Short- and long-term effects of nicotine and histone deacetylase inhibitor on novel object preference in zebrafish.

FAILLACE MP, PISERA-FUSTER A, MEDRANO MP, BEJARANO AC & BERNABEU R

PSYCHOPHARMACOLOGY

SPRINGER

Lugar: Berlin; Año: 2017 vol. 234 p. 943 - 955

0033-3158

AbstractRationale: Several behavioral tasks depend on visual cues. Zebrafish is endowed with a sophisticated color andshape sensitive visual system therefore we set-up conditions to examine novelobject preferencebased on color cues. We evaluated zebrafish preference in theabsence or presence of drugs that affect attention and memory retention inrodents: nicotine and an inhibitor of histone deacetylases,phenylbutyrate(PhB). Objectives: The aim was to evaluate if nicotine andPhB could affect or reverse zebrafish innate preference/avoidance behaviors fornovel objects in the short and long-term. Methods: We developed a modifiedobject recognition (OR) test by employing novel and familiar objects which wereneutral (the only salient cue was novelty) or that had opposite innatesignificance for zebrafish.Results: Zebrafish showedpreference for red or green and aversion for yellow or blue objects.Zebrafishwere more sensitive at discriminating color changes thanchanges inshape or size.Nicotine significantly enhanced short-termnovel object preferenceor aversion whereas PhBshowed similar effectsat 24 h post training. Further analysisof zebrafishbehaviors supported OR results. Conclusions:Zebrafish were unwilling to explore yellow orblue objects and prone toexplore red or green novel objects. This means that bychanging color hue of simple objects drug effects on innate preference oraversion can be evaluated. Zebrafish showed novel object recognition and hencememory retention when objects with features of similar innate significance forzebrafish were evaluated in the OR test. Interestingly, nicotine andPhBenhanced zebrafish natural biasfor exploring or avoiding novel objectswhendissimilarity between objects was based on color cues, which induce oppositeinnate behaviors in zebrafish.These drugs also affected novel objectpreference/avoidance ratio when differences between objects were based on size.