Startle response memory and hippocampal changes in adult zebrafish pharmacologically-induced to exhibit anxiety/depression-like behaviors

Physiol Behav. 2014 Jan 17:123:174-9. doi: 10.1016/j.physbeh.2013.10.023. Epub 2013 Oct 30.

Abstract

Zebrafish (Danio rerio) are rapidly becoming a popular animal model for neurobehavioral and psychopharmacological research. While startle testing is a well-established assay to investigate anxiety-like behaviors in different species, screening of the startle response and its habituation in zebrafish is a new direction of translational biomedical research. This study focuses on a novel behavioral protocol to assess a tapping-induced startle response and its habituation in adult zebrafish that have been pharmacologically-induced to exhibit anxiety/depression-like behaviors. We demonstrated that zebrafish exhibit robust learning performance in a task adapted from the mammalian literature, a modified plus maze, and showed that ethanol and fluoxetine impair memory performance in this maze when administered after training at a dose that does not impair motor function, however, leads to significant upregulation of hippocampal serotoninergic neurons. These results suggest that the maze associative learning paradigm has face and construct validity and that zebrafish may become a translationally relevant study species for the analysis of the mechanisms of learning and memory changes associated with psychopharmacological treatment of anxiety/depression.

Keywords: Anxiety; Depression; Memory; Psychopharmacology; Startle response; Zebrafish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Animals
  • Antidepressive Agents, Second-Generation / therapeutic use
  • Anxiety / chemically induced*
  • Anxiety / drug therapy
  • Anxiety / pathology*
  • Central Nervous System Depressants / adverse effects*
  • Disease Models, Animal
  • Ethanol / adverse effects*
  • Female
  • Fluoxetine / therapeutic use
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Male
  • Reflex, Startle / drug effects*
  • Serotonin / metabolism
  • Substance Withdrawal Syndrome / complications
  • Zebrafish

Substances

  • Antidepressive Agents, Second-Generation
  • Central Nervous System Depressants
  • Fluoxetine
  • Serotonin
  • Ethanol