New York, NY – Scientists in New York have made a groundbreaking discovery that sheds light on how addictive drugs like cocaine and morphine can override our natural instincts for essential needs such as food and water. This finding could pave the way for innovative treatment strategies to combat addiction.
Researchers from Rockefeller University and the Icahn School of Medicine at Mount Sinai utilized mouse models to investigate how cocaine and morphine affect the brain’s reward circuits, typically activated by hunger and thirst. According to neuroscientist Jeffrey Friedman, addictive drugs impact neural activity in these pathways in distinct ways, leading to a disruption in normal behavior.
Using a comprehensive approach that involved mapping brain activity, imaging neurons in live mice, and altering genetic activity with CRISPR technology, the team found that the nucleus accumbens (NAc) in the brain plays a significant role in both natural functions and drug rewards. Neurons from the orbitofrontal cortex were identified as the key players in diminishing the desire for natural rewards when activated by drug use.
Neuroscientist Bowen Tan emphasized the importance of the NAc in directing animals’ behaviors towards their goals. He highlighted how repeated drug exposure alters these neurons, resulting in heightened drug-seeking behaviors and a shift away from healthy activities.
Further studies revealed that cocaine and morphine activate specific subsets of neurons in the mouse NAc, which overlap with neurons responsive to natural rewards. However, these overlapping neurons exhibited increased activity with drug use compared to when exposed to food or water. This shift in behavior, where mice became more interested in drugs and less interested in essential needs, was observed over time.
Researchers also identified a protein encoded by the Rheb gene that disrupts normal neuron communication, altering how the brain processes rewards from food and water. This finding suggests that pathways associated with this protein could be potential targets for addiction therapy.
The implications of this research extend to the development of more effective treatments for addiction, which currently lack sufficient options. Mount Sinai neuroscientist Eric Nestler highlighted the need for ongoing research to understand how addictive drugs manipulate neural pathways, leading to addiction and the hijacking of natural reward processing.
The findings from this study were published in the journal Science, offering valuable insights into the complex mechanisms underlying addiction and providing a foundation for future research in this field.