SV2, a synaptic vesicle antigen in preganglionic terminals, is distinctly affected in the SCG (A,B), SG (C, D), and CG (E, F) of NT-4 mutant mice. SV2-IR is localized in structures, presumed axon terminals on dendrites, surrounding the large cell bodies of sympathetic ganglion cells, which exhibit only background fluorescence. SV2-IR is clearly reduced in axon terminals of the SG and CG, but not the SCG, ofNT-4-deficient mice (B, D,F) compared with wild-type littermates (A, C, E). Scale bar, 100 μm.