Cocaine changes brain to seek more
Cocaine triggers rapid growth in brain structures tied to memory and learning, but only in a way that helps the user seek out more cocaine, according to a study in mice published in the journal Nature Neuroscience. Researchers say that the cocaine users were much better able to find enclosures where they had received cocaine than mice who hadn’t.
For the study, researchers split the mice into two groups. One group received cocaine injections and the other group was given saline injections. Then researchers observed the mice's living brain cells using a 2photon laser-scanning microscope. Immediately the mice that had received cocaine began to grow more new dendritic spines than those in the saline group. Dendritic spines are key for signaling, and pass messages from one nerve cell to another.
In addition, researchers found a link between increased dendritic spine density in the frontal lobe and drug-associated learning. Long-term drug use actually shows a decrease in frontal cortex function when it comes to mundane cues or tasks, but an increase in function when responding to information or activity related to the drug.
The frontal cortex is responsible for behaviors that involve higher reasoning and discipline, such as long-term planning and decision-making. Researchers say that because the frontal cortex is akin to the "steering wheel" of our brain, it may bias decision-making towards drugs when affected by cocaine.