Figure 3.

In the ICc, commissural projections of NPY neurons are more heterotopic than those of non-NPY neurons. The panel shows results from five cases where injections were predominately limited to the ICc. (A) RB deposit site in the right IC and homotopic site in the left IC in experimental Case 25. The right half of the panel includes a gray-scale image showing the center of the RB deposit (circled in gold). The left half of the panel shows an outline of the left IC with the homotopic location of the injection site indicated by a reflected image of the gold outline. The illustrated section (*) is from a series of sections shown in (B). (B) The full series of plots for Case 25 showing the distributions of RB-labeled (commissural) neurons that were NPY+ (magenta triangles) or non-NPY (cyan squares). Sections are numbered from caudal to rostral in each series. The asterisk indicates the section shown in (A) with the area homotopic to the injection outlined in gold. D—dorsal; L—lateral. (C–J) Results from four additional experimental cases, displayed as in (A,B). The locations of the RB deposits in the ICc varied across cases, but the differences in distributions of NPY vs. non-NPY commissural cells were consistent: the NPY cells were less focused in the homotopic site.The main pattern of non-NPY neuron labeling in the ICc was often consistent with the shape of a frequency band, while NPY+ neurons were more common in regions bordering the frequency band. (B) n = 898 non-NPY neurons, 168 NPY neurons. (D) n = 573 non-NPY neurons, 86 NPY neurons. (F) n = 782 non-NPY neurons, 135 NPY neurons. (H) n = 1,095 non-NPY neurons, 161 NPY neurons. (J) n = 1,172 non-NPY neurons, 226 NPY neurons.