Premium
Olfactoretinal centrifugal input modulates zebrafish retinal ganglion cell activity: a possible role for dopamine‐mediated Ca 2 + signalling pathways
Author(s) -
Huang Luoxiu,
Maaswinkel Hans,
Li Lei
Publication year - 2005
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.2005.099531
Subject(s) - dopamine , neuroscience , olfactory bulb , retina , dopaminergic , biology , inner plexiform layer , retinal ganglion cell , microbiology and biotechnology , chemistry , central nervous system
The vertebrate retina receives centrifugal input from the brain. In zebrafish, the major centrifugal input originates in the terminal nerve (TN). TN cell bodies are located in the olfactory bulb and ventral telencephalon. The TN projects axons to the retina where they branch in the inner plexiform layer (IPL) and synapse onto several inner retinal cell types, including dopaminergic interplexiform cells (DA‐IPCs). This olfactoretinal centrifugal input plays a role in modulating retinal ganglion cell (RGC) activity, probably via dopamine‐mediated Ca 2 + signalling pathways. Normally, dopamine inhibits RGC firing by decreasing the inward Ca 2 + current. Olfactory stimulation with amino acids decreases dopamine release in the retina, thereby reducing dopaminergic inhibition of RGCs. This model of olfacto‐visual integration was directly tested by recording single‐unit RGC activity in response to olfactory stimulation in the presence or absence of dopamine receptor blockers. Stimulation of the olfactory neurones increased RGC activity. However, this effect diminished when the dopamine D1 receptors were pharmacologically blocked. In isolated RGCs, the application of dopamine or a dopamine D1 receptor agonist decreased voltage‐activated Ca 2 + current and lowered Ca 2 + influx. Together, the data suggest that olfactory input has a modulatory effect on RGC firing, and that this effect is mediated by dopamine D1 receptor‐coupled Ca 2 + signalling pathways.