Repertoire of behavior and learning exhibited by zebrafish during development together with major experimental techniques and their effective age of use. The timeline at the bottom of the figure indicates important developmental milestones in zebrafish. Note that several forms of learning have been identified as early as 5 dpf, an age at which such powerful experimental techniques as optogenetics are still effective. Note, also, that there are many molecular tools (for example, the GAL4-UAS system; see Halpern et al., 2008) that are effective at all developmental stages in zebrafish.

The C-start reflex in larval zebrafish is mediated by the Mauthner neuron-mediated circuit. (A) An example of a larval zebrafish C-start reflex in response to an auditory/vibrational stimulus. The initiation of the C-start reflex is marked by a white dot and images were recorded every 1 ms. Frames are shown every 2 ms for illustration purposes. (B) Model of the Mauthner neuron circuitry. Potential sites of NMDAR-dependent plasticity are indicated by asterisks. Adapted with permission from Roberts et al. (2011).

Rapid Habituation of the C-start (A) C-start responses to 120 pulses delivered at 1 Hz (binned into groups of 10). (B) Persistence of rapid habituation. The training protocol resulted in short-lived habituation of the C-start, which returned to its original (pretraining) level of responsiveness within 15 min. The asterisk indicates that the 10 s test is significantly different from the pretest and 15 min test; the pound sign indicates that the 1 min test is significantly different from the pretest and the 15 min test. Adapted with permission from Roberts et al. (2011).