Volume 22 Issue 10, October 2019

The authors review the most recent measurement and manipulation approaches that enable links between synaptic plasticity and learning to be examined, and they propose potential future approaches to tackle this endeavor.

When crossing the street, you can ignore the color of oncoming cars, but for hailing a taxi color is important. How do we learn what to represent neurally for each task? Here, Niv summarizes a decade of work on representation learning in the brain.

This paper first reviews the work on brain-machine interfaces (BMIs) for restoring lost motor function and then provides a perspective on how BMIs could extend to the new frontier of restoring lost emotional function in neuropsychiatric disorders.

In this Review, Miller and Sahay discuss how adult-born neurons recruit inhibitory microcircuits to support hippocampal memory indexing and pattern separation.

Memory retrieval involves interactions between internal or external cues and stored engrams. Identification of engrams in mice permits examination of these interactions at the level of neural ensembles. This review highlights emerging findings.

In this Review, Likhtik and Johansen discuss how modern neuroscience techniques applied to the study of emotional learning reveal new principles for how neuromodulatory systems regulate distributed brain circuits and flexibly adjust behaviour.

While we sleep, the brain replays memories of our experiences during the day. In this review, Klinzing et al. provide a concise overview of how the sleeping brain transforms and builds persisting memories through this process.

Using data from 45,615 people, Kaufmann et al. compare the gaps between brain age and chronological age in a number of brain disorders and study the relationship of these gaps with genetics. Their research shows that the brains of individuals with a range of different brain disorders, such as dementia and schizophrenia, are aging faster than normal.

Chronic pain is associated with anxio-depressive comorbidities, but the neuroanatomical substrates remain unknown. A specific serotonergic pathway from the dorsal raphe nucleus to the lateral habenula via the central amygdala is now uncovered as a key neural circuit governing comorbid depressive symptoms in chronic pain.

We express decisions through movements, but not all movements matter to the outcome. For example, fidgeting is a common yet ‘nonessential’ behavior we exhibit. New evidence suggests that this non-task-related movement profoundly shapes neural activity in expert mice performing tasks.

Using structural MRI data from 45,615 individuals aged 3–96 years, Kaufmann and colleagues reveal that common brain disorders are associated with heritable patterns of apparent aging of the brain.

In leukocyte transcriptomes from toddlers with ASD, Gazestani et al. find a perturbed gene network that is involved in fetal brain development and lies downstream of ASD risk genes, and whose dysregulation level correlates with ASD symptom severity.

Microglia and astrocytes propagate neurodegeneration by releasing fragmented and dysfunctional mitochondria into the neuronal milieu. Inhibiting pathological fragmentation of glial mitochondria blunts neuroinflammation and increases neuroprotection.

Zhou et al. report a novel 5-HT circuit from the dorsal raphe nucleus to somatostatin-expressing neurons in the central nucleus of the amygdala that partially mediates depressive-like behavior in a mouse model of chronic pain.

Huang and colleagues functionally map a brain circuit connecting the amygdala and the spinal cord that is altered after nerve injury and contributes to chronic pain.

Ruff and Cohen find that the prominent hypotheses about how attention improves perception do not account for behavioral improvements. Instead, their results suggest that attention reshapes sensory representations so the relevant information guides behavior.

The authors use a linear model to reveal how neural activity patterns are related to cognition or movements. They find that uninstructed movements dominate single-cell and population activity throughout the brain, outpacing task-related activity.

By developing layer-specific functional MRI techniques for a high-order cognitive brain area, Finn et al. dissociate activity in superficial and deeper cortical layers during different periods of a working memory task in human dorsolateral prefrontal cortex.

A single-cell transcriptomic atlas of the aging mouse brain reveals coordinated and cell-type-specific aging signatures across multiple cell populations. Catalogs of aging-related genes, pathways and ligand–receptor interactions are reported.

Furlanis, Traunmüller et al. uncover hundreds of alternative splicing events that distinguish neuronal cell classes. Splice isoforms primarily encode synaptic and intrinsic neuronal properties. Data are available online in the SpliceCode database.

Multi-omic analyses of transcriptional, chromatin occupancy and chromatin interaction dynamics in hippocampal excitatory neurons of adult mice upon activation by status epilepticus or novel context exploration reveals short- and long-lasting changes.

Fecher et al. devise an approach to isolate cell-type-specific mitochondria from the mouse CNS. They demonstrate proteomic diversity of cerebellar mitochondria covering bioenergetics, calcium handling and organelle contact sites.