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Aldred, S.

Publications and source records attributed to Aldred, S..

2 recordsLinked to original sources

Altered metabolic function induced by amyloid-beta oligomers and PSEN1-mutations in iPSC-derived astrocytes.

Altered energy metabolism in Alzheimers disease (AD) is considered a major pathological hallmark implicated in the early stages of the disease process. Astrocytes play a central role in brain homeostasis and are increasingly implicated in multiple neurodegenerative diseases. We report that astrocytes differentiated from early onset familial Alzheimers disease (fAD) patients or control cells treated with Amyloid {beta} oligomers exhibit significant changes in their metabolism including glucose uptake, glutamate uptake and lactate release, with increases in oxidative and glycolytic metabolism. Furthermore, we demonstrate evidence of gliosis in fAD astrocytes in addition to a change in metabolic pathways including glutamate, purines, arginine, and the citric acid cycle. Homeostatic responses to brain activity and cellular metabolism are central to normal brain function. However, altered brain metabolism and cellular stress present significant risk factors for the onset and progression of neurodegenerative disease. This study demonstrates that fAD derived astrocytes present multiple metabolic and disease associated phenotypes early in their development suggesting that chronic alterations in fAD patient early in life that present significant risk factors for disease progression in mid-life and suggest key targets for potential diagnostic features and therapeutic agents late onset dementia in midlife.

neuroscience↗

Unique Neurophysiological Vulnerability of Visual Attention Networks to Acute Inflammation

Illness is often accompanied by perceived cognitive sluggishness, a symptom that may stem from immune system activation. The current study used electroencephalography (EEG) to assess how inflammation affected three different distinct attentional processes: alerting, orienting and executive control. In a double-blinded placebo-controlled within-subjects design (20 healthy males, mean age = 24.5, SD = 3.4), Salmonella typhoid vaccination (0.025 mg; Typhim Vi, SanofiPasteur) was used to induce transient mild inflammation, while a saline injection served as a placebo-control. Participants completed the Attention Network Test with concurrent EEG recorded six hours post-injection. Analyses focused on behavioral task performance and on modulation of oscillatory EEG activity in the alpha band (9-12 Hz) for alerting as well as orienting attention and frontal theta band (4-8 Hz) for executive control. Vaccination induced mild systemic inflammation, as assessed by interleukin-6 (IL-6) levels. While no behavioral task performance differences between the inflammation and placebo condition were evident, inflammation caused significant alterations to task-related brain activity. Specifically, inflammation produced greater cue-induced suppression of alpha power in the alerting aspect of attention while individual variation in the inflammatory response was significantly correlated with the degree of alpha power suppression. Notably, inflammation did not affect orienting (i.e., alpha lateralization) or executive control (i.e., frontal theta activity). These results reveal a unique neurophysiological vulnerability to acute mild inflammation of the neural network that underpins attentional alerting functions. Observed in the absence of performance decrements, these novel findings suggest that acute inflammation requires individuals to exert greater cognitive effort when preparing for a task in order to maintain adequate behavioral performance.\n\nHighlights O_LITyphoid vaccination induced a transient mild inflammatory state\nC_LIO_LIMild inflammation alters neurophysiological process associated with attention\nC_LIO_LIMild inflammation selectively increased alerting-related alpha suppression while behavior was unaffected\nC_LIO_LIA greater inflammatory response was correlated with more alpha suppression\nC_LI

neuroscience↗