Early Appearance of Nonvisual and Circadian Markers in the Developing Inner Retinal Cells of Chicken
Figure 2
Melanopsin expression and light responses in RGC cultures. (a) Primary cultures of embryonic RGCs maintained for 48–72 h were immunolabeled for Opn4x or Opn4m with specific antibodies and DAPI (nuclei staining). The white arrows identify clusters of Opn4 (+) cells present in RGC cultures observed at 40X. (b) Content of inositol phosphates (IPs) in primary cultures of RGCs maintained in the dark (black squares) or stimulated by light (gray squares). Cultures previously incubated with myo-3H inositol for 48 h were light-stimulated during 90 sec to investigate the generation of different IP derivatives directly in RGCs. IP production was evaluated after bright light stimuli and control cells were maintained in the dark as described in the text. Significant increases in radiolabeled IP3 and IP were seen in cultures exposed to bright white light as compared with dark controls (). On the contrary, no significant light-dark differences were found in the content of other IPs determined such as IP2, IP4, and IP5/6. See text for further details.
