Fig.7 . Expression of p75^NTR in the E6 chick retina. p75^NTR immunoreactivity was observed in the prospective ganglion cell layer and optic fiber layer (arrowheads in A-C) of control (A) and anti-TGF-ß-treated (B,C) retinae. Staining was also detectable in the optic nerve (arrows in C). nr, neural retina; on, optic nerve; pe, pigment epithelium. Scale bar: 20 µm.