In the substantia nigra pars compacta (SNc), an area of the brain that plays roles in the processing of movement as well as reward responses, a team of bold researchers from Northwestern University in the US have recently discovered three unique subtypes of dopamine-reactive neurons. It is possible that the discovery does not come as a total surprise in all respects. Still, it is important to remember that the area known as the substantia nigra is the primary site of Parkinson’s disease. Apparently, dopamine-sensitive neurons are involved with the condition’s characteristic symptoms, which include tremors, slowness, and stiffness – these are also related to the death of the neurons.
Check out all the intriguing findings below.
Researchers have hypothesized that the nerve cells that respond to this euphoric hormone exist in more than one type and that some of these nerve cells may be involved in processes that are not directly related to the experience of reward. But how exactly?
[the subtypes] sit right where dopamine neurons first die in Parkinson’s disease; […] that seems to suggest that there’s some genetic subtype that’s more susceptible to degradation over time as people age, explained Daniel Dombeck, a neurobiologist, the co-leader of the study.
To verify that hypothesis, the study team concentrated on three critical genes that are known to work within the cells. These genes are Slc17a6, Calb1, and Anxa1. They tagged transgenic mouse neurons in an approach that would enable them to light when each of the genes was active. The findings are genuinely intriguing!
It was discovered that around thirty percent of the neurons that are sensitive to dopamine were activated whenever the mice moved. This meant that the rest of the nerve cells were responsible for responding to either rewarding or unpleasant activities. The researchers hypothesize that the loss of these dopamine neurons that are particular to accelerators might actually be the cause of a shortage in the brain, which could be the cause of Parkinson’s shaking motions. Because the brain is only left with neurons that control deceleration, it is possible that it is causing musculature to take a longer ‘break,’ and not respond.
More information may be found in Nature Neuroscience, in which the study was published.
