Cutamesine dihydrochloride (SA4503 dihydrochloride; AGY94806 dihydrochloride) is a potent Sigma 1 receptor agonist with an IC₅₀ of 17.4 nM in guinea pig brain membranes. IC50 & Target: IC50: 17.4 nM (σ1receptor, guinea pig brain membranes)^[1] In Vitro: The sigma receptor might be involved in several diseases in the central nervous system. Cutamesine, a potent σ1receptor agonist, has 103-fold higher affinity for σ1 (IC₅₀=17.4 nM) than σ2 (IC₅₀=1,784 nM) sites in guinea pig brain membranes. Cutamesine is 14-fold selective for σ1 (K_i=4.6 nM) over σ2 (K_i=63.1 nM) sites in guinea pig brain homogenates^[1]. Cutamesine protects motor neuron NSC34 cells against superoxide dismutase 1 and serum free neurotoxicity. It upregulates the phosphorylation levels of Akt and extracellular signal-regulated kinase (ERK) 1/2^[2]. Cutamesine reduces the activation of the MAPK/ERK pathway and down-regulated the ionotropic glutamate receptor, GluR1^[3]. In Vivo: Cutamesine extends the survival time in the SOD1G93A mice^[2].