Table 3. LFP magnitude inferential statistics for the transection experiments.
Repeated measures ANOVA was performed to investigate all possible main effects and interactions for LFP data obtained from a group of rats (n=5) where whisker C2 was studied, electrode array was aligned in only one direction, and recordings obtained in two cortical layers before any transection (BT), after a side transection (ST) alongside the electrode array, and after a center transection (CT) between recording locations 4 and 5 (- - - - -). The ANOVA was followed by specific contrasts using C-matrix for specifically locations 4–8 to test differences between TRANSECTION conditions: whether the average of before transection and side transection is the same as center transection (Contrast 1); and whether before transection is the same as side transection (Contrast 2). Alpha level was set to 0.01 and Bonferroni adjustment applied to the alpha level to account for multiple testing with specific contrasts (adjusted alpha level = 0.001), with significant statistics in bold. Statistics for the main effects are summarized here but not for interactions because none were found significant except between TRANSECTION and LOCATION (F[14,56]=22.5, p=2×10−13). See Full Methods for more details. Summary. As expected, the main effect LOCATION was highly significant. More importantly, the main effect TRANSECTION was also highly significant. Complementary to the interaction found between TRANSECTION and LOCATION, the specific contrasts were able to identify that differences existed specifically between center transection vs. the average of before transection and side transection (Contrast 1) for recording locations 5–7. LFP magnitude for locations 5–7 after center transection was reduced to 6–7% of electrode 1, rendering LFP latency and slope determination unreliable under this condition and thus not analyzed further for the transection experiments.
| main effects | P value | |||
|---|---|---|---|---|
| TRANSECTION (BT vs. ST vs. CT) | F[2,8]=73.3 | 1×10−5 | ||
| LOCATION (1–8) | F[7,28]=191.0 | 1×10−15 | ||
| LAYER (supra vs. gran) | F[1,4]=1.2 | 0.34 | ||
| specific contrasts | ||||
| Location 4 | ||||
| Contrast 1 | F[1,4]=2.1 | 0.221 | ||
| Contrast 2 | F[1,4]=0.3 | 0.591 | ||
| Location 5 | ||||
| Contrast 1 | F[1,4]=174.3 | 2×10−4 | ||
| Contrast 2 | F[1,4]=0.8 | 0.421 | ||
| Location 6 | ||||
| Contrast 1 | F[1,4]=120.4 | 4×10−4 | ||
| Contrast 2 | F[1,4]=9.0 | 0.040 | ||
| Location 7 | ||||
| Contrast 1 | F[1,4]=191.2 | 2×10−4 | ||
| Contrast 2 | F[1,4]=0.8 | 0.426 | ||
| Location 8 | ||||
| Contrast 1 | F[1,4]=31.0 | 0.005 | ||
| Contrast 2 | F[1,4]=1.4 | 0.297 | ||