Phencyclidine increases the extracellular acetylcholine level in the rat parietal cortex partly through sigma receptors

The effects of sigma receptor antagonists on phencyclidine (PCP)-induced increase in the extracellular acetylcholine (ACh) level in the rat parietal cortex were examined in freely-moving rats by using the in vive brain microdialysis method. PCP increased the extracellular ACh level in a dose- dependent manner. The effect of PCP was diminished by the pretreatment with sigma receptor antagonists, N,N-dipropyl-2-[4-methoxy-3-(2-phenylethoxy) phenyl]-ethylamine monohydrochloride (NE-100). These results suggest that PCP-induced increase in the extracellular ACh level in the rat parietal cortex is partly mediated by sigma receptors.