Figure 6.

Immunohistochemical Examination of Photoreceptor Precursor Integration and Differentiation

(A) Some migratory transplanted photoreceptor precursors matured in vivo to express M/L opsin.

(B) Neurites from transplanted cells were in contact with host second-order neurons, including G0α+ ON bipolar cell dendrites.

(C and D) Some donor photoreceptor precursors extended axons toward host bipolar cells (PKCα+, C) and expressed the presynaptic protein marker (synaptophysin) (D). While expression of synaptophysin in transplanted cells was disorganized in cells away from the host OPL, processes close to the host INL had pronounced expression of synaptophysin in putative axonal terminals.

(E–H) Some photoreceptor precursors contacted host second-order neurons, including CALB1+ horizontal and bipolar cells (E and F) and expressed synaptophysin (G and H). The white squares in (E) and (G) are shown magnified in (F) and (H), respectively.