Long COVID may involve loss of dopamine-releasing neurons, study says
- Brain scans of 24 people with long COVID reveal signs of potential injury to dopamine-releasing neurons, according to a peer-reviewed study published in the journal eBioMedicine.
- The study utilized positron emission tomography alongside a radioactive tracer to evaluate a specific marker of dopamine nerve endings in the brain.
- Study author psychiatrist Jeffrey Meyer from the Brain Health Imaging Center in Canada suggested that dopamine-releasing neurons may be damaged or lost in some people suffering from long...
Brain scans of 24 people with long COVID reveal signs of potential injury to dopamine-releasing neurons, according to a peer-reviewed study published in the journal eBioMedicine. Canadian researchers using positron emission tomography found a lower signal for a dopamine nerve-ending marker across several areas of the striatum in patients experiencing persistent, debilitating symptoms after clearing an initial SARS-CoV-2 infection. ScienceAlert reported that the signal reduction was associated with higher levels of apathy, cognitive complaints, poorer memory test results, and slower performance on motor and reading tasks.
PET Scans Reveal Dopamine Deficits in Patients
The study utilized positron emission tomography alongside a radioactive tracer to evaluate a specific marker of dopamine nerve endings in the brain. Researchers focused on the striatum, a structure involved in regulating motivation, movement speed, and memory. While none of the 24 participants had an active SARS-CoV-2 infection at the time of the scans, all reported lingering cognitive and physical impairment. As a group, they performed worse on memory and movement speed tests than healthy control participants of the same age. According to findings highlighted by UA.News, about 25 percent of the variation in individual symptoms among the participants could be associated with these altered dopaminergic nerve ending indicators.
Long COVID Involves Loss of Dopamine-Releasing Neurons
Study author psychiatrist Jeffrey Meyer from the Brain Health Imaging Center in Canada suggested that dopamine-releasing neurons may be damaged or lost in some people suffering from long COVID.
Our findings provide compelling evidence that long COVID involves the loss of dopamine-releasing neurons.
Jeffrey Meyer
Meyer noted that this specific type of injury is well recognized for producing symptoms like lack of motivation and motor slowing in other neurological conditions. While previous research among people with long COVID has largely concentrated on brain inflammation and immune system changes, this study points directly toward functional disruption within the brain’s dopamine pathways. The authors proposed two theoretical mechanisms for the damage: either SARS-CoV-2 directly infects dopamine-producing neurons due to a high density of compatible receptors, or elevated markers for brain cells that prune back synapses cause damage to the circuits.
Preliminary Findings Require Larger Groups to Confirm Results
Because PET scanning measures a specific protein located at nerve endings rather than counting neuron density directly, the authors emphasized that their conclusions remain preliminary. The findings indicate an association between lower dopamine markers and specific symptoms, but the study does not establish a definitive causal relationship. Future investigations will require larger, controlled groups to confirm the robustness and generalizability of the results across wider populations. Although the study authors hypothesized that drugs affecting the dopamine system might eventually offer therapeutic value for certain patients, they cautioned that such medications can carry significant side effects. Study author Jeffrey Meyer has a patent application for a dopamine-related method of treating long COVID.