Activity-regulated genes in Drosophila neurons differ from the well-characterized situation in mammals, and these genes provided a strategy to construct reporters for monitoring neuronal activity in fly brains.
As mice learn to associate events separated in time, neurons within the CA1 region of the hippocampus progressively reorganize their firing patterns, leading to a relay of cellular activity that bridges the two events.
When the fear-enhancing effects of prior exposure to stress are absent, the expression of fear reflects normal neural activity in the medial prefrontal cortex, not stress-induced hyperactivity in the amygdala.
A few circadian ‘evening’ neurons within the Drosophila brain play a key role in driving activity as well as keeping time, whereas the well-known PDF-containing morning cells are likely involved in integrating and transmitting light information.
Synaptic scaling maintains motor output from the respiratory network of bullfrogs after months of inactivity in the winter, providing evidence for homeostatic plasticity in response to large ecologically relevant perturbations in neuronal activity.