Cognition, Behavior, and Memory
Author: Leandro Rocco | email: lrocco@fmed.uba.ar
Leandro Rocco 1°, Antonella Pisera-Fuster 1°, María Paula Faillace 1°, Ramón Oscar Bernabeu 1°
1° Department of Physiology and Institute of Physiology and Biophysics (IFIBIO-Houssay, UBA-CONICET), School of Medicine, University of Buenos Aires, Buenos Aires, Argentina
Cognitive strategies involved in drug seeking, which is examined in a specific environment, are mostly unknown. To assess the strength of environmental cues that can be associated with nicotine in the zebrafish brain reward circuitry, we have designed a modified conditioned place preference (CPP) paradigm. This task identifies visual cues relevant for nicotine seeking induction. During testing, background colors of the CPP tank chambers were shifted and color preference associated to nicotine was assessed. Our findings indicated that zebrafish seeking behavior was strongly dependent on compartment color. Combination of red and yellow environments, preferred and avoided compartments respectively, was the most effective design presenting the highest CPP-score. Animals that stayed for longer periods in the environment conditioned to nicotine during a first testing interval were also able to follow the background color conditioned to nicotine across compartments immediately after background colors were relocated. During a second testing period, zebrafish stayed for longer periods in the colored compartment paired to nicotine during conditioning. Our findings suggest that under salient environmental conditions, zebrafish follow a shifting visual cue previously associated with nicotine delivery. This indicates that zebrafish exhibit spatial associative learning and memory, generating a repertoire of conspicuous locomotor behaviors induced by nicotine preference in the CPP task.