FIG. 4.

Dietary ω-3 polyunsasturated fatty acids (PUFA)s prevents sensory dysfunction after chronic spinal cord injury (SCI). (A) Electronic von Frey test shows that SCI results in increased withdrawal threshold (hypoalgesia). Remarkably, ω-3 PUFAs prophylaxis prevented alterations in paw sensitivity when compared with baseline (BL) (p>0.01). Post hoc revealed significant effects were observed between dietary groups at 8 wpi (p<0.05). Data are expressed as %Δ paw withdrawal threshold from BL (and normalized to %Δ in sham animals; mean±standard error of the mean [SEM], n=13). (B) K-means clustering divided mechanical sensory thresholds (g of force required to elicit hind paw withdrawal) into three groups: (1) normal (no differences between baseline and 8 weeks post-operation (wpo); two-way analysis of variance followed by Bonferroni's post-hoc test, p>0.05), (2) hypoalgesia (significant difference between baseline and 8 wpo; p<0.05), and (3) hypoalgesia++ (extremely significant difference between baseline and 8 wpo; p<0.05). Data are presented as mean±SEM. (C) Dietary ω-3 PUFAs prophylaxis significantly reduced the number of animals in which sensory dysfunction developed. K-means clustering was followed by the Fisher exact test to determine whether diet altered the predisposition of animals for development of sensory deficits. Analyses revealed that dietary ω-3 PUFAs reduced the probability of development of major sensory dysfunction (hypoalgesia) by 54% when compared with controls (Fisher exact test p=0.02, n=26). Color image is available online at www.liebertpub.com/neu