(ORDO NEWS) — American biologists have found that the neurons responsible for the production of dopamine decide for themselves when and how much to release this pleasure hormone into the brain, and do not rely on signals coming from neural networks, as was previously thought. The results of the study are published in the journal Cell Reports.
The hormone dopamine is one of the most important neurotransmitters, a key element of the brain’s “reward system”. It influences the processes of motivation and learning, providing a sense of anticipation of pleasure. On the other hand, the death of dopamine neurons is one of the reasons for the development of Parkinson’s disease. All this forces biologists to study these cells especially carefully.
Until now, it was believed that the release of dopamine in specific neurons depends on messages from neighboring cells, but scientists from the Grossman School of Medicine at New York University, in collaboration with colleagues from other institutions, have found that self-regulation plays a central role in this process.
“Our results are the first evidence that dopamine neurons regulate themselves in the brain,” lead author Takuya Hikima of the NYU Langone Health Department of Neurosurgery, an academic medical center in New York, said in a press release from the School of Medicine. York.
The study was started because previous views on the mechanism of dopamine release raised too many questions. First, for one cell to be able to control its neighbor with dopamine, too many synapses or connections are required through which two cells meet and exchange messages. Dopamine neurons do not have enough synapses for this.
Second, it is known that many types of cells that produce hormones in the body use a self-regulating system that is simpler than a system for transmitting signals from neighboring cells.
To prove that dopamine neurons use the same system, the authors conducted an original experiment. They injected some brain cells with botox, a toxin that blocks nerve cells from sending chemical messages to neurons and other cells, and observed whether these cells continued to produce dopamine.
It turned out that the “paralyzed” cells stopped producing the hormone, despite the fact that they continued to receive signals from “healthy” neighboring cells. From this, the researchers conclude that the process of dopamine production is self-regulating. If it were controlled by neighboring dopamine cells, then the release of the hormone would not be affected, because the treated cells would still receive signals from the untreated ones nearby.
In the future, the researchers intend to study how dopamine self-regulation is associated with neuronal death in Parkinson’s disease.
“Now that we better understand how these cells behave when they are healthy, we can begin to unravel the mystery of why they are destroyed in neurodegenerative disorders like Parkinson’s,” says Hikima.
The authors also plan to study the relationship between the activity of dopamine neurons with other factors, for example, with the release of calcium.
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