Related Experiment Video
Updated: Mar 10, 2026
Automated High-throughput Behavioral Analyses in Zebrafish Larvae
Published on: July 4, 2013
Behavioral alterations of zebrafish larvae after early embryonic exposure to ketamine
Luís M Félix1,2,3, Luís M Antunes4,5,6,7, Ana M Coimbra4
1Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes and Alto Douro (UTAD), Vila Real, Portugal. lfelix@utad.pt.
Rationale:
Ketamine has been associated with pediatric risks that include neurocognitive impairment and long-term behavioral disorders. However, the neurobehavioral effects of ketamine exposure in early development remain uncertain.
Objectives:
This study aimed to test stage- and dose-dependent effects of ketamine exposure on certain brain functions by evaluating alterations in locomotion, anxiety-like and avoidance behaviors, as well as socialization.
Methods:
Embryos were exposed to different concentrations of ketamine (0, 0.2, 0.4, and 0.8 mg mL-1) for 20 min during the 256-cell (2.5 h post fertilization-hpf), 50% epiboly (5.5 hpf), and 1-4 somites (10.5 hpf) stages. General exploratory activities, natural escape-like responses, and social interactions were analyzed under continuous light or under a moving light stimulus.
Results:
A dose-dependent decrease in the overall mean speed was perceived in the embryos exposed during the 256-cell stage. These results were related to previously observed head and eye malformations, following ketamine exposure at this stage and may indicate possible neurobehavioral disorders when ketamine exposure is performed at this stage. Results also showed that ketamine exposure during the 50% epiboly and 1-4 somites stages induced a significant increment of the anxiety-like behavior and a decrease in avoidance behavior in all exposed groups.
Conclusions:
Overall, the results validate the neurodevelopmental risks of early-life exposure to ketamine.
