During a 12-year period, 9 consecutive patients with previously embolized cavernous sinus DAVFs underwent retreatment via the transorbital SOV approach. RESULTS: All of the nine cases of previously embolized cavernous sinus DAVFs were successfully embolized. Clinical follow-ups were conducted in all nine cases at the duration of 17-141 months (61.22 ± 39.13 months). No recanalization occurred during the follow-up period. A subtle ptosis appeared in two patients and disappeared in one of the two cases after a 4-year follow-up. One patient suffered from paroxysmal positional vertigo and bruit for nearly 2 years after the treatment, but the follow-up angiography demonstrated no recurrence. One patient had persistent visual impairment caused by the initial venous stasis retinopathy. One patient with a history of a procedure-related transient decrease in visual acuity had it return to the normal level. The remaining four cases had clear improvement in the ocular symptoms and became completely asymptomatic during the follow-up period. No patient worsened or developed new symptoms. CONCLUSION: The approach of surgical cannulation of the SOV for the retreatment of previously embolized cavernous sinus DAVFs was proved feasible and efficient, especially when the transarterial and transfemoral venous approaches were inaccessible. However, if the SOV is not dilated enough or is located deeply in the orbit, transorbital venous puncture access may not be possible.

Expression of cytokines in rat brain with focal cerebral ischemia after grafting with bone marrow stromal cells and endothelial progenitor cells.

BACKGROUND AIMS: This study aimed to observe nine factors expressed in rat ischemic brain after transplantation of bone marrow stromal cells (BMSC) and/or endothelial progenitor cells (EPC). These factors were vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 (SDF-1), basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF-l), transforming growth factor-ß (TGF-ß), platelet-derived growth factor-BB (PDGF-BB), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and nerve growth factor (NGF). METHODS: Adult Wistar rats were divided randomly into four groups: a vehicle group, BMSC group, EPC group and BMSC combined with EPC group. The rats were subjected to middle cerebral artery occlusion (MCAO) then implanted intravenously with 3 × 10(6) BMSC, EPC, BMSC/EPC or phosphate-buffered saline (PBS) 24 h after MCAO. Neurologic functional deficits were measured on days 1, 7, 14, 28 after transplantation. On day 7 after transplantation, quantitative reverse transcription (qRT)-polymerase chain reaction (PCR) and Western blot were employed to detect the expression of VEGF, SDF-1, bFGF, IGF-l, TGF-ß, PDGF-BB, BDNF, GDNF and NGF. RESULTS: The neurologic evaluation found that the neurologic severity scores were no different between the four groups on day 1, and the scores of rats in the BMSC/EPC group were significantly lower than those of rats in the other groups on days 7, 14 and 28 after transplantation. The expressions of bFGF, VEGF and BNDF were significantly higher in the BMSC/EPC group compared with the other groups. CONCLUSIONS: The intravenous transplantation of BMSC combined with EPC could promote the functional rehabilitation of rats with focal cerebral ischemia, and the mechanism may be related to the enhanced expression of factors.

Investigation of a plasmid containing a novel immunotoxin VEGF165-PE38 gene for antiangiogenic therapy in a malignant glioma model.

Inhibition of tumor neovascularization has profound effects on the growth of solid tumors. Our previous studies have shown the effect of VEGF165-PE38 recombinant immunotoxin on proliferation and apoptosis in human umbilical vein endothelial cells in vitro. In this study, we explored the direct inhibition of angiogenesis in chick chorioallantoic membrane and antiangiogenic therapy in a malignant glioma model. HEK293 cells were transfected with the pVEGF165PE38-IRES2-EGFP plasmid. ELISA was used to confirm the expression of VEGF165-PE38 in the transfected cells. These cells released 1396 + or - 131.9 pg VEGF165-PE38/1x10(4) cells/48 h into the culture medium and the supernatant was capable of inhibiting the growth of capillary-like structures in chick chorioallantoic membrane assay. In a murine malignant glioma model, plasmid was directly administered via multiple local intratumoral delivery. After day 16 the tumor volume in mice treated with pVEGF165PE38-IRES2-EGFP was significantly lower than that in mice in the control groups. Immunohistochemistry studies showed that the treated group had decreased expression of CD31. Quantitative analysis of microvessel density in the treated group was 1.99 + or - 0.69/0.74 mm(2), and was significantly lower than that in the control groups (9.33 + or - 1.99/0.74 mm(2), 8.09 + or - 1.39/0.74 mm(2) and 8.49 + or - 1.69/0.74 mm(2)). Immunohistochemistry analysis indicated that immunotoxin VEGF165-PE38 was distributed in the treated group in malignant glioma tissue. Our findings provide evidence that the in vivo production of VEGF165-PE38 through gene therapy using a eukaryotic expression plasmid had potential antiangiogenic activity in malignant glioma in vivo.

Human umbilical vein-derived dopaminergic-like cell transplantation with nerve growth factor ameliorates motor dysfunction in a rat model of Parkinson's disease.

Mesenchymal stem cells are capable of differentiating into dopaminergic-like cells, but currently no report has been available to describe the induction of human umbilical vein mesenchymal stem cells (HUVMSCs) into dopaminergic-like cells. In this study, we induced HUVMSCs in vitro into neurospheres constituted by neural stem-like cells, and further into cells bearing strong morphological, phenotypic and functional resemblances with dopaminergic-like cells. These HUVMSC-derived dopaminergic-like cells, after grafting into the brain of a rat model of Parkinson's disease (PD), showed a partial therapeutic effect in terms of the behavioral improvement. Nerve growth factor was reported to improve the local microenvironment of the grafted cells, and we therefore further tested the effect of dopaminergic-like cell grafting combined with nerve growth factor (NGF) administration at the site of cell transplantation. The results showed that NGF administration significantly promoted the survival of the grafted cells in the host brain and enhanced the content of dopaminergic in the local brain tissue. Behavioral test demonstrated a significant improvement of the motor function of the PD rats after dopaminergic-like cell grafting with NGF administration as compared with that of rats receiving the cell grafting only. These results suggest that transplantation of the dopaminergic-like cells combined with NGF administration may represent a new strategy of stem cell therapy for PD.

Passive immunization with LINGO-1 polyclonal antiserum afforded neuroprotection and promoted functional recovery in a rat model of spinal cord injury.

LINGO-1 (leucine-rich repeat and Ig domain-containing, Nogo receptor-interacting protein) is an important component of the NgR receptor complex involved in RhoA activation and axon regeneration. The authors report on passive immunization with LINGO-1 polyclonal antiserum, a therapeutic approach to overcome NgR-mediated growth inhibition after spinal cord injury (SCI). The intrathecally administered high-titer rabbit-derived antiserum can be detected around the injury site within a wide time window; it blocks LINGO-1 in vivo with high molecular specificity. In this animal model, passive immunization with LINGO-1 antiserum significantly decreased RhoA activation and increased neuronal survival. Adult rats immunized in this manner show recovery of certain hindlimb motor functions after dorsal hemisection of the spinal cord. Thus, passive immunotherapy with LINGO-1 polyclonal antiserum may represent a promising repair strategy following acute SCI.

Immune-Related lncRNA Correlated with Transcription Factors Provide Strong Prognostic Prediction in Gliomas.

Glioma is the most common and deadly tumor in central nervous system. According to previous studies, long noncoding RNAs (lncRNA) and transcription factors were significant factors of gliomas progression by regulating gliomas immune microenvironment. In our study, we built two independent cohorts from CGGA and TCGA. And we extracted 253 immune-related lncRNA correlated with prognosis. After LASSO analysis and multivariate Cox regression analysis, 8 immune-related lncRNA were used to construct classifier. The effectiveness of classifier was confirmed in both CGGA (AUC = 0.869) and TCGA (AUC = 0.902) cohorts. The correlation between transcription factors and immune-related lncRNA was calculated by WCGNA. Eventually, we built a network between 8 lncRNA and transcription factors. The function of core immune-related lncRNA in gliomas immune microenvironment was also investigated by CIBERTSORT. Our research provided a strong classifier of immune-related lncRNA to predict gliomas patient outcome. We also found the correlation between core immune-related lncRNA and transcription factors. These results may stimulate new strategy of immunotherapy in gliomas patients.

Human mesenchymal stem cells-like cells as cellular vehicles for delivery of immunotoxin in vitro.

Human mesenchymal stem cells-like cells (hMSCs-like cells) were used as a tumor treatment platform for the systemic delivery of immunotoxin genes. VEGF165-PE38 recombinant immunotoxin served as the model system. hMSCs-like cells were isolated, expanded, and electroporated with the pIRES2-VEGF165PE38-EGFP plasmid. RT-PCR and ELISA were used to confirm the expression of VEGF165-PE38 in the transfected hMSCs-like cells. These cells released 1390 +/- 137 pg VEGF165-PE38/10(4)cells over 48 h into the culture medium and the supernatant was capable of selectively killing human umbilical vein endothelial cells (HUVECs) and increasing apoptosis in these cells. In contrast, RPMI8226 was not inhibited by identical supernatants. Thus, these results lay the foundation for further studies on the potential role of hMSCs-like cells as a targeted therapeutic delivery vehicle for immunotoxins.

Combination of bone marrow stromal cell transplantation with mobilization by granulocyte-colony stimulating factor promotes functional recovery after spinal cord transection.

PURPOSE: Spinal cord injury (SCI) results in severe neurological deficit. However, the functional recovery following SCI is very poor due to the neural lost and limited axonal regeneration. To date, there was no effective treatment. Recent studies have shown that bone marrow stromal cells (BMSCs) transplantated into the central nervous system (CNS) can survive and differentiate into neuronal-like cells. Additionally, granulocyte colony-stimulating factor (G-CSF) can mobilize hematopoietic stem cells and inhibit neural cell apoptosis. Thus, we aimed to evaluate the combined effect of BMSC transplantation and G-CSF administration on rats with traverse spinal cord injury. METHODS: BMSCs were cultured in vitro, labeled with Hoechst33342, and then transplanted into the lesion site with or without G-CSF administration (50 microg/kg/day) for 5 subsequent days. The groups included an untreated control, along with treatment by G-CSF alone, BMSCs alone, and G-CSF + BMSCs. RESULTS: In this study, by the end of eighth week after SCI injury, the animals in group treated with G-CSF + BMSCs showed higher BBB scores than the other two groups. Morphometric assessment showed that the lesion areas in the rats of the G-CSF + BMSCs group were much smaller. Compared with the control, BMSC, and G-CSF groups, less expression of apoptosis cells and more neural-cell markers around the spinal cord injury were found in rats treated with G-CSF + BMSCs. CONCLUSIONS: The animals with the combination treatment achieved a better functional and morphologic recovery, although partial. This synergistic effect between BMSCs and G-CSF may be attributed to extrinsic and endogenous neurogenesis in the traverse spinal cord injury.

The study of 3-dimensional structures of IgG with atomic force microscopy.

OBJECTIVE: To detect 3-dimensional images of anti-N-methyl-D-aspartate receptor Nr1 (NMDAr1) polycolonal IgG affixed on mica in physiological environment. METHODS: The images and data were obtained from a contact mode and commercial Si3N4 probed tip by using atomic force microscope (AFM). RESULTS: The anti-NMDAr1 polycolonal IgG has a characteristic structure described as an ellipse spherical shape of 136.4 A x 62.8 A x 26.1 A. On the section of the ellipse edge there were two peaks about 13 nm in width. CONCLUSIONS: Using AFM to investigate biomacromolecule can make us deeply understand the structure of IgG, which will instruct us to detect the membrane receptor protein as a labelling agent.

[Changes of brain p38 MAPK in rabbits with craniocerebral gunshot injury in hot and humid environment].

OBJECTIVE: To study the activation of p38 mitogen-activated protein kinase (MAPK) in the brain of rabbits after craniocerebral gunshot injury in a hot and humid environment (HHE) and explore its possible mechanism. METHODS: Craniocerebral gunshot injury model was established in 30 New Zealand white rabbits, which were subsequently exposed to environment of normal temperature (at 22.0% +/- 0.5 degrees C; with relative humidity of 50%) or HHE at 39.0 +/- 0.5 degrees C; with relative humidity of 80%-85% for 10 min, 30 min, 1 h, 1.5 h, and 2 h groups, respectively, with 5 rabbits in each group. p38 MAPK activity in the brain tissues of the rabbits following the injury and environmental exposure were detected by Western blotting and analyzed semi-quantitatively by Bio-Profil gel image analysis system. RESULTS: p38 MAPK activity in the cortex and hypothalamus was significantly elevated following gunshot injury and HHE exposure, reaching the peak level at 1 h of HHE exposure and then decreased. p38 MAPK activity was significantly higher in the hypothalamus than in the cortex. CONCLUSION: p38 MAPK activity increases in the early stage following craniocerebral gunshot injury and HHE exposure in rabbits, the mechanism of which might involve the secondary brain insult.

[Changes of heat-shock protein 70 in the brain of rabbits with craniocerebral missile injury in hot and humid environment].

OBJECTIVE: To study the changes of heat shock protein 70 (HSP70) in the brain of rabbits with craniocerebral missile injury (CMI) and their impact on the injury in a hot and humid environment (HHE). METHODS: Twenty-four New Zealand white rabbits were randomized into 3 equal groups, namely normal temperature (NT) control group (subjected to treatment at temperature of 22.0+/-0.5 degrees C with relative humidity of 50%), NT gunshot group with CMI and HHE gunshot group with CMI. The rabbits in the latter two groups were subjected to normal temperature of 22.0+/-0.5 degrees C with relative humidity of 50% and environmental temperature of 39.0+/-0.5 degrees C with relative humidity of 80% to 85%, respectively, after establishment of CMI models. HSP70 in the brain tissues and lymphocytes was detected by Western blotting and visualized using chemoluminescence and X-ray films, followed by quantitative gel image analysis. RESULTS: Expressions of HSP70 in the cortex, hypothalamus and lymphocytes increased apparently in HHE gunshot group, and the changes of HSP70 in the lymphocytes were consistent with those in the cerebral cortex and hypothalamus. CONCLUSION: HSP70 expression in the brain tissues and the lymphocytes increase evidently after MCI in HHE.

[Dynamic atomic force microscopic observation of the three-dimensional conformation of protein A-gold single molecule].

OBJECTIVE: To determine the three-dimensional (3D) conformation of staphylococcal protein A-gold (SPA-G) single molecule using atomic force microscope (AFM) so as to evaluate the feasibility of using this molecule for in situ labeling of the neuronal membrane protein. METHODS: AFM was used to acquire the images of SPA-G binding to the surface of mica under physiological condition for determining the 3D conformation of the molecule. RESULTS: SPA-G single molecule was shown to contain a characteristic structure with a chain in the shape of mirror image of the letter C, which had the dimension of 48.80 nm x 42.13 nm x 20.53 nm. CONCLUSION: AFM provide a new means for morphological investigation of the biomacromolecule at the nanometer scale in physiological conditions, and SPA-G can be utilized for in situ labeling of the neuronal membrane receptors.

[Application of atomic force microscope in life science research].

OBJECTIVE: Atomic force microscope (AFM) is one of the most recent imaging and manipulation techniques in biological science. Among its various merits, AFM typically enables simple sample preparation, acquisition of three-dimensional images to identify single atoms under different conditions, detection of the interactive forces between two single biomolecules and their manipulation. AFM is currently applied in the research of the structure and function, at the nanometric scale, of various tissues, cells, microbes and biomolecules, and studies of the interaction between two biomolecules as well as the manipulation of some biological processes. AFM possesses the potential to become an important instrument in life science research, in spite of its current limits that require improvements such as in carbon nanotube tip, rigidity of soft biological samples and result interpretation.

[Effect of photodynamic therapy combined with interstitial chemotherapy for gliomas].

OBJECTIVE: To investigate the therapeutic effect of photodynamic therapy (PDT) combined with interstitial chemo- therapy on gliomas after microsurgery. METHODS: Twenty-eight patients with glioma received microsurgery for glioma resection as much as possible, during which PDT was carried out and an Ommaya bursa implanted into the cavity left by the resected tumor. PDT was performed again 24 h after the operation and carmustine injected into the Ommaya bursa for interstitial chemotherapy at the different time after the operation. The follow-up study lasted for 2 years. RESULTS: Two of the 28 patients had relapse of glioma within 1 year after the operation, with the 1-year survival rate of 89.3% (25/28) and 2-year survival rate of 65.7% (17/28). CONCLUSIONS: PDT combined with interstitial chemotherapy following microsurgery provides a safe and effective treatment of glioma, which can inhibit glioma growth, decrease the recurrence rate, prolong the patients' survival and improve their quality of live.

Transplantation of adipocyte-derived stem cells in a hydrogel scaffold for the repair of cortical contusion injury in rats.

Adipocyte-derived stem cells have emerged as a novel source of stem cell therapy for their autologous and readily accessible and pluripotent potential to differentiate into different lineages such as neural stem cells (NSCs) and endothelial progenitor cells (EPCs). Transplantation of NSCs and EPCs has been promising for the repair of brain injury. We explored using co-transplanted hydrogel scaffold to improve the survival of the transplanted cells and recovery of neurological function. Adult Wistar rats were transplanted with EPC-hydrogel, NSC-hydrogel, NSC-EPC-hydrogel, EPC only, or NSC only 7 days after cortical contusion injury. Behavioral tests were performed to evaluate neurological function before, and 1, 2, 3, and 4 weeks after transplantation. Size of injury, extent of vascularization, as well as the survival and differentiation of the transplanted EPCs and NSCs, were evaluated at week 5. All transplantation groups displayed significantly better neurological function compared with the control groups. Improved neurological function correlated with significantly smaller injury volumes than that of the saline group. Using immunostaining, we have shown that while transplanted NSCs differentiated into both neurons and astrocytes, the EPCs were incorporated into vessel epithelia. The extent of reactive gliosis (based on glial fibrillary acidic protein immunostaining) was significantly reduced in all treatment groups (NSC-EPC-hydrogel, NSC-hydrogel, and EPC-hydrogel) when compared with the saline group, with the highest reduction in the NSC-EPC-hydrogel transplantation group. Thus, co-transplantation of hydrogel scaffold provides a more conducive environment for the survival and differentiation of NSCs and EPCs at the site of brain injury, leading to improved vascularization and better recovery of neurological function.

All-trans retinoic acid impairs the vasculogenic mimicry formation ability of U87 stem-like cells through promoting differentiation.

The poor therapeutic effect of traditional antiangiogenic therapy on glioblastoma multiforme (GBM) may be attributed to vasculogenic mimicry (VM), which was previously reported to be promoted by cancer stem-like cells (SLCs). All-trans retinoic acid (ATRA), a potent reagent which drives differentiation, was reported to be able to eradicate cancer SLCs in certain malignancies. The aim of the present study was to investigate the effects of ATRA on the VM formation ability of U87 glioblastoma SLCs. The expression of cancer SLC markers CD133 and nestin was detected using immunocytochemistry in order to identify U87 SLCs. In addition, the differentiation of these SLCs was observed through detecting the expression of glial fibrillary acidic protein (GFAP), ß-tubulin III and galactosylceramidase (Galc) using immunofluorescent staining. The results showed that the expression levels of GFAP, ß-tubulin III and Galc were upregulated following treatment with ATRA in a dose-dependent manner. Furthermore, ATRA significantly reduced the proliferation, invasiveness, tube formation and vascular endothelial growth factor (VEGF) secretion of U87 SLCs. In conclusion, the VM formation ability of SLCs was found to be negatively correlated with differentiation. These results therefore suggested that ATRA may serve as a promising novel agent for the treatment of GBM due to its role in reducing VM formation.

[Clinical analysis of 31 cases of traumatic interhemispheric subdural hematomas].

OBJECTIVE: To analyze the clinical characteristics, pathogenesis and management of traumatic interhemispheric subdural hematomas (ISH). METHODS: Thirty-one traumatic ISH cases were reviewed and analyzed retrospectively. RESULTS: Of the 31 patients, 29 were cured and 2 died of multi-system organ failure (MSOF) and cerebral hernia respectively. Typically, ISH manifested hemiplegia or paralysis of the counterlateral lower limb known as falx syndrome. CONCLUSIONS: CT scans showing hematocele in the interhemispheric subdural space in excess of 20 ml, or with a thickness of hematocele over 1cm, may serve as a diagnostic criteria for ISH. For the treatment of ISH, surgery and conservative management are suggested on the basis of functional disturbance or the stability of the disease.

[Effect of fixation methods on immunocytochemical localization of NMDAR1 on cultured cortical neuron membrane].

OBJECTIVE: To investigate the changes in subcellular localization of NMDAR1 on cultured cortical neurons in response to different methods for fixation of neuron cells. METHODS: Subcellular localization of NMDAR1 in cultured cortical neurons fixed with different fixatives and procedures was studied by immunocytochemical avidin-biotin peroxidase (ABC) method. RESULTS: Neurons fixed with -20 degrees Celsius pure acetone and -20 degrees Celsius pure methanol for 5 min presented typical positive staining of NR1 subunit located on the polar membrane of the neurons where the dendrites originated and on the stem of the dendrites. The neurons fixed with 4% formaldehyde alone for 20 min or in the presence of 0.5% glutaraldehyde (1:1) for 10 min resulted in false-negative staining. Fixation of the neurons with 95% ethanol for 10 min yielded false-negative staining on the membrane and false-positive staining in the nuclei. CONCLUSIONS: Each antigen may have its specific demand for fixation method in immunocytochemistry, and for NMDAR1 antigen, mild fixation is recommended as by -20 degrees Celsius pure acetone and -20 degrees Celsius pure methanol for 5 min. NMDAR1 distributes on the polar membrane of the neurons where the dendrites originate and on the dendritic stem.