Figure 4

The distribution of IB4⁺ neurons in the V ₁ /V ₂ TG divisions and the dural afferent population. (A) Representative images of a TG section containing FG⁺ dural afferent neurons and IB4-labeled neurons. Arrowheads indicate neurons that are both FG⁺ and IB4⁺. (B) The percentages of V₁/V₂ TG neurons and FG⁺ dural afferent neurons that are IB4⁺ (n = 3 mice; on average, 500 V₁/V₂ neurons and 235 FG⁺ neurons were counted from each mouse; * p < 0.05, two-tailed t-test). (C) The size distributions of the IB4⁺/FG⁺ dural afferent neurons (black bars, n = 267 neurons pooled from three mice) are similar to the distributions of the IB4⁺ neurons in the V₁/V₂ divisions of the TG (white bars, n = 686 neurons pooled from three mice, p = 0.1, Mann–Whitney U test). (D) The sizes of IB4⁺ neurons (open bars, the same neurons as in C) are significantly smaller than those of the V₁/V₂ neurons (grey bars, n = 1499 neurons pooled from three mice, p < 0.001, Mann–Whitney U test). (E) The sizes of IB4⁺/FG⁺ dural afferents (black bars, the same neurons as in C) are significantly smaller than those of the total FG⁺ dural afferent neurons (grey bars, n = 704 neurons pooled from three mice, p < 0.001, Mann–Whitney U test).