TitleThe common neural parasite Pseudoloma neurophilia is associated with altered startle response habituation in adult zebrafish (Danio rerio): Implications for the zebrafish as a model organism.
Publication TypeJournal Article
Year of Publication2015
AuthorsSpagnoli, ST, Xue, L, Kent, ML
JournalBehav Brain Res
Date Published2015 Sep 15
KeywordsAnimals, Extinction, Psychological, Female, Fish Diseases, Habituation, Psychophysiologic, Hyperplasia, Male, Microsporidia, Microsporidiosis, Models, Animal, Phenotype, Physical Stimulation, Psychological Tests, Reflex, Startle, Spinal Cord, Swimming, Video Recording, White Matter, Zebrafish

The zebrafish's potential as a model for human neurobehavioral research appears nearly limitless despite its relatively recent emergence as an experimental organism. Since the zebrafish has only been part of the research community for a handful of decades, pathogens from its commercial origins continue to plague laboratory stocks. One such pathogen is Pseudoloma neurophilia, a common microparasite in zebrafish laboratories world-wide that generally produces subclinical infections. Given its high prevalence, its predilection for the host's brain and spinal cord, and the delicate nature of neurobehavioral research, the behavioral consequences of subclinical P. neurophilia infection must be explored. Fish infected via cohabitation were tested for startle response habituation in parallel with controls in a device that administered ten taps over 10 min along with taps at 18 and 60 min to evaluate habituation extinction. After testing, fish were euthanized and evaluated for infection via histopathology. Infected fish had a significantly smaller reduction in startle velocity during habituation compared to uninfected tankmates and controls. Habituation was eliminated in infected and control fish at 18 min, whereas exposed negative fish retained partial habituation at 18 min. Infection was also associated with enhanced capture evasion: Despite the absence of external symptoms, infected fish tended to be caught later than uninfected fish netted from the same tank. The combination of decreased overall habituation, early extinction of habituation compared to uninfected cohorts, and enhanced netting evasion indicates that P. neurophilia infection is associated with a behavioral phenotype distinct from that of controls and uninfected cohorts. Because of its prevalence in zebrafish facilities, P. neurophilia has the potential to insidiously influence a wide range of neurobehavioral studies if these associations are causative. Rigorous health screening is therefore vital to the improvement of the zebrafish as a translational model for human behavior.

Alternate JournalBehav Brain Res
PubMed ID26028515
PubMed Central IDPMC4497864
Grant ListP40 RR012546 / RR / NCRR NIH HHS / United States
T32 RR023917 / RR / NCRR NIH HHS / United States
P40 OD011021 / OD / NIH HHS / United States
2R24OD010998-11 / OD / NIH HHS / United States
R24 OD010998 / OD / NIH HHS / United States