Potential of zebrafish as a model for exploring the role of the amygdala in emotional memory and motivational behavior

Abstract

Emotion is a key aspect of behavior, enabling humans and animals to assign either positive or negative values to sensory inputs and thereby to make appropriate decisions. Classical experiments in mammalian models, mainly in primates and rodents, have shown that the amygdala is essential for appetitive and aversive associative processing and that dysfunction of this brain region leads to various psychiatric conditions, including depression, generalized anxiety disorder, panic disorder, phobias, autism, and posttraumatic stress disorder. In the past 2 decades, the zebrafish (Danio rerio; Cyprinidae) has emerged as a versatile, reliable vertebrate model organism for the in vivo study of development, gene function, and numerous aspects of human pathologies. Small size, high fecundity, rapid external development, transparency, genetic tractability, and high genetic and physiologic homology with humans are among the factors that have contributed to the success with this small fish in different biomedical research areas. Recent findings indicate that, despite the anatomical differences in the brain structure of teleosts and tetrapods, fish possess a structure homologous to the mammalian amygdala, a hypothesis that is supported by the expression of molecular markers, analyses of neuronal projections in different brain areas, and behavioral studies. This Review summarizes this evidence and highlights a number of relevant bioassays in zebrafish to study emotional memory and motivational behavior.

Knockout of histamine receptor H3 alters adaptation to sudden darkness and monoamine levels in the zebrafish

“…36 However, many of the important centres regulating the behaviour and locomotion of the zebrafish are located in the pallium of the telencephalon, which contains the zebrafish functional homologues of the mammalian cortex, amygdala and hippocampus. [37][38][39] As we saw prominent hrh3 expression in both the optic tectum and the dorsal pallium, hrh3 could modulate behavioural responses elicited by light-dark transitions at both of these sites. The increase in locomotor activity after the onset of darkness has occasionally been used as a model of anxiety.…”

Neurodevelopmental Abnormalities and Congenital Heart Disease

“…The zebrafish is a powerful model organism for several reasons: (i) transparent embryos develop quickly ex utero facilitating longitudinal live imaging with microscopy throughout heart development, (ii) inexpensive and large numbers of subjects, and (iii) ease of high-throughput screening paired with sophisticated genetic approaches. Zebrafish as a model of brain development have rapidly increased in popularity over the past two decades and are now being used in a wide variety of studies modeling cognitive disorders, emotional and behavioral motivation, myelination, regeneration, autism, and neuropharmacological screening 136–139 .…”

Animal Consciousness

“…In contrast, a moderate stressor facilitates learning and rats that have received a catecholamine injection, mimicking the physiological component of a moderate emotion, pay more attention and display improved memory (Sandi et al, 1997). Similar modulatory effects have been described in zebrafish (Perathoner et al, 2016).…”