Does long-term physical exercise counteract age-related Purkinje cell loss? A stereological study of rat cerebellum

Physical exercise affects properties of the central nervous system that may increase the brain's ability to counteract degenerative changes. We have previously reported that rats trained from 5 to 23 months of age have less age-related decrease in spontaneous motor activity than sham-treated sedentary rats. Each rat ran at a speed of 20 m/min on a horizontal treadmill, for 20 minutes, two times per day, 5 days a week. In the present study we have carried out stereological analyses of the cerebella of the same rats. The total number of Purkinje cells was estimated with the optical fractionator technique, the local volumes of individual Purkinje cells with the planar rotator technique, and the volumes of the cerebellar layers with Cavalierìs principle. We found that sedentary aged rats have 11% fewer Purkinje cells and 9% smaller Purkinje cell soma volumes (both 2P = 0.02) than exercised aged rats, and that exercised aged rats have the same number of Purkinje cells as young rats. These findings indicate that the degree of age-associated degenerative changes in parts of the central nervous system is dependent on earlier life style and health habits and may be prevented or delayed by physical exercise.     

Histochemical studies on the “dark” and “light” cells of the cerebellum of rat

Summary The distribution of mitochondria, DNA, RNA, phospholipid and other chemical substances in the cerebellum of the rat have been studied. Mitochondria in the Purkinje cells show a variety of distributions — in some cells they are concentrated around the nucleus and in others spread through the cytoplasm. In the former case the nucleolus is in contact with the nuclear membrane. Purkinje cells appear to go through a series of metabolic cycles similar to those described in the spinal ganglion cells. Phospholipid reactions are most intense in the white matter. Various types of lipid positive nerves can also be seen in the granular layer, and lipid granules can be seen in the glomeruli.RNA preparations show prominent cytoplasmic staining in the Purkinje cells and nucleoli. In some cells there was a aggregation of RNA around the nucleus. The nuclei of the cells of the molecular layer gave no reaction either for DNA or RNA. DNA was frequently found to the peripherally located in the nucleus of various cells.All these results are discussed in detail.

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Zusammenfassunng Im Kleinhirn der Ratte wird die Verteilung von Mitochondrien, DNA, RNA, Phosphorlipoiden und anderen chemischen Substanzen untersucht. Die Mitochondrien der Purkinje-Zellen zeigen eine wechselnde Verteilung — in manchen Zellen sind sie um den Kern konzentriert, in anderen im Cytoplasma verstreut. Im ersteren Fall steht der Nucleolus im Kontakt mit der Kernmembran. Die Purkinje-Zellen scheinen in eine Reihe von Stoffwechselcyclen, ähnlich denen, die in den Spinalganglionzellen beschrieben wurden, einbezogen zu sein. Die Phosphorlipoidreaktionen sind in der weißen Substanz stärker. Auch in der Körnerschicht kann man verschiedene Arten von Lipoid-positiven Nervenfasern sehen; ferner Lipoidkörnchen in den Glomeruli.RNA-Präparate zeigen eine hervortretende Färbung des Cytoplasmas der Purkinje-Zellen und der Nucleoli. In manchen Zellen besteht eine Anhäufung von RNA um den Kern. Die Kerne der Zellen der Molekularschicht geben weder auf DNA noch auf RNA eine Reaktion. DNA kann häufig im Kern verschiedener Zellen in peripherer Lokalisation gefunden werden.All diese Ergebnisse werden im einzelnen diskutiert.

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With 23 coloured Figures in the Text     

The male bias in the number of Purkinje cells and the size of the murine cerebellum may require Müllerian inhibiting substance/anti-Müllerian hormone

There is a male bias in the size of the cerebellum, with males, on average, having more Purkinje cells than females. The critical periods in cerebellum development occur when the immature testes secrete Müllerian inhibiting substance (MIS; synonym anti-Müllerian hormone) but only trace levels of testosterone. This suggests that the male bias in the cerebellum is generated by a different mechanism to the testosterone-sensitive reproductive nuclei. Consistent with this, in the present study, we report that Purkinje cells and other cerebella neurones express receptors for MIS, and that MIS(-/-) male mice have female-like numbers of Purkinje cells and a female-like size to other parts of their cerebellum. The size of the cell bodies of Purkinje cells was also dimorphic, although only a minority of this was a result of MIS. This suggests that MIS induces the initial male bias in the cerebellum, which is then refined by pubescent testosterone and/or other sex-specific factors.     

β-amyloid protein structure determines the nature of cytokine release from rat microglia

Activated microglia represent a major source of inflammatory factors in Alzheimer's disease and a possible source of cytotoxic factors. beta-Amyloid (Abeta) peptide, the predominant component in amyloid plaques, has been shown to activate microglia and stimulate their production of inflammatory factors. The present study was performed to analyze the responses of microglia to different forms of Abeta, with regard to release of the proinflammatory cytokines interleukin-1alpha (IL-1alpha), IL-1beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, and interferon-gamma (IFN-gamma), as well as the IL-1 receptor antagonist (IL-1ra). Primary cultures of microglia from rat neonatal cerebral cortex were incubated with freshly dissolved Abeta1-40 or Abeta1-42, Abeta1-40 fibrils, Abeta1-40 betaamy balls, or vehicle. Abeta1-40 fibrils did not significantly stimulate any of these cytokines. Freshly dissolved Abeta1-40 resulted in a marked increase in the release of IL-1beta, and freshly dissolved Abeta1-42 significantly stimulated both IL-1alpha and IFN-gamma secretion. The Abeta1-40 betaamy balls stimulated the secretion of IL-1alpha and IL-1beta. Incubation with Abeta peptides did not affect the secretion of IL-1ra, IL-6, or TNF-alpha. In the case of IL-1beta, the response is correlated with the presence of Abeta peptide as monomers and oligomers.     

Potassium buffering by Müller cells isolated from the center and periphery of the frog retina.

Müller (radial glial) cells span the retina from the outer to the inner limiting membranes. They are the only glial cells found in the amphibian retina. The thickness of the frog (Rana pipiens) retina decreases by a factor of about four from the center to the periphery. Thus, Müller cells were isolated, by enzymatic dissociation, with stalk lengths from 20 to 140 microm. Their ability to transfer K(+) via the stalk between soma and endfoot was studied. Membrane currents were recorded using the whole-cell voltage-clamp technique with the pipette sealed to either the endfoot or the soma. Inward (I(KIN)) or outward (I(KO)) currents were elicited by rapid increases (3 to 10 mM) or decreases (3 to 1 mM) of the extracellular K(+) concentration ([K(+)](o)) either by local application (close or distant to the recording pipette) or around the entire cell (whole cell perfusion). For the long central cells, the ratio I(KIN)/I(KO) was 4.6 +/- 0.6 SE (n = 9) at the endfoot and 1.7 +/- 0.1 SE (n = 8) at the soma. In cells from the retinal periphery, the ratio I(KIN)/I(KO) was higher, 7.0 +/- 0.27 (n = 8) at the endfoot and 3.2 +/- 0.1 (n = 10) at the soma. The results suggest that there is less inward rectification in the somatic than in the endfoot membrane. As expected from previous studies, the sensitivity of the cells to K(+) was higher at the endfoot than at the soma. The amplitude of I(KIN) at the endfoot compared to the soma was about 8-fold for the long central cells but only about 1.5-fold for the short peripheral cells. Currents spread readily from endfoot to soma in the peripheral cells. In the long central Müller cells the soma and endfoot appeared electrotonically isolated. The "functional length constant", lambda, of cell stalk processes was about 70 microm. The relative decrement of large inward currents was stronger than that of smaller outward currents; this difference ("artificial rectification") is explained by a simple model, where larger currents (inward) are attenuated more than smaller (outward) currents. The data support the hypothesis that in the retinal periphery, Müller cells provide extensive spatial K(+) buffering from both plexiform layers into the vitreous body. In the central retina, however, such currents are limited within a short (interlaminar) range.     

Activation of mixed glia by Aβ-specific Th1 and Th17 cells and its regulation by Th2 cells

Microglia are innate immune cells of the CNS, that act as antigen-presenting cells (APC) for antigen-specific T cells and respond to inflammatory stimuli, such as amyloid-beta (Aβ), resulting in the release of neurotoxic factors and pro-inflammatory cytokines. Astrocytes can also act as APC and modulate the function of microglia. However, the role of distinct T cell subtypes, in particular Th17 cells, in glial activation and subsequent modulatory effects of Th2 cells are poorly understood. Here, we generated Aβ-specific Th1, Th2, and Th17 cells and examined their role in modulating Aβ-induced activation of microglia in a mixed glial culture, a preparation which mimics the complex APC types in the brain. We demonstrated that mixed glia acted as an effective APC for Aβ-specific Th1 and Th17 cells. Addition of Aβ-specific Th2 cells suppressed the Aβ-induced IFN-γ production by Th1 cells and IL-17 production by Th17 cells with glia as the APC. Co-culture of Aβ-specific Th1 or Th17 cells with glia markedly enhanced Aβ-induced pro-inflammatory cytokine production and expression of MHC class II and co-stimulatory molecules on the microglia. Addition of Aβ-specific Th2 cells inhibited Th17 cell-induced IL-1β and IL-6 production by mixed glia and attenuated Th1 cell-induced CD86 and CD40 expression on microglia. The modest enhancement of MHC class II and CD86 expression on astrocytes by Aβ-specific Th1 and Th17 was not attenuated by Th2 cells. These data indicate that Aβ-specific Th1 and Th17 cells induce inflammatory activation of glia, and that this is in part regulated by Th2 cells.     

The disappearance of dopamine-β-hydroxylase from the rat salivary glands after extirpation of the superior cervical ganglion

Summary The dopamine--hydroxylase (DBH) activity in the rat salivary glands was followed after ganglionectomy. The results were compared with the corresponding noradrenaline (NA) values from an earlier study. The extraneuronal DBH fraction was 39 per cent of the total DBH activity and remained constant for 2 weeks.The neuronal DBH fraction disappeared almost as fast as NA from the tissue during degeneration. The DBH activity disappeared faster when the axonal stump at axotomy was short than when it was about 2 cm longer, in agreement with an earlier found pattern for NA. There appeared to be no marked trapping in the tissue of DBH released from the degenerating adrenergic neurons, even though NA disappeared somewhat faster than DBH.No signs of inactivation of DBH in the glands were observed. On the other hand, overflow of DBH to the blood, reflected as increased blood levels, was not found during the period of nerve degeneration.     

Effect of chronic administration of estradiol, progesterone, and tibolone on the expression and phosphorylation of glycogen synthase kinase-3β and the microtubule-associated protein tau in the hippocampus and cerebellum of female rat

Gonadal hormones regulate expression and activation of protein tau. Tibolone is a drug used as first- choice comprehensive treatment for the relief of menopausal symptoms, because it and its various metabolites have estrogenic properties and progestogenic/androgenic effects; however, the effect on the activation of tau protein and its signaling cascade in the brain is unknown. We studied the effect of chronic administration of estradiol (E2), progesterone (P4), and tibolone (TIB) on the expression and phosphorylation of microtubule-associated protein tau and glycogen synthase kinase-3β (GSK3β) in the hippocampus and cerebellum of ovariectomized rats. Ovariectomized adult female rats were implanted with pellets of vehicle, E2, or P4 or were treated with TIB by oral administration for 60 days. The animals were sacrificed, and tissue proteins were analyzed by Western blot. We observed that, in the hippocampus, administration of E2, P4, or TIB significantly decreased the protein content of hyperphosphorylated tau and increased the tau dephosphorylated form, whereas only treatment with TIB increased the content of the phosphorylated form of GSK3β. In the cerebellum, E2 and TIB treatments resulted in a significant decrease in the expression of hyperphosphorylated tau, whereas E2 and TIB increased phosphorylated GSK3β; P4 had no effect. These results indicate that chronic administration of gonadal hormones and tibolone modulates tau and GSK3β phosphorylation in hippocampus and cerebellum of the rat and may exert a neuroprotective effect in these tissues.     

Sodium-bicarbonate cotransport in retinal astrocytes and Müller cells of the rat.

Sodium-bicarbonate cotransport in retinal glial cells was studied in the everted eyecup preparation of the rat. Intracellular pH was monitored with the indicator dye BCPCF and fluorescence confocal microscopy. Raising the K+ concentration from 3 to 12 mM in HCO3- -buffered perfusate evoked an intracellular alkalinization in both astrocytes and Müller cells. The alkalinization developed more rapidly and was larger in astrocytes. The K+ -induced alkalinization was HCO3- -dependent; it was reduced by 33% in astrocytes and 71% in Müller cells when HCO3- was removed from the perfusate. The alkalinization was effectively blocked by addition of 0.5 mM 4,4"-diisothiocyanato-stilbene-2,2'-disulfonic acid (DIDS). Removal of Na+ from the perfusate evoked a rapid acidification in both types of glial cells. The results indicate that astrocytes and Müller cells in situ in the rat retina possess an electrogenic Na+/HCO3- cotransporter.     

Expression of the enkephalin precursor gene in C6 rat glioma cells: Regulation by β-adrenergic agonists and glucocorticoids

Cultured C6 rat glioma cells contain mRNA coding for preproenkephalin (A), the precursor of methionine- and leucine-enkephalin. The abundance in untreated cells was determined by blot hybridization methods to be 3–6 pg per μg total RNA. Treatment of confluent cells for 12 h with 10 μM (−)-norepinephrine, which activates C6 adenylate cyclase, transiently elevated preproenkephalin mRNA to 3.3 and 7.7 times the control in the absence and presence of the glucocorticoid dexamethasone, respectively. Hydrocortisone and corticosterone also potentiated the effect of norepinephrine. However, glucocorticoids alone did not alter the preproenkephalin mRNA abundance. The effect of norepinephrine + dexamethasone was blocked by the β-adrenergic antagonist propranolol but not by the α-adrenergic antagonist phentolamine. Forskolin, which directly activates adenylate cyclase, similarly elevated the preproenkephalin mRNA abundance; its effect was also potentiated by dexamethasone. C6 cells contain Met-enkephalin-containing protein resembling proenkephalin (apparent M_r 30,000) but little Met-enkephalin, suggesting a low level of proper precursor processing. Treatment with norepinephrine + dexamethasone raised the content of proenkephalin-like protein 11-fold. Thus, preproenkephalin mRNA levels in C6 cells are regulated synergistically by adenosine 3′:5′-cyclic monophosphate and glucocorticoids. These results suggest modes of regulation of proenkephalin biosynthesis in normal rat enkephalinergic cells.     

Alzheimer's disease-related loss of Pin1 function influences the intracellular localization and the processing of AβPP

Increased amyloidogenic processing of the amyloid-β protein precursor (AβPP) is a characteristic of Alzheimer's disease (AD). We previously observed that the prolyl isomerase Pin1, which is down-regulated in AD, regulates AβPP conformation accelerating cis/trans isomerization of the phospho-Thr668-Pro669 peptide bond, and that Pin1 knockout in mice increases the amyloidogenic processing of AβPP, although the underlying mechanism is still unknown. Since the intracellular localization of AβPP determines whether the processing will be amyloidogenic or non-amyloidogenic, here we addressed the question whether loss of Pin1 function affects the intracellular localization of AβPP, influencing AβPP processing. Using cellular models of Pin1 knockout and Pin1 knockdown, we have demonstrated that lowering Pin1 levels changed the intracellular localization and the processing of AβPP. Under these conditions, less AβPP was retained at the plasma membrane favoring the amyloidogenic processing, and the kinetics of AβPP internalization increased as well as the nuclear trafficking of AβPP C-terminal fragment AICD. In addition, AβPPThr668Ala mutant, which cannot bind to Pin1 and retains more trans conformation, rescued the levels of AβPP at the plasma membrane in Pin1 knockout cells. Thus, loss of Pin1 function contributes to amyloidogenic pathways, by facilitating both the removal of AβPP from compartments where it is mostly non-amyloidogenic and its internalization to more amyloidogenic compartments. These data suggest that physiological levels of Pin1 are important to control the intracellular localization and metabolic fate of Thr668-phosphorylated AβPP, and regulation of AβPP conformation is especially important in pathologic conditions of AβPP hyperphosphorylation and/or loss of Pin1 function, associated with AD.     

Analysis of TGF-β2 and TGF-β3 expression in the hydrocephalic H-Tx rat brain

Introduction Transforming growth factor- (TGF-) is an important cytokine with modulatory actions in the nervous system. The development of hydrocephalus in mouse models resulting from the overexpression of TGF-1 has previously been described, but the mechanism by which this occurs remains obscure.Methods In order to evaluate the role of TGF- in hydrocephalus, we used SYBR Green I-based real-time quantitative RT-PCR method and Western blot analysis to analyze the TGF-2 and TGF-3 mRNA and protein expressions in the cerebral cortex of the H-Tx rat, a model of congenital hydrocephalus.Results The hydrocephalic H-Tx rat expressed significantly higher TGF-3 levels than their normal siblings (p<0.01) at 7 and 14 days of age. This difference became insignificant when analyzed at 21 days of age. On the other hand, such a difference has not been observed in the TGF-2 levels in the hydrocephalic H-Tx rat.Conclusions These results suggest that TGF-2 and TGF-3 expression may be modulated differently in the hydrocephalus, and TGF-3 may contribute to the development of hydrocephalus in this rat model.     

Neuronal-like differentiation of bone marrow-derived mesenchymal stem cells induced by striatal extracts from a rat model of Parkinson’s disease

A rat model of Parkinson’s disease was established by 6-hydroxydopamine injection into the medial forebrain bundle. Bone marrow-derived mesenchymal stem cells (BMSCs) were isolated from the femur and tibia, and were co-cultured with 10% and 60% lesioned or intact striatal extracts. The results showed that when exposed to lesioned striatal extracts, BMSCs developed bipolar or multi-polar morphologies, and there was an increase in the percentage of cells that expressed glial fibrillary acidic protein (GFAP), nestin and neuron-specific enolase (NSE). Moreover, the percentage of NSE-positive cells increased with increasing concentrations of lesioned striatal extracts. However, intact striatal extracts only increased the percentage of GFAP-positive cells. The findings suggest that striatal extracts from Parkinson’s disease rats induce BMSCs to differentiate into neuronal-like cells in vitro.     

Resolution of the pathway taken by implanted Schwann cells to a spinal cord lesion by prior infection with a retrovirus encoding β-galactosidase

Summary This series of experiments is designed to follow the fate of implanted Schwann cells by first labeling them with a recombinant retrovirus encoding the bacterial -galactosidase gene, then injecting them into the spinal cord after a demyclinating lesion has been produced. The label provides a means of distinguishing the exogenous Schwann cells from endogenous ones and of determining their travel pattern and myelinating or ensheathing behavior in the central nervous system (CNS). Neonatal rat primary Schwann cells were stimulated to divide by administering glial growth factor and forskolin. Fresh virus-containing supernatant from Psi2 cells producing retrovirus LZ1 was placed in cell culture to label the cells. The capacity of infected Schwann cells to form myelin was verified by coculturing in vitro with neurons from embryonic dorsal root ganglia. Infected cells were injected into the right side of adult syngenic rat spinal cords after a lysolecithin-induced demyelinating lesion had been produced 1 cm caudal on the left side. After 3 weeks the animals were killed, perfused for electron microscopy, and spinal cord sections histochemically stained for -galactosidase activity using the chromogenic substrate 5-bromo-4-chloro-3-indoyl--d-galactosidase (X-Gal) which forms a blue precipitate in infected cells. The labeled cells, easily recognized macro-and microscopically, were clustered at the cell injection site, in the dorsal meninges and, at the area of demyelination, bilaterally in the superficial aspect of the dorsal funiculi. Labeled cells were not evident in the neuropil midway between the injection and demyelination sites. In the electron microscope, the cells containing the electron-dense precipitate from the hydrolysis of X-Gal were identified at the lesion site and some of these cells ensheathed axons. These data suggest that implanted Schwann cells migrate to a demyelinating lesion in the subarachnoid space rather than through the parenchyma.Supported by grants from the American Paralysis Association (LAL) and National Multiple Sclerosis Society (GCO)     

Influence of leptin on luteinizing hormone and follicle stimulating hormone secreted from cultured rat anterior pituitary cells☆

BACKGROUND： Leptin may regulate reproductive function via release of hypothalamic neuropeptide Y. However, it is unknown whether this regulatory effect is limited to the hypothalamus. OBJECTIVE： To detect the effect of different dosages of leptin on luteinizing hormone （LH） and follicle stimulating hormone （FSH） secretion from in vitro cultured rat anterior pituitary cells. DESIGN： Contrast study based on cells. SETTING： This study was performed in the Basic Institute of Chengde Medical College, Chengde City, Hebei Province, China from March to June 2007. MATERIALS： Eighteen female Wistar rats of three months of age, weighing 200-220 g, and of clean grade were used. Leptin was provided by Peprotech Company, DMEM culture medium by Invitrogen Company, and the radioimmunological kit by Beijing Zhongshan Jinqiao Biotechnology Co., Ltd. METHODS： Three glandular organs were regarded as one group for culture of anterior pituitary cells. In the control group, saline was added to the culture medium instead of leptin. In the leptin group, leptin was prepared into different concentrations of 1×10^-12, 1×10^-11, 1×10^-9, 1×10^-7, and 1×10^-6 mol/L for stimulation of cultured cells. The culture supernatant was obtained at three hours after additional of saline/leptin. MAIN OUTCOME MEASURES： Contents of LH and FSH were detected by radioimmunology. RESULTS： Following leptin stimulation, LH release increased with increasing concentrations of leptin up to 1×10^-9 mol/L, where LH release peaked. LH release then progressively decreased with increasing leptin concentrations （P 〈 0.01）. LH release in the leptin （1×10^-12, 1×10^-11, 1×10^-7, and 1×10^-6 mol/L） groups was significantly higher than that in the control group （P 〈 0.01）. FSH content in the leptin （1×10^-11, 1×10^-9, and 1×10^-7 mol/L） groups was significantly higher than that in the control group （P 〈 0.01）. CONCLUSION： Leptin can directly affect pituitary tissue to promote the secretion of LH and FSH in a d     

Intra-parenchymal injection of tumor necrosis factor-α and interleukin 1-β produces dopamine neuron loss in the rat

Summary. Inflammatory processes are thought to underlie the dopamine (DA) neuron loss seen in Parkinsons disease (PD). However, it is not known if the inflammation precedes that loss, or is a consequence of it. We injected tumor necrosis factor alpha (TNF) and interleukin 1 beta (IL-1) into the median forebrain bundle to determine if these pro-inflammatory cytokines could induce DA neuron loss in the substantia nigra (SN) by themselves. The magnitude of the DA cell loss as well as the decreases in striatal DA, were both dose and time to sacrifice dependent. Injecting both cytokines together produced greater cell losses and DA reductions than that seen when the cytokines were injected alone. The DA neuron loss seen was more pronounced in the lateral nigra and its ventral tier and similar to that seen when other toxins are injected. These data suggest that TNF and IL-1 can induce DA neuron loss by themselves and could produce DA neuron loss independent of other inflammatory events.     

Leptin enhances the release of cytokines by peripheral blood mononuclear cells from acute multiple sclerosis patients

Objective To explore the effect of leptin on cytokine production by PBMCs obtained from MS patients either in acute (relapse) or in stable (nonrelapse) phase of disease. Methods PBMCs were collected from 25 untreated acute MS patients, 11 stable MS patients and 20 healthy controls. PBMCs were cultured either with RPMI-1640 alone or with leptin (1.25 nmol /ml) , phytohemagglutinin (PHA) (100μg/ml) , and leptin PHA. 72 h later the supernate of the culture medium were collected and stored at -70℃. The pro-inflammatory cytokine (IFN-γ) concentration were determined using an enzyme-linked immunosorbent assay (ELISA) , and the anti-inflammatory cytokine (IL-4) concentration were investigated by radioimmunity methods. Results Our data showed that leptin induced IFN-γ production by PBMCs of patients in an acute phase of disease but not in a stable phase or in healthy controls. Moreover, we found that PHA induced IL-4 production by PBMCs of patients in an acute phase of disease, but leptin inhibited this ability of PHA. Conclusiotl Leptin can affect on pro- and anti-inflammatory cytokine production by PBMCs collected from MS patients, may be this connected with leptin increase the susceptiveness of MS.     

The morphology and classification of α ganglion cells in the rat retinae: a fractal analysis study

Rat retinal ganglion cells have been proposed to consist of a varying number of subtypes. Dendritic morphology is an essential aspect of classification and a necessary step toward understanding structure-function relationships of retinal ganglion cells. This study aimed at using a heuristic classification procedure in combination with the box-counting analysis to classify the alpha ganglion cells in the rat retinae based on the dendritic branching pattern and to investigate morphological changes with retinal eccentricity. The cells could be divided into two groups: cells with simple dendritic pattern (box dimension lower than 1.390) and cells with complex dendritic pattern (box dimension higher than 1.390) according to their dendritic branching pattern complexity. Both were further divided into two subtypes due to the stratification within the inner plexiform layer. In the present study we have shown that the alpha rat RCGs can be classified further by their dendritic branching complexity and thus extend those of previous reports that fractal analysis can be successfully used in neuronal classification, particularly that the fractal dimension represents a robust and sensitive tool for the classification of retinal ganglion cells. A hypothesis of possible functional significance of our classification scheme is also discussed.     

β-Estradiol 17-acetate enhances the in vitro vitality of endothelial cells isolated from the brain of patients subjected to neurosurgery

In the current landscape of endothelial cell isolation for building in vitro models of the blood-brain barrier,our work moves towards reproducing the features of the neurovascular unit to achieve glial compliance through an innovative biomimetic coating technology for brain chronic implants.We hypothesized that the autologous origin of human brain mic rovascular endothelial cells(hBMECs) is the first requirement for the suitable coating to prevent the glial inflammato ry response trigge red by f...