1. Human brain cells transplanted into rat brains

The human brain is arguably the most complex structure in the known universe, and studying it can often be difficult. However, in a major breakthrough, neuroscientists from Stanford University were able to successfully transplant human brain tissue to the brains of young rats.

This study, published in the journal Nature in October 2022, is the latest advance in the field of human organoids: miniature, simplified structures of human organs that are fully developed in the lab. Although research on brain organoids has already yielded important insights into brain health and disease, their development in the lab is limited. Neurons derived from brain organoids develop much slower and cannot simulate the complexity of neurons from healthy human brains.

To further their development, a team led by Professor Sergiu Pasca was able to create brain organoids from human skin cells and transplant them into the brain of two- to three-day-old rat pups. The brain organoids survived the transplantation, and quickly joined the hosts’ body systems. The human neurons formed working connections to rat neurons and were permeated by blood vessels, allowing them to participate in cardiometabolic processes. Within six months, neurons from the brain organoids grew to occupy one-third of the brain hemisphere they were transplanted into. They grew six times larger than neurons that remained in the dish and were not transplanted.

Future applications of this technique could allow scientists to perform experiments that would otherwise be too invasive, difficult, or even impossible. Professor Pasca commented that “we can now study healthy brain development as well as brain disorders understood to take root in development in unprecedented detail, without needing to excise tissue from a human brain. We can also use this new platform to test new drugs and gene therapies for neuropsychiatric disorders”.

Research on human organoids has also raised several ethical questions. Researchers from the University Medical Centre Rotterdam highlighted concerns about the treatment of animals and the informed consent of participants providing the tissue for this type of work. But also, and most importantly, about the oversight of this research area, given the possibility of breeding animals with enhanced cognition. Although the rats in this study did not show any human characteristics or improvements in performance, more work is needed to ensure the responsible development of research on human organoids.

2. Moon exploration missions

Following delays and cancellations of space missions due to the coronavirus outbreak in 2019, there was a large number of moon exploration missions scheduled to launch in 2022.

For example, on 16 November 2022, NASA’s new rocket, Artemis 1, blasted from the Kennedy Space Center in Florida, USA. The flight included an uncrewed capsule, Orion, with plans to orbit the moon and travel back to Earth within 26 days. On 25 November 2022 the Orion spacecraft officially entered the lunar orbit and a day later it broke the record for the farthest distance from Earth reached by a crew-capable spacecraft.

Artemis 1 is the first spacecraft in NASA’s Artemis programme, representing the agency’s return to lunar exploration. This is a landmark mission, given it takes place 50 years after the last crewed spacecraft of the Apollo programme reached the moon. The objective of Artemis I is to carry out experiments and test the Orion spacecraft in preparation for future moon exploration missions. Artemis 1 also represents the beginning of a long-term strategy for moon exploration by the US.

South Korea also launched its first lunar orbiter, Danuri (Korea Pathfinder Lunar Orbiter), on 4 August 2022. Developed by the Korea Aerospace Research Institute in collaboration with NASA, Danuri was launched from the Cape Canaveral Space Force Station in Florida, USA. The object of the mission is to identify future lunar landing sites, conduct experiments regarding lunar natural resources and test space internet technology. Danuri comprises the first phase of the Korean Lunar Exploration Program, with the second phase planned to take people to the moon before 2030.

Several other moon exploration missions scheduled to launch in 2022 were postponed. For example, the Smart Lander for Investigating Moon, a lunar lander developed by the Japan Aerospace Exploration Agency, was initially set to launch in 2021 but was subsequently delayed to 2022 and now 2023. The launch of Chandrayaan-3, India’s second attempt at a moon landing, has also been delayed to 2023.

Finally, Russia’s lunar lander mission, Luna 25, has also been subject to a number of delays. It was initially scheduled to launch in 2016, but is now scheduled for 2023. The project aims to represent a new step for the Soviet Luna programme from the 1970s, with hopes that it will also be part of a wider space exploration initiative. The initiative includes a proposed International Lunar Research Station (to be built on the moon or in the moon’s orbit) developed by Russia’s Roscosmos and the China National Space Administration. The station is scheduled to be revealed in 2035.

The UK government released its first ever National Space Strategy in September 2021, with plans to place the UK “in the front rank of the global space industry” and collaborate with NASA on the Artemis programme to return humans to the moon.

Cover image by Ganapathy Kumar on Unsplash.