User:John Riemann Soong/intercellular bridges

Log
On day 1 of this series of experiments, I observed a short bridge between two cells being built from a pair of thin strands, while a series of wide connections adjacent (between the same cells) degenerated into thinnish strands and then disconnected. As you can see, cytoplasm starts to fill in from between these strands (did not observe the original strands being formed). I observed at least one gold particle across it cross onto the "other side", but I am unsure if the other side is in fact part of the "sending cell" because it does not migrate very far in. I observe small, barely visible particles (small vesicles?) freely exchanging across the newly-widened bridge.

On day 3, I essentially took lots of videos -- I summarised what I saw in one image and some arrows. The cyan lines are apparent 'borders' or semi-visible lines that kind of appeared to resist entry and exit of large particles or vesicles across it. I am not sure sometimes if a region is part of one cell or another -- I mean you think that all those regions would be part of the central cell and not the cell north, right? The particles appear to travel near or along thin (barely visible) strands indicated by arrows. The thing that interests me is that the central cell also appears to be sending particles "north" in the other direction, but groups of particles from either side don't mingle very much. I do think I observed some exchange events, but I am not sure if that's simply because portions of membrane from one cell overlap portions from another.

On day 5 I observed two gold particles (possibly aggregates of multiple endosomes containing gold nanorods) being transported across a long thin strand; on the wide side, the bridge is around ~900 nm, but the thinnest part appears to be ~120-150 nm. I spared you guys 40 minutes of video, but the particles exchange focal planes a few times -- one particle appears to be inside the tube and another on the surface at first, but then they switch.

The first particle appears to cross successfully, but it doesn't move very far into the cell. But so far in, surely it "counts" as an intercellular transport event, right? The second particle stalls on the strand -- later I found out the "sending cell" was on the verge of apoptosis (apoptosis 'bubbles' observed).