TRH and Parkinson disease: TRH and its analogs reveal neurotrophic and anti-apoptotic effects by counteracting the toxic effects of various cytotoxins in PD cellular models (Jaworska-Feil et al., 2010) via anti-apoptosis, inhibiting the activity of glycosynthase kinase-3β (GSK-3β), decreasing the phosphorylation level of tau (Luo and Stopa, 2004), protecting against Aβ toxicity and reducing the production of inflammatory cytokines TNF-α and IL-6 in vitro (Faden et al., 2005).