BDNF signaling could be rapidly transmitted from the BLA to IL. A, B, Microinfusion of BDNF into the BLA-induced rapid TrkB activation in the IL (within 20 min). The increased p-TrkB levels in the IL upon BLA BDNF infusion could be blocked by IL BDNF-neutralizing antibody administration. A, Representative immunoblots. B, Relative densitometric analysis. The p-TrkB/TrkB ratio is normalized to the vehicle group (n = 3 per group). *p < 0.05, compared with the vehicle group (one-way ANOVA). ^#p < 0.05, compared with the BLA BDNF + IL vehicle group (one-way ANOVA).