Neuroscience
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Proliferation and differentiation of retinal progenitor cells (RPCs) are tightly controlled by extrinsic cues and distinct combinations of transcription factors leading to the generation of retinal cell type diversity. In this context, we investigated the role of the protein tyrosine phosphatase interacting protein 51 (PTPIP51) in the differentiation of RPCs. The expression pattern of PTPIP51 was analyzed by immunostaining during post-natal retinal development in the rat. ⋯ By contrast, misexpression of PTPIP51 in early or late RPCs failed to modify the differentiation of the RPCs. Our data demonstrate that PTPIP51 is implicated in the differentiation process of immature photoreceptors. Because PTPIP51 is specifically localized in the inner segment, PTPIP51 may contribute to the complex stage of maturation of the apical segment of these cells.
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Schedule-induced polydipsia (SIP) is an adjunctive behavior in which rats exhibit excessive drinking as a consequence of intermittent feeding, and it has been proposed as a candidate model to study the development of compulsive and repetitive behavior. Although several brain structures are involved in compulsive behavior, it has been suggested that alterations in fronto-striatal circuits may underlie compulsive spectrum disorders. In the present work, we examined whether SIP would induce modifications in dorsolateral striatum (DLS) and anterior prefrontal cortex (aPFC) neurons. ⋯ By contrast, we observed no differences either in dendritic spine density or in the morphological structure of the dendrites of the aPFC in SIP rats compared to their control counterparts. We hypothesize that SIP-induced structural plasticity in DLS neurons could be related to inflexible response in compulsive behavior. The findings of this study could provide new insights into the involvement of particular cell populations of the dorsolateral striatum and anterior prefrontal cortex regions in compulsive spectrum disorders.
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Secondary death of neural cells plays a key role in the physiopathology and the functional consequences of traumatic spinal cord injury (SCI). Pharmacological manipulation of cell death pathways leading to the preservation of neural cells is acknowledged as a main therapeutic goal in SCI. In the present work, we hypothesize that administration of the neuroprotective cell-permeable compound ucf-101 will reduce neural cell death during the secondary damage of SCI, increasing tissue preservation and reducing the functional deficits. ⋯ Our studies also suggest that the effects of ucf-101 may be mediated through the inhibition of HtrA2/OMI and the concomitant increase of inhibitor of apoptosis protein XIAP, as well as the induction of ERK1/2 activation and/or expression. In vitro assays confirm the effects of ucf-101 on both pathways as well as on the reduction of caspase cascade activation and apoptotic cell death in a neuroblastoma cell line. These results suggest that ucf-101 can be a promising therapeutic tool for SCI that deserves more detailed analyses.
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Triheptanoin, an oily substance, consists of glycerol bound to three molecules of heptanoic acid, a C7 odd-chain fatty acid. A triheptanoin-rich diet has anaplerotic effects because heptanoate metabolism yields succinate which delivers substrates to the Krebs cycle. While previous studies on the effects of triheptanoin focused on metabolic disorders and epilepsy, we investigated triheptanoin's effect on ischemic stroke. ⋯ We conclude that triheptanoin-fed mice which sustained an experimental stroke had a significantly improved neurological outcome. This beneficial effect is apparently due to an improvement of mitochondrial function and preservation of the cellular energy state. Our findings identify triheptanoin as a promising new dietary agent for neuroprotection.