Learning and visual discrimination in newly hatched zebrafish

Maria Santacà; Marco Dadda; Luisa Dalla Valle; Camilla Fontana; Gabriela Gjinaj; Angelo Bisazza

doi:10.1016/j.isci.2022.104283

Learning and visual discrimination in newly hatched zebrafish

iScience. 2022 Apr 22;25(5):104283. doi: 10.1016/j.isci.2022.104283. eCollection 2022 May 20.

Authors

Maria Santacà¹, Marco Dadda², Luisa Dalla Valle¹, Camilla Fontana¹, Gabriela Gjinaj², Angelo Bisazza^{2

3}

Affiliations

¹ Department of Biology, University of Padova, Viale Giuseppe Colombo 3 - Via Ugo Bassi 58/B, 35131 Padova, Italy.
² Department of General Psychology, University of Padova, 35131 Padova, Italy.
³ Padua Neuroscience Center, University of Padova, 35131 Padova, Italy.

Abstract

With the exception of humans, early cognitive development has been thoroughly investigated only in precocial species, well developed at birth and with a broad behavioral and cognitive repertoire. We investigated another highly altricial species, the zebrafish, Danio rerio, whose embryonic development is very rapid (< 72 h). The hatchlings' nervous system is poorly developed, and their cognitive capacities are largely unknown. Larvae trained at 8 days post fertilization rapidly learned to associate a visual pattern with a food reward, showing significant performance at 10 days post fertilization. We exploited this ability to study hatchlings' discrimination learning capacities. Larvae rapidly and accurately learned color and shape discriminations. They also discriminated a figure from its mirror image and from its 90°-rotated version, although with lower performance. Our study revealed impressive similarities in learning and visual discrimination capacities between newborn and adult zebrafish, despite their enormous differences in brain size and degree of development.

Keywords: Behavioral neuroscience; Cognitive neuroscience.