Exposure to cocaine leads to significant changes in the mitochondria of certain brain cells, new research reports. They are now investigating whether these changes play a hand in shaping addiction, for both cocaine and other classes of drugs.
We’ve known that mitochondria embedded in brain cells play a role in brain disorders ranging from depression, generalized anxiety, and exaggerated stress responses, all the way to bipolar disorders. New research by scientists at the University of Maryland School of Medicine (UMSOM) has found that cocaine use also brings about changes in the little cellular powerhouses, with currently-unknown effects.
The team discovered the changes while working with mice. After repeated exposure to cocaine, cells in the rats’ reward pathways (nucleus accumbens, NAc) showed an increase in dynamin-related protein-1 (Drp1), the molecule that underpins mitochondrial division (fission). Higher levels of Drp1 in the mice’s NAc area caused mitochondria to divide — and thus multiply — faster.
[Read More] If you want to freshen up on your brain anatomy and see exactly where the NAc is, take a minute to peruse 3D Brain.
Such changes could, in turn, explain the chemical fluctuations we’ve seen in the brains of addicts. They report having successfully blocked these changes using a chemical dubbed Mdivi-1. Furthermore, they also blocked responses to cocaine by genetically manipulating the fission molecule within the mitochondria of brain cells.
“We are actually showing a new role for mitochondria in cocaine-induced behavior, and it’s important for us to further investigate that role,” said Mary Kay Lobo, Associate Professor of Anatomy and Neurobiology and corresponding author on the paper.
The team later harvested post-mortem brain tissue samples from individuals with a documented cocaine addiction to confirm that the changes also take place in human brains. Dr. Lobo says these findings could help us better understand how addiction impacts the brain, both from cocaine and other addictive substances.
“We are interested to see if there are mitochondrial changes when animals are taking opiates. That is definitely a future direction for the lab,” she added.
The paper “Drp1 Mitochondrial Fission in D1 Neurons Mediates Behavioral and Cellular Plasticity during Early Cocaine Abstinence” has been published in the journal Neuron.