Figure 10.

The expression of activating transcription factor 3, ATF-3, is elevated in axotomized neurons following cFPI. A–L, Following cFPI in YFP⁺ mice (1 d, A; 3 d, E; 7 d, I; 14 d, C; 28, G; 3 d sham, K), ATF-3 expression is elevated as early as 1 d post-injury (B) in a very limited number of neurons. The number of ATF-3-positive neurons increases at both 3 d (F) and 7 d (J) post-injury. By 14 d (D) and 28 d (H) post-injury, expression returns to levels observed within layer V of sham-injured animals (L). M–R, YFP⁺ neurons at 3 d (M) and 7 d (P) with demonstrable axon pathology (arrowheads) are consistently found to express ATF-3 (arrows: 3 d, N; 7 d, Q; 3 d merged, O; 7 d merged, R). Scale bars: (in L) A–L, 100 μm; (in R) M–R, 25 μm.