Fig. 2.

Comparison of GFP and GnRH expression in GnRH-GFP transgenic mice. A, GFP-expressing neurons, numbered1–11, near the DBB-POA border at the level of the OVLT from the same mouse as in Figure 1A but 300 μm more rostral. The optic chiasm is missing because it detached from the rest of the tissue during slicing. B, Same slice as inA after fixation, which produced additional fluorescence, and after mounting, which flattened the tissue and thereby changed the relative positions of the neurons. Scales inB–D are the same as in A.C, Same slice as in B after immunostaining for GnRH. GnRH-immunopositive neurons are numbered 1–19. The gray levels in this panel and in Figure 3D have been inverted to aid the reader in visualizing the GnRH immunostained neurons, which appear asdark spots. Note that all fluorescent neurons inB are GnRH-immunopositive in C and that the number of GnRH-immunopositive neurons is larger than the number of fluorescent neurons. D, Same slice as inA after biocytin labeling of neuron 1.