Figure 4. Simplified scheme of the complex interactions between CAs, neuropeptides and the CRH/SP-mast cell-histamine axis, and their pro- and anti-inflammatory effects in certain local responses (see text). Solid lines represent stimulation, while dashed lines inhibition.Abbreviations: CGRP, calcitonin gene-related peptide; CRH, corticotropin-releasing hormone (peripheral); EPI, epinephrine; IL, interleukin; NE, norepinephrine; SP, substance P; TNF, tumor necrosis factor.