PUBLICATION

Functional brain imaging in larval zebrafish for characterising the effects of seizurogenic compounds acting via a range of pharmacological mechanisms

Authors
Winter, M.J., Pinion, J., Tochwin, A., Takesono, A., Ball, J.S., Grabowski, P., Metz, J., Trznadel, M., Tse, K., Redfern, W.S., Hetheridge, M.J., Goodfellow, M., Randall, A.D., Tyler, C.R.
ID
ZDB-PUB-210327-6
Date
2021
Source
British journal of pharmacology   178(13): 2671-2689 (Journal)
Registered Authors
Tyler, Charles R.
Keywords
3Rs, CNS safety pharmacology, Drug discovery/target validation, Eluthero-embryo, Functional neuroimaging, Neuropharmacology, Seizures, Zebrafish, in vivo
MeSH Terms
  • Animals
  • Brain*/diagnostic imaging
  • Functional Neuroimaging
  • Larva
  • Seizures/chemically induced
  • Seizures/drug therapy
  • Zebrafish*
PubMed
33768524 Full text @ Br. J. Pharmacol.
Abstract
Functional brain imaging using genetically-encoded Ca2+ sensors in larval zebrafish is being developed for studying seizures and epilepsy as a more ethical alternative to rodent models. Despite this, few data have been generated on pharmacological mechanisms of action other than GABAA antagonism. Assessing larval responsiveness across multiple mechanisms is vital to test the translational power of this approach, as well as assessing its validity for detecting unwanted drug-induced seizures and testing antiepileptic drug efficacy.
Using light-sheet imaging, we systematically analysed the responsiveness of 4 day post fertilisation (dpf ~ which are not considered protected under European animal experiment legislation) transgenic larval zebrafish to treatment with 57 compounds spanning more than 12 drug classes with a link to seizure generation in mammals, alongside 8 compounds with no link.
We show 4dpf zebrafish are responsive to a wide range of mechanisms implicated in seizure generation, with cerebellar circuitry activated regardless of the initiating pharmacology. Analysis of functional connectivity revealed compounds targeting cholinergic and monoaminergic reuptake, in particular, showed phenotypic consistency broadly mapping onto what is known about neurotransmitter-specific circuitry in the larval zebrafish brain. Many seizure-associated compounds also exhibited altered whole brain functional connectivity compared with controls.
This work represents a significant step forward in understanding the translational power of 4dpf larval zebrafish for use in neuropharmacological studies and for studying the events driving transition from small-scale pharmacological activation of local circuits, to the large network-wide abnormal synchronous activity associated with seizures.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping