Response to "Route of IL-4 administration in Li et al.: an inconsistency between the methods and Section 4.4".

In response to the Letter by Song and Luan, we clarify the route and rationale of interleukin-4 (IL-4) administration in our published study. Recombinant mouse IL-4 was administered intracerebroventricularly as a mechanistic intervention to engage central IL-4/STAT6 signaling, whereas the reference to systemic administration in Section 4.4 was intended to describe systemic CGRP receptor blockade. We further clarify the intracerebroventricular procedure, including guide cannula implantation, anesthesia, recovery, and subsequent IL-4 administration. We also acknowledge that the non-IL-4 groups did not undergo matched guide-cannula implantation or intracerebroventricular vehicle administration, which represents a limitation when interpreting the in vivo effects specifically associated with IL-4. These clarifications define the appropriate scope of interpretation of the in vivo IL-4 findings.