What types of massage are there?

 There are many different types of massage. Some aim to relieve muscle problems and injuries, such as sports and deep tissue massages, while others aim to promote relaxation, such as reflexology.

These types of massage are popular in sports and occupational health. Swedish massage is a more common form of massage that is suitable for a range of different purposes.

Some types of massage may have more extensive health benefits. For example, there are claims that reflexology can heal other parts of the body by targeting the hands and feet. However, there is no conclusive evidence to support these claims.

This article will discuss some of the most common types of massage and their benefits.

Hot stone massage

A hot stone massage involves the use of heated stones, usually comprising basalt. Basalt is a type of volcanic rock with a high iron content, which allows it to hold in heat well.

A massage therapist will heat the stones in hot water before placing them on different areas of the body.

They may also hold the stones while performing a variety of other massage techniques.

Hot stone massage provides heat to the body’s muscles. This can help treat muscle injuries, as it relaxes them and increases blood flow to the area. This, in turn, can help reduce stiffness and discomfort.

Deep tissue massage

Deep tissue massage aims to reach deeper layers of muscle and connective tissue.

A massage therapist will slowly press their fingers into the skin with pressure. They will use slow, firm strokes to target deep tissues.

They may specifically target knots in the muscles. Muscle knots, or myofascial trigger points, are specific areas of tension within the muscle fiber. The exact cause of these knots is still unclear, but they can develop from muscle overuse, such as from playing a sport or poor posture.

Because these knots can be sore, deep tissue massage aims to relieve them and provide pain relief. There is some evidence to suggest that this technique is effective for this purpose.

Sports massage

The purpose of a sports massage is to improve the health of the soft tissue in the bodies of people who play sports or exercise regularly. It involves the manipulation of soft tissues, including the:

• skin
• muscle
• tendons
• ligaments
• fascia

Playing sports and regularly exercising can put excessive strain on the muscles and other soft tissues. By targeting all of these soft tissues, a sports massage therapist aims to prevent or relieve injuries, enhance muscle performance, and correct muscle imbalances.

There is evidence to suggest that sports massage can aid recovery from repetitive muscle injuries. There is also some evidence to suggest that sports massage may improve muscle performance, but it is less conclusive.

Swedish massage

In a Swedish massage, the therapist will use less pressure than they would in other types of massage, such as deep tissue or sports massage.

They will combine shorter, tapping strokes and longer, deeper strokes using light to moderate pressure. They may also move the person’s limbs around during the massage.

Swedish massage can help relieve pain, stress, and muscle problems. A systematic review from 2017Trusted Source found that Swedish massage has a range of benefits, including reducing lower back pain.

However, this technique may not be helpful for everyone. For example, one study found that Swedish massage therapy did not help those with fibromyalgia when compared with other types of massage.

Reflexology

Reflexology uses different amounts of pressure on specific parts of the hands and feet with the aim of benefiting other parts of the body. The practice may help promote relaxation and reduce pain.

There are some claims that reflexology can heal certain parts of the body from various conditions, but there is no solid evidenceTrusted Source for this. For example, one high quality systematic review found that reflexology could not reduce chronic pain from multiple sclerosis.

However, reflexology may have other benefits, such as relaxation. One systematic reviewTrusted Source from 2019 found that reflexology helped reduce anxiety in people undergoing treatment for cardiovascular issues.

Risks

There is evidence behind some of the alleged benefits of massage, such as reducing muscle pain and promoting relaxation.

Many different groups of people may benefit from massages, such as those who regularly play sports or have bad posture.

When receiving a massage from a trained massage therapist, there are few risksTrusted Source. However, the risks that do exist may not affect everyone.

People with open wounds or cuts should avoid hot stone massage, as the heat can cause more bleedingTrusted Source. Deep tissue and other forceful types of massage can also make bleeding worse. People with bleeding disorders and those taking anticoagulants may wish to avoid massages altogether.

Also, pregnant women should consult a doctor before having any type of massage.

Summary

Many types of massage can promote relaxation, aid pain relief, and help prevent and treat injuries.

Most types are safe for most people when a trained massage therapist performs them.

However, not everyone should seek massage therapy. For example, hot stone massage can worsen bleeding from a cut or open wound.

Source: Medical News Today

Why are scientists massaging mice with robots?

 

• A new study finds that robot-delivered mechanotherapy decreased muscle damage and boosted muscle repair in mice with a severe skeletal leg muscle injury.
• The scientists also found that mechanotherapy caused a reduction in certain white blood cells responsible for inflammation.
• Next, scientists will need to confirm whether mechanotherapy has the same effects in humans with severe skeletal muscle injury and whether it can be used clinically.

Skeletal muscle enables the body to move and maintain posture. Direct injury — for instance, from trauma — can impair a person’s movement and quality of life.

People have been using massage and other mechanotherapies for thousands of years to soothe aching and injured muscles. However, the science behind the effects of massage has not been examined in detail.

“Lots of people have been trying to study the beneficial effects of massage and other mechanotherapies on the body, but up to this point, it hadn’t been done in a systematic, reproducible way,” explains lead author of the current study Dr. Bo Ri Seo, Ph.D.

“Our work shows a very clear connection between mechanical stimulation and immune function,” he continues.

Muscle repair

Like much of the human body, skeletal muscle can repair itself. The process involves three stages:

• destruction and inflammation: 1–3 days
• repair: 3–4 weeks
• remodeling: 3–6 months

When muscle injury occurs, muscle fibers rupture and die. White blood cells invade the injury site, removing the dead muscle cells and activating cells that help mount an immune response. This includes the release of growth factors, cytokines, and chemokines.

During the repair phase, satellite cells, or muscle precursor cells, grow and differentiate into muscle cells. These then replace injured cells in the muscle fiber, and scar tissue forms.

In the remodeling phase, muscle fibers mature, and scar tissue contracts. However, extensive injuries may cause dense scar tissue formation, impeding muscle repair and resulting in incomplete recovery of muscle function.

Unmet treatment need

Despite its complications, surgical treatment remains the current standard of care for severe muscle injury.

Recognizing the need for an effective noninvasive treatment for severe skeletal muscle injury, researchers from Harvard University in Cambridge, MA, conducted a study investigating the use of mechanotherapy as a potential treatment.

Their findings appear in the journal Science Translational Medicine.

Dr. Seo, who is a postdoctoral fellow at the Wyss Institute at Harvard, explained to Medical News Today:

“Our previous study has shown the beneficial impacts of compressive loading for skeletal muscle regeneration. Based on the finding, we wanted to develop a [scientifically] validated, optimal protocol for mechanotherapy and to understand the mechanisms associated with the therapeutic impacts.”

The researchers developed an external robotic device to deliver a precise, controlled, and measurable pressure to the leg muscle in mice. The scientists also used ultrasound to measure tissue response to the stress applied.

One to 14 days after injury, the scientists gave the mice in the treatment group mechanotherapy with pressure corresponding to muscle strains of 10, 20, or 40% for 5 minutes every 10–12 hours. The scientists did not treat mice in the control group.

Improved functional outcomes

Compared with the control mice, the mice in the treatment group demonstrated a significant reduction in muscle fiber damage and scarring. The authors also note increased muscle fiber diameter, which is an indicator of repair and strength recovery.

Since muscle repair improvements were similar across the 10, 20, and 40% groups, the study continued using the 20% muscle strain pressure setting for the remaining experiments.

To uncover how mechanotherapy promoted muscle repair, the researchers also measured levels of inflammatory factors — cytokines and chemokines — over time.

The study identified that mechanotherapy reduced levels of a cytokine responsible for the movement of neutrophils by more than half by day 3. Neutrophils help clear damaged cells and communicate with other cells to promote repair and immune response. Neutrophils also play a role in inflammation.

To understand why neutrophils and cytokines were moving out of the muscle, the researchers injected a fluorescent compound into the muscle. They observed that mechanotherapy was directly causing this exodus from the muscle.

Next, the scientists cultured satellite cells — which are essentially muscle stem cells — with factors that neutrophils secrete. They wanted to assess their effects on muscle repair.

The study authors found that neutrophil-secreted factors initially promoted repair, but when they were present for a longer time, they impaired muscle fiber production.

After analyzing the muscle fibers produced in the two groups after 14 days, the researchers found that the leg muscle cells treated with mechanotherapy contained more type IIX fibers.

Type IIX fibers have a larger diameter and can produce increased force, consistent with the results the researchers saw in the mice that received mechanotherapy.

In the final experiment, the scientists used an antibody treatment to remove neutrophils in the mice during the first 3 days after injury. They found that the muscles of the treated mice recovered more quickly.

They discovered that both mechanotherapy and antibody treatment led to significantly reduced muscle damage and the development of larger muscle fibers.

Conclusions and the future

Dr. Bert Mandelbaum, who was not involved in the study, also spoke with MNT. Dr. Mandelbaum is an orthopedic surgeon at Cedars-Sinai Kerlan-Jobe Institute and co-director of the Cedars-Sinai Regenerative Orthobiologics Center in Los Angeles.

He was intrigued by the experimental design — particularly the use of robotics to “prescribe” specific muscle loads and then assessing the biological factors that the loads produce.

Speaking about the results, lead author Dr. Seo told MNT:

“It was super exciting to see that the severely injured muscle treated with biologic-free/noninvasive compressive loading shows comparable functional outcomes to the ones treated with biologics-based therapies found from other studies.”

“Also, we were surprised by the fact that neutrophils were significantly involved in this process by directly influencing muscle progenitor cell activities,” he continued.

“In addition, we found that compressive loading rapidly reduces neutrophils and their associated factors by day 3 after injury — with this change […] confined to the injured site. This makes mechanotherapy a great therapeutic candidate for patients who are already using other medical interventions or existing health complications — for example, inflammatory diseases.”

He went on to say: “Our findings are based on [studies in] mice, so further studies are needed to confirm its impacts for larger animals and humans. Furthermore, since the kinetics and amplitudes of immune response can differ depending on types of injuries, how and what to be delivered should be optimized accordingly.”

In conclusion, Dr. Mandelbaum told MNT, “I think it’s a great hypothesis, something needing to be proven over time.”

Source: Medical News Today

No COVID-19 in Turkmenistan?

 

• COVID-19 has been present in nearly every country in the world.
• However, the Turkmenistan government claims that there have been no cases or deaths there. The World Health Organization (WHO) has repeated these claims.
• Experts argue that the WHO needs to do more to investigate the situation.

Since its emergence toward the end of 2019, SARS-CoV-2 has spread around the world. Cases of COVID-19, which is the disease that SARS-CoV-2 causes, have officially been reported in almost every country — as have deaths to the disease. To date, there have been more than 4.8 million confirmed deaths globally.

A small number of countries have reported no cases or deaths. One of these countries is Turkmenistan. The WHO’s official statistics reflect the statistics provided by the country’s government.

However, reports from the country suggest that Turkmenistan has not miraculously escaped the effects of the pandemic. Like the countries it shares a border with, such as Iran and Afghanistan, it has experienced waves of infection — despite the government denying this.

Saving face

Speaking with Medical News Today, Prof. Luca Anceschi — a professor of Eurasian Studies at the University of Glasgow in the United Kingdom and an expert on Central Asia — said that like in North Korea, the authoritarian government was attempting to uphold an image of ushering in a golden age for the country.

For the government, a global pandemic does not fit into this picture, so it denies it.

“Turkmenistan and North Korea are similar in the sense of being very authoritarian regimes, run by people who have a very eccentric approach,” said Prof. Anceschi. “They are also extremely isolated states, using their borders as a control mechanism to stop the access of new ideas that could be destabilizing.”

“Like North Korea, in Turkmenistan, the government has control over the media, and on top of that, there is a particular narrative that the government has been putting out for the last 15 or 20 years about Turkmenistan living in this golden age, and the golden age is there because the government brought it with it.”

“That makes the eruption of a pandemic impossible […] because it would challenge this narrative. We have seen the same with [HIV] and [AIDS], which is another illness [that] was never publicly acknowledged in Turkmenistan. It is characteristic of this regime to hide these kinds of situations,” said Prof. Anceschi.

This analysis was also backed up by Dr. Jason Klocek, an assistant professor in politics and international relations at the University of Nottingham in the U.K. and an expert on state repression. Dr. Klocek has also lived in Turkmenistan for 2 years.

Dr. Klocek told MNT that, “[i]n many ways, the Turkmenistan government’s denial of COVID-19 cases is in line with long standing policy.”

“For more than a decade, the government has also claimed there are no people living with [HIV or AIDS] in the country. And a series of outbreaks, including the bubonic plague, were reported by civil society organizations in the early 2000s but denied by government officials.”

“Add to this the fact that the current president, Gurbanguly Berdimuahamedow, has used the image of a healthy nation — coupled with his previous dentistry career — to bolster his legitimacy. Admitting there is a COVID-19 outbreak could undermine that authority,” said Dr. Klocek.

Difficult conditions

According to Prof. Anceschi, the Turkmenistan government’s denial of COVID-19 in the country has created difficult conditions for people living there.

“It has been very difficult [for people living in the country] because Turkmenistan has had waves of infection, even last year.”

“Turkmenistan shares a border with Iran, which at one point was very significantly hit [by COVID-19], and with Afghanistan, which also has some problems. And, in general terms, all of Central Asia has infection rates as high as everywhere.”

“What is very difficult is the fact that there has been no considered effort to recognize this pandemic, which means no international cooperation. If public health is a human right, which it is, then that’s a lot of human rights violation that the government has perpetrated.”

“So, what can you do? The government at the beginning was saying that [COVID-19] doesn’t exist, and then it said it does exist but we have things like natural cures, and then, of course, people were dying.”

For Dr. Klocek, a key issue is the limited access to the country that makes getting detailed information on the COVID-19 situation difficult.

“The number of infections and the scale of their consequences are difficult to assess from outside the country,” said Dr. Klocek.

“Reports from civil society groups both within and outside the country suggest that the number of infections remains high and [that] hospitals are currently overwhelmed with COVID-19 patients. Individual reports of [citizens with the infection] are starting to surface via various media outlets.”

“The Turkmenistan government has also recently imposed additional travel restrictions in areas of the country where a high number of people are exhibiting COVID-19 symptoms.”

“Sadly, and similar to past outbreaks in the country, the extent of those suffering on the ground may not be known until it is too late to act,” added Dr. Klocek.

WHO failings?

For Dr. Klocek, there has been too little focus on the situation in Turkmenistan from the international community.

“The international community has been largely silent [regarding the government’s claims]. There was a brief uptick in interest during the summer of 2020, when the WHO sent an observation team. But the visit was highly scripted, and the team could not confirm the presence of COVID-19 in the country.”

“[The team] did, however, express concern about ‘increased cases of acute respiratory disease or pneumonia of unknown cause’ and advised the country to carry out measures ‘as if there is coronavirus in the country.’”

“A Turkish diplomat also died of an illness with coronavirus-like symptoms in July 2020, but Turkish authorities remained silent on the matter, including the Turkmenistan government’s refusal to let the diplomat return to Turkey for treatment.”

“Since the summer of 2020, relatively little attention [had been] paid to the situation in Turkmenistan until the WHO’s regional director for Europe, [Dr.] Hans Kluge, traveled to Ashgabat this month.”

“A number of civil society organizations have tried to use the recent visit to put pressure on the WHO to make a formal statement about the situation in Turkmenistan. They are still waiting for a reply,” noted Dr. Klocek.

Prof. Anceschi said that the WHO had a responsibility to not simply repeat the government’s claims that there have been no cases of COVID-19 or related deaths.

“The thing that is surprising is the totally pro-government line we got from the WHO. I tried to contact the WHO. They never replied. Other colleagues have had the same experience.”

“As I understand, in prior epidemic contexts — the avian flu or SARS-CoV-1 — [the WHO] would get back to you within 1 hour. They have been totally uncooperative with disseminating the truth.”

“The problem is that when you create a context in which this information [is] false, you have a further disservice: On top of not providing access to human rights in terms of public health, you also disseminate fake news. And [the WHO is] guilty of this. No one believes that Turkmenistan does not have COVID-19.”

“Now […] the government is making vaccination compulsory [and] running a campaign about washing your hands — what more do the WHO need to say there is a problem in Turkmenistan?”

“This consistent policy of sticking to the government line when the government is corrupt and has a tradition for disseminating fake data — I don’t understand why the WHO keeps being like this. It’s a very big credibility hit,” argued Prof. Anceschi.

On October 8, 2021, the government of Turkmenistan hosted an international forum on infectious disease control and health diplomacy. In it, the WHO’s Dr. Kluge said:

“The COVID-19 pandemic has shown unequivocally the fundamental importance of health for worldwide prosperity and security. There is a demonstrable need to rethink global governance structures, the relationship between the private and public sectors, and the values upon which our nations and societies operate.”

Dr. Kluge also stressed the importance of transparent communication, met with Turkmenistan government officials, and introduced the new WHO representative to Turkmenistan, Dr. Egor Zaitsev, to national officials. According to the WHO’s official page, the meeting explored further opportunities to strengthen the collaboration between the WHO and Turkmenistan.

Source: Medical News Today

What’s the link between mental health and allergies?

 

• Research indicates that people with allergies exhibit a higher incidence of mental health conditions than other people.
• A new study has analyzed UK Biobank data to investigate the possibility of a causal relationship between allergies and mental health conditions.
• The findings confirm a correlation but find no evidence that one type of health issue causes the other.

Earlier research has shown that people with allergies are more likely to have at least one mental health condition. There is an elevated incidence of depression, schizophrenia, and anxiety among people with atopic dermatitis (AD), for example. Asthma and allergic rhinitis, or “hay fever,” have been linked with schizophrenia, depression, and bipolar disorder.

A new study of data from the UK Biobank confirms the correlation between allergies and mental health. However, correlation does not imply causation, and the study also finds it unlikely that allergies cause mental health conditions or vice versa.

The researchers used Mendelian randomizationTrusted Source to investigate possible gene-level causal relationships between mental health disorders and allergies in general — as well as asthma, AD, and hay fever, specifically.

These mental health conditions included depression, major depressive disorder, anxiety, bipolar disorder, schizophrenia, and neuroticism. The researchers concluded, “We did not find evidence of causal effects between allergic disease genetic risk and mental health.”

Senior study author Dr. Hannah Sallis, a senior research associate in genetic epidemiology at Bristol Medical School, explains that the study ultimately utilized a variety of methodologies and data to reach its conclusions. “This helps to strengthen our confidence in the findings. Establishing whether allergic disease causes mental health problems, or vice versa, is important to ensure that resources and treatment strategies are targeted appropriately.”

The study has been published in the journal Clinical and Experimental AllergyTrusted Source.

The team analyzed data in the in the UK Biobank from individuals aged 37–73 years. However, all were of European ethnicity, so the study’s results may not apply to everyone.

The authors acknowledge another limitation, that “Phenotypic analyses were restricted to older adults, so findings may not generalize to younger populations.”

Study does not rule out causal connection

While this study only found weak, statistically insignificant indications of causal relationships, this does not rule them out entirely. According to lead study author Dr. Ashley Budu-Aggrey, also a senior research associate at Bristol Medical School:

The researchers do note a few possible causal mechanisms that might have escaped their analysis.

Visible skin lesions or itching could lead to social consequences that might exacerbate mental health conditions. And sleep deprivation due to allergy discomfort could similarly affect a person’s mental health.

The study also cites the “inflammatory hypothesis,” which proposes that mental health conditions might arise from the immune system’s inflammatory response to allergies.

Tonya Twinders, the CEO of the Allergy & Asthma Network, who was not involved in the present research, mentioned an earlier study in an interview with Medical News Today.

This suggested that a possible shared mechanism might be “psychological distress, which is central to the etiology of psychiatric disorders but can also give rise to allergies.”

The observational associations

The researchers found that allergies correlated in different ways with mental health conditions, as follows:

• Depression: The study confirmed a strong correlation between self-reported depression, major depressive disorder, and allergies in general. Asthma, AD, and hay fever were also strongly associated with depression.
• Anxiety: Allergies in general were associated with anxiety, with a stronger correlation for AD than for asthma or hay fever.
• Bipolar disorder: Asthma was linked with bipolar disorder, as were allergies in general.
• Schizophrenia: The only allergy associated with schizophrenia was hay fever. The effect, however, was protective, meaning that people with hay fever were less likely to have schizophrenia.
• Neuroticism: Allergies in general, asthma, and AD were linked with neuroticism. Hay fever was also associated with neuroticism, to a lesser extent.

The study concludes that “Few of the observed associations between allergic disease and mental health were replicated [in the causal investigation].

“The causal effect we did identify appears to be much lower in magnitude than that suggested observationally,” note the authors.

Twinders told MNT: “Intervening to prevent [the] onset of allergic disease is unlikely to directly improve mental health (and vice versa). Future work should investigate whether interventions that aim to improve allergic disease show stronger evidence of a causal effect on mental health (and vice versa).”

Dr. Budu-Aggrey has observed: “Common mental health disorders, such as anxiety and depression, are some of the largest contributors to the global burden of disease, and the prevalence of these and allergic disease has been increasing for some time.”

Source: Medical News Today

Russians ‘have a hard time trusting their own vaccine,’ expert says

 

• Sunday, October 3, set records for the most COVID-19 deaths in Russia on a single day.
• Only 29% of people in Russia are vaccinated, despite the country being the first to approve a vaccine.
• The vast majority of hospitalized COVID-19 patients in Russia are unvaccinated.

On Sunday, October 3, Russia reported its highest number of COVID-19 deaths per day since the start of the pandemic for the fifth time in a week. That day, 890 people died of the disease. The number of new infections was 25,769, the second-highest of the year.

Russia has the highest COVID-19 death toll of any European nation, with 218,345 fatalities. The country has reported 7,832,964 cases of the disease since the start of the pandemic.

According to The Guardian, publicly available data suggest that 600,000 “excess deaths” have occurred in Russia from the start of the pandemic to July 2021. This statistic suggests that the official death toll may significantly undercount the actual figure.

Rising rates

Prime Minister Mikhail Mishustin says that the government is “seriously concerned” about the rise in COVID-19 infections and fatalities.

Mishustin points out: “Morbidity is increasing in most Russian regions. There are twice as many patients in hospitals as there were at the same time last year.” Mishustin himself was diagnosed with COVID-19 in April.

As SARS-CoV-2’s Delta variant moves through Russia’s population, Mishustin attributes the surge to low vaccination rates among the country’s citizens, saying that “the vaccination level is insufficient to stop the spread of infection.”

Of the people currently hospitalized in Russia with COVID-19, the vast majority are unvaccinated.

This is in spite of the fact that Russia was the first nation to approve a vaccine for COVID-19, its own Sputnik V vaccine. Today, three different vaccines are available throughout the country.

Low vaccination factors

President Vladimir Putin has consistently urged the Russian people to get vaccinated, saying, “[COVID-19 is] dangerous, dangerous to your life. The vaccine is not dangerous.”

Nonetheless, just 29% of people in Russia are fully vaccinated. Almost 33% have received a single dose.

Last summer, an independent survey explored Russians’ resistance to vaccination. In that study, 33% of people surveyed said they were fearful of side effects, 20% said they were waiting for the completion of clinical trials, and 16% saw no reason to get vaccinated. Russia finished phase 3 clinical trials of the Sputnik V vaccine on September 30.

Of those surveyed, 57% said they were not afraid of getting COVID-19. A similar number said they were opposed to mandatory vaccinations.

Dr. Anna Gotlib, a Russian-born philosopher and bioethicist, told Medical News Today that another factor is a longstanding distrust of the federal government in Russia that can leave people “sort of stuck.”

According to Dr. Gotlib, the Russian people also have a long history of faith in home remedies, “going back even before the Soviet Union, going back all the way to the tzars and beyond.”

She continued: “I remember even my own grandmother, she was an educated woman, but she had her own ways. If I got sick, unless I was really sick, the first trip wasn’t to the doctor. She had her own little medicine cabinet of things.”

A recent Russian studyTrusted Source suggests that “the attitude toward immunoprophylaxis against COVID-19 in Russia can be characterized as distrust of a specific vaccine and approval of vaccination in general as an effective technology for combating epidemics.”

Dr. Gotlib also described the degree to which disinformation regarding COVID-19 and vaccines has “drenched” Russian media.

When people complain about how pervasive disinformation is in the United States, asserted Dr. Gotlib, “they have no idea how bad it is in Russia, to the extent where when you look at Russian media sometimes it’s really hard to make your way through all the pseudoscientific anti-vaccine [nonsense] claims.”

Others have suggested that the popularity of antibody tests in Russia may somewhat account for the low vaccination numbers. Although such tests can only detect antibodies from a previous infection and cannot assess immunity to COVID-19 or diagnose a current case, some may be more comfortable with the test than vaccinations.

Aversion to mandates

The Russian government has been reluctant to impose social restrictions that might limit the person-to-person spread of SARS-CoV-2 due to concerns that such measures might negatively affect the economy.

Bars, restaurants, and nightclubs remain open throughout the country.

Moscow briefly attempted to require negative PCR COVID-19 tests for local restaurant and bar customers but abandoned the effort after complaints from business owners over lost income. On October 5, however, Moscow mayor Sergei Sobyanin announced that mass PCR testing will begin in the city in 1–2 weeks.

In the face of the current surge, some other Russian regions are now saying they will begin requiring vaccination proof before allowing entrance to some venues. The country has 85 regions, of which Moscow is one.

On October 5, Deputy Prime Minister Tatiana Golikova also announced that the federal government now recommends regions implement vaccination QR codes as a requirement for attending large gatherings.

Source: Medical News Today

Scientists investigate how our ‘second brain’ may influence gut disorders

 

• Glial cells modulate the communication between neurons in the brain and play an active role in specific brain circuits.
• These cells perform a similar role in the enteric nervous system, which regulates how food travels through the gut.
• Until now, scientists did not know whether these glial cells belonged to specific circuits in the enteric nervous system of the gut or whether they played a more general role.
• A new study reports that glial cells do belong to specific circuits, interacting with particular neurons to produce a defined functional outcome.
• The results may ultimately lead to the development of treatments for conditions that affect the gut, such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD).

The nervous system consists of two primary cell types: neurons and glia. Neurons transmit messages using electrical or chemical signals. Historically, scientists consideredTrusted Source glial cells to play only a supportive and protective role.

However, recent evidence suggests that glial cells can communicate directly with neurons and can actively influence or modulate the transmission of signals between neurons.

Studies have shown that glial cells play a specific role in brain circuits, interacting with certain types of neurons to modulate the transmission of specific information.

Dr. Brian Gulbransen, lead author of the recent study and a professor at Michigan State University in East Lansing, explains the role of glial cells using the analogy of notes produced by an electric guitar.

He says, “[G]lia aren’t carrying the notes played on an electric guitar; they’re the pedals and amplifiers modulating the tone and volume of those notes.”

The digestive system has its own local nervous system known as the enteric nervous systemTrusted Source. The enteric nervous system contains at least as many neuronsTrusted Source as the spinal cord, which is why scientists sometimes call it the “second brain.”

Notably, the enteric nervous system can still control gut motility even when the nerve connections with the brain and spinal cord are severed.

Scientists know that glial cells in the enteric nervous system actively communicate with neurons and impact gut function.

However, they did not know whether enteric glial cells were a part of a specific network. In other words, they did not know whether glial cells in the enteric nervous system exclusively communicated with specific neurons to modulate the response to specific stimuli or generate specific outputs.

A new study that appears in the journal Proceedings of the National Academy of Sciences shows that glial cells in the enteric nervous system indeed belong to specific networks.

Describing the study results, Dr. Gulbransen said, “The main finding of this study is that there are distinct subsets of enteric glia that ‘listen’ to specific neural pathways and that these subsets of glia play specialized roles in modifying those, and the surrounding pathways.”

He explained that this is interesting “because it highlights a new mechanism whereby neural circuits in the gut are ‘tuned’ by enteric glia. […] This finding highlights a new layer of complexity in how enteric neurocircuits work, and this is important in understanding how gut motility is controlled.”

Understanding gut motility is of importance, because changes in motility play a part in a number of conditions, including gastroesophageal reflux disorder, IBDTrusted Source, and IBSTrusted Source.

Peristalsis and enteric nervous system

Food is propelled through the digestive system by a process called peristalsis, which involves involuntary rhythmic contractions of the smooth muscle wall of the digestive tract.

During peristalsis, the gut segment directly above the lump of swallowed food contracts. At the same time, muscles in the segment below the food relax. This forces food through the digestive tract.

Peristalsis is controlled by threeTrusted Source enteric nervous system pathways: the ascending, descending, and circumferential pathways.

As food passes through, the circular muscles in the gut stretch, which activates these pathways. The ascending pathway causes contraction of the segment above the food, and the descending pathway causes relaxation of the gut segment below the food.

The ascending pathway consists of excitatory neurons that mostly release the neurotransmitter acetylcholine. Neurons in the descending pathway generally release nitric oxide or purines to communicate with other neurons.

The circumferential pathway consists of neurons that encircle the wall of the digestive tract and relays changes in the smooth muscle wall to neurons in the ascending and descending pathways.

Selective response

In the recent study, the researchers used tissue dissected from the gastrointestinal (GI) tract of male and female mice to understand how the cells of the enteric nervous system work together in a network.

The researchers first determined whether some glial cells selectively responded to the activation of the three major enteric nervous system pathways.

They individually stimulated the ascending, descending, and circumferential pathways and measured the activation of glia in response to the stimulation of each pathway.

The researchers found that a majority of glia responded upon the activation of all three pathways. Significantly, over 10% of glia selectively responded to the stimulation of only the ascending (13%) or descending (12%) pathway.

These results show that subpopulations of glial cells exclusively belong to either the ascending or descending pathway.

The study authors observed similar results with the response of neurons to the stimulation of the ascending and descending pathways.

Interestingly, they also found that the magnitude of glial cell responses in the ascending and descending pathways of female mice was greater than it was in male mice.

Response of glial cells to neurotransmitters

Purines are one of the neurotransmitters that neurons use in the descending pathway to communicate with each other. In contrast, acetylcholine is mostly released by neurons to communicate with other neurons in the excitatory ascending pathway.

To investigate whether these neurotransmitters produce a specific response in glial cells, the researchers used inhibitors for acetylcholine and purine receptors. These inhibitors selectively blocked the action of neurotransmitters on glia but did not impact signaling between neurons.

The researchers found that stimulation of the descending or ascending pathway in the presence of either one of the neurotransmitter inhibitors activated a distinct population of neurons and glia, compared with the untreated control group.

For instance, the glial purine receptor blocker increased the proportion of neurons solely activated upon stimulation of the descending pathway while reducing the proportion of neurons activated by both pathways.

Similarly, the acetylcholine receptor blocker increased the proportion of glia that were activated upon stimulation of both the descending and ascending pathways.

Blocking the action of these neurotransmitters on glial cells also influenced the activity in each pathway. The purine receptor blocker reduced the activation of the ascending pathway but not the descending pathway. By contrast, the acetylcholine receptor blocker increased neuronal response in the descending pathway but not in the ascending pathway.

These experiments show that glial cells respond to purines and acetylcholine released by neurons, resulting in a change in the population of neurons and glia associated with each pathway, subsequently modulating the activity of each pathway.

Effects of glial cells on neurons

The study authors then investigated the role of glial cells in regulating specific motor pathways using chemogenetics.

Chemogenetics is a technique that allows for the selective activation or inhibition of a specific subset of cells, such as glial cells, by using an engineered protein synthesized in the laboratory.

The researchers used this approach to selectively activate the glial cells. The activation inhibited both ascending and descending pathways, showing that glial cells could influence downstream neurons.

Moreover, the stimulation of glial cells reduced the response of neurons in both the descending and ascending pathways in female mice and only in the descending pathway in male mice.

The results from the previous experiment using the glial receptor blockers alone and the use of these blockers in combination with the chemogenetic approach helped the researchers elucidate how neurotransmitters activated glial cells to modulate the response of neurons in the ascending and descending pathways.

These experiments showed that the activation of glial cells by acetylcholine played an important role in inhibiting the descending pathway. However, glial cells activated by acetylcholine also seemed to inhibit the ascending pathway to a certain extent.

Moreover, purine neurotransmitter-induced activation of glial cells stimulated the ascending excitatory pathway.

In sum, the results of these experiments showed that the release of purines and acetylcholine activate glial cells to result in the recruitment of neurons to either the ascending or descending pathway, leading to specific changes in gut motility.

Dr. Keith Sharkey, a professor at the University of Calgary in Canada, explained to Medical News Today how these results show that “the neural networks of the enteric nervous system that control all gut function are very finely regulated in a directional and sex-specific manner by enteric glial cells.”

Dr. Sharkey was not involved in the study.

Implications

MNT spoke with Dr. Nick Spencer, a professor at Flinders University in Australia, who was not involved in the study.

He said the study shows that “enteric glial cells actually interact with certain types of enteric neurons in a highly specific and network-specific manner. Until now, it had remained mysterious whether enteric glia communicate in any ordered pattern with the known, highly polarized ascending excitatory and descending inhibitory enteric neural pathways in the gut wall.”

Dr. Sharkey noted that the findings of the study “allow for a completely new understanding of gut dysmotility, which are common and highly debilitating disorders of gut function, such as [IBS], to be reframed as diseases of neural network connections — that is, conditions in which network-level [perturbations] drive disease and the symptoms experienced by patients.”

“These findings will therefore allow for the development of better diagnostics and treatment, as well as novel therapies, etc. This work will allow for more personalized approaches to treatment as well — as opposed to the one-size-fits-all model that is common in much of medicine.”

“Moreover, by showing that the glial control is sex-specific, these authors help us understand why so many [GI] diseases occur in a sex-specific manner. And beyond these more practical implications, the work also has a lot of biological and physiological implications for understanding neural control mechanisms,” Dr. Sharkey continued.

Describing future research directions, Dr. Gulbransen noted: “We have ongoing studies that are addressing how glia and enteric motor neurocircuits are affected following inflammation. This is important, since neuroplasticity following acute inflammation is thought to produce [GI] dysmotility in common diseases, such as [IBS] and [IBD].”

“The hope is that by understanding how the glial control over motor neurocircuits is changed during inflammation, we will identify ways in which this mechanism can be harnessed to improve gut motility.”

Source: Medical News Today