̽��ֱ�� of Cambridge - Richard Bethlehem

Largest genetic study of brain structure identifies how the brain is organised

cjb250 — Thu, 17 Aug 2023 15:00:47 +0000

Our brains are very complex organs, with huge variety between individuals in terms of the overall volume of the brain, how it is folded and how thick these folds are. Little is known about how our genetic make-up shapes the development of the brain.

To answer this question, a team led by researchers at the Autism Research Centre, ̽��ֱ�� of Cambridge, accessed MRI scans from over 32,000 adults from the UK Biobank cohort and over 4,000 children from the US-based ABCD study. From these scans, the researchers measured multiple properties of the outermost layer of the brain called the cortex. These included measures of the area and volume of the cortex as well as how the cortex is folded.

They then linked these properties, measured both across the entire cortex as well as in 180 individual regions of the cortex, to genetic information across the genome. ̽��ֱ��team identified over 4,000 genetic variants linked to brain structure.

These findings have allowed researchers to confirm and, in some cases, identify, how different properties of the brain are genetically linked to each other.

Dr Varun Warrier from the Autism Research Centre, who co-led the study, said: “One question that has interested us for a while is if the same genes that are linked to how big the cortex is – measured as both volume and area – are also linked to how the cortex is folded. By measuring these different properties of the brain and linking them to genetics, we found that different sets of genes contribute to folding and size of the cortex.”

̽��ֱ��team also checked whether the same genes that are linked to variation in brain size in the general population overlap with genes linked to clinical conditions where head sizes are much larger or smaller than the general population, known as cephalic conditions.

Dr Richard Bethlehem, also from the Autism Research Centre and a co-lead of the study, said: “Many of the genes linked with differences in the brain sizes in the general population overlapped with genes implicated in cephalic conditions. However, we still do not know how exactly these genes lead to changes in brain size.”

Dr Warrier added: “This work shows that how our brain develops is partly genetic. Our findings can be used to understand how changes in the shape and size of the brain can lead to neurological and psychiatric conditions, potentially leading to better treatment and support for those who need it.”

This study was supported by the Wellcome Trust. It was conducted in association with the NIHR CLAHRC for Cambridgeshire and Peterborough NHS Foundation Trust, and the NIHR Cambridge Biomedical Research Centre.

Reference
Warrier, V et al. Genetic insights into human cortical organisation and development through genome-wide analyses of 2,347 neuroimaging phenotypes. Nat Gen; 17 Aug 2023; DOI: 10.1038/s41588-023-01475-y

̽��ֱ��largest ever study of the genetics of the brain – encompassing some 36,000 brain scans – has identified more than 4,000 genetic variants linked to brain structure. ̽��ֱ��results of the study, led by researchers at the ̽��ֱ�� of Cambridge, are published in Nature Genetics.

Our findings can be used to understand how changes in the shape and size of the brain can lead to neurological and psychiatric conditions, potentially leading to better treatment and support for those who need it

Varun Warrier

holdendrils

Illustration of brain anatomy

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Charts map rapid growth and slow decline of brains

cjb250 — Wed, 06 Apr 2022 15:00:33 +0000

An international team of researchers has created a series of brain charts spanning our entire lifespan – from a 15 week old fetus to 100 year old adult – that show how our brains expand rapidly in early life and slowly shrink as we age.

Scientists link genes to brain anatomy in autism

cjb250 — Mon, 26 Feb 2018 18:59:50 +0000

Previous studies have reported differences in brain structure of autistic individuals. However, until now, scientists have not known which genes are linked to these differences.

̽��ֱ��team at the Autism Research Centre analysed magnetic resonance imaging (MRI) brain scans from more than 150 autistic children and compared them with MRI scans from similarly aged children but who did not have autism. They looked at variation in the thickness of the cortex, the outermost layer of the brain, and linked this to gene activity in the brain.

They discovered a set of genes linked to differences in the thickness of the cortex between autistic kids and non-autistic children. Many of these genes are involved in how brain cells (or neurons) communicate with each other. Interestingly, many of the genes identified in this study have been shown to have lower gene activity at the molecular level in autistic post mortem brain tissue samples.

̽��ֱ��study was led by two postdoctoral scientists, Dr Rafael Romero-Garcia and Dr Richard Bethlehem, and Varun Warrier, a PhD student. ̽��ֱ��study is published in the journal Molecular Psychiatry and provides the first evidence linking differences in the autistic brain to genes with atypical gene activity in autistic brains.

Dr Richard Bethlehem said: “This takes us one step closer to understanding why the brains of people with and without autism may differ from one another. We have long known that autism itself is genetic, but by combining these different data sets (brain imaging and genetics) we can now identify more precisely which genes are linked to how the autistic brain may differ. In essence, we are beginning to link molecular and macroscopic levels of analysis to better understand the diversity and complexity of autism.”

Varun Warrier added: “We now need to confirm these results using new genetic and brain scan data so as to understand how exactly gene activity and thickness of the cortex are linked in autism.”

“ ̽��ֱ��identification of genes linked to brain changes in autism is just the first step,” said Dr Rafael Romero-Garcia. “These promising findings reveal how important multidisciplinary approaches are if we want to better understand the molecular mechanisms underlying autism. ̽��ֱ��complexity of this condition requires a joint effort from a wide scientific community.”

̽��ֱ��research was supported by the Medical Research Council, the Autism Research Trust, the Wellcome Trust, and the Templeton World Charity Foundation, Inc.

Reference
Romero-Garcia, R et al. Synaptic and transcriptionally downregulated genes are associated with cortical thickness differences in autism. Molecular Psychiatry; 26 Feb; DOI: 10.1038/s41380-018-0023-7

A team of scientists at the ̽��ֱ�� of Cambridge has discovered that specific genes are linked to individual differences in brain anatomy in autistic children.

This takes us one step closer to understanding why the brains of people with and without autism may differ from one another

Richard Bethlehem

Lance Neilson

What are you looking at?

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Does your empathy predict if you would stop and help an injured person?

cjb250 — Mon, 31 Oct 2016 11:51:39 +0000

A team of psychologists at the ̽��ֱ�� of Cambridge has conducted a social psychology experiment to test the theory that an individual’s level of empathy influences their behaviour. ̽��ֱ��results of their preliminary study, dubbed “ ̽��ֱ��Trumpington Road Study” and published in the journal Social Neuroscience, suggest that this theory is correct.

In the experiment, one of the team posed as an injured person, sitting on the grass on Trumpington Road, one the main roads running through Cambridge, next to the Cambridge ̽��ֱ�� Botanic Garden. Next to the ‘injured’ person was his upturned bicycle. Another member of the team was standing innocently across the road, watching to see if anyone was approaching from the side road of Brooklands Avenue.

As soon as a member of the public approached the street corner, alone, and was about to turn into Trumpington Road, he gave a quiet signal to the ‘injured’ person to start rubbing his ankle. ̽��ֱ��experiment had begun. ̽��ֱ��researcher across the street then noted if the passer-by stopped to ask the ‘injured’ man if he was OK.

Irrespective of whether passers-by stopped or not, once they had walked further up Trumpington Road, they were intercepted by a third researcher who told them she was conducting a ‘memory’ experiment, inviting them to describe what they had seen along the road in the last few minutes. Various items had been left on the sidewalk (such as a scarf) to make this a plausible cover story. Those who agreed to take part were also asked to visit a website in their own time, and complete the Empathy Quotient (EQ) and Autism Spectrum Quotient (AQ) questionnaires, and were told they would receive a token payment of £6 for taking part.

As the team predicted, EQ scores were higher in those who had stopped to help the injured cyclist, than in those who walked past him, presumably focused on their own agenda.

̽��ֱ��study was led by Richard Bethlehem, a Cambridge PhD student, and Professor Simon Baron-Cohen, Director of the Autism Research Centre at the ̽��ֱ�� of Cambridge. 37 (19 males, 18 females) completed both the EQ and also the AQ. They ranged in age from 18 to 77 years old.

Interestingly, how many autistic traits a person recorded was not related to whether they stopped to help or not, suggesting that empathy is the key factor, not autistic traits. Nor did age predict who stopped or not. Of those who stopped to help, 80% were female.

Richard Bethlehem said: “Experimental studies are often confined to the lab, which means they lack ‘ecological validity’. In this novel study we tested if empathy scores predict if people will act altruistically in a real-world setting. Our results support the theory that people who do good are, at least partially, driven by empathy.”

Dr Carrie Allison, a member of the team, commented: “How much empathy one has is itself a complex outcome of both biological factors and early upbringing and is a skill that can improve with development, learning, and practice.”

Professor Baron-Cohen, author of Zero Degrees of Empathy and the Chair of Trustees of the Canadian-based charity “Empathy for Peace”, said: “This research is a first step towards understanding why some people may or may not stop to help a person in distress. Studies conducted ‘in the wild’ are notoriously difficult to undertake, and even this small sample was derived from over 1,000 passers by. We will need to await a larger-scale replication. These results suggest that one factor that predicts which individuals will not stand idly by, is how many degrees of empathy they have.”

̽��ֱ��study was supported by the Autism Research Trust, the Medical Research Council, the Pinsent Darwin Trust, and the Cambridge Trust, and was conducted in association with the NIHR CLAHRC for Cambridgeshire and Peterborough NHS Foundation Trust.

Reference
Bethlehem, CA et al. Does empathy predict altruism in the wild? Social Neuroscience; 19 Oct 2016; DOI: 10.1080/17470919.2016.1249944

If you see an injured person by the side of the road, would you stop and help them, or are you more likely to walk on by? What motivates people to do good in such a situation?

How much empathy one has is itself a complex outcome of both biological factors and early upbringing and is a skill that can improve with development, learning, and practice

Carrie Allison

'Injured' cyclist on Trumpington Road

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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