Fig. 4
From: CGRP-dependent sensitization of PKC-δ positive neurons in central amygdala mediates chronic migraine
CGRPR antagonist microinfusion in the CeA. A Schematic illustration and the experimental timeline of bilateral CGRP8–37 or saline microinfusion in the CeA. B Representative images of the cannulas injection sites, confirming the correct injection of CGRP8–37 or saline at bilateral CeA. a: cannula tract. Scale bar: 200 μm. C Chronic CGRP8–37 infusion persistently alleviated NTG induced mechanical hyperalgesia (n = 4 per group; p < 0.05 *). D Representative images of rostral-caudal distribution of colocalized pERK- and PKC-δ- positive neurons in the CeA. Scale bar: 100 μm. E Schematic illustration of the rostro-caudal anatomical location of CeA relative to the position of bregma. F After CGRP8–37 infusion, the numbers of pERK positive neurons in the CeA were significantly lower than those in the saline group (n = 4 per group; p = 0.011). G Rostro-caudal distribution of the percentage of pERK positive neurons colocalized with PKC-δ positive neurons in the CeA (left, n = 4 per group; − 1.82 mm; p = 0.005; − 1.94 mm; p = 0.013); the percentage of pERK/PKC-δ positive neurons of the entire CeA was significantly lower in the CGRP8–37 treatment group than that in the saline group (right, n = 4 per group; p < 0.0001). H Rostro-caudal distribution of the percentage of PKC-δ positive neurons colocalized with pERK positive neurons in the CeA (left, n = 4 per group; − 1.82 mm; p = 0.014); the percentage of PKC-δ/pERK positive neurons of the entire CeA was significantly lower in the CGRP8–37 treatment group than that in the saline group (right, n = 4 per group; p = 0.0007). All data shown are mean ± SEM and analyzed by Friedman tests with Dunn’s post hoc test (C) or Mann-Whitney U test (F-H). Significance levels set at p < 0.05 *, p < 0.01 **, and p < 0.001 ***