Figure 4. Arciform density/plasma membrane
proteins are stable components at the ribbon synaptic site. A-D:
Representative
images of the outer plexiform layer with the
photoreceptor ribbon synapses double labeled for RIBEYE (green) and
components of the arciform density/plasma membrane compartment (red)
from untreated (A, C) and EGTA-treated (B, D)
retinae.
The arciform density/plasma membrane proteins RIM2 (B)
and the L-type Ca2+ channel subunit Cacna1f (D) often
show a horseshoe-shaped labeling under EGTA treatment, when RIBEYE has
already disintegrated into aggregates. Scale bar: 5 µm.