fig6

Figure 6. Root visibility depends on the depth of implantation and pigment production during the anagen stage of the hair cycle. The panels on the left (A, B, C) display the surface view of the grafts and hair, while the panels on the right (A’, B’, and C’) are schematic drawings of the visible dermal aspects of the same samples. The spontaneous - non-synchronized - cycling is reflected in the hair production from two grafted scalp follicles after hair dying, before clipping (A), immediately after clipping (B), and 48 h later (C). In the original surface views (panels on the left), attention is drawn to the visible root segments (in the middle of two yellow bars for the proximal graft and two turquoise bars for the distal graft). The unclipped, relatively long hair from the proximal grafted follicle is shown on the extreme left (A and A1). This follicle has recently entered the resting (telogen) phase after terminating its growth (anagen), as demonstrated by repeated clipping and imaging. There is “no elongation” of the clipped hair fiber (as indicated by the green dot in b1 and c1, respectively). The surface imaging cannot capture the deeper root of the proximal graft [the magenta bar between the two parallel yellow bars in A’, B’ and C’ highlights intra-epidermal segments A’1, B’1 and C’1 (length ± 100 µm)]. The follicle on the right side (A2 in A; distal graft) displays a tapered, less pigmented tip. After hair dying, the tip appears as a recently regrown, thin fiber. The root length is roughly displayed (seen in A2, B2, and C2, and schematically in A’2, B’2, and C’2; marked by a black vertical line between two magenta bars [estimated depth inside the follicle: 300 to 500 µm)]. The stubble remaining after clipping (B2; red bar) significantly elongates, reflecting hair growth as seen in image C2, which was captured 48h after the image in B2, and the added blue proximal segment demonstrates the production of anagen hair (with an estimated linear growth rate of 120 µm/day).