BDNF and chronic cystitis: Intrathecal injection of BDNF (3 ng/10 μL/rat, every other day for one month) to rats with CYP-induced cystitis enhanced the activation of astrocytes and microglia to release pro-inflammatory cytokines such as TNF-α and IL-1β, exacerbating neuroinflammation and resulting in mechanical allodynia through BDNF-TrkB-p38/JNK signaling [239].