PMC

Representative top-view head photos and their respective hair loss severity heatmaps of the subject with the overall healthy state (a,d); moderate hair loss (b,e); and severe hair loss (c,f). On the top of the head photos, the local hair loss severity index P is presented with the images taken from different locations of the scalp. The hair loss severity estimation for the healthy, moderate hair loss and severe hair loss is 0.879, 0565, and 0.160, respectively, reflecting a gradual decrease in the value as hair loss progresses.

a Cicatricial alopecia in a male androgenetic distribution. Bitemporal (arrow) and parietal hair loss. a1 Hyperpigmented perifollicular halo, scattered white small patches, hair diameter diversity, loss of follicular ostia. a2 AGA, horizontal section, papillary dermis with some terminal and many vellus hairs. b Cicatricial alopecia in a female androgenetic distribution. b1 Perifollicular erythema and scaling, loss of follicular ostia, keratotic follicular plugs, and hair diameter diversity. b2 Concentric fibrosis and fibrous tracts. c Cicatricial alopecia in a female androgenetic distribution. ­Arrow shows cicatricial parietal involvement. c1 Loss of follicular ostia, white perifollicular ostia, hair diameter diversity, and a honeycomb ­hyperpigmented network. c2 Concentric fibrosis with intense perifollicular lymphocytic infiltrate. Terminal and vellus hair involvement. d Cicatricial alopecia in a female androgenetic distribution with parietal involvement. d1 Loss of follicular ostia, perifollicular erythema and scaling, and hair diameter diversity. d2 AGA features with a lichenoid infiltrate around the vellus hair. Premature desquamation of the inner root sheath.e Diffuse hair thinning associated with recession of the frontotemporal hairline. Arrows showing the recession and the eyebrow thinning. e1 Perifollicular scaling, loss of follicular ostia, a white perifollicular halo and perifollicular scaling, and hair diameter diversity. e2 Concentric fibrosis with perifollicular lymphocytic infiltrate. f Cicatricial alopecia in a female andro­ge­netic distribution with a central non­affected parietal area (arrow). f1 Loss of follicular ostia, a whitish and hyperpigmented perifollicular halo, white patches, hair diameter diversity, and a honeycomb pigmented network. f2 Vellus hair involvement. g Diffuse hair thinning with a temporal nonaffected area. g1 Loss of follicular ostia, a whitish and hyperpigmented perifollicular halo, white patches, hair diameter diversity, and a honeycomb pigmented network. g2 Premature desquamation of the inner root sheath.

(A) Whole-mount preparation showing myosin VIIa–positive hair cells in the cochlear basal turn. Three rows of outer hair cells and a single row of inner hair cells are present in saline-treated animals. (B) Sisomicin treatment caused outer hair cell loss. (C) Hair cells are preserved in N1MS-treated animals. (D) Quantification of myosin VIIa–positive outer hair cells shows dramatic cell loss (as percentages of saline-treated controls) in a basal-apical gradient after sisomicin treatment, whereas N1MS treatment preserved markedly more hair cells. Treatment with 400 mg/kg N1MS produced hair cell loss. Data are shown as average ± SEM. For D, n = 57 for saline control; n = 9–14 for other groups. Scale bar: 25 μm.

A–DTop views of cochlear hair cells from CIB2 ^+/− and CIB2 ^−/− P120 mice. (A, C) The normal architecture of the sensory epithelium and hair bundles from CIB2 ^+/− P120 mice is shown for comparison. (B, D) At this stage, most of the IHC and OHC hair bundles, and the apical surface of hair cells, have entirely disappeared (asterisks). The scarce persisting IHC hair bundles (arrows in B) are composed of few stereocilia, often fused or forming bleb‐like structures, as shown in the mid‐apical region of the cochlea in CIB2 ^−/− P120 mice.E, FTop views of the vestibular utricular hair cells from CIB2 ^+/− (E) and CIB2 ^−/− (F) P120 mice, showing preserved and normally shaped hair bundles even in the absence of CIB2 (F), contrasting with the severe loss at this stage of the hair bundles in the cochlea (B).Data information: Scale bars: 2 μm.