Elevated dopamine concentration in light‐adapted zebrafish retinas is correlated with increased dopamine synthesis and metabolism

Abstract

Probing zebrafish (Danio rerio) retinal cryostat sections, collected either 8 h into the light or dark cycle, with an antibody against tyrosine hydroxylase (TH) identified a single population of immunopositive cells in the inner retina. However, the observed labeling patterns were not identical in both sets of tissues -label intensity was brighter in light-adapted tissue. This difference was quantified by probing western blots of retinal homogenates with the same TH antibody, which showed that TH expression increased by 42% in light-adapted tissue. High-performance liquid chromatography with electrochemical detection revealed that the concentrations of both dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) are also elevated in light-adapted zebrafish retinal tissue. Dopamine levels increased by 14% and DOPAC levels increased by 25% when measured in retinal homogenates harvested during the light cycle. These results indicate that dopamine levels in zebrafish retina are significantly increased in lightadapted tissue. The increase in dopamine content is correlated with an increase in both TH and DOPAC, suggesting that changes in dopamine concentration are due to light-adaptive changes in the synthesis, release and metabolism of dopamine.

Bright Light Suppresses Form-Deprivation Myopia Development With Activation of Dopamine D1 Receptor Signaling in the ON Pathway in Retina

“…This neurotransmitter appears to play an important role in vision-guided eye growth because its synthesis and release are positively associated with the light intensity impinging on the retina, and BL partially rescued the drop in retinal DA. 16 Another indication of DA involvement in mediating light inhibitory effects on FDM is that the nonselective DA receptor agonist apomorphine inhibited FDM in chicks, 17 mice, 18 guinea pigs, 19 and rhesus monkeys, 20 which indicates that activation by BL of DA receptor-linked signaling pathways contributes to controlling myopia progression by BL. 21 The two DA receptor subtypes expressed in the retina are the D1-like (including D1/D5R) and D2-like receptors (including D2/D4R).…”

The Effects of High Lighting on the Development of Form-Deprivation Myopia in Guinea Pigs

“…Much evidence has been reported suggesting that the protective effect of high lighting may be mediated through the retinal dopamine (DA) system. 29,[33][34][35][36][37][38][39][40] Moreover, a DA receptor antagonist promoted the progressive myopia in guinea pigs 39 and reversed the inhibitory effects of bright light on myopia in mice. 22 However, the precise molecular mechanism by which the DA system mediates the protective effect of high light is unclear, and requires further studies to identify more related molecular signals.…”

A microfluidic device to study electrotaxis and dopaminergic system of zebrafish larvae

“…7 For instance, it has been demonstrated that the activities of dopamine receptors alter in zebrafish during the light-dark cycle. 58 It is also shown that mutation in the circadian gene period1b (per1b) 57 or exposure of zebrafish larvae to the dopamine agonist apomorphine 7 can alter the dopamine level or receptor activities and result in significant changes in zebrafish's general locomotion behavior. For instance, exposing zebrafish to 0.2 lM and 50 lM apomorphine in darkness resulted in a strong increase in larvae's average travel distance, and an intermediate exposure to 1.8 lM apomorphine significantly lowered that activity.…”