Selective Lesioning of Nuclear Factor-κ B Activated Cells in the Nucleus Accumbens Shell Attenuates Alcohol Place Preference

Abstract

Nuclear factor κ -light chain enhancer of activated B cells (NF-κ B) is a transcription factor commonly associated with innate immunity and is activated by infection and inflammation. NF-κ B has recently gained attention as a mediator of complex psychiatric phenomena such as stress and addiction. In regards to alcohol, most research on NF-κ B has focused on neurotoxicity and few studies have explored the role of NF-κ B in alcohol reward, reinforcement, or consumption. In these studies, we used conditioned place preference to assess the activity of NF-κ B in response to rewarding doses of alcohol. To measure NF-κ B activity we used a line of transgenic mice that express the LacZ gene under the control of an NF-κ B-regulated promoter. In these animals, staining for β-galactosidase (β-gal) identifies cells in which NF-κ B has been activated. We then used the Daun02 inactivation method to specifically silence NF-κ B-expressing cells during place preference conditioning. Daun02 is an inactive prodrug that is converted to the inhibitory molecule daunorubicin by β-gal. After alcohol place conditioning, we observed increased β-gal staining in the nucleus accumbens (NAC) shell and dorsal raphe nucleus, and found that disruption of NF-κ B-expressing cells using Daun02 attenuated the development of alcohol place preference when infused into the NAC shell following conditioning sessions. We found this effect to be regionally and temporally specific. These results suggest that, in addition to its role in alcohol-induced neurotoxicity, NF-κ B mediates the development of alcohol place preference via its actions in the NAC shell.