Brain Serotonin Transporter in Human Methamphetamine Users

Kish, S., Fitzmaurice, P., Boileau, I., Schmunk, G., Ang, L., Furukawa, Y., & ... Tong, J. (2009). Brain serotonin transporter in human methamphetamine users. Psychopharmacology, 202(4), 649-661. Retrieved from EBSCOhost. doi:10.1007/s00213-008-1346-x

Chapter 8 of our textbook discusses amphetamines and how they release dopamine into its synapse and also block the reuptake of dopamine.  Methamphetamine, which is an illegal amphetamine, is easy to make and is very intoxicating.  Due to the fact that it is inexpensive and easy to obtain, this drug can potentially be extremely devastating.  In the current study, the researchers discuss how methamphetamine usage can damage not only dopamine neurons but serotonin neurons as well.  Many previous research studies have suggested that problems in cognition and aggression may be due to the reduction of serotonin levels.  There was not much research conducted on protein levels of the serotonin transporter (SERT) in methamphetamine users, so the purpose of this study was to determine if there was a decrease in protein levels of the serotonin transporter (SERT) in the brains of chronic methamphetamine (MA) users.  Post-mortem brains were used in this study with 24 controls and 16 chronic users of MA.  Blood samples and scalp hair samples were obtained from the majority of the post-mortem brains.  All of the control brains were neurologically normal and tested negative for drugs of abuse.  All of the brains of chronic MA users tested positive for the presence of MA.  SERT immunoreactivity was measured using an immunoblotting procedure in the brains of chronic MA users.  The researchers found that there was a significant decrease in SERT levels in the orbitofrontal and occipital cortices.  There were other areas, such as the caudate, putamen, and thalamus, that showed a decrease in SERT levels, but it was not a significant decrease.  By conducting this study, the researchers found that in chronic MA users, SERT is somewhat decreased in the brain but that there is a much more significant decrease in dopamine levels.