Serotonergic Modulation as Effective Treatment for Dravet Syndrome in a Zebrafish Mutant Model.

Article Details

Citation

Sourbron J, Schneider H, Kecskes A, Liu Y, Buening EM, Lagae L, Smolders I, de Witte P

Serotonergic Modulation as Effective Treatment for Dravet Syndrome in a Zebrafish Mutant Model.

ACS Chem Neurosci. 2016 May 18;7(5):588-98. doi: 10.1021/acschemneuro.5b00342. Epub 2016 Feb 17.

PubMed ID
26822114 [ View in PubMed
]
Abstract

Dravet syndrome (DS) is a severe epilepsy syndrome that starts within the first year of life. In a clinical study, add-on treatment with fenfluramine, a potent 5-hydroxytryptamine (5-HT) releaser activating multiple 5-HT receptor subtypes, made 70% of DS children seizure free. Others and we recently confirmed the efficacy of fenfluramine as an antiepileptiform compound in zebrafish models of DS. By using a large set of subtype selective agonists, in this study we examined which 5-HT receptor subtypes can be targeted to trigger antiseizure effects in homozygous scn1Lab(-/-) mutant zebrafish larvae that recapitulate DS well. We also provide evidence that zebrafish larvae express the orthologues of all human 5-HT receptor subtypes. Using an automated larval locomotor behavior assay, we were able to show that selective 5-HT1D-, 5-HT1E-, 5-HT2A-, 5-HT2C-, and 5-HT7-agonists significantly decreased epileptiform activity in the mutant zebrafish at 7 days post fertilization (dpf). By measuring local field potentials in the zebrafish larval forebrain, we confirmed the antiepileptiform activity of the 5-HT1D-, 5-HT2C-, and especially the 5-HT2A-agonist. Interestingly, we also found a significant decrease of serotonin in the heads of homozygous scn1Lab(-/-) mutants as compared to the wild type zebrafish, which suggest that neurochemical defects might play a crucial role in the pathophysiology of DS. Taken together, our results emphasize the high conservation of the serotonergic receptors in zebrafish larvae. Modulating certain serotonergic receptors was shown to effectively reduce seizures. Our findings therefore open new avenues for the development of future novel DS therapeutics.

DrugBank Data that Cites this Article

Drugs
Drug Targets
DrugTargetKindOrganismPharmacological ActionActions
Fenfluramine5-hydroxytryptamine receptor 1DProteinHumans
Yes
Agonist
Details
Fenfluramine5-hydroxytryptamine receptor 2AProteinHumans
Unknown
Agonist
Details
Fenfluramine5-hydroxytryptamine receptor 2BProteinHumans
No
Agonist
Details
Fenfluramine5-hydroxytryptamine receptor 2CProteinHumans
Yes
Agonist
Details