Long COVID linked to dopamine neuron injury
Long COVID may damage dopamine-releasing neurons in the brain, potentially explaining persistent fatigue, reduced motivation, slower movement and memory difficulties, according to a new Canadian study, reports a Qazinform News Agency correspondent.
Researchers at the Centre for Addiction and Mental Health used positron emission tomography scans to examine a marker associated with dopamine neuron integrity in people with long COVID and healthy participants.
The study, published in eBioMedicine, found significantly lower levels of the marker across major regions of the striatum, an area involved in motivation, movement and thinking. The findings indicate reduced density of dopamine nerve terminals.
Lower marker levels in the ventral striatum were linked to a greater loss of motivation. Reductions in the dorsal putamen were associated with slower movement, while changes in the caudate putamen were connected to memory difficulties.
“Our findings provide compelling evidence that long COVID involves the loss of dopamine-releasing neurons,” said senior author Dr. Jeffrey Meyer. “Our results suggest a similar process is occurring in long COVID.”
The findings build on earlier research by the same team that detected elevated brain inflammation in regions rich in dopamine neurons.
“We know that inflammation can injure dopamine neurons,” Meyer said, adding that the latest study showed a reduction in the dopamine neuron marker in the same areas.
Researchers said the results suggest long COVID is, at least partly, a disorder of the brain’s dopamine system. Medications that strengthen dopamine function, including dopamine precursors and inhibitors of dopamine metabolism, could therefore offer a possible treatment strategy.
The team plans to launch a clinical trial with University Health Network to determine whether targeting dopamine function can improve fatigue, memory and motivation in people with long COVID.
Earlier, Qazinform News Agency reported that scientists at Stanford University had created mice whose brains contained millions of functioning human neurons, providing a new model for studying neurological disorders and potential treatments.
