Active substances tested in weightlessness

A total of eleven experiments from the fields of biology, physics, technology and materials science were on board the Airbus A310 ZERO-G during the 43rd DLR parabolic flight campaign in Bordeaux, France, in September. The experiments were tested in weightlessness on three consecutive campaign days. Each flight maneuver consisted of 31 consecutive parabolas, each of which created weightlessness for around 22 seconds. In total, a flight campaign provided around 35 minutes of weightlessness - alternating between normal and almost double the acceleration due to gravity - which researchers could use for their experiments.

Nils Drouvé from Prof. Dr. El Sheikh's working group was on board the Airbus A310 ZERO-G as part of his doctorate. (Image: DLR)

One project of the scientists in this campaign was the cell biology experiment “RUTH”, which investigates the effects of weightlessness on neuronal networks and brain organoids. It is a joint project of the University Hospital Bonn (AG Prof. Dr. Volker Busskamp), the TH Köln (AG Prof. Dr. Sherif El Sheikh), the GSI Helmholtzzentrum Darmstadt (AG Dr. Insa Schroeder) and the Applied Aerospace Biology department of the DLR Institute of Aerospace Medicine (Dr. Christian Liemersdorf). The background to the study is that long periods of weightlessness could have a negative impact on the brain structure and function of astronauts. This could limit cognitive and motor performance and jeopardize the safety of missions. The physiological mechanisms underlying these changes have not yet been sufficiently investigated. In order to investigate possible countermeasures, the RUTH experiment is therefore investigating the influence of changes in gravity on the development, structure and function of neuronal networks.

I am super happy that I was able to take part in both the test of the sounding rocket in Kiruna and the parabolic flight in Bordeaux as part of my doctoral thesis. They were exciting experiments and the fact that the science behind them also worked makes it all the better,” says Drouvé.

The experimental use of multi-electrode array (MEA) technology on a parabolic flight made it possible for the first time to extend the electrophysiological investigation of a single cell to the level of an entire neuronal network. The MEA system has already been used on various gravitational research platforms such as the DLR short-arm centrifuge, the ZARM drop tower in Bremen and the DLR sounding rockets MAPHEUS-12, -13, and -14 in Kiruna (Sweden). Together with the working group of Prof. Dr. Volker Busskamp, the spontaneous activity of the neuronal networks formed by artificially modified and cultivated stem cells was investigated in real time. The data show that gravity as an environmental stimulus triggers changes in neuronal activity. In addition, the neuronal networks responded particularly to acute changes in mechanical load (hypergravity) or unloading (microgravity), which significantly impair neuronal function. Using specially developed and synthesized pharmacological agents, the research group at TH Köln led by Prof. Dr. Sherif el Sheikh is also analyzing acute and preventive treatment options to counteract the effects of altered gravitational conditions on neuronal transmission.

In the MiHBO (MicroHeavy Brain Organoids) sub-project, brain organoids generated from human stem cells were used, which are routinely used in the Schroeder working group (GSI Helmholtzzentrum, Darmstadt) as a model system for the complex human brain. During the parabolic flight, it was tested whether samples of these organoids could be taken in hypergravity and microgravity phases for complex analyses of changes in brain structure. Hardware developed specifically for this purpose (Rocket Organoids in Space, ROMS) was used, which had already been tested on the MAPHEUS-14 sounding rocket in February and has now been successfully used in an improved form for a larger sample size. The samples obtained will provide valuable information on changes in the development, structure and function of neuronal networks in microgravity and contribute to the assessment of astronauts' cognitive performance. They will also be used to prepare for possible studies on the International Space Station.