OBJECTIVETo observe the dynamic changes of proliferation and differentiation of neural stem cells (NSCs) in subventricular zone (SVZ) and dentate gyrus (DG) in vascular dementia (VD) rats.

METHODSVD models were established by repeatedly clipping the common carotid arteries of the rat in combination with an intraperitoneal injection of sodium nitroprusside solution in anesthetized SD rats. Morris maze test was used to detect the learning and memory ability of the rats and immune fluorescence single and double labeling method to detect the proliferation and differentiation of neural stem cells and the expression of neurogranin (Ng) at 15 d, 1 month, 2 month, 4 month time points.

RESULTSCompared with sham-operated group, the escape latency of model group rats were significantly longer at all the time points (P < 0.01). The BrdU positive cells in SVZ and DG of VD model groups were markedly increased in comparison with sham-operated group at 15 d and 1 month time point (P < 0.01), and the number of BrdU positive cells in SVZ of model groups were still larger than that of sham-operated group at 2 month and 4 month time point (P < 0.01). In model group, the number of the BrdU/Ng double staining cells were increased and higher than that in sham-operated groups (P < 0.05).

CONCLUSIONThe proliferation of NSCs can be enhanced noticeably in a certain time in SVZ and DG region and NSCs differentiate into mature neurons with the expression of Ng in DG region in VD rats, which may play some compensatory roles in the nerve regeneration and functional repairmen after cerebral injury of VD.

Animals ; Cell Differentiation ; Cell Proliferation ; Dementia, Vascular ; Dentate Gyrus ; cytology ; Ependyma ; cytology ; Male ; Maze Learning ; Nerve Regeneration ; Neural Stem Cells ; cytology ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: This study investigates the effect of valproic acid (VPA) on expression of neural stem/progenitor cells (NSPCs) in a rat spinal cord injury (SCI) model. METHODS: Adult male rats (n=24) were randomly and blindly allocated into three groups. Laminectomy at T9 was performed in all three groups. In group 1 (sham), only laminectomy was performed. In group 2 (SCI-VPA), the animals received a dose of 200 mg/kg of VPA. In group 3 (SCI-saline), animals received 1.0 mL of the saline vehicle solution. A modified aneurysm clip with a closing force of 30 grams was applied extradurally around the spinal cord at T9, and then rapidly released with cord compression persisting for 2 minutes. The rats were sacrificed and the spinal cord were collected one week after SCI. Immunohistochemistry (IHC) and western blotting sample were obtained from 5 mm rostral region to the lesion and prepared. We analyzed the nestin immunoreactivity from the white matter of ventral cord and the ependyma of central canal. Nestin and SOX2 were used for markers for NSPCs and analyzed by IHC and western blotting, respectively. RESULTS: Nestin and SOX2 were expressed significantly in the SCI groups but not in the sham group. Comparing SCI groups, nestin and SOX2 expression were much stronger in SCI-VPA group than in SCI-saline group. CONCLUSION: Nestin and SOX2 as markers for NSPCs showed increased expression in SCI-VPA group in comparison with SCI-saline group. This result suggests VPA increases expression of spinal NSPCs in SCI.
Aneurysm ; Animals ; Blotting, Western ; Ependyma ; Immunohistochemistry ; Intermediate Filament Proteins ; Laminectomy ; Male ; Nerve Tissue Proteins ; Neurons ; Rats ; Spinal Cord ; Spinal Cord Injuries ; Valproic Acid

Cerebrospinal fluid (CSF) plays an important role in providing brain tissue with a stable internal environment as well as in absorbing mechanical and thermal stresses. From its initial composition, derived from the amniotic fluid trapped by the closure of neuropores, CSF is modified by developing and differentiating ependymal cells lining the ventricular surface or forming the choroid plexus. Its osmolarity and ionic composition brings about a change through the action of many channels expressed on the ependymal cells. Some newly discovered transient receptor potential (TRP) channels are known to be expressed in the choroid plexus ependyma. To detect additional TRP channel expression, immunohistochemical screening was performed at the choroid plexus of 13-, 15-, 17-, and 19-day embryos, using antibodies against TRPV1, TRPV3, and TRPA1, and the expression was compared with those in the adult TRP channels. The level of TRP channel expression was higher in the choroid plexus which suggests more active functioning of TRP channels in the developing choroid plexus than the ventricular lining ependyma in the 15- and 17-day embryos. All the expression of TRP channels decreased at the 19th day of gestation. TRPA1 was expressed at a higher level than TRPV1 and TRPV3 in almost all stages in both the choroid plexus and ventricular lining epithelium. The highest level of TRPV1 and TRPV3 expression was observed in association with the glycogen deposits in the cytoplasm of the choroid plexus ependymal cells of the 15- and 17-day embryos.
Adult ; Amniotic Fluid ; Animals ; Antibodies ; Brain ; Choroid Plexus ; Cytoplasm ; Embryonic Development ; Embryonic Structures ; Ependyma ; Epithelium ; Female ; Glycogen ; Humans ; Mass Screening ; Osmolar Concentration ; Pregnancy ; Rats ; Transient Receptor Potential Channels

The establishment of a polarized cellular morphology is essential for a variety of processes including neural tube morphogenesis and the development of the brain. Cdc42 is a Ras-related GTPase that plays an essential role in controlling cell polarity through the regulation of the actin and microtubule cytoskeleton architecture. Previous studies have shown that Cdc42 plays an indispensable role in telencephalon development in earlier embryo developmental stage (before E12.5). However, the functions of Cdc42 in other parts of brain in later embryo developmental stage or in adult brain remain unclear. Thus, in order to address the role of Cdc42 in the whole brain in later embryo developmental stage or in adulthood, we used Cre/loxP technology to generate two lines of tissue-specific Cdc42-knock-out mice. Inactivation of Cdc42 was achieved in neuroepithelial cells by crossing Cdc42/ flox mice with Nestin-Cre mice and resulted in hydrocephalus, causing death to occur within the postnatal stage. Histological analyses of the brains from these mice showed that ependymal cell differentiation was disrupted, resulting in aqueductal stenosis. Deletion of Cdc42 in the cerebral cortex also induced obvious defects in interkinetic nuclear migration and hypoplasia. To further explore the role of Cdc42 in adult mice brain, we examined the effects of knocking-out Cdc42 in radial glial cells by crossing Cdc42/flox mice with human glial fibrillary acidic protein (GFAP)-Cre mice. Inactivation of Cdc42 in radial glial cells resulted in hydrocephalus and ependymal cell denudation. Taken together, these results highlight the importance of Cdc42 for ependymal cell differentiation and maintaining, and suggest that these functions likely contribute to the essential roles played by Cdc42 in the development of the brain.
Animals ; Brain ; metabolism ; pathology ; Cell Differentiation ; Cell Polarity ; Cerebral Cortex ; cytology ; metabolism ; Constriction, Pathologic ; Embryo, Mammalian ; metabolism ; Embryonic Development ; Ependyma ; cytology ; metabolism ; Glial Fibrillary Acidic Protein ; genetics ; metabolism ; Humans ; Hydrocephalus ; metabolism ; pathology ; Integrases ; genetics ; metabolism ; Mice ; Mice, Knockout ; cdc42 GTP-Binding Protein ; genetics ; metabolism

OBJECTIVETo determine cell proliferation and nestin expression in the ependyma of adult rat spinal cord after injury.

METHODSRat spinal cord injury models were established by aneurysm clip compression, and nestin expression and proliferation of ependymal cells at different times were shown with pathological and immuno-histochemical staining.

RESULTSEpendymal cells adjacent to the injured site demonstrated a dramatic increase in nestin expression 24 hours after compression. Proliferating cell nuclear antigen was positive, and significant proliferation was observed after 7 days. Nestin expression was down regulated as time went by.

CONCLUSIONNormally quiescent mature ependymal cells appear to revert to an embryonic state in response to spinal cord injury.

Animals ; Cell Division ; Ependyma ; cytology ; metabolism ; Immunohistochemistry ; Intermediate Filament Proteins ; biosynthesis ; Male ; Nerve Tissue Proteins ; Nestin ; Rats ; Rats, Wistar ; Spinal Cord Injuries ; metabolism ; pathology

The distinguishing morphological features of the ependyma lining ventriculus terminalis in human fetus have suggested that its differentiation would be somewhat delayed or arrested as compared with the ependyma lining central canal. To demonstrate this hypothesis, GFAP was used as a marker to compare the developmental state of the ependyma lining ventriculus terminalis and central canal along fetal age (18 -to 24 -week -old fetuses were investigat-ed). PCNA was also used as a marker to identify whether proliferation potentiality of the ependyma lining ventriculus terminalis lasted longer than that of the ependyma lining central canal as a result of differentiation delay. GFAP -positive ependymal cells were restricted to dorsal plate at central canal but at ventriculus terminalis, many positive cells were identified in all regions compared with the ependyma lining central canal. The number of PCNA -positive ependymal cells lining central canal decreased sharply about the time of 20th week, but at ventriculus terminalis, many ependymal cells continued to express PCNA after 20th week. As a result, we could conclude that differentiation of the ependyma lining ventriculus terminalis is delayed as compared with the ependyma lining central canal. In accordance with its developmental delay, it lasts longer proliferation potentiality than the ependyma lining central canal.
Ependyma* ; Fetus* ; Gestational Age ; Glial Fibrillary Acidic Protein* ; Humans* ; Proliferating Cell Nuclear Antigen*

The ventriculus terminalis, also known as the 'fifth ventricle', is a dilated cavity in the conus medullaris. It is formed by degenerative process in the course of neural tube development, but the definite function is unclear. And the reports, which have studied the morphological variation according to fetal age, are insufficient. So, in this report, we observed the morphological variation of the ventriculus terminalis and measured the areal ratio of the ventriculus terminalis to the parenchyma of conus medullaris by fetal age. We also studied the fine structure of the conus medullaris and ependyma by electron microscope. The ventriculus terminalis began at the level at which the ependymal cells proliferated and the central canal moved to the dorsal region. Periependymal islet was observed at this level. At the lower level, it immediately extended both lateral sides and finally switched over to the filum terminale. The area ratio of the ventriculus terminalis to the parenchyma of the conus medullaris increased from above downward. Especially, It increased steeply between the Leaf-shaped region and the transitional zone, where the ventriculus terminalis began. But the increasing pattern was too irregular to generalize its pattern by fetal age. The ependyma lining the ventriculus terminalis was composed of pseudostratified ciliated columnar epithelium layer about 5~7 cells thick. It had conspicuous intercellular junctional complexes close to the lumen into which microvilli and cilia projected. At the junction where the ependyma meets the parenchyma of the conus medullaris, we could observe many myelin-like structures made by basolateral membrane of the ependymal cell. In the conus medullaris, we could observe many obscure cell types because they were in the course of differentiation. On the other hand, we could also observe the fully differentiated nerve cells, astrocytes and oligodendrocytes which seemed to play its own role. A lot of developing myelin sheaths were observed and the majority was the degenerative one. Some ependymal cells showed the apoptotic characteristics and many cell debris were observed in the lumen. As a result, the ventriculus terminalis was formed by the combination of cell differentiation and degeneration, and its development was independent of the spinal cord.
Apoptosis ; Astrocytes ; Cauda Equina ; Cell Differentiation ; Cilia ; Conus Snail ; Ependyma ; Epithelium ; Gestational Age ; Hand ; Humans* ; Membranes ; Microvilli ; Myelin Sheath ; Neural Tube ; Neurons ; Oligodendroglia ; Spinal Cord*

Isolated fourth(IV) ventricle in shunted patients has been reported with increasing frequency. Symptomatic isolated IV ventricular hydrocephalus in adults, however, has seldom been described. We report five such cases among total of 420 shunted cases in our institution from January 1992 to December 1995. The causes of initial hydrocephalus were postsurgical meningitis(SAH, teratoma and abscess of posterior fossa), tuberculous meningitis and neurocysticercosis of the IV ventricle. All cases were symptomatic with clinical findings related to posterior fossa lesions. Two patients developd symptoms in 2 months after V-P shunts and the others between 17 and 118 months after V-P shunts. These 5 patients required IV ventricular shunting. All patients improve postoperatively except one patient who developed 6th nerve palsy related to secondary irritation of the brainstem by the IV ventricular catheter. Inflammatory changes in the ependyma of both aqueduct of Sylvius, foramina Luschka and Magendi have been regarded as the most important factors in the development of the isolation of IV ventricle, especially in adults. It is generally recommended to shunt in cases of the adult symptomatic isolated IV ventricle. Alternative surgical techniques and prevention of such complications are discussed.
Abducens Nerve Diseases ; Abscess ; Adult* ; Brain Stem ; Catheters ; Cerebral Aqueduct ; Diagnosis* ; Ependyma ; Humans ; Hydrocephalus* ; Neurocysticercosis ; Teratoma ; Tuberculosis, Meningeal

Proximal cerebrospinal fluid shuntmalfunction due to ventricular catheter occlusion remains the most common sourceof the shunt problem. The position of the hole-bearing segment of the catheter affects the long term patency of the ventricular catheter of a cerebrospinalfluid shunt.Placementof thissegmentnear thechoroidplexus or injured ependyma increases the probability of obstruction. Accurate locationof ventriculoperitoneal(V-P)shunt tip inrelation to foramen Monro canbe well establishedby plain radiographyregardless of agesor sizes and shapes of head dueto the fact that foramen Monro tothe spatial matrix of the skull is constant. Of 147patients who underwentV-P shunt operations, 49(33.3%)patients had more thanone operations. Radiologicgradingof theventricularcatheterposition is compared betweensingle operatedgroup andreoperated group.Single operated group showed excellentin 33.6%, good41.8%, poor 24.4%of accuracy rateof catheter tip position. Incases ofreoperation, placement ofcatheter tipresulted in excellent 12.5%, good21.8%, and poor 65.6%.These results indicatethat accurate location of ventricular catheter tip affects favorably to the patency of V-P shunt.
Catheters ; Cerebrospinal Fluid ; Ependyma ; Head ; Skull ; Ventriculoperitoneal Shunt*

Morphological changes in the ependymal lining of the hydrocephalic brain included stretching and tearing of the ependyma, thickening and gliosis of the subependymal layer, progressive loss of cilia and microvilli from the ependymal surface, and widening of the extracellular space. In the CT scan of the brain, periventricular low density was one of the common findings in hydrocephalus. The present experiment was performed to investigate not only the ultrastructural changes of the ventricular walls in hydrocephalus but also the morphological basis of periventricular lucency detected in the brain CT scan of the hydrocephalic patients. Hydrocephalus was induced in rats by intracisternal injection of thick kaolin suspension after surgical exposure of atlanto-occipital membrane. Lateral wall of the lateral ventricle was examined with transmission electron microscope in 3 different groups(6 rats at 1 week after the hydrocephalus, 8 at 2 weeks, and 4 at 8 weeks). The results were as follows: 1) Ultrastructural changes of the ependymal lining in hydrocephalic rat were flattening of ependymal cell and its nucleus, loss of cilia and microvilli from the ependymal surface, widening of the junctional complex, vacuoles and enlargement of cisternal space of rough endoplasmic reticulum in cytoplasm, and thicking and gliosis of subependymal layer. 2) These changes became more severe with longer duration of hydrocephalus. 3) Widening of junctional complex was considered to be the morphological basis for migration of ventricular cerebrospinal fluid into the periventricular white matter with resultant periventricular low density in the CT scan of the brain.
Animals ; Brain ; Cerebrospinal Fluid ; Cilia ; Cytoplasm ; Endoplasmic Reticulum, Rough ; Ependyma ; Extracellular Space ; Gliosis ; Humans ; Hydrocephalus ; Kaolin ; Lateral Ventricles ; Membranes ; Microvilli ; Rats* ; Tomography, X-Ray Computed ; Vacuoles