Visuomotor deficiency in panx1a knockout zebrafish is linked to dopaminergic signaling

Pannexin 1 (Panx1) forms ATP-permeable membrane channels that play roles in the nervous system. The analysis of roles in both standard and pathological conditions benefts from a model organism with rapid development and early onset of behaviors. Such a model was developed by ablating the zebrafsh panx1a gene using TALEN technology. Here, RNA-seq analysis of 6 days post fertilization larvae were confrmed by Real-Time PCR and paired with testing visual-motor behavior and in vivo electrophysiology. Results demonstrated that loss of panx1a specifcally afected the expression of gene classes representing the development of the visual system and visual processing. Abnormal swimming behavior in the dark and the expression regulation of pre-and postsynaptic biomarkers suggested changes in dopaminergic signaling. Indeed, altered visuomotor behavior in the absence of functional Panx1a was evoked through D1/D2-like receptor agonist treatment and rescued with the D2-like receptor antagonist Haloperidol. Local feld potentials recorded from superfcial areas of the optic tectum receiving input from the retina confrmed abnormal responses to visual stimuli, which resembled treatments with a dopamine receptor agonist or pharmacological blocking of Panx1a. We conclude that Panx1a functions are relevant at a time point when neuronal networks supporting visualmotor functions undergo modifcations preparing for complex behaviors of freely swimming fsh.


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