In Alzheimer’s disease, neurons are considered the sole source of amyloid-β (Aβ) peptides that form plaques. Here the authors show that oligodendrocytes, the myelinating glial cells of the brain, also contribute to Aβ plaque burden alongside neurons.

What makes the brain maintain voluntary exercise despite attractive alternative options such as eating? Tesmer et al. show that orexin/hypocretin neurons are crucial for implementing the underlying valuation of eating versus running in mice.

Neuronal activity contributes to synapse formation and plasticity. Here the authors demonstrate that activity stimulates developmental programs to directly modulate synapse formation.

Ehret et al. uncover neural activity patterns in the prefrontal cortex that link sensory stimuli to learned behavioral responses by isolating interpretable activity patterns that are shared among mice performing the same task.

Comprehensive profiling of a circumventricular organ with leaky blood vessels, and comparison to cortex vasculature reveal that blood–brain barrier heterogeneity reflects differences in endothelial cells and their interactions with perivascular cells.

The authors find a newly evolved progenitor domain extends and expands spinal motor neurogenesis in humans.

Activation of nested, but not discrete, neural circuits drives alternative courtship songs in male Drosophila melanogaster, providing further insight into how the nervous system can drive the same motor systems to rapidly switch between different actions.

Using human cerebrospinal fluid proteomics, the authors found that proteins associated with Aβ pathology in Alzheimer disease were mainly expressed in glial cells, whereas those associated with tau tangle were linked to metabolism and mainly expressed in neurons.

Goodman et al. found that Tau is critical for ROS-induced lipid droplet formation in glia from flies and mammals. Too much or too little glial Tau disrupts lipid droplets, leaving the glia susceptible to neuronal ROS-induced damage and causing phenotypes in tau^−/− flies.

Understanding brain development and systems linked to behavioral change is a key goal in population neuroscience. The authors show the ventral attention network is key for brain development and cognitive ability in cross-culture longitudinal cohorts.

What follows is not a detailed biography of Jim Simons, whose diversity of talents and activities as a mathematician, educator, administrator, life scientist, philanthropist and visionary in this country and abroad would fill several volumes. It is simply a glance at this wonderful man as I knew him in connection with his growing interest in life sciences and as a friend.

In this special issue of Nature Neuroscience, we shine a spotlight on glia. Research into glia has become one of the most exciting and dynamic subfields of neuroscience, yet there is still much to be discovered about the diverse forms and functions of these cells.

As part of our special issue focused on glia, Nature Neuroscience is having conversations with both established leaders in the field and those earlier in their careers to discuss how the field has evolved and where it is heading. Here, we speak with Sonia Mayoral, the Robert J. and Nancy D. Carney Assistant Professor of Neuroscience at Brown University in Providence, RI, USA. We spoke about her work on oligodendrocytes and their interactions with neurons, the importance of exploring glia in brain health and function, and her own academic journey and advice for early-career researchers.