Neuropathology and applied neurobiology
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Neuropathol. Appl. Neurobiol. · Aug 2014
ReviewReview: Hippocampal sclerosis in epilepsy: a neuropathology review.
Hippocampal sclerosis (HS) is a common pathology encountered in mesial temporal lobe epilepsy (MTLE) as well as other epilepsy syndromes and in both surgical and post-mortem practice. The 2013 International League Against Epilepsy (ILAE) classification segregates HS into typical (type 1) and atypical (type 2 and 3) groups, based on the histological patterns of subfield neuronal loss and gliosis. In addition, granule cell reorganization and alterations of interneuronal populations, neuropeptide fibre networks and mossy fibre sprouting are distinctive features of HS associated with epilepsies; they can be useful diagnostic aids to discriminate from other causes of HS, as well as highlighting potential mechanisms of hippocampal epileptogenesis. ⋯ Post-mortem based research in HS, as an addition to studies on surgical samples, has the added advantage of enabling the study of the wider network changes associated with HS, the long-term effects of epilepsy on the pathology and associated comorbidities. It is likely that HS is heterogeneous in aspects of its cause, epileptogenetic mechanisms, network alterations and response to medical and surgical treatments. Future neuropathological studies will contribute to better recognition and understanding of these clinical and patho-aetiological subtypes of HS.
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Neuropathol. Appl. Neurobiol. · Jun 2014
Cellular sources of cyclooxygenase-1 and -2 up-regulation in the spinal dorsal horn after spinal nerve ligation.
Recent studies suggested that the development of neuropathic pain associated with neural injury may be partly due to up-regulation of cyclooxygenase (COX) in the central nervous system. However, the cellular sources of COX-1 and COX-2 up-regulation following nerve injury are unclear. ⋯ These findings demonstrate that while spinal dorsal horn neurones are important source of COX-1 and COX-2 after nerve injury, microglia also contribute to the pathogenesis of neuropathic pain, partly by producing additional COX-1.
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Neuropathol. Appl. Neurobiol. · Apr 2014
Possible involvement of cathepsin B/D and caspase-3 in deferoxamine-related neuroprotection of early brain injury after subarachnoid haemorrhage in rats.
Deferoxamine (DFX) has recently been shown to have a neuroprotective effect in animal models of subarachnoid haemorrhage (SAH). However, the precise mechanisms underlying these effects remain unclear. Our previous studies found that iron overload in lysosomes leads to lysosomal membrane damage and rupture, and then induces cell apoptosis in the oxidative stress conditions in vitro. We therefore analysed the time-course of the two of major lysosomal cathepsins (cathepsin B/D) and caspase-3 expression in brain and evaluated how DFX might affect these proteins and the parameters concerning early brain injury (EBI) after SAH. ⋯ These results suggest that the lysosomal membrane may be damaged after SAH, which leads to the release of proteases (cathepsin B/D) and activates the apoptotic pathway. Iron overload may be one key mechanism underlying SAH-induced oxidative stress and DFX may protect the lysosomal membrane, inhibit the release of cathepsin B/D, and ameliorate EBI by suppressing iron overload in the acute phase of SAH.
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Neuropathol. Appl. Neurobiol. · Feb 2014
ReviewEnvironmental enrichment and brain repair: harnessing the therapeutic effects of cognitive stimulation and physical activity to enhance experience-dependent plasticity.
Environmental enrichment (EE) increases levels of novelty and complexity, inducing enhanced sensory, cognitive and motor stimulation. In wild-type rodents, EE has been found to have a range of effects, such as enhancing experience-dependent cellular plasticity and cognitive performance, relative to standard-housed controls. Whilst environmental enrichment is of course a relative term, dependent on the nature of control environmental conditions, epidemiological studies suggest that EE has direct clinical relevance to a range of neurological and psychiatric disorders. ⋯ This review will focus on the effects of EE observed in animal models of neurodegenerative brain diseases, at molecular, cellular and behavioural levels. The proposal that EE may act synergistically with other approaches, such as drug and cell therapies, to facilitate brain repair will be discussed. I will also discuss the therapeutic potential of 'enviromimetics', drugs which mimic or enhance the therapeutic effects of cognitive activity and physical exercise, for both neuroprotection and brain repair.
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Neuropathol. Appl. Neurobiol. · Dec 2013
Chaperone-mediated autophagy components are upregulated in sporadic inclusion-body myositis muscle fibres.
Sporadic inclusion-body myositis (s-IBM) is an age-associated degenerative muscle disease. Characteristic features are muscle-fibre vacuolization and intramuscle-fibre accumulations of multiprotein aggregates, which may result from the demonstrated impairments of the 26S proteasome and autophagy. Chaperone-mediated autophagy (CMA) is a selective form of lysosomal degradation targeting proteins carrying the KFERQ motif. Lysosome-associated membrane protein type 2A (LAMP2A) and the heat-shock cognate protein 70 (Hsc70) constitute specific CMA components. Neither CMA components nor CMA activity has been studied in normal or disease human muscle, to our knowledge. ⋯ Our study demonstrates, for the first time, up-regulation of CMA components in s-IBM muscle, and it provides further evidence that altered protein degradation is likely an important pathogenic aspect in s-IBM.