FIGURE 3.

Microglia are not enriched around developmental torpedoes. (A) Sample images from P11 (left) and P30 (right) of Purkinje cells and their axons (green, eGFP), and activated microglia (red, Alexa 594). Scale bar, 20 μm. (B) The density of activated microglia increases in the developing granule cell layer between P11 and P30. (C) Sample images highlighting how analysis was done. After identifying stretches of axon with torpedoes (top) or without torpedoes (bottom) in the green channel, the red channel was added and the number of nearby microglia (within a 25 μm³ box centered on the torpedo or axon) were counted: merged examples show 0 microglia (left) and 2 microglia (right). Scale bar, 5 μm. (D) Number of microglia in the vicinity of torpedo or axon, from 0 to 2 microglia/section (white–gray). No significant differences were observed between microglia density around torpedoes or non-torpedo axons at either P11 (left; P = 0.84), or P30 (right; P = 0.84). Significance determined by Student’s t-test (B) or Mann–Whitney U test (D). ^∗P < 0.05, ns P > 0.05.