Human amygdala reactivity is diminished by the β-noradrenergic antagonist propranolol

Human amygdala reactivity is diminished by the β-noradrenergic antagonist propranolol
Hurlemann, R., Walter, H., Rehme, A. K., Kukolja, J., Santoro, S. C., Schmidt, C., Schnell, K., Musshoff, F., Keysers, C., Maier, W., Kendrick, K. M., & Onur, O. A. (2010).  Psychological Medicine 40(1839-1848).  Retrieved from Psychology Journals.  doi:10.1017/S0033291709992376

I chose the article “Human amygdala reactivity is diminished by the β-noradrenergic antagonist propranolol” for the chapter on drugs.  In this study, the researchers wanted to see if propranolol would diminish activation of the basolateral(BLA) complex of the amygdala.  Eighteen healthy adults were recruited for this experiment.  They were screened and determined free of current or past medical, neurological, or psychiatric disorders.  The neuropsychological screening included:  the Mehrfachwahl-Wortschartz-Intelligenztest estimating verbal IQ, Rey Auditory Verbal Learning Test assessing verbal learning and memory, and the Trail Making Test examining motor speed and visual attention.  Facial emotion recognition was assessed with the Facial Expressions of Emotions: Stimuli and Test (FEEST).  Participants were to sleep at regular times and to abstain from nicotine and alcohol the day before fMRI scans.

Participants were either given a dose of propranolol or a placebo before the fMRI scans.  Participants were exposed to fifteen pseudorandom movies displaying either neutral, fearful, or happy facial expressions.  The movies were played twice over a twenty minute period.  Results indicated that propranolol reduces human BLA responses to fearful, happy, and neutral facial expressions.  Results suggest that propranolol is analogous to a light switch to the BLA.  Other studies conducted helped show that norepinephrine could be a key modulator of BLA response sensitivity.  So what does this research mean for us?  This is useful information when it comes to anxiety disorders and it might help with people calming down when feeling overstressed.