Alcohol-related olfactory cues may be powerful appetitive cues, particularly because they are present both before (nasally) and during drinking (retronasally). This would make them effective conditioned cues for alcohol’s immediate reward (Grüsser et al., 2000; Rohsenow et al., 1997). It is known that peripheral acute injection of LPS induces neuronal apoptosis in the olfactory bulb in mice (Mori et al., 2010) and changes the dopamine content in the anterior olfactory nucleus (Ota et al., 2008). Therefore, these degenerative changes might modify the olfactory perception of ethanol and change ethanol intake. However, LPS injection did not alter the perception of ethanol smell in different olfactory tests. Taken together, these data show that LPS effects on sensory perception of ethanol cannot explain the excessive alcohol consumption.
