Reviews & Analysis

Yang et al. demonstrate that sensory neurons are enriched for the anthrax toxin receptor-2. Edema toxin, which acts via this receptor, induces analgesia in mice and can also be engineered to deliver large cargoes such as botulinum toxin in order to selectively silence sensory neurons.

Allen et al. introduce the Natural Scenes Dataset — high-resolution fMRI data from eight individuals scanned as they collectively viewed more than 70,000 natural images and performed a continuous recognition task. This resource promises to yield insights into visual perception and memory and to help bridge cognitive neuroscience and artificial intelligence.

Our brains are wired to steer us toward novel experiences. Ogasawara et al. define nodes in a network that underlies novelty-seeking behavior distinct from novelty-orienting responses. In this network, anterior ventral medial temporal cortex (AVMTC) mediates novelty-related sensory processing, and zona incerta uses input from AVMTC to guide gaze shifts for novelty seeking.

The structural basis for the clinical and side effects of antipsychotic drugs has not been resolved. A new study combined X-ray crystallography with medicinal chemistry and behavioral pharmacology to design a new dopamine D₂ receptor partial agonist that, in mice, shows not only antipsychotic-like activity but also 5-HT_1A-receptor-dependent antidepressant-like effects.

Microglia form barriers that attenuate the propagation of amyloid pathology in Alzheimer’s disease. d’Errico et al. have uncovered a paradoxical ability of microglia to spread amyloid plaques, which depends on the transcription factor IRF8. Here, we highlight the contexts in which this may happen and discuss outstanding questions.

Describing cognitive processes without reference to their neural underpinnings has led to conceptualizations that do not match how the brain functions. A data-driven re-examination of the neuroimaging literature reveals an alternate conceptual framework combining mind and brain that disrupts current neuroscientific thought.

Using a deep neural network, Frey et al. are able to track participants’ eye movements using functional magnetic resonance imaging of the eyes. This technique can be applied across studies to new and old data alike, allowing retrospective analyses of past studies.

Positive and negative valence are encoded in specific neural populations of the basolateral amygdala, but only few of these populations have been characterized. A new study identifies a novel population, defined by the molecular marker Fezf2, and demonstrates that two of its output pathways differentially encode emotional valence.

Grid cells produce exceptionally regular firing patterns as animals navigate in 2D spaces. Two new studies show that in flying and climbing animals, the activity patterns of these cells in 3D space are irregular. These results reveal an unexpected way in which the brain represents spatial location.

Placental allopregnanolone affects oligodendrocyte differentiation and myelination in the developing cerebellum. Male mice deprived of allopregnanolone in utero show impaired sociability and communication in later life; their female littermates are unaffected. Allopregnanolone replacement restores normal myelination and behavior.

Everyday phrases like ‘top dog’ and ‘low status’ suggest that we may mentally represent social and spatial information similarly. To what extent is that true? New research suggests that, like physical space, social knowledge is encoded as a cognitive map in the human brain and represented with a grid-like code.

Visually guided behavior begins with inputs to sensory cortices, but the decision to initiate actions engages the frontal cortex. A new study dissects a microcircuit for visual-to-motor transformation in the anterior cingulate cortex of the mouse with implications for impulsivity and disease states.

Shamash et al. probe the navigational strategies mice use as they escape from a threat. By systematically placing and removing obstacles blocking their initial path, the authors find evidence that mice memorize intermediate ‘subgoal’ locations to find their way home.

Understanding how the brain makes decisions is a major area of focus in both animal and human cognitive neuroscience. Much of this work, especially in primates, has explicated the role of various cortical areas in forming decisions. In new research, perturbations of the superior colliculus by Jun et al. reveal a large and causal role in accumulating evidence for this midbrain structure classically thought of as being involved in simpler functions related to eye movement control.

Ketamine has transformed the treatment of depression by providing rapid relief from depressive symptoms, but the mechanisms mediating its long-term effects are unclear. Kim et al. show that MeCP2 signaling in the hippocampus is critical for supporting sustained antidepressant effects.

Sensory information encoding in the mouse brain is more suboptimal when mice make correct decisions than when they make incorrect ones. These suboptimal encoding structures can help information flow between different brain regions, enhancing the ability of these brain regions to work together to make decisions.

Gene replacement therapies have shown remarkable advances recently, including onasemnogene abeparvovec for treatment of symptomatic and presymptomatic patients with spinal muscular atrophy. A recent report by Van Alstyne and colleagues in a mouse model of spinal muscular atrophy raises concerns that such treatment can generate toxic overexpression of SMN protein.

For decades, researchers have wondered whether algorithms used by artificial neural networks might be implemented by biological networks. Payeur et al. have strengthened the connection between neuroscience and artificial intelligence by showing that biologically plausible mechanisms can approximate key features of an essential artificial intelligence learning algorithm.

Hu et al. show that the posterodorsal medial amygdala selectively controls social-reward seeking through its intersection with canonical dopaminergic reward circuits. To identify this circuitry, the authors developed an elegant new affiliative social operant procedure that separates social interaction from social-reward seeking.

In neurodegenerative diseases, certain types of neurons perish first, but the mechanisms of this selective neuronal vulnerability remain unclear. A new study now highlights a crucial role for apolipoprotein E in driving neuronal death in both ageing and Alzheimer’s disease.