Search results for "atomic"
showing 10 items of 27529 documents
Homeostatic interplay between electrical activity and neuronal apoptosis in the developing neocortex
2017
An intriguing feature of nervous system development in most animal species is that the initial number of generated neurons is higher than the number of neurons incorporated into mature circuits. A substantial portion of neurons is indeed eliminated via apoptosis during a short time window - in rodents the first two postnatal weeks. While it is well established that neurotrophic factors play a central role in controlling neuronal survival and apoptosis in the peripheral nervous system (PNS), the situation is less clear in the central nervous system (CNS). In postnatal rodent neocortex, the peak of apoptosis coincides with the occurrence of spontaneous, synchronous activity patterns. In this …
Critical re-evaluation of neuroglobin expression reveals conserved patterns among mammals.
2016
Neuroglobin (Ngb) is a respiratory protein that is almost exclusively expressed in the vertebrate nervous system. Despite many years of research, the exact function and even the expression sites of Ngb are still a matter of debate. However, to investigate hypotheses surrounding the potential roles of Ngb, a detailed knowledge of its major and minor expression sites is indispensable. We have therefore evaluated Ngb expression by extensive bioinformatic analysis using publicly available transcriptome data (RNA-Seq). During mammalian brain development, we observed low embryonic expression of Ngb mRNA and an increase after birth, arguing against a role of Ngb in fetal hypoxia tolerance. In adul…
Neurodegenerative diseases: Might citrus flavonoids play a protective role?
2016
Neurodegenerative diseases (ND) result from the gradual and progressive degeneration of the structure and function of the central nervous system or the peripheral nervous system or both. They are characterized by deterioration of neurons and/or myelin sheath, disruption of sensory information transmission and loss of movement control. There is no effective treatment for ND, and the drugs currently marketed are symptom-oriented, albeit with several side effects. Within the past decades, several natural remedies have gained attention as potential neuroprotective drugs. Moreover, an increasing number of studies have suggested that dietary intake of vegetables and fruits can prevent or delay th…
Influence of Commensal Microbiota on the Enteric Nervous System and Its Role in Neurodegenerative Diseases
2017
When thinking about neurodegenerative diseases, the first symptoms that come to mind are loss of memory and learning capabilities, which all resemble hallmarks of manifestation of such diseases in the central nervous system (CNS). However, the gut comprises the largest nervous system outside the CNS that is autonomously active and in close interplay with its microbiota. Therefore, the enteric nervous system (ENS) might serve as an indicator of degenerative pathomechanisms that also affect the CNS. On the other hand, it might offer an entry point for devastating influences from the microbial community or – conversely – for therapeutic approaches via gut commensals. Within the last years, the…
Extracellular vesicles: interneural shuttles of complex messages.
2016
A core function of neural cells is the exchange and integration of information. Extracellular vesicles such as exosomes and microvesicles recently entered the scene of neuroscience as novel vehicles transmitting complex signals between neural cells. Carrying a defined but mixed cargo of biomolecules, extracellular vesicles possess versatile biological activities with the ability to profoundly modulate the molecular configuration and behaviour of target cells. Extracellular vesicles are suggested to carry out functions during neural development and maintenance, they appear to spread neuropathology and furthermore, convey neuroprotection and regeneration. Understanding the molecular mechanism…
Profilin 1 delivery tunes cytoskeletal dynamics toward CNS axon regeneration
2020
After trauma, regeneration of adult CNS axons is abortive, causing devastating neurologic deficits. Despite progress in rehabilitative care, there is no effective treatment that stimulates axonal growth following injury. Using models with different regenerative capacities, followed by gain- and loss-of-function analysis, we identified profilin 1 (Pfn1) as a coordinator of actin and microtubules (MTs), powering axonal growth and regeneration. In growth cones, Pfn1 increased actin retrograde flow, MT growth speed, and invasion of filopodia by MTs, orchestrating cytoskeletal dynamics toward axonal growth. In vitro, active Pfn1 promoted MT growth in a formin-dependent manner, whereas localizati…
Effects of the Genetic Depletion of Polysialyltransferases on the Structure and Connectivity of Interneurons in the Adult Prefrontal Cortex
2019
Polysialic acid (polySia) is a complex sugar that in the nervous system appears mainly as a posttranslational modification of the neural cell adhesion molecule (NCAM). PolySia plays important roles during brain development, but also in its plasticity during adulthood. Two polysialyltransferases (polyST), ST8SIA2 and ST8SIA4, are involved in the synthesis and attachment of polySia. Both polyST are relevant for developmental migration of cortical interneurons and their establishment in the prefrontal cortex (PFC). In contrast, only ST8SIA4 appears to be important for the structural plasticity of a subpopulation of cortical interneurons in the adult. Interestingly, ST8SIA2 and NCAM are candida…
LPA1, LPA2, LPA4, and LPA6receptor expression during mouse brain development
2019
Background:LPA is a small bioactive phospholipid that acts as an extracellularsignaling molecule and is involved in cellular processes, including cell prolifera-tion, migration, and differentiation. LPA acts by binding and activating at least sixknown G protein–coupled receptors: LPA1–6. In recent years, LPA has beensuggested to play an important role both in normal neuronal development andunder pathological conditions in the nervous system. Results:We show the expression pattern of LPA receptors during mouse braindevelopment by using qRT-PCR, in situ hybridization, and immunocytochemistry.Only LPA1,LPA2,LPA4,and LPA6 mRNA transcripts were detected throughoutdevelopment stages from embryoni…
Impairment of learning and memory performances induced by BPA Evidences from the literature of a MoA mediated through an ED
2018
International audience; Many rodent studies and a few non-human primate data report impairments of spatial and non-spatial memory induced by exposure to bisphenol A (BPA), which are associated with neural modifications, particularly in processes involved in synaptic plasticity. BPA-induced alterations involve disruption of the estrogenic pathway as established by reversal of BPA-induced effects with estrogenic receptor antagonist or by interference of BPA with administered estradiol in ovariectomized animals. Sex differences in hormonal impregnation during critical periods of development and their influence on maturation of learning and memory processes may explain the sexual dimorphism obs…
New Functions of APC/C Ubiquitin Ligase in the Nervous System and Its Role in Alzheimer’s Disease
2017
The E3 ubiquitin ligase Anaphase Promoting Complex/Cyclosome (APC/C) regulates important processes in cells, such as the cell cycle, by targeting a set of substrates for degradation. In the last decade, APC/C has been related to several major functions in the nervous system, including axon guidance, synaptic plasticity, neurogenesis, and neuronal survival. Interestingly, some of the identified APC/C substrates have been related to neurodegenerative diseases. There is an accumulation of some degradation targets of APC/C in Alzheimer’s disease (AD) brains, which suggests a dysregulation of the protein complex in the disorder. Moreover, recently evidence has been provided for an inactivation o…