Basic Science and Pathogenesis.

Background: Alzheimer's disease is a progressive form of dementia where cognitive capacities deteriorate due to neurodegeneration. Interestingly, Alzheimer's patients exhibit cognitive fluctuations during all stages of the disease. Though it is thought that contextual factors are critical for unlocking these hidden memories, understanding the neural basis of cognitive fluctuations has been hampered due to the lack of behavioral approaches to dissociate memories from contextual-performance.

The Gut Microbial Bile Acid Modulation and Its Relevance to Digestive Health and Diseases.

The human gut microbiome has been linked to numerous digestive disorders, but its metabolic products have been much less well characterized, in part due to the expense of untargeted metabolomics and lack of ability to process the data. In this review, we focused on the rapidly expanding information about the bile acid repertoire produced by the gut microbiome, including the impacts of bile acids on a wide range of host physiological processes and diseases, and discussed the role of short-chain fatty acids and other important gut microbiome-derived metabolites. Of particular note is the action of gut microbiome-derived metabolites throughout the body, which impact processes ranging from obesity to aging to disorders traditionally thought of as diseases of the nervous system, but that are now recognized as being strongly influenced by the gut microbiome and the metabolites it produces.

Author Correction: Dissociating task acquisition from expression during learning reveals latent knowledge.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Dissociating task acquisition from expression during learning reveals latent knowledge.

Performance on cognitive tasks during learning is used to measure knowledge, yet it remains controversial since such testing is susceptible to contextual factors. To what extent does performance during learning depend on the testing context, rather than underlying knowledge? We trained mice, rats and ferrets on a range of tasks to examine how testing context impacts the acquisition of knowledge versus its expression. We interleaved reinforced trials with probe trials in which we omitted reinforcement.