Figure 5.

Perineurial olfactory nerve fibroblasts form an anatomical barrier

Confocal images of sections through olfactory mucosa of COVID #68 (Alpha), #87 (Delta), #89 (Delta), #94 (Delta), and #108 (Omicron BA.1).

(A) N puncta do not invade a fascicle of TUBB3-IR OSN axons.

(B) A swarm of N puncta stays separate from fascicles containing OSN axons and GFAP-IR OECs.

(C) In a section close to (B), N puncta remain outside the enwrapment by p75-IR pONFs.

(D) A longitudinally sectioned olfactory axon fascicle containing S100B-IR OECs and p75-IR pONFs is devoid of N puncta. The blood vessel at the left emits autofluorescence.

(E) The area marked with an asterisk in (D) imaged at higher magnification.

(F and G) Arrays of N puncta do not invade axon fascicles containing OECs and enwrapped by pONFs.

(H) Fascicles of OMP-IR and TUBB3-IR OSN axons remain free of N puncta. The blood vessel at the center emits autofluorescence.

(I) N puncta stay clear of a fascicle of OSN axons.

(J) An ant-like column of N puncta escorts a fascicle of OSN axons. See also Figure S4.