Brainstem circuits help zebrafish get into the swim of things.

In this issue of Neuron, Berg et al. investigate the functional contribution of two molecularly distinct subpopulations of spinal-projecting midbrain neurons in adult zebrafish, shedding light on mechanisms regulating properties of locomotion such as speed and bout duration.

Structural and functional map for forelimb movement phases between cortex and medulla.

The cortex influences movement by widespread top-down projections to many nervous system regions. Skilled forelimb movements require brainstem circuitry in the medulla; however, the logic of cortical interactions with these neurons remains unexplored. Here, we reveal a fine-grained anatomical and functional map between anterior cortex (AC) and medulla in mice.

Networking brainstem and basal ganglia circuits for movement.

The execution and learning of diverse movements involve neuronal networks distributed throughout the nervous system. The brainstem and basal ganglia are key for processing motor information. Both harbour functionally specialized populations stratified on the basis of axonal projections, synaptic inputs and gene expression, revealing a correspondence between circuit anatomy and function at a high level of granularity.

Absence of familiarity triggers hallmarks of autism in mouse model through aberrant tail-of-striatum and prelimbic cortex signaling.

Autism spectrum disorder (ASD) involves genetic and environmental components. The underlying circuit mechanisms are unclear, but behaviorally, aversion toward unfamiliarity, a hallmark of autism, might be involved. Here, we show that in Shank3 ASD model mice, exposure to novel environments lacking familiar features produces long-lasting failure to engage and repetitive behaviors upon re-exposure.