After cocaine, nerve cells send signals that intensify cravings
One way to control cravings for cocaine may be to reverse a process that allows nerve cells to mature and send signals that intensify the urge to use the drug.
Researchers used rats to examine the effects of cocaine addiction and withdrawal on nerve cells in the nucleus accumbens, a small region in the brain that is commonly associated with reward, emotion, motivation, and addiction. Specifically, they investigated the roles of synapses—the structures at the ends of nerve cells that relay signals.
When an individual uses cocaine, some immature synapses are generated, which are called “silent synapses” because they send few signals under normal physiological conditions. After quiting cocaine, these “silent synapses” go through a maturation phase and acquire the ability to send signals.
The synapses will then send craving signals for cocaine if the individual is exposed to cues that previously led him or her to use the drug.
The researchers hypothesize that if they could reverse the maturation of the synapses, the synapses would remain silent, thus rendering them unable to send craving signals. They examined a chemical receptor known as CP-AMPAR that is essential for the maturation of the synapses. In their experiments, the synapses reverted to their silent states when the receptor was removed. Their findings appear in Nature Neuroscience.
“Reversing the maturation process prevents the intensification process of cocaine craving,” says Yan Dong, a neuroscience professor at the University of Pittsburgh who led the research team. “We are now developing strategies to maintain the ‘reversal’ effects.”
The National Institutes of Health’s National Institute on Drug Abuse and the German Research Foundation supported the study.
Source: University of Pittsburgh