Land-cover changes and serotonin levels: News from Imperial

Credit: Matthew Clark
Credit: Matthew Clark

Here’s a batch of fresh news and announcements from across Imperial.

From a simulation to understand why land-cover changes have occurred, to a study that found different antidepressants all target serotonin, here is some quick-read news from across Imperial.

Changing landscapes

When land-cover changes happen, such as during the expansion of agriculture, there are numerous possible interacting reason for such changes, from environmental to social. While simulations can help researchers posit what the main drivers might be, knowing how well they match the real-world situation has been difficult to achieve.

Now, an international team, including researchers from the Centre for Environmental Policy , have come up with a way to compare simulations of land systems processes with observed land cover change, and demonstrated it with a real-world example. They looked at the agricultural expansion on the island of Pemba, Tanzania, and used their technique to show it was more likely that observed deforestation from 2018 to 2021 was driven by soil degradation rather than external forces such as market changes or population growth.

This kind of information allows researchers to suggest ways to mitigate against further detrimental land-use changes. In Pemba, for example, the team suggest that regenerative agriculture programs, along with rainwater catchment systems, could help preserve soil fertility and prevent further deforestation.

Read the full paper in Land Use Policy.

Serotonin levels

Different antidepressants have ’strikingly similar’ effects on serotonin in mice, Imperial research suggests.

Researchers measured serotonin levels in the brains of mice before and after administering common antidepressant types - SSRIs, NRIs or ketamine - to assess how the neurotransmitter is targeted despite their different modes of action.

Testing revealed that each drug increased serotonin in the brain through different mechanisms - including serotonin transporters, noradrenaline transporters, and even histamine.

Professor Parastoo Hashemi , study author from the Department of Bioengineering , said: "It is widely thought that the brain has low levels of serotonin when people have depression, but it is difficult to test this hypothesis. Understanding more about the chemical basis of depression can help us to develop new drugs.

"We hope this animal study brings us one step closer to a screening process which could measure a biomarker - like serotonin - of disease and gauge its response to potential drugs. This would spell a new chapter in more accurate, personalised depression treatment. Next, my group are looking to create ’brain organoids on a chip’ to rapidly test thousands to millions of samples."

Last year the research group showed that serotonin is a good biomarker of depression in mouse models and now that common antidepressants all target serotonin.

The paper ’Serotonin is a common thread linking different classes of antidepressants ’ was published in Cell Chemical Biology.

Probiotics for lettuce

Total Controlled Environment Agriculture (TCEA) involves growing crops indoors, in systems like vertical farms or hydroponic greenhouses. These systems have the advantage of delivering worldwide, year-round, resource-efficient, low-emission, climate-resilient food production.

However, they face challenges in several areas. Plant beneficial microbe levels are low, in part due to rigorous sanitation. Pathogen outbreaks can also spread easily in connected water systems. A healthy microbiome would reduce crop losses and increase yields, but farmers have struggled to achieve this without soil.

Now, Professor Thomas Bell in the Department of Life Sciences is teaming up with startup company Concert Bio to develop a programme for TCEA lettuce growers. The team have recently secured a £1m grant from Innovate UK that will help them create a genetic-sequencing-based microbiome monitoring system to identify beneficial microbes for TCEA systems.

By optimising environmental interventions such as growing conditions, sterilisation procedures, and input composition (including beneficial microbes), the team hope to improve plant growth and reduce emissions, building world-leading TCEA capacity.

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