Fig. 3: The whole-brain inputs of CeA-CRF neurons have a centralized distribution pattern.

a The input strength was defined as the number of input neurons divided by the number of starter neurons to normalize the variation in the number of starters between each case. The input strengths and variabilities in 44 nested anatomical subregions grouped by gross anatomical regions are shown. Notably, more than half of the input subregions were in the cortical plate (CTXpl) and Striatum (STR, 23 out of 44, 52.27%), and the input strengths in the AI, PIR, CP, and CeA were higher than those of other subregions. b The input strengths in each anatomical region and their variability are shown. The input strengths of CTXpl and STR were nearly three-quarters of the sum of all regions (74.13 ± 1.74%). c The input strengths (thick line) and the corresponding s.e.m (shadow) of inputs from anterior-to-posterior throughout the brain are shown. The inputs were centrally distributed, such that most of the input strength (73.54 ± 2.96%) was situated between bregma 0 and 3.0, and the maximum value of input strength was at bregma −1.4 (2.00 ± 0.22), where the amygdala is located. These results suggest that the axonal innervation of input neurons onto CeA-CRF neurons was mainly concentrated around the amygdala, and that it was gradually weakened by this boundary. d The percentages of input strengths in several subregions, including the amygdala (16.90 ± 2.41%), PIR (11.94 ± 3.63%), AI (12.28 ± 1.55%), and CP (9.51 ± 3.04%). The combined percentage of input strengths from these regions exceeded 50%. e The inputs located in the amygdala were distributed from bregma −0.4 to −3.4, and the maximum input strength was at bregma −1.4 (0.67 ± 0.07%). f The distribution of inputs in the PIR ranged from bregma 2.0 to −3.4, and the maximum input strength was at bregma −1.4 (0.24 ± 0.10%). g The inputs in the AI were distributed from bregma 2.6 to −2.0, but there were two peaks at bregma 1.0 (0.29 ± 0.03%) and −1.0 (0.19 ± 0.03%). h In the CP subregion, inputs were distributed from bregma 0.2 to −2.4, and bregma −1.6 was the location of maximum input strength (0.38 ± 0.17%). The line refers to the mean input strength, and the shadow refers to the corresponding s.e.m. (e–h). i The input regions was grouped into the top–down, intra-amygdala, and bottom–up groups according to the relative positions between the input regions and the start region, CeA (the grouping of subregions is detailed in Supplementary Table 1–3). The input strength in the top–down group was significantly larger than that of the other two regions. (F (2, 12) = 72.88, p < 0.0001, one-way ANOVA with Tukey correction). j The input strength was defined as the number of input neurons divided by the number of starter neurons, which also represents the input patterns of these brain regions. The brain regions with input strengths greater than a value of 1.0 were designated to the convergent group, which indicated that more than one input neuron in these regions may innervate a single starter neuron in the CeA. k On the contrary, the brain regions in the diffuse group were defined as those with an input strength value of <1.0, which demonstrated that an individual input neuron in these regions may innervate multiple starter neurons in the CeA. l Most of the inputs in top–down regions converged onto a single starter neuron in the CeA. The percentages of convergent input patterns in the subregions of top–down (66.67%), intra-amygdala (20.00%,) and bottom–up (13.33%) groups are shown. m In contrast, the inputs in bottom–up regions diffused into more than one starter neuron in the CeA. The percentages of diffuse input patterns in the subregions of top–down (44.83%), intra-amygdala (6.90%), and bottom–up (48.28%) groups are shown. Data are mean ± s.e.m., N = 5.