Neuronal Basis for Pre-mature Ejaculation?

That’s right, lifelong premature ejaculation is considered one of the
most common, if not THE most common sexual disorder. While some people
believe that this results from psychological issues (a self-learned
behavior during your first hurried sexual encounters as a teenager),
many scientists are coming to believe that premature and delayed
ejaculation are just two ends of a big bell-shaped distribution of
ejaculation latency in humans.

(Interesting side note, did you know that they did a study where they
timed men in intravaginal ejaculation latency, and the result was 5.4
minutes on average?! I really hope they had a positive skew…and Sci
NEEDS to blog that paper…next week, kids, next week!)

The biological explanation for premature ejaculation is backed up by
the fact that you can treat premature ejaculation with SSRIs (where
normally the decreased sexual function in response to an SSRI, a
popular type of antidepressant drug, if considered a nasty side
effect, there’s a use for just about every side effect if you put your
mind to it), though of course the possible placebo effects of the
treatment shouldn’t be underestimated either.

So the big question is how to really get apart whether premature
ejaculation is a biological phenomenon, or a psychological phenomenon
(which could, of course, have a biological basis). And one way to do
this is to attempt to change ejaculation latency in animals, like
rats. Unfortunately, when people do studies to change ejaculation
latency, they always take care of pick rats that display “normal”
ejaculatory behavior. But not all rats are normal. There are
differences in ejaculation latency between experienced and
inexperienced rats, as well as differences in hormone levels. One of
the hormones most involved with ejaculation in males and females?
Oxytocin! So for this study, the scientists wanted to look at a full
population of rats, determine just what kind of ejaculation latency
was “normal”, and see how this correlated with oxytocin levels in the
rats’ brains.

And here’s where we take a moment to think about the poor grad student
or lab tech who, in a huge sacrifice to science, took a whole bunch of
rats, every week, and watched them mate. Every week. Watching rats
mate. With a stopwatch (or probably several) recording how long it
took males to mount a female, how many times he did it, when he
finally ejaculated, and how frequently he ejaculated during a 30
minute session. Sci wonders a little how they could tell, by the
number of cigarettes the rat smoked during the session?

Yeah. I wouldn’t want to be them. Though I bet they had a GREAT time
explaining their research in bars.

Based on the many, many weeks (apparently rats receiving six training
sessions and then were tested, so that’s seven weeks) of sexual
activity, the rats were grouped into three groups, sluggish
ejaculators (0-1 total during the session), normal ejaculators (1-3
total), and rapid ejaculators (more than 3).

Bring on the graphs!

pattij 2005-1.png

You can see above the ejaculation numbers during a session for all
rats over all the experiments performed. Interestingly, the curve fit
has a rightward skew, with relatively few really high ejaculators,
though this could be due to some rats maybe not habituating to the
environment well and thus not performing as well.

To show you the other data, Sci’s going to have to graph. Sigh…I
graph because I love, I graph because I love…the things I do for
science…

pattij 2005-2.png

So what Sci has graphed for you there is the mount frequency, or the
number of times during a sexual session that a male mounted a female.
You can see that the sluggish ejaculators mounts far more than normal
or rapid ejaculators, but that’s probably just a function of how long
it took them (or possibly a measure of their sheer persistence). So we
get to this graph:

pattij 2005-3.png

Here you can see the ejaculation latency for the rats, and clearly
there’s a pretty big difference. And Sci has to hand it to these
scientists. That’s 12 rats, and small error bars, which is something
for behavioral measures. Excellent job habituating, peeps!

So what is the cause for some rats being slow and other rats being
fast? It could be a matter of penile sensitivity, as human men who
suffer from premature ejaculation are known to be more sensitive. But
it could ALSO be oxytocin! The scientists point that
oxytocin-containing neurons in the hypothalamus showed more activation
in rapidly-ejaculating rats than in sluggish rats, as you can see
below.

pattij 2005-4.png

So what did the scientists conclude from this? First, they concluded
that “premature” ejaculation is probably just the far end of a bell
curve in rats, and this may possibly be the same in humans, no
psychological issues involved. They also suggest that rapid
ejaculators may have higher oxytocin neuronal activity, which could
have something to do with their impressive abilities. So who knows,
perhaps carefully applied oxytocin antagonists (you wouldn’t want to
use too much, and you’d definitely want to watch for side effects)
could save some people some major embarrassment in the future, and
maybe oxytocin agonists could help out those who…take a little
longer.

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Belgian Man Trapped In Coma For 23 Years Was Conscious Throughout

Rom Houben, a Belgian man whom doctors believed to have been in a coma for 23 years following a car crash in 1983, was conscious all the time:
we know because Houben himself has told us, in several media interviews conducted over the last few days.

Doctors in Zolder, Belgium, had repeatedly diagnosed Houben using the internationally accepted Glasgow Coma Scale to assess his eye, verbal and motor
responses. But each time he was incorrectly graded as being in a vegetative state, reported the Daily Mail.

It was only when Steven Laureys, a doctor and researcher at the University of Liège, scanned Houben’s brain in 2006 and discovered it was still
working, although his body was paralysed, that doctors began to realize he may be conscious.

Now 46, Houben told the BBC that he had to learn to be patient. He was very angry at first when he realized other people had an opinion of him that
was rather pathetic, but he had to learn to be patient, he said.

Intense physiotherapy for the last three years has been helping him regain some movement, reports the Guardian.

Houben said he realized when he came round after his accident that his body was paralyzed, and while he could hear everything the doctors were
saying, he couldn’t communicate with them.

“I screamed, but there was nothing to hear,” said Houben.

“I dreamed myself away,” he added, using one finger on a computer touchscreen attached to his wheelchair. The computer is also fitted with a special
device that allows him to read books while lying down, reported the Daily Mail.

Houben said he just spent the time dreaming of a better life.

“Frustration is too small a word to describe what I felt.” he said.

Houben’s paralysis was the result of his brain being starved of oxygen when his heart stopped for a few minutes.

A former engineering student who speaks four languages, Houben said he coped by meditating, according to a Guardian report.

He told his doctors that sometimes he was only his consciousness and “nothing else” as he travelled with his thoughts into the past or “into another
existence”.

When the doctors discovered he was not in a vegetative state, Houben described feeling reborn:

“It was my second birth,” he said.

Time-space fusion | Mind Hacks

Neurophilosophy has an excellent piece on ‘time-space’ synaesthesia where affected individuals experience units of time – such as hours, days, or months – as occupying specific locations in space relative to their own body.

The image on the right is taken from a BBC News article on time-space synaesthesia and was drawn by one lady to illustrate how days of the week appear to her.

However, Neurophilosophy piece covers two new studies, one on a person with synaesthesia who experiences months in the space around her body in the form of a ‘7’ shape:

Michelle Jarick of the Synaesthesia Research Group at the University of Waterloo in Ontario and her colleagues describe the case of an individual whose time-space synaesthesia has a previously undescribed feature. Like other time-space synaesthetes, the 21-year-old individual, known as L, experiences the time of day and the months of the year as being represented in the space around her body. She experiences the hours of the day in the form of a large “clock face”, and her mental calender consists of a giant number “7”, which extends for approximately 1 meter around her waist, and on which the months of the year are arranged.

Both of the studies covered in the article demonstrate a crucial technique in synaesthesia research – in part, a demonstration that the effect is a genuine cross-over of the senses.

The general technique is the same no matter what form of synaesthesia you’re testing. It involves finding a task which will be changed by the triggered sense but not (or not so much) by the original perception.

For example, with the lady who drew the layout of her months in the image above, October appears on her right and July appears on her left.

So if you did a reaction task that involved indicating what side a word appeared on, you’d expect someone with this form of synaesthesia to do worse when October appeared on the left and July appeared on the right, owing to the confusion caused by the unfamiliar associations, or better when they appeared on the expected sides.

This form of study, where synaesthesia can be shown to improve or worsen performance on other tasks related mostly to the triggered perception is the basis of much research in this area, and the Neurophilosophy piece outlines how these two new studies have shown how time-space fusion is associated with better abilities in understanding time and space.

Vaughan.

Link to Neurophilosophy on ‘The cognitive benefits of time-space synaesthesia’.

Link to BBC News on time-space synaesthesia.

 

High unexpressed anger in multiple sclerosis patients linked to nervous system damage, not disease severity

Italian researchers assessed 195 patients with MS, using a range of scales that measure anger, depression and anxiety, and then compared them with the general population.

They were surprised by the results, which showed that while patients experienced almost twice the normal level of withheld anger and exerted low levels of control on their anger, their expressed anger levels were similar to the general population.

This, together with the fact that the elevated withheld anger levels were not related to the severity of the patients’ MS, suggests that these inconsistent changes were caused by nervous system damage, rather than an emotional reaction to the stress of the disease.

“We believe that the higher levels of withheld anger shown by the study subjects is due to demyelination, loss of the substance in the white matter that insulates the nerve endings and helps people receive and interpret messages from the brain” explains lead researcher Dr Ugo Nocentini from the IRCCS S Lucia Foundation in Rome.

“The way we process anger is controlled by complex interconnections between the subcortical and cortical systems, notably the amygdale and basal ganglia and the medial prefrontal cortex. We believe that the demyelination process that causes the root symptoms of MS also disrupts the pathways that control how we deal with withheld anger.”

The patients who took part in the study comprised 150 with relapsing-remitting MS and 45 with progressive MS. More than two-thirds (68 per cent) were women, the average age of the participants was 40 and the average time since diagnosis was 11 years.

Researchers evaluated the participants using the State Trait Anger Expression Inventory, the Chicago Multiscale Depression Inventory and the State Trait Anxiety Inventory.

The researchers then looked at age and sex-matched subjects in the general population and identified the levels of anger experienced by the 25 per cent of people with the highest scores.

They found that MS patients:

  • Were more than twice as likely to experience high levels of withheld anger, with 60 per cent of patients recording the same high levels as the top 25 per cent of the general population.
  • Exerted a low level of control on their anger, with just 11 per cent of patients reporting the same high levels of control compared to the top 25 per cent of the general population.
  • Were about the same as non MS patients when it came to expressed anger, with 30 per cent of patients reporting the same high levels as the top 25 per cent of the general population.

During the study the authors also compared the anger scores against selected demographic and clinical characteristics and found they were independent of age, education, disease duration and course, disability and fatigue severity. The only notable difference was that women reported higher levels of current anxiety.

“Our findings clearly show that anger characteristics in MS patients differ from those observed in the general population and the overall results surprised the research team” concludes Dr Nocentini.

“For example, patients reported low levels of anger control and high levels of withheld anger, yet the scores for expressed anger were similar to those of the general population.

“We would have expected greater consistency between withheld and expressed anger and higher levels of expressed anger as a consequence of low anger control.”

The authors conclude that damage to the fibres in the areas of the brain where anger issues are processed is the most logical explanation. They also say the findings have important implications for clinical practice.

“Anger disrupts interpersonal relationships and this is particularly true for withheld anger, which might go unrecognised by other people” says Dr Nocentini. “Witheld anger has been reported to be associated with physical problems, in particular high blood pressure and vascular disorders, and may have a negative effect on the general health of MS patients.

“Because withheld anger has no, or few, overt manifestations, and is unlikely to be recognised by clinicians or reported by patients, it is important that MS patients are asked if they experience abnormal anger.”

Do blind people hallucinate on LSD? | Mind Hacks

I’ve just found a remarkable 1963 study [pdf] from the Archives of Opthalmology in which 24 blind participants took LSD to see if they could experience visual hallucinations.

It turns out, they can, although this seems largely to be the case in blind people who had several years of sight to begin with, but who later lost their vision.

Those blind from a very early age (younger than two years-old) did not report visual hallucinations, probably because they never had enough visual experience to shape a fully-functioning visual system when their brain was still developing.

It is evident that a normal retina is not needed for the occurrence of LSD-induced visual experiences. These visual experiences do not seem to differ from the hallucinations reported by normal subjects after LSD.

Such phenomena occurred only in blind subjects who reported prior visual activity. The drug increased the frequency of visual events such as spots, lights, dots, and flickers. However, the complex visual experiences reported by 3 subjects after LSD did not occur after placebo or in ordinary experience.

It is interesting to note that duration of blindness was not related to the occurrence of visual hallucinations; nor was intelligence, acuity of visual memory, or use of visual imagery in speech.

I mentioned in an earlier post on auditory hallucinations in deaf people that I’d heard rumours of studies on LSD in blind people but never found any reports. This study is not the only one it seems. The paper reviews several other studies in the same area.

Three other reports deal with the effects of hallucinogenic drugs on blind subjects. Alema reported that 50 micrograms of orally administered LSD induced elaborate visual hallucinations in a subject with bilateral enucleations of the eyeball. However, the effects of 50 micrograms of LSD are stated to have persisted for the incredibly long period of 5 days (they usually last 6 hours). This subject was noted to have spontaneous visual activity.

Zador administered mescaline orally in doses of 0.05 to 0.4gm to 10 blind subjects. Elaborate visual hallucinations usually followed. Most of the subjects had prior spontaneous visual activity, but it is difficult to evaluate this activity because they also had central nervous system diseases. The presence or absence of light perception was not specified for this group, and no control studies were carried out.

Forrer and Goldnerr gave LSD, 1 microgram per kilogram to 2 blind volunteers, both of whom had suffered destruction of the optic nerves. Neither reported visual hallucinations, no mention was made of prior spontaneous hallucinations, and no mention was made of prior spontaneous visual activity.

Vaughan.

pdf of full text of study.
Link to PubMed entry for study.

 

Disruption Of Circadian Rhythms Affects Both Brain And Body, Mouse Study Finds

A new study has found that chronic disruption of one of the most basic circadian (daily) rhythms — the day/night cycle — leads to weight gain, impulsivity, slower thinking, and other physiological and behavioral changes in mice, similar to those observed in people who experience shift work or jet lag.

“Our findings have implications for humans,” said lead author Ilia Karatsoreos, PhD, of Rockefeller University. “In our modern industrialized society, the disruption of our individual circadian rhythms has become commonplace, from shift work and jet lag to the constant presence of electric lighting. These disruptions are not only a nuisance, they can also lead to serious health and safety problems,” he said.

Karatsoreos and his colleagues housed the animals in a day/night cycle of 20 hours (10 hours of light and 10 hours of dark), rather than the roughly 24-hour cycle to which the animals’ internal brain and body clocks are normally set. After six to eight weeks, the mice exhibited numerous physiological changes not seen in a control group.

While not any more active than the control mice, the disrupted mice were impulsive, a behavior measured in part by how long they wait to emerge into the light from a dark compartment in a cage. They were slower to figure out changes made to a water maze they had mastered, suggesting reduced mental flexibility. Physically, their body temperature cycles were disorganized when compared to their peers and the levels of hormones related to metabolism, such as leptin, which regulates appetite, and insulin, were elevated. Consequently the mice gained weight even though they were fed the same diet as the controls.

The researchers also found that the brains of the disrupted mice had shrunken and less complex neurons in the medial prefrontal cortex, an area important to the so-called executive function, which regulates mental flexibility among other things. “Those changes may help explain some of the behavioral effects of circadian disruptions,” Karatsoreos says.

Do better school lunches help kids learn? | The Washington Post

jamieoliverbooks.JPG

In 2005, British celebrity chef Jamie Oliver convinced London’s Greenwich borough to let him remake their school-lunch system. Armed with some publicity, some private funding and some ideas about how school lunches should look, he began remaking the kitchens and training the cafeteria workers. Neat stunt, right? Tim Harford picks up the story:

What caught the attention of Michele Belot and Jonathan James, though, was the way Oliver’s project had been implemented. Belot and James – economists at Nuffield College, Oxford, and at the University of Essex respectively – noted that the campaign had created a near-perfect experiment. The chef had convinced Greenwich’s council and schools to change menus to fit his scheme; he mobilised resources, provided equipment and trained dinner ladies. Other London boroughs with similar demographics received none of these advantages – and indeed, because the programme wasn’t broadcast until after the project was well under way, probably knew little about it. The result was a credible pilot project. It wasn’t quite up to the gold standard of a randomised trial, but it wasn’t far off.

Thanks to the UK’s exhaustive school testing regime, Belot and James were able to track pupils’ performance in some detail. They concentrated on primary schools, figuring that secondary school pupils could (and probably would) avoid eating school lunches that were too worthy. (This is surely correct. My own habitual sixth-form lunch was four bars of chocolate – a pound a day well spent.)

Their answer – a provisional one, since they are still refining the research – is that feeding primary school kids less fat, sugar and salt, and more fruit and vegetables, has a surprisingly large effect. Authorised absences, the best available proxy for illness, fell by 15 per cent in Greenwich, relative to schools in similar London boroughs. And relative to other boroughs, the proportion of children reaching Level Four in English rose by four and a half percentage points (more than six per cent), while the proportion of children achieving Level Five in Science rose by six points, or almost 20 per cent.

“What astonishes me,” writes Harford, “is that it took a television company and a celebrity chef to carry out a proper policy experiment.” And what astonishes me is that it’s not being replicated. Those are huge results. It’s just one project, but the way you find out if the numbers hold is by re-creating the experiment. If something as cheap as good food can deliver something as important as better school performance, it’s time to fund some serious pilot projects.

Photo credit: By Rick Nederstigt/Getty Images