Zebrafish as a Model for Revealing the Neuronal Basis of Behavior

Whole-brain optical access in small adult vertebrates with two- and three-photon microscopy

“…The small size of the adult D. dracula brain is particularly exciting for implementing whole-brain in vivo volumetric imaging with high temporal resolution. With MPM enabling optical access to adult brains and a repertoire of methods that allow observation of larval brains [9,31], aquatic vertebrates such as Danionella and other small species [19,20,32] become readily amenable for studying brain organization over the lifetime of a vertebrate for the first time.…”

“…High scattering and absorption of tissue limits the penetration depth of high-resolution optical imaging inside the brain [1,2]. Small animals such as zebrafish larva and frog tadpoles allow non-invasive, in vivo access to vertebrate brains due to relative transparency of the skin and late ossification of the skull [3][4][5][6][7][8][9][10][11]. However, they often lack the behavioral complexity that develops in adulthood, especially in social contexts related to reproduction such as courtship, copulation, and resource defense.…”

The Formin Fmn2b Is Required for the Development of an Excitatory Interneuron Module in the Zebrafish Acoustic Startle Circuit

“…Zebrafish is an excellent vertebrate model to interrogate gene function in the establishment of neural circuits in vivo and associated behaviors ( Kalueff et al, 2013 ; Mcarthur et al, 2020 ). One of the most studied neural circuits is the Mauthner cell (M-cell)-mediated acoustic startle circuit ( Swain et al, 1993 ; Jontes et al, 2000 ; Korn and Faber, 2005 ; Burgess et al, 2009 ; Sillar, 2009 ; Issa et al, 2011 ; Kinkhabwala et al, 2011 ; Hale et al, 2016 ; Liu and Hale, 2017 ; Hecker et al, 2020 ).…”

Whole-brain optical access in a small adult vertebrate with two- and three-photon microscopy

“…Fishes alone account for more than half of all extant vertebrate species ( Nelson et al., 2016 ) and most do not currently have readily available genetic lines. Nonetheless, diverse fish species are increasingly important for comparative studies addressing how divergent patterns of brain organization contribute to the variation and evolution of complex behavioral repertoires ( Bukhari et al., 2019 ; Dunlap et al., 2021 ; Isa et al., 2021 ; Jaggard et al., 2020 ; Jeffery, 2020 ; McArthur et al., 2020 ). Deep, high-resolution imaging in small animal species like the one studied here thus provides the potential for investigating the functional organization of all brain regions of an adult vertebrate.…”

“…High scattering and absorption of tissue, including that of the pigmented skin and skull, and the head size of most commonly-used vertebrate species ( Takasaki et al., 2020 ; Theer and Denk, 2006 ; Wang et al., 2020b ) currently limits high-resolution optical imaging at the greatest depths of the adult brain ( Horton et al., 2013 ; Takasaki et al., 2020 ; Wang et al., 2018a ). Small animals such as zebrafish larva and frog tadpoles allow non-invasive, in vivo access to brains due to both the relative transparency of their skin and late ossification of the skull ( Ahrens et al., 2012 ; Andalman et al., 2019 ; Cox and Fetcho, 1996 ; Fetcho and O’Malley, 1995 ; He et al., 2016 ; Higashijima et al., 2003 ; Koyama et al., 2016 ; McArthur et al., 2020 ; Vladimirov et al., 2014 ). However, these organisms often lack the behavioral complexity that develops in adulthood, especially in social contexts such as courtship, copulation, and resource defense ( Rubenstein and Alcock, 2019 ).…”