Tag Archives: hormones

What stress is, how it affects us, and how to handle it

Stress has many definitions, but it most usually refers to feeling overwhelmed or unable to cope with pressures in our lives. Rest assured, stress is a normal part of being alive. We all feel it to some degree in these scary, uncertain times.

Image via Pixabay.

Stress itself isn’t a bad thing. It’s our response to events that require us to change and adapt to threats or demands. It helps spur us to action and to overcome such moments in any area of our lives including family, work, hobbies, or education.

The negative effects, those we think of when saying “I’ve just been under a lot of stress lately”, stem from a build-up of this tension. When we feel that we’re not up to the challenges in our lives, or when we go too long without resting and relaxing, stress becomes chronic. This can have negative effects on our mood, performance, decision-making, and eventually on our health.

Why is stress a thing?

Stress is the product of our minds working in concert with our bodies to keep us safe. Its roots are firmly placed in the fight-or-flight response. This response is housed in our ‘lizard brain‘, meant to keep us alive in the face of danger, and shared among all vertebrates.

Stress happens in response to internal and external stimuli that place a demand upon us, either mentally or physically. It is a neutral, non-specific response (it happens for a lot of reasons and doesn’t carry any emotional charge). What it does vary in, based on the stressor, is intensity. The context shapes our emotional reaction to it.

For example, finding you’re all out of gum is a weak, negative stressor. Taking a ride on a roller coaster is a huge stressor, but a positive one (because you’re enjoying it, hopefully).

We seek out situations of controlled danger because danger can be exciting.
Image via Pixabay.

A lot of people will describe feeling ‘pumped up’ after such a ride, which is the effect of adrenaline. The release of adrenaline, also known as epinephrine, is closely tied to the fight-or-flight response — as are many other hormones such as cortisol, the stress hormone. They prime our body for either fighting off or running away from a threat by heightening physical performance, activating our immune systems (in case we get wounded), and interfering with processes that aren’t needed in a fight, such as digestion.

Boiled down, this response is our body’s go-to emergency mode when we’re threatened. It’s good at what it does, but it was meant to work in a savanna where “threatened” meant there was a lion or somebody with a sharp rock looking at you. Deadlines, lay-offs, mortgages still register as threats to our brains, but we can neither run from nor smack them, sadly, so the same response stays constant, depletes our bodies, and we become stressed.

As a general guideline, psychologists distinguish four classes of stressors: crises (such as a pandemic), major life events (getting wed, a relative dying), daily annoyances (traffic, work), and ambient stressors (pollution, climate change, crowding).

Eustress and distress

Psychologists sometimes make a distinction between eustress (‘good stress’) and distress (‘bad stress’). Stress, as we’ve seen, takes on certain emotional charges depending on the context and our reaction to it.

‘Eustress’ is an umbrella term that denotes healthy levels of positive stress which give rise to emotions such as hope, excitement, fulfillment, and being energized. It’s most commonly produced by events or demands that are outside our current zone of comfort but are still within our means to achieve. Feeling challenged and motivated to see such a task through is in no small part the product of stress.

‘Distress’, on the other hand, refers to stress caused by conditions that are far from our control or ability to rectify. It is usually characterized by prolonged periods of stress which becomes chronic, and almost always leads to maladaptive behavior (substance abuse, social retreat, irritability, aggressiveness) as a means to cope. People under distress will start experiencing problems sleeping, focusing, working, and eventually will see their health worsen.

Do we need it?

In many ways, stress impacts our performance similarly to arousal as described by the Yerkes-Dodson law. The right amount can keep us running merrily at peak performance; too much and we’re a mess. Too little arousal means that our performance suffers just as it does on the other end of the spectrum.

File:HebbianYerkesDodson.svg
Yerkes Dodson curve showing the impact of arousal on simple tasks.
Image via Wikimedia.

Stress plays a similar function to arousal. While they’re different concepts, there’s a lot of overlap between them, and they’re both linked in our bodies alongside sensations of anxiety. Stress is our initial response to events in our bodies or the environment; it’s the kick that jump-starts our response. It generally leads to arousal (which basically means ‘activation’ of our bodies and minds). Anxiety, a negative emotional state associated with feelings of worry or apprehension, is our bodies’ natural reaction to stress. Too much stress (i.e. of us being or coming close to being overwhelmed by what’s required of us) will lead to a build-up of anxiety that makes us avoid dealing with a certain task or event.

So, sadly, we can’t just do away with stress — we need it in order to function properly. But too much stress can impair our work by interfering with attention, muscle coordination and contraction, and other bodily processes.

As we’ve seen previously, one of the elements of stress involves the release of hormones that alter bodily processes (among others, making energy reserves quickly available for our muscles and organs). Spending too much time in a state of stress, then, will deplete such resources, and we’ll find ourselves running on an empty tank (which hurts our health).

How to handle stress

When dealing with stress, management is key. Keeping an eye on your stress level, and pushing it down when it becomes overwhelming, can lead to better health, productivity, and enjoyment of life.

Chronic stress keeps our fight-or-flight response always on. The hormonal changes this causes can lead to circulatory issues (due to high levels of adrenaline damaging blood vessels), heart attacks, or strokes. High levels of cortisol over long periods of time lead to issues with metabolism and energy management, i.e. it can make us eat more and fatten up.

Some of the most common signs that you’re under a lot of stress include overeating or not eating, problems sleeping, rapid weight gain (or loss in some cases), irritability, trouble concentrating, a retreat from social activities or hobbies. Some harder-to-spot ones include higher levels of anxiety, random pains and aches, issues with digestion, with memory, a drop in libido and sexual enjoyment, even autoimmune diseases.

Managing stress, unsurprisingly, involves either putting the body at ease, or giving it an outlet to channel this tension through. One useful relaxation exercise you can do is to sit in a comfortable position, breathe regularly and deeply, take a few moments to experience and enjoy what your senses are telling you, and imagine tranquil, pleasant, nice scenes or events. Physical exercise can give your body a way to expend stress (it’s the “fight or flight” mechanism, and you’re doing just that). If you just can’t fit any of those into your schedule, talking to a friend or pretty much anyone who will listen about your issues can help lower your levels of stress by giving you emotional support.

Wherever stress stems from in your life, keep in mind that our feelings are not an accurate representation of reality. They’re a product of millions of years of evolution and biochemical tweaking whose sole purpose is to keep you from dying — and if they have to ruin your mood to do so, they will. But you don’t have to bear it alone, and you don’t have to listen to it more than necessary. Take some time every day to relax, unwind, and take care of your mental health, no matter how hopeless things may seem. It’s darkest at midnight, but that’s also when things start getting brighter.

Salve and oil.

Compounds in essential oil may impact hormones, promote male breast development

Essential oils do more than make your skin smell good — they also interfere with your hormonal balance, new research has found.

Salve and oil.

Image credits Kathy Zinn.

Pre-puberty male gynecomastia (breast tissue growth) is a relatively rare condition. There are numerous underlying conditions that can lead to gynecomastia, however, and in certain cases, doctors can’t pinpoint any immediately apparent cause.

A new study could shed light on the root of such cases: the team found that eight chemical compounds contained in lavender and tea tree oils interfere with hormone levels by promoting estrogen and inhabiting testosterone secretion.

Essential oils are used in the manufacturing of many products such as soaps, lotions, shampoos, or hair-styling products. They’re sometimes mixed in cleaning products, even seeing some use in medicinal treatments, but despite being widely seen as benign, even health-promoting compounds, lead researcher Tyler Ramsey from the National Institute of Environmental Health Sciences says caution is the better part of valor when using such oils.

“Our society deems essential oils as safe. However, they possess a diverse amount of chemicals and should be used with caution because some of these chemicals are potential endocrine disruptors,” he says.

The research was prompted by a growing number of reported cases of gynecomastia associated with an usage or exposure to essential oils. More damning, the symptoms subsided once the patients stopped using the oils, associated products, or otherwise limited exposure to the oils. It was also spurred on by previous findings of co-author Dr. Kenneth Korach, who reported back in 2007 that lavender and tea tree oil would interfere with the activity of male-specific hormones, which could affect the development of boys hitting puberty.

The new study took an in-depth look at eight key chemicals contained in the oils. Four of these were shared in both lavender and tea tree oil, while the other four were found in either oil. To determine the effect of each compound, the team isolated samples of each, and then applied these to human cancer cells in the lab, recording any changes they observed.

All eight compounds showed varying degrees of estrogen promotion, testosterone inhibition, or both. More worryingly, most of these eight compounds are found in some 65 other types of essential oils, Ramsey explains.

“Lavender oil and tea tree oil pose potential environmental health concerns and should be investigated further,” he said.

This hormonal effect could explain why people using essential containing such chemicals run a higher risk of developing breast tissue. Naturally, some individuals will be more sensitive to the effects than others, and the level of use/exposure is also an important factor — so individual mileage may vary. So far, the results do suggest that better regulation or a higher level of consumer awareness are required to limit the negative health impacts of essential oils and products that contain them.

But before you assault an essential oil stand crying bloody vengeance, keep in mind that this study has some significant limitations. Chief among them stand the use of cancer cells and the dosages used. Cancer cells, which is what the team used as a subject, may or may not accurately represent the response of other tissues — say, of healthy breast tissue. The dosages (concentrations) the team used could also not accurately recreate the dosage a living, in-vivo cell might experience.

Living organisms also maintain a complex set of checks and balances on hormonal levels, which a culture of cancer cells in a lab couldn’t replicate.

All these limitations should be addressed by future studies before a definite link between gynecomastia in children and tea tree or lavender oil can be established. Until then, here is a list of safety guidelines on the use of essential oils from the Aromatherapy Trade Council:

  • Precautions should be observed when using essential oils since they are highly concentrated.
  • Do not apply undiluted essential oils directly to the skin.
  • Never use undiluted oils on children under the age of three.
  • If you are pregnant you must seek the advice of your doctor, midwife or aromatherapist before using any essential oils.
  • When used appropriately, essential oils and aromatherapy products are safe for all the entire family.

The study results will be presented today, 19 March, at the Endocrine Society’s annual meeting in Chicago.

Fruit fly.

Neuron cluster which can override sleep identified in the fruit fly brain

Certain neurons in the brains of male fruit flies will suppress the animal’s sleep if they have any female to court nearby.

Fruit fly.

Image credits John Tann / Flickr.

Who here hasn’t had to forgo the sweet embrace of sleep when something important pops up — a paper due in the morning, a book you just can’t put down. Or, if you’re a male fruit fly, because there’a a change you might get some action.

A team of researchers from the Sidney Kimmel Medical College at Thomas Jefferson University found that like humans, fruit flies (Drosophila melanogaster) can keep themselves awake if something important pops up. More specifically, they report that a certain group of neurons in the males’ brains can suppress their sleep so they can court female flies.

Up all night to get lucky

The study started from the observation that although male flies usually spend most of the night awake trying to court nearby ladies, those who have recently mated several times (and thus have a low sexual drive) tend to ignore females and simply go to sleep.

It would suggest that something in the fly’s brains has to (consciously or unconsciously) decide what was more important to the fly at one point — sex or sleep. But nobody knew exactly how this process unfolded, and that’s what the team set out to understand.

“The idea that sleep and courtship might compete with each other is intuitive but had not been studied experimentally, and the underlying neural mechanisms had not been explored. We wanted to know how the sleep drive and sex drive compete to determine behavior,” says Kyunghee Koh, PhD, Associate Professor of Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University and senior author on the study.

The team zeroed in on a bunch of neurons dubber MS1 (male specific 1) that seem to be at the root of this process. MS1 neurons aren’t part of any previously known groups of neurons which play a part in male sexual behavior, but work by keeping the males awake so they can ply their charm. They release octopamine, a neurotransmitter similar in function to noradrenalin, which will keep male flies awake in a sexual setting. Experiments showed that silencing the MS1 cluster caused males to go to sleep even if there were females around, and artificially activating the neurons kept males awake even in the absence of females.

Interestingly enough, while females have the same bunch of neurons they don’t seem to function the same — activating or inactivating the cluster had no effect on the females’ sleep.

We don’t yet know whether there are similar mechanisms functioning in our brains, but we do know that noradrenalin creates wakefulness in humans. This would suggest that the neurotransmitter plays a key role when we’re trying to consciously suppress sleep, the team notes.

But until we get a definitive answer on that, the team wants to identify which neuron communicate directly with the MS1 cluster, examine how their activation leads to sleep suppression and how MS1 neuronal activity is regulated.

The full paper “Identification of octopaminergic neurons that modulate sleep suppression by male sex drive” has been published in the journal eLife.

Bioprosthetic ovary.

Female mice birth and nurse healthy offspring after being grafted with prosthetic ovaries

A team of researchers from the Northwestern University Feinberg School of Medicine and McCormick School of Engineering has developed a process to create for fully-organic, 3D-printed ovarian bioprosthesis. Trials on mice showed that females implanted with the ovary could ovulate normally, even give birth to healthy pups and successfully nurse them, the team reports.

Bioprosthetic ovary.

Image credits Northwestern University.

The research stands out in regards to the prosthesis’ architecture and of the team’s choice of ‘ink’. They used gelatin, a hydrogel made from processed collagen, to create a scaffold-like structure which is safe to use in living organisms. Gelatin is a lot more resilient than other hydrogels, meaning the prosthetics can be made porous while staying hardy enough to be handled during surgery.

“We found a gelatin temperature that allows it to be self-supporting, not collapse, and lead to building multiple layers. No one else has been able to print gelatin with such well-defined and self-supported geometry,” said Ramille Shah, assistant professor of materials science and engineering at McCormick and of surgery at Feinberg.

Holesome prosthetics

That porosity is a critical element for a functioning ovarian replacement. The team was the first to show that the hormone-producing cells of the ovaries, called follicles, the same cells which surround and care for immature eggs/ova, have a much better chance of surviving in a scaffolding-like structure than on a solid platform.

Ovarian scaffolding structure.

Image credits M. Laronda et al., Nature Communications, 2017.

Creating the prosthetics is similar to building a house of logs, said Alexandra Rutz, co-lead author of the study and a former biomedical engineering graduate fellow in Shah’s Tissue Engineering and Additive Manufacturing (TEAM) lab at the Simpson Querrey Institute. You lay the logs at right angles to form the overall structure, and simply leave more space between them when you want a window or a door. Similarly, the printer lays down filament-like structures. By altering the distance between them as well as the angle between successive layers, the team can create any arrangement of pores of variable sizes.

They designed this prosthetic based on the structure of the “ovary skeleton”, and liken it to the scaffolding that surrounds buildings undergoing repairs or those still under construction. But unlike traditional scaffolding, it’s meant to be permanent. The prosthetic is meant to be implanted into a female, where it will promote and guide the development of new follicles, and then keep these cells and the developing eggs safe and happy to boost their effectiveness. Because the prosthetic is mostly open space, there’s enough room for blood vessels to grow and shuttle hormones and nutrients to and from the rest of the body. It also ensures there’s enough space for eggs (which are some of the largest single human cells at 0.12 millimeters) to mature in.

Printing for posterity

The bioprosthetic scaffolding should help restore fertility and normalize hormone production for women who risk infertility and hormone-associated developmental issues following childhood or adult cancer treatments. Some patients’ ovaries can partially or completely shut down following treatment and need to undergo hormone replacement therapies to maintain a normal developmental pattern — such as triggering puberty, for example. The prosthetics should offer an alternative long-term treatment for these patients, who didn’t have any alternative apart from ovarian transplants (usually from cadavers) address their condition until now.

“The purpose of this scaffold is to recapitulate how an ovary would function. We’re thinking big picture, meaning every stage of the girl’s life, so puberty through adulthood to a natural menopause,” said Monica Laronda, co-lead author of the paper.

Mice females who had their ovaries replaced with the scaffolding had healthy pups and showed normal nursing behaviors, suggesting a normal hormone balance. Successful creation of 3D-printed implants which can replace complex soft tissue could significantly aid future research into soft tissue regenerative biomedicine, the team notes.

The full paper “A bioprosthetic ovary created using 3D printed microporous scaffolds restores ovarian function in sterilized mice” has been published in the journal Nature Communications.

Hormone therapy successfully used to stop cells from aging for the first time

Researchers have discovered they can use a male hormone to reverse cell ageing, offering hope for treating a host of conditions caused by cell degradation. Their clinical trial is the first time hormones have been proved to reverse the processes that naturally take place in human cells as they age.

Image via Flickr

US and Brazilian researchers have successfully used danazol, a synthetic male hormone, to stop cells from deteriorating with age. The hormone stimulates the production of telomerase, an enzyme which keeps cells “young” by stopping their genetic material from shrinking. It does this by keeping telomeres — the red caps you see in the picture at the end of chromosomes — intact.

“One of the processes associated with ageing is progressive shortening of telomeres, DNA-protecting structures at the ends of chromosomes, like the plastic tips on shoelaces,” explained one of the researchers, Rodrigo Calado from the University of São Paulo in Brazil.

“Each time a cell divides, its telomeres get shorter,” Calado added. “Eventually, the cell can’t replicate anymore and dies or becomes senescent [biologically aged]. However, telomerase can keep the length of telomeres intact, even after cell division.”

In the study, danazol was prescribed over two years for 27 patients suffering from aplastic anaemia (premature ageing of bone marrow stem cells), caused by telomerase gene mutations. Over this time, a person would typically lose 100 to 120 telomere base pairs per year, but someone with a telomerase deficiency could lose between 200 and 600 base pairs.

Telomerase is naturally produced in cells that constantly divide, such as blood-forming stem cells. Previous research has shown that it has a huge role to play in maintaining these cells in working order, and increasing levels of telomerase helps protect them from wearing out over time. On the other hand, a lack of this enzyme can cause organ damage and increases the risk of cancer.

Under the new treatment, the study participants’ cell telomere length not only stopped shrinking but increased by 386 base pairs on average. Hemoglobin mass rose too, which meant patients were no longer dependent on blood transfusions.

This study proves that prescription steroids can be used to increase telomerase production on demand. confirming the results previously seen in the lab in live humans. Based on these findings, new treatments for conditions such as aplastic anemia or pulmonary fibrosis (where the lungs become scarred) could be developed, the team said.

But they should be cautious in developing new treatments – sex hormones can come with notable side effects, including mood swings, tiredness, and digestive system problems.

The full paper, titled “Danazol Treatment for Telomere Diseases” have been published in the New England Journal of Medicine.

What are hormones — everything you need to know

Let’s talk about hormones — what are they?

3D model of the hormone adrenaline.
Image via pixabay

Hormones are all molecules that serve as chemical messengers inside our organisms. In animals, they’re produced in endocrine glands (glands that pour their secretions directly in the blood), although the term is sometimes used to refer to autocrine and paracrine chemicals too. Hormones are found in both plants and animals and they underpin communication inside the organism. They govern almost everything from hydration, hunger or sleep to reproduction, emotions, and mood.

In a sense, they are your internal equivalent of an inter-department e-mail, only actually important — the term hormone comes from the ancient-Greek word for “impetus,” showing the power they have to activate or inhibit the cells and organs in our body.

Some of the most important endocrine glands are:

  • Pituitary – the hormonal capo di tutti capi, the pituitary gland controls other glands and makes the hormones that trigger growth.
  • Hypothalamus – responsible for body temperature, hunger, moods. Triggers the release of hormones from other glands; and also controls thirst, sleep, and sex drive.
  • Thyroid – produces hormones associated with calorie burning and heart rate.
  • Adrenal – produce the hormones that control sex drive and cortisol, the stress hormone.
  • Pineal – produces serotonin derivatives of melatonin, which affects sleep.
  • Ovaries – female exclusive, the ovaries secrete estrogen, testosterone and progesterone, the female sex hormones.
  • Testes – a dudes’ special, the testes produce the male sex hormone, testosterone, and produce sperm.

 

As I’ve said earlier, while the cardinal example of hormonal secretion takes place in glands, it’s not limited to them.

Thyroid gland tissue.
Image via flickr

Specialized cells in other organs also produce hormones in response to specific signals from your body’s regulatory systems. Insulin, for example, is produced in the pancreas in response to blood sugar. Your intestines secrete hormones to tell your stomach or pancreas to scale up or cut down on their activity depending on how full they are.

Some of the most important human hormones

As listed by healthguidance.org, are:

  • Melatonin – kind of like your internal clock, it anticipates the daily onset of darkness. Melatonin has a huge role to play on your energy levels throughout the day, and it’s what makes you drowsy at night.
  • Serotonin – controls appetite, mood and sleep cycles. The extra serotonin produced during puberty is what gives teens their emotional volatility.
  • Thyroxin – secreted by the thyroid. Increases the rate of your metabolism and affects the process that cells go through to build protein.
  • Epinephrine – also known as adrenaline. Responsible for the fight-or-flight response during stressful situations.
  • Norepinephrine – also known as noradrenaline. It controls the heart and blood pressure, contributes to the control of sleep, arousal, and emotions. An excess of norepinephrine can make you feel anxious while too little will have you feeling depressed or sedated.

So how do hormones work?

I’m glad you asked.

In broad strokes, hormones need to be secreted, stored, released & transported, recognized by the cells, relayed and amplified, then broken down, in this order.

The first step, secreting the right hormone for the right job, takes place in glands; in general, these messengers fall under one of three chemical classes: eicosanoid hormones, steroids, and amino acid derivatives. They’re synthesized in an inactive state (pre- or prohormones) by the associated gland’s cells and are stored. They can be quickly converted to an active state when required, and then released.

Hormones are released when regulatory systems signal a particular need inside the body that this hormone can address. This can be caused by unusual concentrations of a particular substance or nutrient in the body, changes in the environment, but also directly dictated by other hormones (known as tropic hormones.)

Water-soluble hormones are released directly into the blood. They then travel around until they meet a specific “receptor” protein. These are found embedded on the cellular wall or membrane of cells, and bind the hormone to them.

The hormone-protein interaction generates an electric potential which leads to the activation of a signal transduction pathway through the membrane. This in turn causes so-called “second messengers” to be secreted beyond the membrane, that interact with the cell and cause a response. This system has the advantage of creating signal transduction cascades, which greatly amplify the strength of the original first messenger signal.

Lipid (or fat)-soluble hormones such as steroids can pass through the membranes of cells and act directly on their nucleus.

Left: a steroid (lipid) hormone (1) entering a cell and (2) binding to a receptor protein in the nucleus, causing (3) mRNA synthesis which is the first step of protein synthesis.
Right: protein hormones (1) binding with receptors which (2) begins a transduction pathway. The transduction pathway ends (3) with transcription factors being activated in the nucleus, and protein synthesis beginning.
(a) is the hormone, (b) is the cell membrane, (c) is the cytoplasm, and (d) is the nucleus.
Image via wikimedia

No matter the mechanism, once in contact with a hormone the cell is informed that it’s either supposed to do something, stop doing something, or just do it differently, depending on the need. Cells do this either through non-genomic effects (any action that does not directly and initially influence gene expression — thus can be performed quickly, from seconds to minutes) and genomic responses (where the hormone activates gene transcription, causing an increased expression of a desired protein.)

Now the message is transmitted and the cells are hard at work doing what they’re supposed to. Regulatory systems pick up on the new conditions (for example, that the blood sugar level isn’t low any more or that core temperature has been adjusted) and relay this back to the glands, which adjust or shut down synthesis. This is called a homeostatic (maintaining internal balance despite external factors) negative (diminishing effect) feedback-loop, and characterizes most hormonal processes.

All that’s left to do now is for the hormones already in the system to break down and the cycle is complete. Pretty elegant.

But what if I don’t want any?

Gynecomastia (male breast development).
Image via flickr

By their very nature, hormones are involved in processes that require coordinated action throughout the body. They control growth, the metabolism and take the body through developmental phases (such as puberty). Hormones also dictate the timing of cell deaths, ramp up the immune system and control the metabolism.

They help us fit into and survive in our world by synchronizing the wake-sleep cycle and other circadian rhythms with the environment, initiating the fight-or-flight response, or giving our muscles a boost when our life depends on it.

They also have a powerful effect on how you feel; hormones can cause mood swings and govern sexual arousal (aka being “hor”-ny).

Because of their role as signaling molecules, hormonal imbalances tend to impact several organs or systems at once. For example, PCOS (Polycystic Ovary Syndrome), the most common hormonal condition in US women, can cause irregular or missed periods, heavy periods, difficulty becoming pregnant, male-pattern hair growth, weight gain, acne, and formation of cysts on the ovaries. In men, androgen (male sexual hormone) deficiency leads to reduced sexual desire, reduced mass of bone and muscle, depression, loss of body hair and breast growth. Too much of the growth hormone can lead to gigantism.

That’s why hormones are essential, but also why too much or too less can be a bad thing. Somehow, nature has found a way to keep things balanced for most of us. Sure, when things seem hectic, depressing or downright scary, you can pin it on hormones. But there’s also love, sexual desire and good old appetite. Hormones make life possible worth living.

 

 

Study finds why men have a better sense of direction

Each sex’s take on navigating through the world around us, and especially the differences between them, is a subject that often surfaces during stand-up acts and day-to-day humour; “Women can’t drive,” or “men never stop to ask for directions” are all things you’ve probably heard before and to an extent, believe. There’s a kernel of truth here; it’s been well established experimentally that men in general handle specific spacial tasks better than the fairer sex.

But what generates these different takes on the same problem? It’s not the brain — we know that for all intents and purposes, brains can’t be distinguished by sex (but they do form connections differently). Cultural conditioning, upbringing and other factors certainly play a part in this, and that can’t be quantified. But Norwegian University of Science and Technology (NTNU) team was interested in the effect of something we can quantify — sexual hormones.

The researchers created two teams of 18 members, divided by sex, and asked them to orient themselves through a very large virtual maze using 3D goggles and a joystick, while the researchers looked at their neural activity.

Study explains why men tend to have a better sense of direction than women.
Image via psypost

Who wants to be a Maze runner?

After familiarizing themselves with the maze for an hour, the subjects were strapped to a fMRI scanner and their brain activity was recorded while the tests progressed. They were given 45 navigational tasks (such as “find the yellow car” from different starting points) and 30 seconds to solve each one of them in.

“Men’s sense of direction was more effective. They quite simply got to their destination faster,” says Carl Pintzka, a medical doctor and PhD candidate at NTNU’s Department of Neuroscience.

The men solved 50 per cent more of the tasks than the women. The recordings show that men took several shortcuts, relied on cardinal directions to a greater degree and, more importantly for Pintzka, used a different part of the brain to orient themselves than the women in the study. And this is the reason why the guys were able to solve more of the tasks; using cardinal directions allows for a much greater flexibility while navigating, and lends itself better to reaching a known point from an unknown position as long as you know where you have to go.

“If they’re going to the Student Society building in Trondheim, for example, men usually go in the general direction where it’s located. Women usually orient themselves along a route to get there, for example, ‘go past the hairdresser and then up the street and turn right after the store’,” he says.

1-0 for the dudes, time for round two

The fMRI scans showed that navigating through space is a complex process — large areas of the brain are involved in orienting ourselves, but there are some key differences. In men, the team saw more activity in the hippocampus, whereas women tended to show more activation in the frontal areas of the brain.

“That’s in sync with the fact that the hippocampus is necessary to make use of cardinal directions,” says Pintzka.

And, from an evolutionary point of view, these results make perfect sense. While our brains are structurally the same, gender roles in those primitive human communities meant that they had to be good at different tasks.

“In ancient times, men were hunters and women were gatherers. Therefore, our brains probably evolved differently. For instance, other researchers have documented that women are better at finding objects locally than men,” Pintzka says.

In simple terms, women are faster at finding things in the house, and men are faster at finding the house.”

A little testosterone under the tongue

The next step was to try and see if the women’s brains could be made to navigate similarly to that of the men.

This time, 42 women were divided into two groups, receiving either a drop of testosterone or placebo under the tongue. To increase accuracy, the team used a double-blinded test so that neither Pintzka nor the subjects knew who got what.

“We hoped that they would be able to solve more tasks, but they didn’t. But they had improved knowledge of the layout of the maze, and they used the hippocampus to a greater extent, which tends to be used more by men for navigating,” says Pintzka.

Pintzka’s research could offer doctors insight into Alzheimer’s disease. As two in three patients are female and loss of direction is one of the first symptoms.

“Almost all brain-related diseases are different in men and women, either in the number of affected individuals or in severity. Therefore, something is likely protecting or harming people of one sex. Since we know that twice as many women as men are diagnosed with Alzheimer’s disease, there might be something related to sex hormones that is harmful,” says Pintzka.

He hopes that by understanding how men and women use different brain areas and strategies to navigate, researchers will be able to enhance the understanding of the disease’s development, and develop coping strategies for those already affected.

The paper can be found online here.

Is it possible to inherit happiness?

So here it is: a new study comes to show that the way we feel throughout our lives may determine our children’s development. It’s all a problem of chemistry: the “chemistry” of happiness or sadness. However, don’t think that the fact that one’s parents had a bad day at work turned him or her into a emo kid. The other factors such as education, family situation and genetic traits remain just as important as before.

What Dr, Halabe Bucay of Research Center Halabe and Darwich, Mexico, wanted to suggest is that different moods lead to the release of certain substances and hormones by the brain, substances that could affect eggs and sperm, which means the offspring too. Some genes may be modified by these substances, which should ultimately influence the way a child develops.

So, one’s depression, generalised happiness or other mental states could lead to some changes at the time of the conception in the child to be born 9 months later.

Prior to this discovery scientists were fully aware of the effects endorphins or drug consumption, especially marijuana and heroin, could have on the development of a baby as they alterned the patterns of the genes.

And talking about genes: the genes you receive from your parents are also very likely to influence or maybe even determine your character ( the old nature versus nurture question).

And still, it seems very likely that one’s parents’ behavior and state of mind before the time of the conception may very well have a say in the way a child will evolve. The idea is more than intriguing and the debate is yet to start. More data is necessary before actually making parents reconsider their lifestyle and level of happiness before having a baby.

sourcr: Elsevier

Women’s infidelity caused by high level of hormones

Apparently, scientists have finally found the answer (or, at least part of it) to the QUESTION: what is it that makes women cheat on their partners? Before starting to call names if it has already happened to you, find out that it’s not a more expensive car or a bigger account, but something else: a high level of hormones.

Doctoral candidate Kristina Durante and Assistant Professor of Psychology Norm Li from The University of Texas at Austin discovered that having too much of the sex hormone called oestradiol can determine a woman to become infidel.

The researchers found a connection between the hormone, which is related to fertility, and sexual motivation after studying women aged between 17 and 30 who were not using contraception.

The subjects’ level of oestradiol was measured two times during their ovulatory cycle, while they were asked to say how physically attractive they thought they were, being asked about their likelihood to cheat on a partner too. Independent observers were also asked to rate the women’s attractiveness.

It was discovered that the participants with the highest level of oestradiol considered themselves the most attractive, also claiming to have a higher tendency towards flirting, kissing or having a serious relationship with another man (however, not towards a one-night stand). Oestradiol levels are also associated with a feeling of dissatisfaction with one’s primary relationship.

This shows that women who are very fertile are hardly satisfied by a long-term partner and are more likely to search for another one, who is more desirable. This is not related to engaging into casual sex tough. These women are more likely to choose serial monogamy.

It seems that physiological mechanisms are still highly important for a woman, influencing both her partner choices and behavior. So that sports car may not help, after all!

source: The University of Texas