FIG. 6.

Quantification of cortical tissue damage. (A) Representative tracings of the dorsal regions of the ipsilateral and contralateral neocortex containing morphologically identifiable neurons at the epicenter of injury 1h after impact with a flat-tip impactor and 1 h and 4 h after injury with a rounded-tip impactor. Arrows mark the location of the craniotomy edges as in Figure 4. (B) The volume of cortical damage produced by injury with a flat-tip impactor was maximal by 4 h and was unchanged out to 9 days. In contrast, cortical injury with a rounded-tip impactor led to a more slowly developing cortical contusion that increased in size over 24 h, reaching a contusion volume equivalent to that of the flat-tip impactor group. Square symbols denote flat-tip impactor group means; diamond symbols denote round-tip impactor group means. Error bars represent standard deviations. (+p<0.0005 compared to the previous time point for the flat-tip impactor group; **p<0.001 compared to the previous time point for the rounded-tip impactor group; # p<0.005 comparing flat-tip and rounded-tip impactor groups at the same time point).