A key aspect of the survival of an organism is the ability to adapt to its environment. Sensory (for example, tactile, visual and motor) stimuli are processed by sensory regions of the brain, but how these stimuli effect changes in local and global brain circuitry is poorly understood. You et al. have used resting-state fMRI and sensory-stimulus-evoked fMRI along with behavioural tasks to investigate changes in brain activity and connectivity in adolescent male mice under different environmental conditions: social isolation and enriched, group-housed environments.

Mice raised in enriched settings showed stronger responses in subcortical and association cortices, particularly during behavioural tasks involving tactile and visual stimuli. These mice also showed proper network segregation (indicating specificity in the network response). By contrast, socially isolated mice showed hyperactivity in olfactory and limbic regions, less segregation and lower olfactory perception. These changes were accompanied by increased anxiety-like behaviours in socially isolated mice.