Cognition, Behavior, and Memory
Author: Nicolas Gustavo Calleja | Email: nicoocalleja97@gmail.com
Nicolas Gustavo Calleja1°2°, Ruben Nestor Muzio1°2°, Maria Florencia Daneri1°2
1° Grupo de Aprendizaje y Cognición Comparada, Laboratorio de Biología del Comportamiento (IBYME-CONICET)
2° Instituto de Investigaciones, Facultad de Psicología (UBA)
Fear and anxiety responses depend on the interaction between phylogenetically ancient
brain structures and more modern ones. The lateral and basal nuclei of the amygdala are
believed to be a site of memory storage in fear learning. Studying the responses to
aversive stimuli in amphibians is crucial for understanding the function of these ancient
structures. In our laboratory, we have developed a series of aversive stimulation
procedures in the toad Rhinella arenarum using saline solutions and recording the
increase in heart rate. In this study, we successfully recorded cardiovascular conditioning
and its subsequent extinction through the implantation of electrodes. The subjects were
exposed to a neutral solution followed by an aversive solution, leading to an increase in
heart rate (Unconditioned Response). Over the sessions, this increase was observed upon
the presentation of the neutral solution (Conditioned Response), indicating anticipatory
tachycardia to the aversive event. During extinction, the aversive solution was substituted
with a neutral one, leading to the elimination of the Conditioned Response. After verifying
the protocol’s effectiveness, we decided to measure the neural activity. We used the
AgNOR technique to identify which areas of the amphibian brain show activity. Preliminary
data suggest increased activation in areas known to be associated with fear, such as the
amygdala, revealing similarities with mammals.