Volume 23 Issue 7, July 2020

Our light environment can strongly influence our mental health. Kai An and colleagues dissect the neuronal circuit mediating depression-related behaviors induced by mistimed light input in mice, implicating the nucleus accumbens as the downstream target of the neural pathway between intrinsically photosensitive retinal ganglion cells and the perihabenular nucleus.

Keysers et al. show why P values do not differentiate inconclusive null findings from those that provide important evidence for the absence of an effect. They provide a tutorial on how to use Bayesian hypothesis testing to overcome this issue.

Greater novelty and diversity in one’s daily physical environment is associated with positive affect, and functional connectivity within a hippocampal–striatal circuit is related to the strength of this effect.

Brain connectivity and normalized wiring costs are conserved across mammals independently of brain size according to a common principle: species with fewer interhemispheric connections exhibit better intrahemispheric connectivity.

A genetic study of problematic alcohol use in 435,563 individuals, including data from the Million Veteran Program, Psychiatric Genomics Consortium and UK Biobank, found many novel risk loci and provided new insights into trait biology.

Precisely timed motor learning promotes remyelination in the motor cortex by enhancing oligodendrogenesis and stimulating mature oligodendrocytes to generate new myelin, presenting mature oligodendrocytes as new targets in remyelinating therapies.

Shen et al. report that prolonged obesity is associated with cerebrovascular dysfunction and Tak1 activation in brainstem microglia. Pharmacological inhibition or genetic depletion of Tak1 restores cerebrovascular function in obese mice.

Medulloblastomas lacking p53 do not express surface class I major histocompatibility complex (MHC-I) and are resistant to immune rejection. Tumor necrosis factor rescues MHC-I expression and synergizes with immune checkpoint inhibitors to promote rejection.

Hua and Chen et al. show that general anesthesia activates a distinct population of central amygdala neurons and that these neurons can potently suppress pain responses through their widespread projections to many pain-processing centers in the brain.

An et al. discovered a new brain pathway in mice that conveys light signals from the retina to mood-relevant subcortical nuclei under circadian gating and thereby mediates depressive-like behaviors induced by abnormal nighttime light exposure.

Place cell responses are strongly modulated by context, allowing the hippocampus to effectively encode different environments. Electrical recordings show that the context-dependent representation of environmental features is present in the CA3 subregion and is inherited by CA1.

Learning new associations that reappraise the behavioral significance of previously irrelevant cues requires gamma-frequency synchronization between parvalbumin interneurons in the left and right prefrontal cortex.