Atlas of Science о статье Е.А. Будыгина

Дата: 
07/04/2017
Sugar consumption can be reduced by tonic activation of dopamine reward pathway.
 
Rewarding ( pleasurable ) and aversive events give us dissimilar perceptions, which powerfully shape our decisions and therefore behavioral outcomes. In fact, chemical changes, which take place in our brain, are very different under these opposite circumstances. Dopamine is a natural substance that belongs to a class of molecules called neurotransmitters whose role is to mediate communication between nerve cells in the brain. A number of previous studies have shown that dopamine release in a small brain region called the “nucleus accumbens” causes, or at least is coincident with, feelings of pleasure and reward. Therefore, dopamine is often thought of as the “reward chemical”. A number of recent studies have revealed that increases in dopamine release within nucleus accumbens are critical for triggering behaviors directed at obtaining drugs of abuse, like cocaine, and natural rewards, like sweet tastants. However, this increased release needs to occur with a specific pattern, characterized by rapid, transient and relatively large rises in extracellular dopamine concentrations. This happens when the cells that release dopamine fire at high frequencies (>30 Hz). Recently, we demonstrated that if dopamine cells are experimentally driven to fire at a low frequency (5 Hz) for a relatively long time (minutes), dopamine is released with a very different pattern (lower concentrations which persists for a longer time). Interestingly, we discovered that this low frequency dopamine signaling, termed “tonic” release, dampens alcohol intake in rats, possibly by preventing the large, transient dopamine spikes that are associated with drug and alcohol consumption. In this study, we explored whether driving dopamine activity into this tonic mode affects natural reward consumption in a similar fashion.
 
Alex Deal, Maria Mikhailova, Jeff Weiner, Raul Gainetdinov, Evgeny Budygin
Wake Forest School of Medicine, Winston Salem, NC, USA
Institute of Translational Biomedicine, St. Petersburg State University, Russia