Assessment of mouse cognitive and anxiety-like behaviors and hippocampal inflammation following a repeated and intermittent paradoxical sleep deprivation procedure.

It has been reported that more than one fourth of the world's population suffers from sleep problems. However, there is not a stable and reliable animal model to mimic the persistent and periodic features of sleep disorders, and correspondingly, the feasibility and effectiveness of repeated behavioral tests remains to be determined. In the present study, we repetitively, and intermittently, treated mice with 3days and 7days of paradoxical sleep deprivation (SD), using the modified multiple small-platforms-over-water method for 3 months. The behavioral results suggested that repeated open field and Y-maze tests are able to successfully detect anxiety-like behaviors and working memory dysfunction of the model mice. The Morris water maze test is not suitable for evaluating spatial learning ability following SD because the long-term utilization of the flower-pot method increases the familiarity of mice with the water environment. Moreover, neuroinflammation, microglial activation and neuronal apoptosis were observed in the hippocampus of model mice even recovery for 3 weeks later. This animal model and corresponding behavioral evaluation method will help to explore the pathogenesis and therapeutic strategies of chronic sleep disorders.

Multiparameter toxicity assessment of novel DOPO-derived organophosphorus flame retardants.

Halogen-free organophosphorus flame retardants are considered as replacements for the phased-out class of polybrominated diphenyl ethers (PBDEs). However, toxicological information on new flame retardants is still limited. Based on their excellent flame retardation potential, we have selected three novel 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) derivatives and assessed their toxicological profile using a battery of in vitro test systems in order to provide toxicological information before their large-scale production and use. PBDE-99, applied as a reference compound, exhibited distinct neuro-selective cytotoxicity at concentrations ≥10 µM. 6-(2-((6-oxido-6H-dibenzo[c,e][1,2]oxaphosphinin-6-yl)amino)ethoxy)-6H-dibenzo[c,e][1,2]oxaphosphinine 6-oxide (ETA-DOPO) and 6,6'-(ethane-1,2-diylbis(oxy))bis(6H-dibenzo[c,e][1,2]oxaphosphinine-6-oxide) (EG-DOPO) displayed adverse effects at concentrations >10 µM in test systems reflecting the properties of human central and peripheral nervous system neurons, as well as in a set of non-neuronal cell types. DOPO and its derivative 6,6'-(ethane-1,2-diylbis(azanediyl))bis(6H-dibenzo[c,e][1,2]oxaphosphinine-6-oxide) (EDA-DOPO) were neither neurotoxic, nor did they exhibit an influence on neural crest cell migration, or on the integrity of human skin equivalents. The two compounds furthermore displayed no inflammatory activation potential, nor did they affect algae growth or daphnia viability at concentrations ≤400 µM. Based on the superior flame retardation properties, biophysical features suited for use in polyurethane foams, and low cytotoxicity of EDA-DOPO, our results suggest that it is a candidate for the replacement of currently applied flame retardants.

Characterization of the Kallikrein-Kinin System Post Chemical Neuronal Injury: An In Vitro Biochemical and Neuroproteomics Assessment.

Traumatic Brain Injury (TBI) is the result of a mechanical impact on the brain provoking mild, moderate or severe symptoms. It is acknowledged that TBI leads to apoptotic and necrotic cell death; however, the exact mechanism by which brain trauma leads to neural injury is not fully elucidated. Some studies have highlighted the pivotal role of the Kallikrein-Kinin System (KKS) in brain trauma but the results are still controversial and inconclusive. In this study, we investigated both the expression and the role of Bradykinin 1 and 2 receptors (B1R and B2R), in mediating neuronal injury under chemical neurotoxicity paradigm in PC12 cell lines. The neuronal cell line PC12 was treated with the apoptotic drug Staurosporine (STS) to induce cell death. Intracellular calcium release was evaluated by Fluo 4-AM staining and showed that inhibition of the B2R prevented calcium release following STS treatment. Differential analyses utilizing immunofluorescence, Western blot and Real-time Polymerase Chain Reaction revealed an upregulation of both bradykinin receptors occurring at 3h and 12h post-STS treatment, but with a higher induction of B2R compared to B1R. This implies that STS-mediated apoptosis in PC12 cells is mainly conducted through B2R and partly via B1R. Finally, a neuroproteomics approach was conducted to find relevant proteins associated to STS and KKS in PC12 cells. Neuroproteomics results confirmed the presence of an inflammatory response leading to cell death during apoptosis-mediated STS treatment; however, a "survival" capacity was shown following inhibition of B2R coupled with STS treatment. Our data suggest that B2R is a key player in the inflammatory pathway following STS-mediated apoptosis in PC12 cells and its inhibition may represent a potential therapeutic tool in TBI.

The neurobiology of depression in later-life: clinical, neuropsychological, neuroimaging and pathophysiological features.

As the population ages, the economic and societal impacts of neurodegenerative and neuropsychiatric disorders are expected to rise sharply. Like dementia, late-life depressive disorders are common and are linked to increased disability, high healthcare utilisation, cognitive decline and premature mortality. Considerable heterogeneity in the clinical presentation of major depression across the life cycle may reflect unique pathophysiological pathways to illness; differentiating those with earlier onset who have grown older (early-onset depression), from those with illness onset after the age of 50 or 60 years (late-onset depression). The last two decades have witnessed significant advances in our understanding of the neurobiology of early- and late-onset depression, and has shown that disturbances of fronto-subcortical functioning are implicated. New biomedical models extend well beyond perturbations of traditional monoamine systems to include altered neurotrophins, endocrinologic and immunologic system dysfunction, inflammatory processes and gene expression alterations. This more recent research has highlighted that a range of illness-specific, neurodegenerative and vascular factors appear to contribute to the various phenotypic presentations. This review highlights the major features of late-life depression, with specific reference to its associated aetiological, clinical, cognitive, neuroimaging, neuropathological, inflammatory and genetic correlates. Data examining the efficacy of pharmacological, non-pharmacological and novel treatments for depression are discussed. Ultimately, future research must aim to evaluate whether basic biomedical knowledge can be successfully translated into enhanced health outcomes via the implementation of early intervention paradigms.

Alzheimer's disease plaques and tangles: cemeteries of a pyrrhic victory of the immune defence network against herpes simplex infection at the expense of complement and inflammation-mediated neuronal destruction.

Plaques and tangles are highly and significantly enriched in herpes simplex (HSV-1) binding proteins (by 11 and 15 fold respectively (P<4.47466E-39) and 132/341 (39%) of the known HSV-1 binding partners or associates are present in these structures. The classes involved include the majority (63-100%) of the known HSV-1 host protein carriers and receptors, 85-91% of the viral associated proteins involved in endocytosis, intracellular transport and exocytosis and 71% of the host proteins associated with the HSV-1 virion. The viral associated proteins found in plaques or tangles trace out a complete itinerary of the virus from entry to exocytosis and the virus also binds to plaque or tangle components involved in apoptosis, DNA transcription, translation initiation, protein chaperoning, the ubiquitin/proteasome system and the immune network. Along this route, the virus deletes mitochondrial DNA, as seen in Alzheimer's disease, sequesters the neuroprotective peptide, ADNP, and interferes with key proteins related to amyloid precursor protein processing and signalling as well as beta-amyloid processing, microtubule stability and tau phosphorylation, the core pathologies of Alzheimer's disease. Amyloid-containing plaques or neurofibrillary tangles also contain a large number of complement, acute phase and immune-related proteins, and the presence of these pathogen defence related classes along with HSV-1 binding proteins suggests that amyloid plaques and tangles represent cemeteries for a battle between the virus and the host's defence network. The presence of the complement membrane attack complex in Alzheimer's disease neurones suggests that complement mediated neuronal lysis may be a consequence of this struggle. HSV-1 infection is known to increase beta-amyloid deposition and tau phosphorylation and also results in cortical and hippocampal neuronal loss, cerebral shrinkage and memory deficits in mice. This survey supports the contention that herpes simplex viral infection contributes to Alzheimer's disease, in genetically predisposed individuals. Genetic conditioning effects are likely to be important, as all of the major risk promoting genes in Alzheimer's disease (apolipoprotein E, clusterin, complement receptor 1 and the phosphatidylinositol binding clathrin assembly protein PICALM), and many lesser susceptibility genes, are related to the herpes simplex life cycle. 33 susceptibility genes are related to the immune system. Vaccination or antiviral agents and immune suppressants should therefore perhaps be considered as viable therapeutic options, prior to, or in the early stages of Alzheimer's disease.

Flow cytometric assessment of anti-neuronal antibodies in central nervous system involvement of systemic lupus erythematosus and other autoimmune diseases.

The objective of this study is to evaluate the association between anti-neuronal antibody (anti-NA) and central nervous system (CNS) manifestations of systemic lupus erythematosus (SLE) and other rheumatic diseases using a flow cytometric method. Anti-NA was measured by flow cytometry in serum and cerebrospinal fluid (CSF) samples from patients with SLE (n=44 for serum, n=17 for CSF), other rheumatic diseases (n=64 for serum, n=21 for CSF) and from healthy controls (n=65 for serum, n=18 for CSF). Serum anti-NA was more frequently observed in SLE (31.8%, 14/44) than in other rheumatic diseases (4.7%, 3/64, P<0.001) or in healthy controls (0%, 0/65, P<0.00001). In SLE patients, the frequency of serum anti-NA was significantly higher in CNS-SLE (76.5%, 13/17) than in non CNS-SLE (3.7%, 1/27, P<0.000001). CSF anti-NA was detected in 88.2% (15/17) of CNS-SLE and was more frequently detected in CNS-SLE (15/17, 88.2%) than in other rheumatic diseases with CNS involvement (1/21, 4.8%, P<0.000001) or in healthy controls (0/18, P<0.000001). In conclusion, serum anti-NA was more frequently found in CNS-SLE than in non CNS-SLE, other rheumatic diseases or in healthy controls. The frequency of CSF anti-NA in CNS-SLE was significantly higher than in other rheumatic diseases with CNS involvement or in healthy controls.

Transplantation of neural stem cells in a rat model of stroke: assessment of short-term graft survival and acute host immunological response.

The use of progenitors and stem cells for neural grafting is promising, as these not only have the potential to be maintained in vitro until use, but may also prove less likely to evoke an immunogenic response in the host, when compared to primary (fetal) grafts. We investigated whether the short-term survival of a grafted conditionally immortalised murine neuroepithelial stem cell line (MHP36) (2 weeks post-implantation, 4 weeks post-ischaemia) is influenced by: (i) immunosuppression (cyclosporin A (CSA) vs. no CSA), (ii) the local (intact vs. lesioned hemisphere), or (iii) global (lesioned vs. sham) brain environment. MHP36 cells were transplanted ipsi- and contralateral to the lesion in rats with middle cerebral artery occlusion (MCAo) or sham controls. Animals were either administered CSA or received no immunosuppressive treatment. A proliferation assay of lymphocytes dissociated from cervical lymph nodes, grading of the survival of the grafted cells, and histological evaluation of the immune response revealed no significant difference between animals treated with or without CSA. There was no difference in survival or immunological response to cells grafted ipsi- or contralateral to the lesion. Although a local upregulation of immunological markers (MHC class I, MHC class II, CD45, CD11b) was detected around the injection site and the ischaemic lesion, these were not specifically upregulated in response to transplanted cells. These results provide evidence for the low immunogenic properties of MHP36 cells during the initial period following implantation, known to be associated with an acute host immune response and ensuing graft rejection.

Assessment of immunological properties of neurofilament triplet proteins.

The relationship between mammalian neurofilament triplet proteins was studied immunologically using rabbit and guinea pig antibodies to bovine neurofilament triplet proteins. Neurofilament proteins were separated by preparative electrophoresis, each protein being isolated and re-electrophoresed to enhance purification. Antisera to 68,000 (P68), 150,000 (P150) and 200,000 (P200) dalton neurofilament proteins showed greatest activity with the corresponding protein immunogen but also revealed cross-reactivity with the other two neurofilament proteins when assessed by the ELISA method. The same antigenic inoculum elicited variable cross-reactivity, more in the guinea pig than in the rabbit. Rabbit antisera to P68 was specific in that it did not cross-react with P150 or P200. Rabbit antisera to P150 and to P200 were rendered specific by absorption with P200 and P150, respectively. By electron microscopy, isolated neurofilaments became decorated with an uniform coat of antibodies when exposed to specific antisera for each of the neurofilament proteins. By indirect immunofluorescence, each antisera showed identical patterns of tissue localization, corresponding to the distribution of neurofilaments in peripheral nerve, spinal ganglia, spinal cord, cerebellum and cerebrum. Neurofilament antigens were not detected in liver, kidney, spleen, lung, bladder, intestine, aorta, heart or tongue.