Volume 22 Issue 7, July 2019

The creation of a murine Cre driver specific to CNS capillary pericytes has opened a major bottleneck in brain microvascular research. Using this tool, pericyte loss in the adult brain is shown to induce neuronal loss due to concurrent microcirculatory failure and depletion of the protective trophic factor pleiotrophin.

Shahmoradian and colleagues report that the structure of Lewy bodies in Parkinson’s disease consists of α-synuclein and lipid vesicle clusters instead of the long-assumed amyloid fibril core. This finding has implications for our understanding of the underlying pathogenesis of synucleinopathies.

Lloyd et al. find that regeneration of CNS myelin requires death of proinflammatory microglia followed by repopulation to a pro-regenerative state, revealing new therapeutic targets for neurodegenerative disease.

The authors show that decreased synaptic efficacy onto raphe-projecting lateral habenula neurons supports opiate withdrawal-induced sociability deficits, and they demonstrate a role for TNF-α signaling in this process.

Norman-Haignere et al. report that humans but not macaque monkeys possess cortical regions with a strong preference for harmonic tones compared to noise. This species difference may be driven by the demands of speech and music perception in humans.

Optogenetics has revolutionized neuroscience, but intracranial illumination can cause off-target effects. Owen et al. identify a temperature-sensitive potassium current that modulates neuronal activity and behavior independent of opsin expression.

The study reports a genome-wide significant locus for cannabis use disorder, replicating in an independent cohort, and implicates CHRNA2, which encodes an acetylcholine receptor subunit, in the disorder by analyses of genetically regulated gene expression.

Microglia are resident immune cells of the CNS. Here the authors show that neurons communicate to microglia via activity-dependent fractalkine and ADAM10 signaling to induce removal of synapses in the brain after sensory loss.

Using pericyte-specific Cre and ablation mouse lines, the authors show that loss of brain pericytes leads to circulatory failure and reduced pleiotrophin causing rapid neuron loss. These findings link pericyte loss to a rapid neurodegeneration cascade.

Using three-dimensional correlative light and electron microscopy of Lewy bodies and Lewy neurites in postmortem brains of Parkinson’s disease patients, researchers show that the major constituents are membranes rather than proteinaceous filaments.

Namboodiri, Otis et al. reveal that orbitofrontal cortex acquires and maintains a long-term memory of cue–reward associations to guide multiple aspects of behavioral learning, and that it routes select information to a downstream learning center.

Different body parts must be coordinated to perform skills. Lemke et al. report that distinct patterns of brain activity emerge during learning related to each body part and conclude that such patterns are refined independently yet function together.

Ache et al. show that neurons controlling landing in flies are permissively gated by flight, indicating that brain sensory networks are flexibly coupled to or decoupled from motor networks in the nerve cord to promote contextually appropriate actions.

Synapses of retinal bipolar cells encode contrast through changes in both the frequency and amplitude of release events. The amplitude code contains symbols up to 11 vesicle equivalents and increases the efficiency of information transmission.

Shahidi et al. show that the brain uses different strategies to encode sensory stimuli and behavior. They find that visual stimuli are encoded in firing rates, whereas behavioral accuracy is correlated with spike timing regardless of spike counts.

The role of persistent spiking activity in working memory has recently come under debate. Here the authors use biologically realistic recurrent neural networks to explain why the strength of persistent activity can vary markedly between tasks.

How does the hippocampus learn with only a single presentation of a stimulus? Nicola and Clopath show how interneuron networks can dilate pre-existing spike sequences during sharp waves into theta sequences for one-shot learning.

Gouwens et al. established a morpho-electrical taxonomy of cell types for the mouse visual cortex via unsupervised clustering analysis of multiple quantitative features from 1,938 neurons available online at the Allen Cell Types Database.