FIGURE 3. Camera lucida drawings taken from the L4-L5 level of rats killed 
at various times after plantar hindpaw formalin injection. Maximal 
Fos immunoreactivity is present at 2 to 4 hours postinjection and 
then it disappears slowly. Staining is barely above control by 16 
hours postinjection. 
SOURCE: Presley et al. 1 990. Copyright 1 990 by the Society for 
Neuroscience (New York). 
140 
