Publications by authors named "Kimberley Evans"

In the central nervous system, oligodendrocyte precursor cells (OPCs) proliferate and differentiate into myelinating oligodendrocytes throughout life, allowing for ongoing myelination and myelin repair. With age, differentiation efficacy decreases and myelin repair fails; therefore, recent therapeutic efforts have focused on enhancing differentiation. Many cues are thought to regulate OPC differentiation, including neuronal activity, which OPCs can sense and respond to via their voltage-gated ion channels and glutamate receptors.

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Myelin, a lipid membrane that wraps axons, enabling fast neurotransmission and metabolic support to axons, is conventionally thought of as a static structure that is set early in development. However, recent evidence indicates that in the central nervous system (CNS), myelination is a protracted and plastic process, ongoing throughout adulthood. Importantly, myelin is emerging as a potential modulator of neuronal networks, and evidence from human studies has highlighted myelin as a major player in shaping human behavior and learning.

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Background: While the overall percentage of residents who withdraw (2.7%) or take extended leave (1.0%) are low, subgroup analysis has found that minority physicians are approximately 30% more likely to withdraw from residency than their white counterparts and 8 times more likely to take extended leave of absence.

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Oligodendrocyte precursor cells (OPCs) give rise to oligodendrocytes which myelinate axons in the central nervous system. Although classically thought to be a homogeneous population, OPCs are reported to have different developmental origins and display regional and temporal diversity in their transcriptome, response to growth factors, and physiological properties. Similarly, evidence is accumulating that myelinating oligodendrocytes display transcriptional heterogeneity.

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Plasticity in the central nervous system (CNS) allows for responses to changing environmental signals. While the majority of studies on brain plasticity focus on neuronal synapses, myelin plasticity has now begun to emerge as a potential modulator of neuronal networks. Oligodendrocytes (OLs) produce myelin, which provides fast signal transmission, allows for synchronization of neuronal inputs, and helps to maintain neuronal function.

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Background: There is a high prevalence of smoking among people with severe mental ill health (SMI). Helping people with SMI to quit smoking could improve their health and longevity, and reduce health inequalities. However, those with SMI are less likely to access and engage with routine smoking cessation services than the general population.

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Background: People with severe mental illnesses such as schizophrenia are three times more likely to smoke than the wider population, contributing to widening health inequalities. Smoking remains the largest modifiable risk factor for this health inequality, but people with severe mental illness have not historically engaged with smoking cessation services. We aimed to test the effectiveness of a combined behavioural and pharmacological smoking cessation intervention targeted specifically at people with severe mental illness.

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Oligodendrocyte progenitor cells (OPCs), which differentiate into myelinating oligodendrocytes during CNS development, are the main proliferative cells in the adult brain. OPCs are conventionally considered a homogeneous population, particularly with respect to their electrophysiological properties, but this has been debated. We show, by using single-cell electrophysiological recordings, that OPCs start out as a homogeneous population but become functionally heterogeneous, varying both within and between brain regions and with age.

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The CNS is extremely responsive to an ever-changing environment. Studies of neural circuit plasticity focus almost exclusively on functional and structural changes of neuronal synapses. In recent years, however, myelin plasticity has emerged as a potential modulator of neuronal networks.

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Light is extensively used to study cells in real time (live cell imaging), separate cells using fluorescence activated cell sorting (FACS) and control cellular functions with light sensitive proteins (Optogenetics). However, photo-sensitive molecules inside cells and in standard cell culture media generate toxic by-products that interfere with cellular functions and cell viability when exposed to light. Here we show that primary cells from the rat central nervous system respond differently to photo-toxicity, in that astrocytes and microglia undergo morphological changes, while in developing neurons and oligodendrocyte progenitor cells (OPCs) it induces cellular death.

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Two populations of oligodendrogenic progenitors co-exist within the corpus callosum (CC) of the adult mouse. Local, parenchymal oligodendrocyte progenitor cells (pOPCs) and progenitors generated in the subependymal zone (SEZ) cytogenic niche. pOPCs are committed perinatally and retain their numbers through self-renewing divisions, while SEZ-derived cells are relatively "young," being constantly born from neural stem cells.

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Article Synopsis
  • Myelin regeneration can happen naturally in diseases like multiple sclerosis, but it often fails, and researchers are exploring why.
  • In a study using an animal model, it was found that damaged axons are active and form new connections with oligodendrocyte progenitor cells (OPCs), which are sensitive to neuronal activity.
  • Blocking neuronal activity reduces the differentiation of OPCs into myelinating cells, indicating that neuronal signaling is crucial for effective remyelination; this suggests new potential therapeutic targets.
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Myelination is essential for rapid impulse conduction in the CNS, but what determines whether an individual axon becomes myelinated remains unknown. Here we show, using a myelinating coculture system, that there are two distinct modes of myelination, one that is independent of neuronal activity and glutamate release and another that depends on neuronal action potentials releasing glutamate to activate NMDA receptors on oligodendrocyte lineage cells. Neuregulin switches oligodendrocytes from the activity-independent to the activity-dependent mode of myelination by increasing NMDA receptor currents in oligodendrocyte lineage cells 6-fold.

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Potassium is the principal intracellular cation, and maintenance of the distribution of potassium between the intracellular and the extracellular compartments relies on several homeostatic mechanisms. When these mechanisms are perturbed, hypokalemia or hyperkalemia may occur. This review covers hyperkalemia, that is, a serum potassium concentration exceeding 5 mmol/L.

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Background: Little is known about the efficacy of educational interventions for reducing the stigma associated with depression.

Aims: To investigate the effects on stigma of two internet depression sites.

Method: A sample of 525 individuals with elevated scores on a depression assessment scale were randomly allocated to a depression information website (BluePages), a cognitive-behavioural skills training website (MoodGYM) or an attention control condition.

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Congestive heart failure (CHF) and hyperkalemia are the two leading reasons for emergency dialysis among individuals with end-stage renal disease (ESRD). While hemodialysis provides definitive treatment of both hyperkalemia and volume overload among ESRD patients, for those who present outside of "regular dialysis hours," institution of dialysis may be delayed. Nondialytic management can be instituted immediately and should be the initial therapy in the management of hyperkalemia and CHF in these individuals.

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