A team of researchers at the USC Mark and Mary Stevens Neuroimaging and Informatics Institute (Stevens INI) at the Keck School of Medicine of USC has identified important differences in how early Alzheimer’s disease-related brain changes appear across racial and ethnic groups, underscoring the need for more inclusive approaches to studying and diagnosing the disease. In a large, racially and ethnically diverse study of older adults without dementia, researchers found that Black and Hispanic participants showed higher levels of tau, a protein linked to Alzheimer’s, in key memory-related regions of the brain compared to non-Hispanic white participants, even before the buildup of amyloid plaques typically associated with Alzheimer’s disease. The findings come from the Health and Aging Brain Study–Health Disparities (HABS-HD), one of the largest and most diverse brain-imaging studies of aging in the US and were made possible by advanced PET brain scans that can detect abnormal protein buildup years before symptoms appear. Using a newer generation tau PET tracer, the research team examined brain scans and memory test results from more than 1,500 adults who were cognitively normal or had mild cognitive impairment.  While higher tau levels were linked to worse memory overall, amyloid buildup strengthened this link only in non-Hispanic white and Hispanic participants, not in Black participants. This suggests that memory changes in Black adults may be influenced more strongly by factors beyond amyloid and tau alone. Vascular health, the presence of other health conditions, life-long stress exposure, and other social factors may play a prominent role and deserve closer study.

 

A new study from Emory University explains the gut-brain connection, indicating that live bacteria from the gut can directly enter the brain, with potential implications for neurological health. Researchers also identified similar low-levels of bacteria in the brains of mouse models of neurological diseases, such as Parkinson’s Disease, Alzheimer’s and more. During this study, a group of germ-free mice consumed a “Paigen’s Diet,” similar to a Western Diet, with a 45% carbohydrate and 35% fat content. These diets in humans are known to contribute to intestinal permeability or a “leaky gut” where compounds can escape the intestine. The resulting gut microbiome changes seen in the mice were associated with increased intestinal barrier permeability, or leakage, enabling live bacteria to travel from the intestine directly to the brain via the vagus nerve, without any detectable amounts of bacteria in the blood or other organs. 

Salk researchers create epigenetic atlas of cell type-specific changes in the aging mouse brain, representing eight different brain regions and 36 different cell types to show clear epigenetic differences associated with different ages. The new resource—available publicly on Amazon Web services—can be used to unravel age-related contributions to neurodegenerative diseases like Alzheimer’s, Parkinson’s, and ALS.

A retinal image could help doctors quickly distinguish between similar neurodegenerative diseases such as ALS and Alzheimer’s disease, and with remarkable accuracy, according to new research.  

Researchers from the University of Waterloo are leading the development of a fast, non-invasive, and affordable diagnostic tool. There is currently no objective diagnostic test for ALS or Frontotemporal Lobular Dementia (FTLD-TDP), in which the protein TDP-43 forms deposits in the spinal cord and brain, respectively.