To determine whether the p75NTR signaling pathway participates in the PM pathogenesis, regulates p75NTR can directly affect the clinical and pathological severity post-infection, the rats were pretreated with a small-molecule p75NTR signaling modulator, LM11A-31, once daily for 3 consecutive days prior to S. pneumoniae inoculation. The gene discussed is NGFR; the disease is infection.