Table 1.

Number of pCREB-positive neurons in the subregions of ipsilateral laminae I–II (Ipsi I–II) and III–VI (Ipsi III–VI), contralateral laminae I–II (Contra I–II) and III–VI (Contra III–VI), and lamina X in the spinal cord (L4–L5) of control animals and animals subjected to formalin, formalin + MK-801, and formalin + halothane 40 min after injection into the left paw

SubregionControlFormalinFormalin + MK-801Formalin + halothane
Ipsi I–II8.2  ± 2.21-165 53.8  ± 4.029.2  ± 3.91-165 (46%)20.8  ± 4.51-165 (61%)
Contra I–II8.2  ± 2.21-165 44.6  ± 1.820.4  ± 2.31-165 (54%)20.1  ± 1.91-165 (55%)
Ipsi III–IV6.5  ± 1.81-165 30.2  ± 3.916.1  ± 2.11-160 (47%)15.7  ± 2.11-160 (48%)
Contra III–VI6.5  ± 1.81-165 26.5  ± 2.813.9  ± 2.01-160 (48%)15.1  ± 2.01-160 (43%)
Lamina X7.9  ± 0.91-165 28.5  ± 2.913.5  ± 2.71-165 (53%)18.0  ± 1.81-160 (37%)
  • Results are presented as the mean ± SEM from 4–5 rats. For each rat, counts from 6–8 sections (20 μm) were averaged. The numbers in the parentheses indicate the percentage of inhibition as compared to the formalin group.

  • F1-160 p < 0.01,

  • F1-165 p < 0.001 compared to the formalin group; ANOVA followed by ScheffeF-test. CREB phosphorylation is low in the unstimulated control spinal cord. Formalin-induced pCREB is significantly inhibitied by MK-801 and halothane in all of the spinal subregions examined.