Volume 23 Issue 10, October 2020

A new study shows that, immediately after axon injury, glycolysis is increased in Schwann cells to provide axons with energy and prevent them from degenerating. The authors also identify possible therapeutic targets that could be modulated to promote axonal protection.

Following learning, memories for events are reorganized in a time-dependent manner in distributed hippocampal–cortical networks. While previous studies have focused on neural contributions to this process of systems consolidation, a new study by Kol et al. reveals that astrocytes play crucial modulatory roles in the formation of remote memories.

Busche and Hyman review emerging evidence for an interaction between Aβ and tau during Alzheimer’s disease (AD) progression that challenges the classical linear trajectory model and offers a new perspective on AD pathophysiology and therapy.

This study shows that the dorsal hippocampus is necessary for goal-directed action, but only transiently, during initial learning. Convergently, goal-directed actions also depend transiently on the physical context.

Toren et al. show that outcomes that are better or worse than expected lengthen or shorten the perceived duration of stimuli, respectively, and that this interaction between teaching signals and time perception occurs in the human striatum.

Parkinson’s disease brain neurons exhibit a widespread epigenetic dysregulation of enhancers that is linked to an upregulation of TET2. Inactivation of TET2 protects against nigral dopaminergic neuronal loss and neuroinflammation.

Babetto et al. demonstrate an axonal injury-induced glycolytic surge in Schwann cells that supplies perturbed axons with glycolytic energy substrates. Disruption of this metabolic coupling of axons and glial cells promotes axonal degeneration.

Kol et al. show that the foundation of remote memory is formed during acquisition by the massive recruitment of ACC-projecting CA1 neurons. Remote memory acquisition involves projection-specific effects of astrocytes on CA1-to-ACC neuronal communication.

Yamamuro et al. show that juvenile social isolation disrupts prefrontal neurons projecting to the paraventricular thalamus and associated prefrontal somatostatin interneurons, and thereby impairs sociability in adulthood.

Mazzone and Liang-Guallpa et al. demonstrate that consuming high-fat foods rapidly and durably tunes parallel brain circuits to drive intake of a high-fat diet while devaluing a nutritionally balanced, standard diet even under states of intense hunger.

The nervous system is hypothesized to calculate reward prediction errors to estimate reward availability in the environment. The authors quantify a robust prediction error signal in the ventral pallidum derived from recently received rewarding outcomes.

The authors showed that the ‘moment of perception’ is causally related to dendritic activity in subcortically projecting layer 5 pyramidal neurons that project to the higher-order thalamus, superior colliculus and striatum.

The authors demonstrate that strongly recurrent circuits inferred from neural activity, even with unlimited data from every neuron, are biased. Synapses are inferred between unconnected but correlated neurons. Inference based on non-equilibrium activity may help remedy this.

Chen et al. define previously unreported zebrafish astrocytes, provide new insights into vertebrate astrocyte development and lay the foundation for studying astrocyte function in the entire nervous system of an intact and behaving animal.