Figure 3.

Effect of deprivation pattern on spine formation and elimination. A, AWD evenly deprives the barrel field of its principal whisker input and does not significantly alter principal whisker responses (white bars), nor the strongest (S1) spared surround whisker responses (black bars) after 1 or 7 d of deprivation. B, Similarly, AWD does not affect spine formation (black bars) or elimination (black bars, plotted as negative values for clarity), which remain constant following deprivation compared with formation and elimination in undeprived animals (white bars). C, Therefore, AWD cumulative formation (blue line) and elimination curves (red line) entirely overlap with those for undeprived cases (see key). D, CWD results in alternate deprived and spared barrels in the cortex (diagram; spared barrels dark gray) and causes potentiation of spared whisker responses in deprived barrels (black bars) and principal whisker responses to depressed (white bars). E, Similarly, CWD causes spine formation and elimination to increase significantly 1 d following deprivation and remain elevated for at least 11 d following deprivation compared with undeprived values. ***p < 0.001. **p < 0.01. *p < 0.05. F, Consequently, cumulative spine formation is increased over 14 d to ∼90% of the originally present spines (blue line) compared with ∼40% in undeprived animals (green line). Cumulative spine elimination in CWD (red line) is similar to formation over 14 d and significantly higher than in undeprived animals (purple line).