Volume 25 Issue 3, March 2022

As researchers uncover new roles for the microbiome in health and disease, recent studies have emerged linking the microbiome to aspects of aging. Mossad and colleagues demonstrate that a microbiome-mediated disruption of the intestinal barrier, associated with aging, can contribute to dysfunction of microglia in mice.

A study by Cook et al. shows that mice can use auditory feedback from their own actions to precisely time an interval. This feedback is processed in the secondary auditory cortex and regulates performance via a corticostriatal circuit.

Palser et al. show that at the top 100 journals in psychology and neuroscience, male editors and those from the USA outnumber female editors and those affiliated with other countries, at rates significantly beyond their participation in the fields.

Oligodendrocyte precursor cells exist in abundance throughout the brain lifelong, with unclear functions. Xiao et al. show that, in zebrafish, these cells regulate the precise formation of retinal ganglion cell arbors and fine-tune visual processing.

Ratz et al. present an easy-to-use method to barcode progenitor cells, enabling profiling of cell phenotypes and clonal relations using single-cell and spatial transcriptomics, providing an integrated approach for understanding brain architecture.

Due to a microbiota-dependent increase in intestinal permeability with age, the gut metabolite N⁶-carboxymethyllysine accumulates in the microglia of mouse and human brains. As a result, microglia display increased oxidative stress and mitochondrial dysfunction.

Marsh et al. demonstrate that enzymatic dissociation induces an aberrant ex vivo gene expression signature, most prominently in microglia, which when not addressed can substantially confound downstream analyses. They also identify a similar signature in postmortem human brain in snRNA-seq.

Benzodiazepines, used to treat anxiety and sleep disorders, may cause cognitive impairment. Shi et al. demonstrate that this is caused by interaction with the mitochondrial protein TSPO, which drives microglia to excessively remove synapses.

By applying operant conditioning, behavioral manipulation, in vivo electrophysiology, computational modeling, and closed-loop optogenetics, the authors reveal a mechanism for action timing in mice mediated by the secondary auditory cortex.

The authors use virtual reality tasks and a latent state modeling approach to demonstrate that the opposing control of behavior by striatal pathways is dependent on both task demands and changes in internal state.

Continuous experience is segmented into discrete mnemonic episodes. The authors identify neurons in the human brain whose responses to cognitive boundaries predict memory encoding success and mark timepoints that are reinstated during retrieval.

Deep language models have revolutionized natural language processing. The paper discovers three computational principles shared between deep language models and the human brain, which can transform our understanding of the neural basis of language.

The authors obtained transcriptomes from anterior cingulate cortex and amygdala samples from post-mortem brains of individuals with bipolar disorder and neurotypical controls. They observed decreased expression of neuroimmune and synaptic pathways.

This study introduces genetically encoded imaging probes that convert intracellular calcium signaling into hemodynamic fMRI responses. The authors show how the probes can be used to map information flow in reward-related brain circuitry in rats.