Ulriksenwolff8589

William Tuten and Wolf Harmening introduce the anatomical and functional signatures of foveated vision in humans.Interview with Dori Derdikman, who studies spatial memory and navigation at the Technion - Israel Institute of Technology.Severe cognitive decline is a hallmark of Alzheimer's disease (AD). In addition to gray matter loss, significant white matter pathology has been identified in AD patients. Here, we characterized the dynamics of myelin generation and loss in the APP/PS1 mouse model of AD. Unexpectedly, we observed a dramatic increase in the rate of new myelin formation in APP/PS1 mice, reminiscent of the robust oligodendroglial response to demyelination. Despite this increase, overall levels of myelination are decreased in the cortex and hippocampus of APP/PS1 mice and postmortem AD tissue. Genetically or pharmacologically enhancing myelin renewal, by oligodendroglial deletion of the muscarinic M1 receptor or systemic administration of the pro-myelinating drug clemastine, improved the performance of APP/PS1 mice in memory-related tasks and increased hippocampal sharp wave ripples. Taken together, these results demonstrate the potential of enhancing myelination as a therapeutic strategy to alleviate AD-related cognitive impairment.Diatoms, an evolutionarily successful group of microalgae, display high levels of intraspecific genetic variability in natural populations. However, the contribution of various mechanisms generating such diversity is unknown. Here we estimated the genetic micro-diversity within a natural diatom population and mapped the genomic changes arising within clonally propagated diatom cell cultures. Through quantification of haplotype diversity by next-generation sequencing and amplicon re-sequencing of selected loci, we documented a rapid accumulation of multiple haplotypes accompanied by the appearance of novel protein variants in cell cultures initiated from a single founder cell. Comparison of the genomic changes between mother and daughter cells revealed copy number variation and copy-neutral loss of heterozygosity leading to the fixation of alleles within individual daughter cells. The loss of heterozygosity can be accomplished by recombination between homologous chromosomes. To test this hypothesis, we established an endogenous readout system and estimated that the frequency of interhomolog mitotic recombination was under standard growth conditions 4.2 events per 100 cell divisions. This frequency is increased under environmental stress conditions, including treatment with hydrogen peroxide and cadmium. These data demonstrate that copy number variation and mitotic recombination between homologous chromosomes underlie clonal variability in diatom populations. We discuss the potential adaptive evolutionary benefits of the plastic response in the interhomolog mitotic recombination rate, and we propose that this may have contributed to the ecological success of diatoms.Mechanical signals from the tumor microenvironment modulate cell mechanics and influence cell metabolism to promote cancer aggressiveness. Cells withstand external forces by adjusting the stiffness of their cytoskeleton. Microtubules (MTs) act as compression-bearing elements. Yet how cancer cells regulate MT dynamic in response to the locally constrained environment has remained unclear. Orantinib Using breast cancer as a model of a disease in which mechanical signaling promotes disease progression, we show that matrix stiffening rewires glutamine metabolism to promote MT glutamylation and force MT stabilization, thereby promoting cell invasion. Pharmacologic inhibition of glutamine metabolism decreased MT glutamylation and affected their mechanical stabilization. Similarly, decreased MT glutamylation by overexpressing tubulin mutants lacking glutamylation site(s) decreased MT stability, thereby hampering cancer aggressiveness in vitro and in vivo. Together, our results decipher part of the enigmatic tubulin code that coordinates the fine-tunable properties of MT and link cell metabolism to MT dynamics and cancer aggressiveness.Insulin resistance results when peripheral tissues, including adipose, skeletal muscle, and liver, do not respond appropriately to insulin, causing the ineffective uptake of glucose. This represents a risk factor for the development of type 2 diabetes mellitus. Along with abdominal obesity, hypertension, high levels of triglycerides, and low levels of high-density lipoproteins, insulin resistance is a component of a condition known as the metabolic syndrome, which significantly increases the risk of developing cardiometabolic disorders. Accumulating evidence shows that biological sex has a major influence in the development of cardiometabolic disturbances, with females being more protected than males. This protection appears to be driven by female sex hormones (estrogens), as it tends to disappear with the onset of menopause but can be re-established with hormonal replacement therapy. Current knowledge on the protective role of estrogens in the relevant pathways associated with insulin resistance is evaluated in this review. We emphasize the importance of increasing our understanding of sex as a biological variable in cardiometabolic research to promote the development of more effective preventative strategies.Chemosensory changes are well-reported symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The virus targets cells for entry by binding of its spike protein to cell-surface angiotensin-converting enzyme 2 (ACE2). It was not known whether ACE2 is expressed on taste receptor cells (TRCs) or if TRCs are infected directly. Using an in situ hybridization probe and an antibody specific to ACE2, ACE2 is present on a subpopulation of TRCs (namely, type II cells in taste buds in taste papillae). Fungiform papillae of a SARS-CoV-2+ patient exhibiting symptoms of coronavirus disease 2019 (COVID-19), including taste changes, were biopsied. On the basis of in situ hybridization, replicating SARS-CoV-2 was present in type II cells. Therefore, taste type II cells provide a potential portal for viral entry that predicts vulnerabilities to SARS-CoV-2 in the oral cavity. The continuity and cell turnover of the patient's fungiform papillae taste stem cell layer were disrupted during infection and had not completely recovered 6 weeks after symptom onset.