Posted on 05/30/2009 1:43:56 AM PDT by Schnucki
The female brain reacts differently to stressful situations, distress and depression than the male brain. Research in psycho-pharmacology - the study of drug-induced changes in mood and behaviour - however, is primarily done with male lab animals and therefore provides a distorted picture, Dutch researchers say.
Gert ter Horst, a professor of neurobiology at the University Medical Centre in Groningen , and his colleagues have examined the way male and female rats deal with stress. They published their findings in the scientific magazine Physiology & Behavior. "Gender differences have become a booming field of research only recently," they write.
"We have this running gag in the lab: 'If you know how a man responds to something, can you predict how a woman will? Exactly the opposite!,'" Ter Horst says. "But it is not a joke, really. When it comes to the brain, the male and female are completely different worlds."
Sex hormones
Chronical stress, Ter Horst explains, is often a precursor to anxiety disorders and depression. Therefore psychiatrists are very interested in the subject and much research is done on animals, like rats, whose brains have physiologic resemblances to the human brain. Most studies use male rats, because the cycle makes researching females more difficult. The female sex hormones have highs and lows and influence emotions, causing fluctuations in the test results.
"But the prevalence of anxiety disorders in women exceeds that in men two to three times," according to Ter Horst. "So it is very weird that the research is conducted only with male rats."
The rats tested in Groningen showed significant differences in the activities in certain areas of the brain that play an important role in emotions, such as the pre-frontal cortex. Under low stress circumstances, activities in this area of the brain are much lower amongst male rats than their female counterparts.
Exposure to stress increases brain activity in both sexes, but females have more difficulty sustaining that activity. At a certain point they overload, after which their brain sort of shuts down and psychiatric disorders can develop.
"There is a limit to brain activity", Ter Horst explains. "And because the natural level in the female brain activity is closer to that saturation point, they reach it sooner when suffering from stress."
The neurobiologist emphasises that the level of the basic brain activity is not caused by female sex hormones. The difference is rooted in the brain itself, research shows. Ter Horst also used female rats whose ovaries had been removed so that they no longer secreted sex hormones to the blood. Females without a cycle also had a higher level of brain activity than males - even more so than those with ovaries. "Apparently sex hormones mute the brain activities and mitigate the effect of stress."
Social support
Hormones do not make females more resilient to stress, however, because the hormone levels fluctuate and alter the brain activities. "Those fluctuations make women more vulnerable to stress. Depression and anxiety mostly strike during times when there are severe changes in hormone levels. Not so much during their monthly periods, but after giving birth, during puberty or during menopause."
Through the course of evolution, female animals seem to have developed a strategy to cope with this: social support. Women mammals lick each other or lie against each other in times of stress. Ter Horst and his team discovered that female rats recover from stress better when they are surrounded by those of the same sex. This form of social support did not seem to have much of an effect on the brain of male rats. A mixed group added to the stress level.
Through the course of evolution, female animals seem to have developed a strategy to cope with this: social support. Ter Horst and his team discovered that female rats recover from stress better when they are surrounded by those of the same sex. This form of social support did not seem to have much of an effect on the brain of male rats. A mixed group even added to the stress level.
The researchers worked with single sex groups only and the impact on females was striking. The social support stimulated the production of the neurotransmitter serotonin. That substance mutes the effects of stress the same way anti-depressants do. When the female rats are isolated, their serotonin system is not activated. "When you expose a rat to stress and then bring it back to its group, the others in the cage start taking care of the suffering animal. They will lick each other or lie against each other in times of stress, the males as well," says Ter Horst.
Ter Horst doesn't like translating his results to human situations, but here he makes an exception. "When women go through something stressful, they want to talk about it, again and again. That relieves their stress. Men don't have that desire so much."
Same old “people are vermin” meme.
Anyone who’s ever kept pet rats already knew this! It’s common knowledge that females are much happier kept in pairs at a minimum, and thrive in colonies of several.
Rats are intensely social creatures. Anyone who’s seen a cageful of them sleeping in a pile or grooming each other can figure this out. Females are social, males are territorial.
Only recently has it been deemed necessary to study that which is intuitively obvious.
I’ve had lots of pet rats.
If a male’s cage mate died, the survivor did pretty well.
[except for Rex who was inconsolable when his pal Pete died. He grieved for 2 days until I brought home “Bucky” who was very young and Rex set about “mothering” him. immediately]
The last 2 females I had, it was totally the opposite.
Pinky passed away from old age and within 2 days, an otherwise healthy and much younger Mouse died, too.
She just gave up and even showering her with attention did not help.
For years, I preferred the females as pets because they were more independent, personable and active.
I learned fast that if a “gal pal” died, I had to haul arse to the pet store immediately and get another girl.
Whereas we men just need to go out and build or shoot at something. Or watch football. Or drink.
>>>>> Only recently has it been deemed necessary to study that which is intuitively obvious. <<<<<<
For 35 years there’s been an extremely crude and really bizarre assault on men and women, mainly by feminist whackos but also by gays and others.
It’s core belief is that “there’s no essential difference between men and women.”
Of course this it utter and complete hogwash as is plainly and simply evidenced by 6,000 years of recorded human history, but also as you said above by the intuitively obvious physical, hormonal, and instinctual differences that are part of human existence.
The contemporary notion that recognizing and stating these clear human differences is somehow “politically incorrect” is literal cultural insanity.
It is the sign that out civilization has gone completely mad.
My ex GF did have beady red eyes like the Sprague-Dawley Rats so I guess this makes sense!
So now we know it applies to female rats, how about female Republicans?
Anotehr piece of evidence from science that humans were created to live in polygamist marriage arrangements.
The male auxiliary brain is in control under low stress circumstances. Always a dangerous proposition.
Well, that pretty much confirms things for me. Thank God I’m a male rat.
Nothing like having science validate from which man has already known.
I don’t agree that the female brain shuts down under stress. It just goes into the mode where it tries to find a male to deal with the problem. :^)
I knew that
I had that happen with brothers once.
There were 3 males out of that litter...2 huge, good natured fellows who got along splendidly and then the third brother had a serious case of littleman syndrome. I had to seperate him before he got his dumb butt squished picking fights...he was only a little bigger than my females.
The two big guys were really attached to each other...when one died, after a day or two of illness, the other died less than a week later. You could tell he was absolutely lost.
I ended up keeping the mother of that litter in with her daughters...everyone seemed happy with that arrangement.
I’d originally gotten her to be a cagemate to a female I’d gotten from a petstore several weeks before, but it turns out Bear was quite happy to have her cage to herself. Figures that I’d have the rats who break every established rule. I’m pretty sure Bear took perverse delight in that, too...she was one of the smartest critters of any type I’ve ever had.
Have you seen the movie, “One Rat Short”? Its only ten minutes long. I recommend it. Excellent animation.
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