It’s common knowledge that the neurons in the brain store memories. But a team of scientists has discovered that cells from other parts of the body also perform a memory function, opening new pathways for understanding how memory works and creating the potential to enhance learning and to treat memory-related afflictions.
“Learning and memory are generally associated with brains and brain cells alone, but our study shows that other cells in the body can learn and form memories, too,” explains New York University’s Nikolay V. Kukushkin, the lead author of the study in Nature Communications.
The research sought to better understand if non-brain cells help with memory by borrowing from a long-established neurological property – the massed-spaced effect – which shows that we tend to retain information better when studied in spaced intervals rather than in a single, intensive session – better known as cramming for a test.
In the Nature Communications research, the scientists replicated learning over time by studying two types of non-brain human cells in a laboratory (one from nerve tissue and one from kidney tissue) and exposing them to different patterns of chemical signals – just like brain cells are exposed to patterns of neurotransmitters when we learn new information. In response, the non-brain cells turned on a “memory gene” – the same gene that brain cells turn on when they detect a pattern in the information and restructure their connections in order to form memories.
“Learning and memory are generally associated with brains and brain cells alone, but our study shows that other cells in the body can learn and form memories, too.”
NYU’s Nikolay Kukushkin
To monitor the memory and learning process, the scientists engineered these non-brain cells to make a glowing protein, which indicated when the memory gene was on and when it was off.
The results showed that these cells could determine when the chemical pulses, which imitated bursts of neurotransmitter in the brain, were repeated rather than simply prolonged – just as neurons in our brain can register when we learn with breaks rather than cramming all the material in one sitting. Specifically, when the pulses were delivered in spaced-out intervals, they turned on the “memory gene” more strongly, and for a longer time, than when the same treatment was delivered all at once.
“This reflects the massed-space effect in action,” says Kukushkin, a clinical associate professor of life science at NYU Liberal Studies and a research fellow at NYU’s Center for Neural Science. “It shows that the ability to learn from spaced repetition isn’t unique to brain cells, but, in fact, might be a fundamental property of all cells.”
The researchers add that the findings not only offer new ways to study memory, but also point to potential health-related gains.
“This discovery opens new doors for understanding how memory works and could lead to better ways to enhance learning and treat memory problems,” observes Kukushkin. “At the same time, it suggests that in the future, we will need to treat our body more like the brain – for example, consider what our pancreas remembers about the pattern of our past meals to maintain healthy levels of blood glucose or consider what a cancer cell remembers about the pattern of chemotherapy.”
A little-noticed change to South Africa’s national health research guidelines, published in May of this year, has put the country on an ethical precipice. The newly added language appears to position the country as the first to explicitly permit the use of genome editing to create genetically modified children.
Heritable human genome editing has long been hotly contested, in large part because of its societal and eugenic implications. As experts on the global policy landscape who have observed the high stakes and ongoing controversies over this technology — one from an academic standpoint (Françoise Baylis) and one from public interest advocacy (Katie Hasson) — we find it surprising that South Africa plans to facilitate this type of research.
The fate of these three children, and whether they have experienced any negative long-term consequences from the embryonic genome editing, remains a closely guarded secret.
Controversial research
Considerable criticism followed the original birth announcement. Some argued that genetically modifying embryos to alter the traits of future children and generations should never be done.
Many pointed out that the rationale in this case was medically unconvincing – and indeed that safe reproductive procedures to avoid transmitting genetic diseases are already in widespread use, belying the justification typically given for heritable human genome editing. Others condemned his secretive approach, as well as the absence of any robust public consultation, considered a prerequisite for embarking on such a socially consequential path.
In the immediate aftermath of the 2018 revelation, the organizing committee of the Second International Summit on Human Genome Editing joined the global uproar with a statement condemning this research.
At the same time, however, the committee called for a “responsible translational pathway” toward clinical research. Safety thresholds and “additional criteria” would have to be met, including: “independent oversight, a compelling medical need, an absence of reasonable alternatives, a plan for long-term follow-up, and attention to societal effects.”
Notably, the additional criteria no longer included the earlier standard of “broad societal consensus.” https://www.youtube.com/embed/XAhFoaT6Kik?wmode=transparent&start=0 Nobel laureate David Baltimore, chair of the organizing committee for the Second International Summit on Human Genome Editing, talks about the importance of public global dialogue on gene editing.
New criteria
Now, it appears that South Africa has amended its Ethics in Health Research Guidelines to explicitly envisage research that would result in the birth of gene-edited babies.
Section 4.3.2 of the guidelines on “Heritable Human Genome Editing” includes a few brief and rather vague paragraphs enumerating the following criteria: (a) scientific and medical justification; (b) transparency and informed consent; (c) stringent ethical oversight; (d) ongoing ethical evaluation and adaptation; (e) safety and efficacy; (f) long-term monitoring; and (g) legal compliance.
While these criteria seem to be in line with those laid out in the 2018 summit statement, they are far less stringent than the frameworks put forth in subsequent reports. This includes, for example, the World Health Organization’s report Human Genome Editing: Framework for Governance (co-authored by Françoise Baylis).
Alignment with the law
Further, there is a significant problem with the seemingly permissive stance on heritable human genome editing entrenched in these research guidelines. The guidelines clearly require the research to comply with all laws governing heritable human genome research. Yet, the law and the research guidelines in South Africa are not aligned, which entails a significant inhibition on any possible research.
This is because of a stipulation in section 57(1) of the South African National Health Act 2004 on the “Prohibition of reproductive cloning of human beings.” This stipulates that a “person may not manipulate any genetic material, including genetic material of human gametes, zygotes, or embryos… for the purpose of the reproductive cloning of a human being.”
When this act came into force in 2004, it was not yet possible to genetically modify human embryos and so it’s not surprising there’s no specific reference to this technology. Yet the statutory language is clearly wide enough to encompass it. The objection to the manipulation of human genetic material is therefore clear, and imports a prohibition on heritable human genome editing.
Ethical concerns
Photo by Tingey Injury Law Firm on Unsplash
The question that concerns us is: why are South Africa’s ethical guidelines on research apparently pushing the envelope with heritable human genome editing?
In 2020, we published alongside our colleagues a global review of policies on research involving heritable human genome editing. At the time, we identified policy documents — legislation, regulations, guidelines, codes and international treaties — prohibiting heritable genome editing in more than 70 countries. We found no policy documents that explicitly permitted heritable human genome editing.
It’s easy to understand why some of South Africa’s ethicists might be disposed to clear the way for somatic human genome editing research. Recently, an effective treatment for sickle cell disease has been developed using genome editing technology. Many children die of this disease before the age of five and somatic genome editing — which does not involve the genetic modification of embryos — promises a cure.
Implications on future research
But that’s not what this is about. So, what is the interest in forging a path for research on heritable human genome editing, which involves the genetic modification of embryos and has implications for subsequent generations? And why the seemingly quiet modification of the guidelines?
How many people in South Africa are aware that they’ve just become the only country in the world with research guidelines that envisage accommodating a highly contested technology? Has careful attention been given to the myriad potential harms associated with this use of CRISPR technology, including harms to women, prospective parents, children, society and the gene pool?
Is it plausible that scientists from other countries, who are interested in this area of research, are patiently waiting in the wings to see whether the law in South Africa prohibiting the manipulation of human genetic material will be an insufficient impediment to creating genetically modified children? Should the research guidelines be amended to accord with the 2004 statutory prohibition?
Or if, instead, the law is brought into line with the guidelines, would the result be a wave of scientific tourism with labs moving to South Africa to take advantage of permissive research guidelines and laws?
We hope the questions we ask are alarmist, as now is the time to ask and answer these questions.
Katie Hasson, Associate Director at the Center for Genetics and Society, co-authored this article.
The Swedish Board of Health and Welfare reports that in 2022 10.5% of boys and 6% of girls received an ADHD diagnosis, which is 50% more than in 2019. And the board forecast that the rates will eventually plateau at 15% for boys and 11% for girls.
So, what might be the reasons behind the startling rise? Here are eight possible causes, many of which overlap and interact with each other.
1. Multiple diagnoses made in the same person
Previously, doctors were recommended by diagnostic manuals and trained to limit diagnoses in an individual to the most prominent one, and not to make certain combinations of diagnoses at all – for example, autism and ADHD. Today, it is recommended and common practice in the mental health sector to make as many diagnoses needed to meaningfully describe and cover the symptoms and challenges of a person.
2. Increased knowledge and awareness by professionals
Today, there is a new generation of professionals working in services with higher awareness and knowledge of ADHD. This has led to earlier detection and to ADHD being diagnosed in groups that were previously neglected, particularly girls and women – but also in adults, generally
3. Reduced stigma
In many societies, ADHD is far less stigmatised than previously. Doctors have fewer doubts about making the diagnosis, and those receiving it feel less stigmatised. For more and more people, ADHD has fewer negative connotations and is becoming a natural part of people’s identities .
4. Modern society places higher demands on cognitive skills
ADHD is not a disease but a malfunctioning composition of cognitive traits that exist on more functional levels even in the general population, such as “attention control” (concentration) and organisational and self-regulation skills. Modern societies are fast and complex, placing high demands on these cognitive traits. So people with lower than average skills in these key cognitive areas begin struggling to cope with everyday demands and might receive an ADHD diagnosis.
5. Higher expectations on health and performance
People’s expectations of their own and others’ performance and health are rising. The so-called “social baseline” of average health and performance is higher today. Therefore, people may express concerns about their own and others’ functioning earlier and more often, and may presume that ADHD could be an explanation.
6. Changes in schools have led to more students struggling
Schools have gone through substantial changes in how they teach, such as digitisation and introducing more project- and group-based learning, as well as much more self-guided education.
These changes have led to a less clear learning environment, including increased demands on students’ motivation and their cognitive skills, factors that can make it harder for students with even just a few traits of ADHD to succeed. It has also caused schools to refer more students whom they suspect of having ADHD for assessment.
7. Policymakers prioritise assessment
Politicians in many countries have tried to address the rising diagnosis rates predominantly by making diagnostic assessments more accessible so that people don’t have to wait a long time to receive a diagnosis.
While this is understandable, it fuels the number of diagnoses made and does not focus on avoiding diagnoses, such as by improving how children are taught, improving workplaces to make them more neurodivergent friendly, and offering support without requiring that a person have a diagnosis.
8. Diagnosis guarantees access to support and resources
In most societies, services are constructed as such that only a clinical diagnosis guarantees access to support and resources. It is often the only way for people and their families to get support.
Generally, not a lot is done for people without a diagnosis as service providers do not get reimbursed and are therefore less obliged to take action. So people in need of support are more likely to actively seek a diagnosis. And professionals are more inclined to assist them by giving a diagnosis, even if the person doesn’t quite meet the diagnostic criteria for ADHD – a phenomenon called “diagnostic upgrading”.
