BDNF, Brain, and Regeneration: Insights from Zebrafish

Abstract

Zebrafish (Danio rerio) is a teleost fish widely accepted as a model organism for neuroscientific studies. The adults show common basic vertebrate brain structures, together with similar key neuroanatomical and neurochemical pathways of relevance to human diseases. However, the brain of adult zebrafish possesses, differently from mammals, intense neurogenic activity, which can be correlated with high regenerative properties. Brain derived neurotrophic factor (BDNF), a member of the neurotrophin family, has multiple roles in the brain, due also to the existence of several biologically active isoforms, that interact with different types of receptors. BDNF is well conserved in the vertebrate evolution, with the primary amino acid sequences of zebrafish and human BDNF being 91% identical. Here, we review the available literature regarding BDNF in the vertebrate brain and the potential involvement of BDNF in telencephalic regeneration after injury, with particular emphasis to the zebrafish. Finally, we highlight the potential of the zebrafish brain as a valuable model to add new insights on future BDNF studies.

Neuroanatomical distribution and functions of brain‐derived neurotrophic factor in zebrafish (Danio rerio) brain

“…In zebrafish, evaluating BDNF's role in adult neurogenesis and brain regeneration is a nascent field. Only a few recent studies have reported the likely involvement of BDNF/TrkB system in mediating reparative brain regeneration (reviewed in (Cacialli, Palladino, & Lucini, ) and (Lucini, D'Angelo, Cacialli, Palladino, & de Girolamo, )). Inducing an injury in the mid‐dorsal region of the right telencephalic hemisphere in zebrafish causes a dramatic increase in the proliferation of neural progenitors.…”

Neuron-glia interaction through Serotonin-BDNF-NGFR axis enables regenerative neurogenesis in Alzheimer’s model of adult zebrafish brain

“…The highest upregulation was observed for bdnf ( Fig 3D). From single-cell analyses, we found that bdnf was predominantly expressed in neuronal clusters (90% in neurons and 8% in glial cells; Fig 3E, S4H Fig), whereas its receptor ntrk2 [37,38] was expressed mainly in neurons (68% neuronal and 28% glia; Fig 3E, S4H Fig), and another BDNF receptor ngfra [37][38][39] was mostly glial (93% in glia and 5% in neurons; Fig 3E; S4H Fig). Therefore, we hypothesized that 5-HT dependent regulation of bdnf expression might signal to the glial cells through ntrk2 and ngfra in the adult zebrafish brain.…”

Zebrafish Larvae as a Behavioral Model in Neuropharmacology

“…The mammalian and zebrafish behavioral paradigms are in close parallel suggesting the evolutionarily conserved nature of many behaviors across species [3,5,11]. Despite neuroanatomical differences between the mammals and teleosts, evidence shows homologous functions in several key zebrafish brain areas [12,13,14,15]. The recent emergence of high-throughput tracking of zebrafish embryos and larvae has further bolstered the behavior research in the zebrafish field, making the research more objective, replicable, and efficient.…”