TRPV1 and Parkinson disease: However, another study showed that TRPV1 is upregulated in the hippocampus and prefrontal cortex of 6‐hydroxydopamine (6‐OHDA)–treated mice, another PD animal model, and both EA treatment and rivastigmine reduce this upregulation, normalize plasma levels of inflammatory cytokines (e.g., IL‐1β, TNF‐α, IL‐6), and improve cognitive performance [120].