Optimal sparsity in autoencoder memory models of the hippocampus.

Storing complex correlated memories is significantly more efficient when memories are recoded to obtain compressed representations. Previous work has shown that compression can be implemented in a simple neural circuit, which can be described as a sparse autoencoder. The activity of the encoding units in these models recapitulates the activity of hippocampal neurons recorded in multiple experiments.

Impaired spatial coding and neuronal hyperactivity in the medial entorhinal cortex of aged mice.

The progressive accumulation of amyloid beta (Aβ) pathology in the brain has been associated with aberrant neuronal network activity and poor cognitive performance in preclinical mouse models of Alzheimer's disease (AD). Presently, our understanding of the mechanisms driving pathology-associated neuronal dysfunction and impaired information processing in the brain remains incomplete. Here, we assessed the impact of advanced Aβ pathology on spatial information processing in the medial entorhinal cortex (MEC) of 18-month knock-in (APP KI) mice as they explored contextually novel and familiar open field arenas in a two-day, four-session recording paradigm.

Understanding the neural code of stress to control anhedonia.

Anhedonia, the diminished drive to seek, value, and learn about rewards, is a core feature of major depressive disorder. The neural underpinnings of anhedonia and how this emotional state drives behaviour remain unclear. Here we investigated the neural code of anhedonia by taking advantage of the fact that when mice are exposed to traumatic social stress, susceptible animals become socially withdrawn and anhedonic, whereas others remain resilient.

Rarely categorical, always high-dimensional: how the neural code changes along the cortical hierarchy.

The brain is highly structured both at anatomical and functional levels. However, within individual brain areas, neurons often exhibit very diverse and seemingly disorganized responses. A more careful analysis shows that these neurons can sometimes be grouped together into specialized subpopulations (categorical representations).

Food environments in the Pacific region and efforts to improve them: a scoping review.

Objective: To understand the characteristics of food environments in the Pacific region, and the broader economic, policy and sociocultural surroundings that influence food choices and interventions to improve food environments for Pacific communities.

Design: Systematic searches were conducted for articles related to food environments or factors influencing food choices from 1993 to 2024 in five academic databases, Google, Google Scholar and relevant organisations' websites. Studies were included if they meet the eligibility criteria.