It has been widely believed that a key function of sleep is to actively clear metabolites and toxins from the brain. Miao, Luo et al. show in mice that brain clearance is markedly reduced—not increased—during sleep and anesthesia.

Physiologically relevant stimulation of dopamine neurons does not function as a reward and does not endow cues with a reward representation. However, high-frequency stimulation is represented as a sensory-specific goal that motivates behavior.

Neural activity does not always lie in a low-dimensional subspace. The authors extend this classic view to show that task-relevant information is distributed across multiple covariability classes and propose a new method, sliceTCA, to disentangle them.

Neuroinflammation and microglia significantly contribute to Alzheimer’s disease pathology, depending on their activation state. We found that TREM2-expressing microglia are a heterogenous population spanning activated to senescent cells.

Christenson et al. describe hue-selective neurons in the fruit fly optic lobe. Using a connectomics-constrained model combined with genetic manipulations of the circuit, they show that recurrent connections are critical for hue selectivity.

It has been widely believed that a key function of sleep is to actively clear metabolites and toxins from the brain. Miao, Luo et al. show in mice that brain clearance is markedly reduced—not increased—during sleep and anesthesia.

Physiologically relevant stimulation of dopamine neurons does not function as a reward and does not endow cues with a reward representation. However, high-frequency stimulation is represented as a sensory-specific goal that motivates behavior.

The subcommissural organ (SCO) is a gland in the brain, and relatively little is known about its function. Zhang et al. genetically ablated SCO cells and observed severe hydrocephalus and neuronal defects. The reintroduction of SCO-derived peptides into SCO-ablated brain substantially rescued developmental defects.

Brain tissue from patients with focal cortical dysplasia type II (FCDII) exhibits dysmorphic neurons bearing hallmarks of senescence. Treatment with a senolytic drug reduces seizures in an FCDII preclinical mouse model.

Neural activity does not always lie in a low-dimensional subspace. The authors extend this classic view to show that task-relevant information is distributed across multiple covariability classes and propose a new method, sliceTCA, to disentangle them.

Effective science communication is necessary for engaging the public in scientific discourse and ensuring equitable access to knowledge. Training doctoral students in science communication will instill principles of accessibility, accountability, and adaptability in the next generation of scientific leaders, who are poised to expand science’s reach, generate public support for research funding, and counter misinformation. To this aim, we provide a guide for implementing formal science communication training for doctoral students.

As Nature Neuroscience celebrates its 25th anniversary, we are 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. This month we are talking to Fernando de Castro Soubriet, principal investigator at the Instituto Cajal (Spain). He is a neurodevelopmental biologist who is actively involved in championing the history of neuroscience. He is among the group of Spanish scientists who ensured that the Archives of Santiago Ramón y Cajal and the Spanish Neurohistological School are registered as World Heritage with UNESCO (United Nations Educational, Scientific and Cultural Organization). Here, we discuss science and the legacy of the Spanish Neurohistological School.