Study: New findings on how serotonin controls behaviour
New York, US: The COVID-19 pandemic has significantly accelerated a trend that has seen rising rates of anxiety and depression for many years. Frank Schroeder of the Boyce Thompson Institute's latest research could eventually result in novel treatments that could lessen the burden of mental illness around the world.
Serotonin, a neurotransmitter that is generated by many animals and was first identified in the 1930s, regulates a wide range of behaviours including feeding, sleep, mood, and cognition. The primary tool for treating psychological illnesses including anxiety and depression and eating disorders is a medication that modifies serotonin levels.
The tiny roundworm Caenorhabditis elegans has been extensively used as a straightforward model for neurobiology research to examine serotonin's function in controlling behaviour and food intake. For a long time, scientists believed that C. elegans had a single biochemical pathway for producing serotonin, which was subsequently rapidly destroyed. Now it has been established by Schroeder's group and associates at Columbia University that none of those presumptions was entirely accurate.
In our model system, around half of the serotonin is created by a second, parallel biosynthetic pathway, according to Schroeder.
An article that was published in 'Nature Chemical Biology' describes the findings.
The project got underway roughly three years ago when scientists unintentionally found an enzyme that breaks down serotonin into its derivatives.
We discovered that serotonin is employed as a building block for other molecules accountable for some of the serotonin's function, contrary to what most experts in the area had previously believed. "So, we chose to start at the beginning and observe how serotonin is made, and then how it is changed into these other molecules once it is made," the researcher said.
Further research by Jingfang Yu, a graduate student in Schroeder's lab and the paper's first author, demonstrated how the novel serotonin derivatives influence feeding behaviour.
According to Yu, when worms are deficient in endogenous serotonin, they have a propensity to move fast across the bacterium food lawn on an agar plate and turn only occasionally to investigate the food. We discovered that dosing the worms with serotonin derivatives can stop this behaviour, indicating that these recently discovered substances are responsible for the effects once assigned to serotonin.
Serotonin's molecular signalling pathways are largely conserved across species, including humans, making the worm C. elegans an ideal model organism. For instance, studies have demonstrated that the gut is where a significant part of serotonin is produced in C. elegans, as it is in humans.
According to Schroeder, there are indications that human serotonin is changed into metabolites that resemble those seen in C. elegans.
Schroeder, a professor in the Department of Chemistry and Chemical Biology in the department of Arts and Sciences at Cornell University, said that this finding "opens up the door for many other paths of inquiry in humans."
"Do humans need the corresponding metabolites? What function does one manufacturing pathway serve in comparison to another?" He questioned.
"How are these production pathways and metabolites significant for human behaviours, such as mental health and food patterns?"
The effect of the novel serotonin derivatives on C. elegans behaviour is currently being studied, as is the possibility that human beings have serotonin metabolites that are similar.
