A transparent larval zebrafish brain showing a flux of chemical messengers: serotonin (red), dopamine and norepinephrine (yellow), and acetylcholine (cyan)KARL DEISSEROTH, STANFORD UNIVERSITY
Scientists have developed a new imaging method to examine the brain circuitry underlying alertness in zebrafish. The method—Multi-MAP—integrates real-time neuroimaging with activity monitoring of chemicals in the brain. The technique allowed the researchers to identify cell types whose activity increased during periods of heightened alertness. They considered the animals to be “alert” when the fish were on the verge of swishing their tails in response to a threatening stimulus.
M. Lovett-Barron et al., “Ancestral circuits for the coordinated modulation of brain state,” Cell, doi:10.1016/j.cell.2017.10.021, 2017.