Chiot and colleagues investigated whether peripheral macrophages play a role in amyotrophic lateral sclerosis (ALS) pathology, finding that macrophages along peripheral motor neuron axons react to neurodegeneration. Modifying reactive oxygen species (ROS) signaling in peripheral macrophages, using bone marrow cell replacement, reduces both macrophage and microglia inflammatory response, delays pathology and increases survival in ALS mouse models.

Abrupt spatial changes in anatomic and functional properties of the brain demarcate boundaries between discrete functional areas. While previous work has identified these boundaries in cortex, a new study by Tian et al. applies this approach for the first time to subcortical structures within the in vivo human brain.

By building a richer behavioral vocabulary, Wiltschko et al. tease apart subtle differences in how pharmacological agents affect animal behavior, mapping on- and off-target effects of drugs with improved precision.

Aggression is an instinctive behavior supported by hardwired neural circuits. Julieta Lischinsky and Dayu Lin review our current understanding of the neural circuits of aggression across species and their modulation by internal state.

Kusick et al. capture snapshots of synaptic vesicle docking and fusion using a new time-resolved electron microscopy technique. They find that vesicles are replaced milliseconds after they fuse, which may contribute to short-term synaptic plasticity.

Peripheral macrophages located along motor axons react differently to neurodegeneration compared to CNS microglia in ALS mice. Modifying peripheral macrophages suppresses proinflammatory microglial responses, shifting them toward neuronal support.

When co-cultured with activated microglia, iPSC-derived interneurons from individuals with schizophrenia and from healthy controls show defects in metabolic pathways, but only the interneurons from individuals with schizophrenia showed prolonged metabolic deficits.

Donegan et al. show that hippocampal CA2 neurons contribute to social memory by encoding social novelty. Abnormal CA2 coding and social memory in a mouse model of the 22q11.2 microdeletion are rescued by blocking elevated CA2 TREK-1 K⁺ current.

Kohro et al. identify a population of astrocytes located in the superficial dorsal horn of adult spinal cord (genetically defined by Hes5) that acts as a gate for locus coeruleus descending noradrenergic control of mechanosensory hypersensitivity.

This study demonstrates that basal ganglia functional topography is maintained across and downstream of its output nuclei, and in closed loops. Focal stimulation of distinct striatal subregions induces distinct action, supporting a model of parallel behavioral control.

Han et al. find that, in addition to powerfully exciting Purkinje cells, climbing fibers rapidly suppress firing in nearby Purkinje cells. Current from glutamate receptor activation generates large extracellular signals that inhibit neighboring cells.

Aoi et al. used a new dimensionality-reduction method to disentangle the contributions of different task variables to neural population activity, which revealed rotational dynamics in monkey PFC during context-dependent decision-making.

This work by Tian and colleagues unveils the extraordinarily complex layout of the human subcortex by identifying 27 new functional regions that organize hierarchically across four scales and adapt to changing cognitive demands.

By analyzing hundreds of mice treated with a library of neuro- and psychoactive drugs, Wiltschko et al. show that Motion Sequencing can effectively discriminate and categorize drug effects and link molecular targets to behavioral syllables.

The ventral hippocampus is central in the processing of emotional information. Here, a combination of viral and sequencing approaches defines the organizational logic of the extended ventral CA1 circuit.