Four days ago, the 32nd Annual Research Society on Alcoholism meeting commenced with an opening reception on the USS Midway docked in the San Diego Harbor. The massive ship was utilized as a maritime airport (i.e. planes were housed and a landing strip was provided) during the Vietnam War. In addition to having worldly themed hors devours, my lab mates and I rode a flight simulator which mimicked the taking off, combat, and landing of an F-16 during the Gulf War.
On Sunday, the symposia, plenary, and posters began. Eliana Howard, a recent doctoral graduate from the University of Texas, presented interesting work on dopamine release in the central drug reward circuit in the brain that is closely associated with alcohol use. In addition to viewing a video in which a rat licked its water bottle 1300 times (yes, I have the correct amount of zeros) in 5 minutes during limited access to alcohol, I learned about a new neuroanatomical “zone:” the shell-core border in the nucleus accumbens. For background, the nucleus accumbens is a structure within the central reward circuit that is divided into two distinctive areas—the shell and the core. It appears, however, that dopamine neurotransmission within these two areas is quite different from dopamine neurotransmission in areas bordering the shell and the core. Hence, the name shell-core border. This disparity was confounding for Eliana as it yielded significance or insignificance if the probe was or wasn’t within the border zone, respectively!
Yesterday, I went to two 2-hour symposia on the associated role of glutamate in alcohol dependence, addiction, relapse, and recovery. Alcohol-induced blockades of glutamate release not only determine one’s sensitivity to the intoxicating effects of alcohol and subsequent drive to consume more, but also determine the severity of withdrawal. Glutamate neurotransmission during alcohol withdrawal is vastly different from alcohol use; glutamate inhibition is reversed, and more glutamate is released relative to before alcohol use. This effect, in turn, facilitates neurotoxicity: the death of neurons from over-stimulation by glutamate (this is why MSG, an additive in Chinese food, is unhealthy. It does kill brain cells!). Though there were many discussions in today’s symposia over the time-course of glutamate release during this withdrawal period and additionally, the efficacy of glutamate antagonists currently available for recovering alcoholics, there certainly is no question that glutamate is critically involved.
Until next time, ask for NO MSG. Your brain will be happy.