Fig. 2.

Immunofluorescence image showing abundance of Cx34.7/Cx35 puncta in horizontal sections at a rostral level of goldfish hindbrain and at a dorsal-ventral level of the Mauthner cell (M-cell). Some of the images are shown with blue fluorescence Nissl counterstaining. (A) Low magnification bilateral overview (dotted line indicates midline), showing a high density of immunofluorescent puncta associated with M-cell lateral dendrites (arrows), and similarly dense puncta at more rostral (single asterisk) and caudal (double asterisk) regions to the M-cell, including labeling along bundles of laterally directed dendrites (arrowheads). (B) Magnification of M-cell dendrite, showing numerous patches of labeling (arrows) localized to the dendritic surface. (C,D) Rostral and caudal regions indicated by single and double asterisks in A are shown in C and D, respectively, but taken from different sections and magnified. At the rostral level, groups of large neurons on either side of the midline are outlined by labeling of Cx34.7/Cx35 puncta on their somata and dendrites (C, arrows). At the more caudal level shown unilaterally, large neurons located medially (D, upper arrow, in boxed area) and medium size neurons located laterally (D, lower arrow) are heavily laden with punctate labeling (widefield multiple scan Z-stack). (E,F): Higher-magnification confocal scans of boxed areas in C and D, respectively, showing exclusively punctate appearance of labeling associated with neuronal somata (arrows). Image in F (from box in D) is magnified still further in Figure 8A. Calibration bars are labeled individually on each image.