Dopamine and serotonin are brain chemicals associated with a range of neurological disorders, including Parkinson’s disease and depression, so understanding how they work may be key to developing more effective treatments for these diseases,media New Atlas reported. A new tool provides an unprecedented opportunity to observe the effects of these neurotransmitters, allowing scientists to monitor their real-time activity for the first time.
Dopamine and serotonin have long been associated with the brain’s ability to process rewards, but scientists have recently turned their attention to how they play a broader role in the body as a whole. This includes how serotonin in the gut regulates blood sugar or how ketamine solves low levels, and how deep brain region stimulation (DBS) promotes dopamine production in people with Parkinson’s disease.
The last example is a particularly promising one, as Parkinson’s disease is characterized by the depletion of dopamine production in the brain, which can lead to loss of control over body movement. The use of DBS, in which tiny wires are implanted into the patient’s body to deliver electricity to specific areas of the brain, is one way to address symptoms such as tremors and slow movement, as well as dopamine deficiency.
Five patients were placed on DBS at Wake Forest Baptist Medical Center, two with Parkinson’s disease and three with idiopathic tremors, an involuntary movement disorder of the nervous system. When neurosurgeons implanted their electrode arrays to provide DBS treatment, another team, including scientists from Virginia Tech, joined them in inserting their carbon fiber microelectrides deep into the brain to detect and record serotonin and dopamine released by neurons.
While the patients were still awake, the researchers asked them to perform some decision-making exercises, and they had to decide the direction in which a series of dots disappeared and moved across the screen. Each patient performed 200 to 300 tasks and was asked from time to time to show how confident they were with their answers.
At the same time, low voltage is pressed on the electrode to detect dopamine and serotonin activity in real time. Scientists call this electrochemical method the fast-scanning cyclic vodka, which for the first time in their history records subsecond fluctuations in dopamine and serotonin signals.
“There are a lot of people around the world who are taking drug compounds to disrupt dopamine and serotonin transmitter systems to change their behavior and mental health,” said P. Read Montague of Virginia Tech, the study’s senior author. “For the first time, moment-to-moment activity in these systems was measured and their participation in perception and cognitive ability was determined. These neurotransmitteres work at the same time and integrate activities on very different time and spatial scales, better than anyone expected. “
The team says this is a huge improvement over previous efforts to track these neurotransmitters, which do not provide the same frequency and number of measurements.
Scientists can draw some useful insights from their experiments. They found that serotonin levels rose when subjects were more uncertain about their answers, and decreased when they were more certain. When the subjects expected to make a decision, dopamine appeared to increase, while serotonin levels declined, and when both reached a certain level, the final choice was made.
“This study sheds light on the role of these neuromules in learning, brain plasticity, and how we perceive the environment,” said lead researcher Kenneth T. Kishida. “We now have a more detailed understanding of how our brains build what we perceive, use those perceptions to make decisions, and explain the consequences of the choices we make. Dopamine and serotonin seem to be crucial in all of these processes. Importantly, such research will help us and other scientists better understand how drugs or drugs such as serotonin reuptake inhibitors affect cognition, decision-making, and mental illnesses such as depression. “
The study was published in the journal Neurons.