Figure 4

Comparison between CSF (A) and serum (B) Nf-L levels across age groups of healthy animals. There were significant differences in CSF NF-L levels between animals aged 2–12 months and 6–12 years, and between animals aged 2–12 months and ≥ 12 years (A), and in serum NF-L levels between animals aged 0–2 months and 1–6 years (B). The median, IQR, maximum and minimum are shown. The Kruskall-Wallis test with pairwise comparisons was used, and the Benjamini–Hochberg procedure applied to adjust the p-values. Asterisks (*) denote the level of statistical significance: *p < 0.05, **p < 0.01. CSF denotes cerebrospinal fluid, IQR interquartile range, Nf-L neurofilament light chain.