(Press-News.org) Zebrafish exposed to the leading cannabinoids found in cannabis in the earliest stages of development suffer a significant drop in neural activity later in life, according to a University of Alberta study that has implications for prenatal development in humans.
Richard Kanyo, the lead author on the study and post-doctoral fellow in the Faculty of Medicine & Dentistry, said despite the popular narrative that the health benefits of cannabis are many, it turns out there is a surprisingly large knowledge gap.
"Once the legalization happened, people got really excited about it and there's a lot of bias in the media about positive effects, so we began wondering about the negative implications," said Kanyo.
Kanyo teamed up with Declan Ali, a biological sciences researcher in the Faculty of Science, whose lab had an ongoing interest in how certain chemicals and compounds alter development in young animals "when their neurons are contacting each other and trying to communicate."
For the study, developing zebrafish embryos were left to incubate for 10 hours in a solution containing one of the two main active cannabinoids found in cannabis--tetrahydrocannabinol (THC) or cannabidiol (CBD)--or a combination of these two compounds, immediately after fertilization.
Ali explained that 10 hours represents a period in animal development that includes a stage of development known as gastrulation, when the multiplying cells start to form multiple tissue layers. In zebrafish it happens between five and 10 hours after the egg has been fertilized; in humans it lasts about a week and occurs roughly three weeks after egg fertilization.
The amount of drug used would be equivalent to someone consuming cannabis or the active compounds every day for two to three weeks at the very start of a pregnancy.
On the fourth day of development, Kanyo looked at brain activity using cutting-edge fluorescing calcium sensors that measure calcium, which is increased in active neurons.
He found that neural activity decreased by 60 to 70 per cent in the group bathed in THC and by more than 70 per cent in the group immersed in CBD. The decrease was even more pronounced in zebrafish that developed in a solution containing both compounds.
"The interesting part is when combined, like how it is found in a cannabis edible or cigarette, we needed much less to get the same reduction in neural activity," said Kanyo.
Ali said the concentrations used in the experiment are a little bit on the high side for just a single cigarette, to make up for the fact that the compounds have to work their way through an outer egg casing to get to the embryo.
"By the time that happens, we don't know what the exact concentrations are, but they're definitely going to be much lower than what we put in the baths themselves."
Compared with one of the control compounds, MS222, a local anesthetic that blocks activity along nerves, the drop in neural activity on the high end of the concentrations tested was the equivalent to the drop in animals that have been anesthetized, Kanyo noted.
At five days after fertilization, when the larvae slowly begin to swim, the reduction in activity compared with normally developed zebrafish was about 20 per cent for CBD and THC individually, but 80 per cent or higher when in combination.
"This reduction in locomotion is consistent with earlier studies as well," said Ali.
Ali said the research follows earlier studies showing that exposure of young organisms to THC and CBD, either alone or in combination, could have a detrimental impact on overall brain and neural activity that could be manifested in different ways.
And though more work is needed to better understand the mechanism behind the effects on neural activity, Ali said people who are thinking of having children would certainly want to limit exposure to any of these compounds in the same way they would limit exposure to nicotine and alcohol.
"We're not saying that these compounds are bad for you," he said. "I think in some contexts--pain relief or reducing seizures--there's a great potential there.
"However, what we're seeing is cannabis is not all good for everyone all the time and probably should not be taken during pregnancy."
INFORMATION:
The study, "Medium-throughput zebrafish optogenetic platform identifies deficits in subsequent neural activity following brief early exposure to cannabidiol and Δ?-tetrahydrocannabinol," was published in Scientific Reports.
The number of specialty behavioral health establishments, their workforce and their wages have increased steadily between 2011 and 2019, according to a new study by Indiana University and University of Michigan researchers.
The largest increases were found in the number of outpatient establishments and the size of their workforce, as well as an increase in the average wage at residential health establishments.
Researchers say while these increases are important in closing the gaps in needed treatment, more work needs to be done to increase behavioral health workforce deficits, especially in areas with an elevated drug overdose mortality rate.
At ...
By Karina Toledo | Agência FAPESP - The novel coronavirus is transmitted mainly via inhalation of saliva droplets or respiratory secretions suspended in air, so that face covering and social distancing are the most effective ways to prevent COVID-19 until enough vaccines are available for all. In Brazil, fabric masks are among the most widely used because they are cheap, reusable and available in several colors or designs. However, this type of face covering's capacity to filter aerosol particles of a size equivalent to the novel coronavirus can vary between 15% and 70%, according to a study conducted in Brazil by the University of São Paulo (USP).
The study was supported by FAPESP, and the principal investigator was Paulo Artaxo, a professor in the university's ...
(10 a.m. EDT, June 2, 2021--Denver) - New research published in the Journal of Thoracic Oncology (JTO) suggests the method used to calculate how obesity is measured may affect whether it is considered a risk factor for lung cancer. The JTO is an official journal of the International Association for the Study of Lung Cancer.
Although the association between measures of obesity and both cancer incidence and outcome are clear in some solid tumor types such as breast, esophageal, and colon cancer, the relationship between obesity and lung cancer is more nuanced.
Now, a group of researchers led by Sai Yendamuri, M,D, from Rosewell Comprehensive ...
Fluorinated compounds are an important group of compounds that are widely used in pharmaceuticals, agricultural chemicals, functional resins, and organic electronic materials. In particular, perfluorinated compounds with multiple carbon-fluorine bonds are attracting attention because of their high thermal and chemical stability and various excellent properties such as water and oil repellency and chemical resistance.
"C-F bonds are extremely strong; hence, their transformation under mild conditions is difficult, and the selective activation of a specific C-F bond from among multiple C-F bonds in perfluorinated compounds has not been achieved," explains Prof. Makoto Yasuda, corresponding author of the study.
The research team led by Prof. Makoto Yasuda has discovered ...
What makes cheetah the fastest land mammal? Why aren't other animals, such as horses, as fast? While we haven't yet figured out why, we have some idea about how--cheetahs, as it turns out, make use of a "galloping" gait at their fastest speeds, involving two different types of "flight": one with the forelimbs and hind limbs beneath their body following a forelimb liftoff, called "gathered flight," while another with the forelimbs and hind limbs stretched out after a hind limb liftoff, called "extended flight" (see Figure 1). Of these, the extended flight is what enables cheetahs to accelerate to high ...
Developing vaccines against bacteria is in many cases much more difficult than vaccines against viruses. Like virtually all pathogens, bacteria are able to sidestep a vaccine's effectiveness by modifying their genes. For many pathogens, such genetic adaptations under selective pressure from vaccination will cause their virulence or fitness to decrease. This lets the pathogens escape the effects of vaccination, but at the price of becoming less transmissible or causing less damage. Some pathogens, however, including many bacteria, are extremely good at changing in ways that allow them to escape the effects of vaccination while remaining highly ...
The white-tailed sea eagle is known for reacting sensitively to human disturbances. Forestry and agricultural activities are therefore restricted in the immediate vicinity of the nests. However, these seasonal protection periods are too short in the German federal States of Brandenburg (until August 31) and Mecklenburg-Western Pomerania (until July 31), as a new scientific analysis by a team of scientists from the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) suggests. Using detailed movement data of 24 juvenile white-tailed sea eagles with GPS transmitters, they were able to track when they fledge and when they leave the parental territory: on average, a good 10 and ...
Materials have a variety of properties that can be used to solve computational problems, according to studies in substrate-based computing. BZ computers, slime mould computers, plant computers, and collision-based liquid marbles computers are just a few examples of prototypes produced for future and emergent computing devices. Modelling the computational processes that exist in such systems, however, is a difficult task in general, and determining which part of the embodied system is doing the computation is still somewhat ill-defined.
Claiming that fungi are the most intelligent living organisms in the world sounds like an exaggeration. However, a recent study by Mohammad Mahdi Dehshibi, a UOC researcher who is contributing to a growing body of knowledge on the use of fungal materials, ...
Eating at least two serves of fruit daily has been linked with 36 percent lower odds of developing type 2 diabetes, a new Edith Cowan University (ECU) study has found.
The study, published today in the Journal of Clinical Endocrinology and Metabolism, revealed that people who ate at least two serves of fruit per day had higher measures of insulin sensitivity than those who ate less than half a serve.
Type 2 diabetes is a growing public health concern with an estimated 451 million people worldwide living with the condition. A further 374 million people are at increased risk of developing type 2 diabetes.
The study's lead author, Dr Nicola ...
Researchers at Linköping University in Sweden have developed an app to help women achieve a healthy weight gain and lifestyle during a pregnancy. The results from an evaluation of the app have now been published in two scientific articles. Using the app contributed to a better diet. Pregnant women with overweight or obesity who received the app also gained less weight during pregnancy.
"Pregnancy is a phase in life when many people try to do what is best for themselves and their baby. We think it's important to be able to offer a tool that has ...
