Fig. 5

Patterns of 4C4-ir microglial profiles after deafferentation by chemical ablation.

Olfactory bulbs deafferented by chemical ablation of the sensory epithelium of the right olfactory organ were labeled with 4C4. Boxes indicate areas magnified in A’-F”. A) At 1 h, there appeared to be no difference in 4C4 labeling between left, intact and right, deafferented (*) bulbs. There was a small increase in ramified (arrowheads) microglial profiles around the periphery of both the intact (A’) and deafferented (A”) olfactory bulbs. B) At 4 h, there was still no obvious change in 4C4 labeling with deafferentation (*). There seemed to be more amoeboid (arrows) and transitioning (long arrow) in both olfactory bulbs (B’, B”). C) At 12 h, there seemed to be more 4C4 profiles on the deafferented side (*), and there was a noticeable increase in amoeboid profiles in the right olfactory bulb (C”) compared to the internal control side (C’). D) At 24 h, there appeared to be an increase in total number of microglia in the affected bulb (*); most of the profiles were in the olfactory nerve layer and were of the amoeboid and transitioning morphology (D’, D”). E) At 48 h, the 4C4 profiles in the deafferented bulb (*) were localized to the olfactory nerve layer. Most profiles at this time point were transitioning or amoeboid in both olfactory bulbs (E’, E”). F) At 72 h, the distribution of 4C4-ir profiles resembled control fish. Most labeled profiles continued to exhibit primarily the ramified morphologies (F’, F”). Scale bar =200 μm for A–F; 20 μm for A’-F”.