PRESS-NEWS.org - Press Release Distribution
FREE PRESS RELEASES DISTRIBUTION

Team from UHN, CAMH identify unique characteristics of human neurons

These findings may have implications for brain disease, disorders

2021-05-03
(Press-News.org) TORONTO - Scientists at the Krembil Brain Institute, part of University Health Network (UHN), in collaboration with colleagues at the Centre for Addiction and Mental Health (CAMH), have used precious and rare access to live human cortical tissue to identify functionally important features that make human neurons unique.

This experimental work is among the first of its kind on live human neurons and one of the largest studies of the diversity of human cortical pyramidal cells to date.

"The goal of this study was to understand what makes human brain cells 'human,' and how human neuron circuitry functions as it does," says Dr. Taufik Valiante, neurosurgeon, scientist at the Krembil Brain Institute at UHN and co-senior author on the paper.

"In our study, we wanted to understand how human pyramidal cells, the major class of neurons in the neocortex, differ between the upper and bottom layers of the neocortex," says Dr. Shreejoy Tripathy, a scientist with the Krembil Centre for Neuroinformatics at CAMH and co-senior author on this study.

"In particular, we wanted to understand how electrical features of these neurons might support different aspects of cross-layer communication and the generation of brain rhythms, which are known to be disrupted in brain diseases like epilepsy."

With consent, the team used brain tissue immediately after it had been removed during routine surgery from the brains of patients with epilepsy and tumours. Using state-of-the-art techniques, the team was then able to characterize properties of individual cells within slices of this tissue, including visualizations of their detailed morphologies.

"Little is known about the shapes and electrical properties of living adult human neurons because of the rarity of obtaining living human brain tissue, as there are few opportunities other than epilepsy surgery to obtain such recordings," says Dr. Valiante.

To keep the resected tissue alive, it is immediately transferred into the modified cerebrospinal fluid in the operating room then taken directly into the laboratory where it is prepared for experimental characterization.

It is rare to study human tissue because accessing human tissue for scientific inquiries requires a tight-knit multidisciplinary community, including patients willing to participate in the studies, ethicists ensuring patient rights and safety, neurosurgeons collecting and delivering samples, and neuroscientists with necessary research facilities to study these tissues.

After initial analysis, members of the Krembil Centre for Neuroinformatics used further large-scale data analysis to identify the properties that distinguished neurons in this cohort from each other. These properties were then compared to those from other centres doing similar work with human brain tissue samples, including the Allen Institute for Brain Sciences in Seattle, Washington.

Noted in the team's findings: A massive amount of diversity among human neocortical pyramidal cells Distinct electrophysiological features between neurons located at different layers in the human neocortex Specific features of deeper layer neurons enabling them to support aspects of across-layer communication and the generation of functionally important brain rhythms

The teams also found notable and unexpected differences between their findings and similar experiments in pre-clinical models, which Dr. Tripathy believes is likely reflective of the massive expansion of the human neocortex over mammalian and primate evolution.

"These results showcase the notable diversity of human cortical pyramidal neurons, differences between similarly classified human and pre-clinical neurons, and a plausible hypothesis for the generation of human cortical theta rhythms driven by deep layer neurons," says Dr. Homeira Moradi Chameh, a scientific associate in Dr. Valiante's laboratory at Krembil Brain Institute and lead author on the study.

In total, the team was able to characterize over 200 neurons from 61 patients, reflecting the largest dataset of its kind to-date and encapsulating almost a decade's worth of painstaking work at UHN and the Krembil Brain Institute.

"This unique data set will allow us to build computational models of the distinctly human brain, which will be invaluable for the study of distinctly human neuropathologies," says Dr. Scott Rich, a postdoctoral research fellow in Dr. Valiante's laboratory at the Krembil Brain Institute and co-author on this work.

"For instance, the cellular properties driving many of the unique features identified in these neurons are known to be altered in certain types of epilepsy. By implementing these features in computational models, we can study how these alterations affect dynamics at the various spatial scales of the human brain related to epilepsy, and facilitate the translation of these 'basic science' findings back to the clinic and potentially into motivations for new avenues in epilepsy research."

"This effort was only possible because of the very large and active epilepsy program at the Krembil Brain Institute at UHN, one of the largest programs of its kind in the world and the largest program of its kind in Canada," says Dr. Valiante.

INFORMATION:

Please view the paper, "Diversity amongst human cortical pyramidal neurons revealed via their sag currents and frequency preferences," here: http://www.nature.com/ncomms (DOI: 10.1038/s41467-021-22741-9).

We acknowledge generous support from UHN Foundation, Krembil Foundation, CAMH Discovery Fund, NIH, Natural Sciences and Engineering Research Council of Canada, and Kavli Foundation.

About the Krembil Brain Institute The Krembil Brain Institute at Toronto Western Hospital, part of University Health Network, is home to one of the world's largest and most comprehensive teams of physicians and scientists uniquely working hand-in-hand to prevent and confront problems of the brain and spine. One in three Canadians will experience a brain-related condition such as Parkinson's, Alzheimer's or epilepsy in their lifetime. Through state-of-the-art patient care and advanced research, we are working relentlessly to find new treatments and cures. http://www.uhn.ca/krembil

About University Health Network University Health Network consists of Toronto General and Toronto Western Hospitals, the Princess Margaret Cancer Centre, Toronto Rehabilitation Institute, and The Michener Institute of Education at UHN. The scope of research and complexity of cases at University Health Network has made it a national and international source for discovery, education and patient care. It has the largest hospital-based research program in Canada, with major research in cardiology, transplantation, neurosciences, oncology, surgical innovation, infectious diseases, genomic medicine and rehabilitation medicine. University Health Network is a research hospital affiliated with the University of Toronto. http://www.uhn.ca

About The Centre for Addiction and Mental Health (CAMH) CAMH is Canada's largest mental health and addiction teaching hospital and a world leading research centre in this field. CAMH combines clinical care, research, education, policy development and health promotion to help transform the lives of people affected by mental illness and addiction. CAMH is fully affiliated with the University of Toronto, and is a Pan American Health Organization/World Health Organization Collaborating Centre. http://www.camh.ca

MEDIA CONTACTS: Heather Sherman
Senior Public Affairs Advisor, Krembil Brain Institute/UHN
heather.sherman@uhn.ca

Hayley Chazan
Media Relations, Krembil Centre for Neuroinformatics/The Centre for Addiction and Mental Health
media@camh.ca



ELSE PRESS RELEASES FROM THIS DATE:

Personalised medications possible with 3D printing

2021-05-03
Customised medicines could one day be manufactured to patients' individual needs, with University of East Anglia (UEA) researchers investigating technology to 3D 'print' pills. The team, including Dr Andy Gleadall and Prof Richard Bibb at Loughborough University, identified a new additive manufacturing method to allow the 3D printing of medicine in highly porous structures, which can be used to regulate the rate of drug release from the medicine to the body when taken orally. Dr Sheng Qi, a Reader in Pharmaceutics at UEA's School of Pharmacy, led the research. The project findings, 'Effects of porosity on drug release kinetics of swellable and erodible porous pharmaceutical solid dosage forms ...

Same drug can have opposite effects on memory according to sexual differences

Same drug can have opposite effects on memory according to sexual differences
2021-05-03
A research team from the Institut de Neurociències at the Universitat Autònoma de Barcelona (INc-UAB) has showed that inhibition through a drug of the Tac2 neuronal circuit, involved in the formation of the memory of fear, has opposite effects on the ability to remember aversive events in mice according to sex: it is reduced in male mice and increased in female mice. Is the first time that a drug has been shown to produce this opposite effect on the memory of male and female mice. The study also evidences that opposing molecular mechanisms and behaviours can occur ...

Oceans' microscopic plants -- diatoms -- capture carbon dioxide via biophysical pathways

2021-05-03
Diatoms are tiny unicellular plants -- no bigger than half a millimeter -- which inhabit the surface water of the world's oceans where sunlight penetration is plenty. Despite their modest size, they are one of the world's most powerful resources for removing carbon dioxide (CO2) from the atmosphere. They currently remove, or "fix," 10-20 billion metric tons of CO2 every year by the process of photosynthesis. But not much is known about which biological mechanisms diatoms use, and whether these processes might become less effective with rising ocean acidity, temperatures, and, in particular, CO2 concentrations. A new study in Frontiers in Plant Science shows that diatoms predominantly ...

Planned cesarean births safe for low-risk pregnancies

2021-05-03
New research shows that planned cesarean deliveries on maternal request are safe for low-risk pregnancies and may be associated with a lower risk of adverse delivery outcomes than planned vaginal deliveries. The study is published in CMAJ (Canadian Medical Association Journal). The study used province-wide data from the Better Outcomes Registry & Network (BORN), Ontario's provincial birth registry. The authors analyzed data on 422,210 low-risk pregnancies over 6 years (2012 to 2018). There were 46,533 cesarean deliveries, of which 1827 (3.9%) were planned at the request of the mother; this proportion was unchanged during the years of study. Mothers who requested cesarean delivery ...

Structural racism contributes to the racial inequities in social determinants of psychosis

2021-05-03
The legacy of systemic racism in the U.S impacts psychosis risk at the individual and neighborhood level, according to a definitive review published online today. Researchers examined U.S. based evidence connecting social and environmental factors with outcomes relating to psychotic experiences, including schizophrenia. The review examined potential risk factors and influence of structural racism within three key areas. These included disparities in neighborhoods; trauma and stress experienced at both collective and individual levels; and complications experienced around pregnancy. Disparities in U.S. neighborhoods perpetuate disadvantage for racially minoritized ...

Election campaigns: attacks and smearing backfire and can benefit other candidates

Election campaigns: attacks and smearing backfire and can benefit other candidates
2021-05-03
Candidates often give in to temptation to attack opponents in electoral campaigns through negative ads (more than 55% of the ads aired by the Clinton and Trump campaigns in 2016 were negative), even if evidence of this tactic effectiveness is, at least, mixed. A study by Bocconi University professors Vincenzo Galasso, Tommaso Nannicini and Salvatore Nunnari, just published in the American Journal of Political Science, reveals the backlash of electoral smearing and shows that, in a three-candidate race, it's the "idle candidate" (the one neither attacking nor being attacked) to have the upper hand. During a three-candidate mayoral race in a mid-sized Italian town in 2015, the authors ...

Technique to automatically discover simulation configurations for behaviors hard to test

Technique to automatically discover simulation configurations for behaviors hard to test
2021-05-03
The research team led by Fuyuki Ishikawa at the National Institute of Informatics (NII, Japan) developed a technique to search automatically for simulation configurations that test various behaviors of automated driving systems. This research was conducted under the ERATO-MMSD project (*1) funded by the Japan Science and Technology Agency (JST, Japan). The proposed technique iterates trials on simulations using an optimization method called evolutionary computation so that it discovers simulation configurations that lead to specific features of driving behaviors such as high acceleration, deceleration, and steering operation. The outcome of this research was presented in ICST 2021 (*2), a flagship conference on software testing ...

Screening healthcare workers could serve as early warning system for future viruses

2021-05-03
New research has shown that COVID-19 infections in healthcare workers during the first wave of the pandemic provided an accurate sample of the general population, suggesting that data from healthcare workers could be used to estimate the severity of future viruses more quickly. The study, led by researchers from RCSI University of Medicine and Health Sciences in collaboration with IBM Research, is published in PLOS ONE. The researchers analysed the infection data from healthcare workers and the progression of the first wave of the COVID-19 outbreak using the reported daily infection numbers in Ireland. Using similar data in four other countries (Germany, UK, South Korea and Iceland), computer models showed how the disease progressed in different countries related to ...

Volunteer firefighters have higher levels of 'forever chemicals'

2021-05-03
Volunteer firefighters -- who comprise more than 65 percent of the U.S. fire service -- have higher levels of "forever chemicals," per- and polyfluoroalkyl substances (PFAS), in their bodies than the general public, according to a Rutgers study. The study, which was published in the International Journal of Environmental Research and Public Health, compared the levels of nine PFAS chemicals in the blood of volunteer firefighters against levels in the general population. It is the first study to evaluate volunteer firefighters' exposure to PFAS, which are chemicals that accumulate in human bodies and in the environment and ...

Study finds heart transplantation using donation after cardiac death with NRP

2021-05-02
Boston, MA (May 2, 2021) - A new study, presented today at the AATS 101st Annual Meeting, found that heart transplantation using donation after cardiac death (DCD) with normothermic regional perfusion (NRP) is feasible in the United States. Broader application of DCD heart transplantation has the potential to increase cardiac allograft availability by 20-30 percent. Over a one-year period, from January 2020 to January 2021, eight heart transplants were performed using cardiopulmonary bypass (CPB) for immediate regional reperfusion and cardiac unloading to accomplish optimal myocardial salvage. All hearts ...

LAST 30 PRESS RELEASES:

Cat-borne parasite Toxoplasma induces fatally bold behavior in hyena cubs

Nature article: Dieting and its effect on the gut microbiome

NIH scientists describe "Multi-Kingdom Dialogue" between internal, external microbiota

Melatonin in mice: there's more to this hormone than sleep

Wild bees need deadwood in the forest

A triple-system neural model of maladaptive consumption

Milk protein could help boost blueberries' healthfulness

Seeking a treatment for IBS pain in tarantula venom

Addressing inequity in air quality

Roughness of retinal layers, a new Alzheimer's biomarker

Study links sleep apnea in children to increased risk of high blood pressure in teen years

Black patients with cirrhosis more likely to die, less likely to get liver transplant

Researchers outline specific patterns in reading in Russian

These sea anemones have a diverse diet. And they eat ants

Viruses as communication molecules

Spirituality can promote the health of breast cancer survivors

Tiny ancient bird from China shares skull features with Tyrannosaurus rex

University of Minnesota Medical School report details the effects of COVID-19 on adolescent sexual health

Odd smell: flies sniff ammonia in a way new to science

Fracture setting method could replace metal plates, with fewer complications

Sneeze cam reveals best fabric combos for cloth masks (video)

'Lady luck' - Does anthropomorphized luck drive risky financial behavior?

People willing to pay more for coffee that's ethical and eco-friendly, meta-analysis finds

Low-cost imaging technique shows how smartphone batteries could charge in minutes

Pleistocene sediment DNA from Denisova Cave

Quantum birds

Antibody therapy rescues mice from lethal nerve-muscle disease

Life in these star-systems could have spotted Earth

Cutaneous reactions after mRNA COVID-19 vaccines

Skin reactions after COVID-19 vaccination: Rare, uncommonly recur after second dose

[Press-News.org] Team from UHN, CAMH identify unique characteristics of human neurons
These findings may have implications for brain disease, disorders