Ketamine acutely impairs memory consolidation and repeated exposure promotes stereotyped behavior without changing anxiety- and aggression-like parameters in adult zebrafish.
Paula Michelotti, Francini Franscescon, T. E. Müller, D. B. Rosemberg, M. E. Pereira
Physiology and Behavior January 18, 2022 DOI: 10.1016/j.physbeh.2022.113708 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Experimental study Peer reviewed |
|---|---|
| Population | Adult zebrafish |
| Intervention | Ketamine exposure |
| Dose | 0, 2, 20, or 40 mg/L |
| Duration | 20-minute exposure (acute); 7 daily 20-minute exposures (repeated) |
| Topics | Anxiety Esketamine Ketamine |
| Key findings | A single high dose of ketamine (40 mg/L) impaired memory consolidation, and repeated exposure at the same dose increased circling behavior without affecting locomotion, aggression, anxiety, or cortisol levels. |
Abstract
Ketamine is a dissociative anesthetic in human and veterinary clinic, as well as an abuse drug that acts on several neurotransmitter systems. The use of alternative animal models, such as zebrafish, is emerging to study the effects of drugs on neurobehavioral responses. Here, we evaluated the effects of ketamine on memory consolidation (acute protocol), as well as on anxiety-, aggressive-like behavior, and whole-body cortisol levels in adult zebrafish after a repeated exposure. For the acute protocol, fish were tested in the inhibitory avoidance task (training and testing with 24-hour intervals). Immediately after the training session, fish were exposed to ketamine (0, 2, 20, or 40 mg/L) for 20 min. The exploratory activity was also measured 24 h after acute exposure to exclude the influence of impaired locomotion on memory performance. For the repeated exposure, animals were exposed to the same concentrations of ketamine for 20 min (7 days). After the last exposure (24 h later), anxiety- and aggression-like behaviors were quantified in the novel tank and mirror-induced aggression tests, respectively, as well as whole-body cortisol levels measurements were performed. The higher ketamine concentration tested (40 mg/L) acutely induced a slight memory impairment in the inhibitory avoidance task without changing locomotion and anxiety-like behaviors. Although locomotion, anxiety-, aggressive-like behaviors, and whole-body cortisol levels did not change after repeated exposure, 40 mg/L ketamine increased circling behavior. Overall, our data reinforce that ketamine acutely affects multiple behavioral domains in zebrafish, in which repeated ketamine exposure elicits stereotyped behavior, without changing locomotion, aggression, and anxiety/stress-like parameters.
Comparable studies
Other preclinical and animal studies on ketamine for anxiety, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psychedelics, but Not Ketamine, Produce Persistent Antidepressant-like Effects in a Rodent Experimental System for the Study of Depression Rats | 2020 | Preclinical study | |
| Psilocin and ketamine microdosing: effects of subchronic intermittent microdoses in the elevated plus-maze in male Wistar rats Wistar rats | 2018 | Experimental study | n = 40 |
| Repeated Dosing of Ketamine in the Forced Swim Test: Are Multiple Shots Better Than One? Rodents | 2021 | Review | |
| Psychedelics: A review of their effects on recalled aversive memories and fear/anxiety expression in rodents Rodents | 2024 | Review | |
| Sexually Dimorphic Behavioral Profile in a Transgenic Model Enabling Targeted Recombination in Active Neurons in Response to Ketamine and (2R,6R)-Hydroxynorketamine Administration Arc-CreERT2 × CAG-Sun1/sfGFP mice | 2020 | Experimental study |