Striatum

In this issue of Nature Neuroscience, Menegas et al. demonstrate a role for midbrain dopamine neurons projecting to the tail of the striatum in encoding stimulus novelty and threat avoidance. From this study emerges a model whereby distinct dopaminergic projections to striatum influence behavior along at least two axes, one representing value and one representing threat.

Opiate drugs and opioid peptides differ in their effects on intracellular signalling, in which following ligand–receptor binding and internalization, opioids continue to signal from endosomes, whereas opiates activate receptors located at the Golgi.

In mice, the nutritional and hedonic values of sugar ingestion are mediated by the dorsal and ventral striatum, respectively.

Disruption of actin polymerization in the frontal cortex, which causes abnormal dendritic spine structures, results in locomotor hyperactivity owing to dysregulation of a midbrain dopaminergic circuit.