Research articles

Inhibiting CaMKII impairs short-term memory (STM) in mice during an avoidance task but does not affect long-term memory (LTM). This suggests that STM and LTM are processed differently, with CaMKII critical for STM but not LTM.

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.

The authors test the model that microglia are crucial for the developmental refinement of neural circuitry by depleting them with PLX5622. Microglia prove dispensable for the experience-dependent maturation of visual circuitry during development.

Snyder et al. report that hippocampal neurons in Egyptian fruit bats modulate their activity depending on the position and identity of human experimenters when bats are flying and encode experimenter position and identity when bats are stationary.

The involvement of age-related myelin damage in Alzheimer’s disease is unclear. Kedia et al. show that T cell-mediated microglia activation triggers a response against myelinating oligodendrocytes contributing to neurodegenerative diseases with amyloidosis.

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.

Muller et al. show that some neurons in the cortex learn faster from better-than-expected outcomes compared to worse-than-expected ones; others do the converse, resulting in simultaneous optimism and pessimism, as predicted by distributional reinforcement learning.

In this study the authors show that in the mouse anterior thalamus, the activity of head-direction cells is selectively modulated by sensory stimuli and by the animal’s behavioral state.

The biological meaning of eye pupil size is a subject of intense research. This study shows that pupil fluctuations reveal information about hypothalamic orexin cells, which control pupil size via a noradrenaline neural circuit.

Using depth electrodes in human patients, scientists at the Mayo Clinic found that the map of the body in motor cortex extends deep into the central sulcus. Unexpectedly, the nonsomatotopic ‘Rolandic motor association’ (RMA) area interrupts this organization.

This study mapped the developmental trajectory of transmission speed in the human brain by using electrical pulses and intracranial recordings. The authors found that these pulses travel with increasing speeds up to at least the age of 30.

Oligodendrocyte precursor cells (OPCs) have functions beyond oligodendrogenesis. Here the authors show that OPCs can engulf thalamocortical presynapses in response to sensory experience in mice.

Fiber photometry can record brain dynamics, but the biological source of the signal remains unclear. The authors report that fiber photometry in striatum mainly reflects nonsomatic, and not somatic or spiking-related, changes in calcium.

The structural and functional development of the human cerebellum is not well known. The cerebellum shows a gradient of tissue properties across its lobules, each of which develops at a unique rate and closely follows changes in function across childhood.

Consumption of excessive high-fat diet (HFD) induces compulsive feeding. Here the authors show HFD-induced microglia activation in the anterior paraventricular nucleus of the thalamus plays a crucial role in promoting compulsive eating behavior.

fMRI reveals similar topography, selectivity and inter-connectedness of language brain areas across 45 languages. These properties may allow the language system to handle the shared features of languages, shaped by biological and cultural evolution.

The authors found that the expression of spatial maps in the hippocampus is modulated by the internal state of an animal. Thus, the brain’s code for spatial positions within an environment can transform even without changes to the external world.

Mazzitelli, Smyth and colleagues show that cerebrospinal fluid gains direct access to skull bone marrow niches via dura–skull channels, allowing for the CNS context-dependent regulation of immune supply to the meninges.

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.