Estrogen’s a Pain (Or Is It?) Part Two

Estrogen’s a funny thing.  It has purpose throughout the female body, and is even produced in men’s bodies.  It also serves as a suspect in many researcher’s minds as a key source of pain in women.  It’s a fact that women experience more chronic pain conditions than men, including painful bladder syndrome, endometriosis, fibromyalgia, irritable bowel syndrome, chronic pelvic pain, temporomandibular joint disorder, and migraines.  Women naturally produce more estrogen than men, and thus estrogen is being vigorously studied by pain scientists as a potential target to alleviate many of the chronic pain conditions experienced largely by women. 

The thing is, each lab comes up with something of a different conclusion.  Some experiments show that the presence of estrogen alleviates both chronic  and short-term pain, others show that it makes it worse.  Sometimes the relief is temporary, and sometimes permanent.  All of the experiments are carefully thought out, well-done peer-reviewed studies, good enough to be trusted and believed.  So, what could be going on here?  One idea out there is that fluctuating levels of estrogen somehow trigger certain pain conditions.  This is a popular emerging idea, especially in migraine research.  Still, this idea doesn’t experimentally fit for all pain conditions.

Of course, part of the frustration of research is that the best of intentions and hard work don’t necessarily lead to an answer right away, if ever.  And, the less success we have with our basic research, the less informed physicians are.  And this leads to a lot of unresolved pain.  The average time for diagnosis of endometriosis after onset of symptoms ranges from about 5-10 years.  Endometriosis is a painful condition in which tissue like the inner lining of the uterus appears in other parts of the body.  The average time for diagnosis of painful bladder syndrome (also called interstitial cystitis) is about 4 years.  All of the pain conditions I’ve named are conditions that affect daily life, pain that sometimes gets better or worse throughout a month, pain that can come suddenly in spells over many years, or more constant, daily, chronic suffering. 

So, a considerable amount of research is currently being carried out on all of these topics.  And, for each chronic pain condition I’ve named, there is at least one laboratory exploring the role of estrogen in that pain condition.  The fact that some laboratories report that estrogen improves painful conditions, and that others are just as certain that that the opposite is true makes for some interesting (and heated) discussions at scientific conferences.  (I know, I’ve been privy to several).  I’m hoping someone can brilliantly gather up all the information that is out there so far on the topic, and be able to put all the pieces together.  Once we know what estrogen might be doing in all of this, we might have a new way to alleviate some of this pain!  Until then, there are some useful coping mechanisms out there:

http://www.howtocopewithpain.org/

http://www.painclinic.org/aboutpain-copingwithpain.htm

Of course, I am only skimming the surface of this field.  Check out the further reading to learn more.

Further reading:

Aloisi AM, Bonifazi M (2006)  Sex hormones, central nervous system and pain.  Hormones and Behavior: 50: 1-7.

Sanoja R, Cervero F  (2009)  Estrogen-dependent changes in visceral afferent sensitivity.  Autonomic Neuroscience: Basic and Clinical.  153: 84-89.

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001913/

http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001508/

http://health.howstuffworks.com/wellness/women/general/women-and-pain-what-a-pain.htm

Charlie Murphy Says

Charlie Murphy says, "Deal me in.  I'm feelin' lucky today."

Charlie Murphy Says

Charlie Murphy says, "Some days, it might just be better to stay in bed."

Estrogen’s a Pain (Or Is It?)

One of the common side effects of pursuing the PhD-postdoc path is that you tend to become super-focused on a very small piece of your field.  Lately, I am so focused that I have almost completely lost track of why I study what I study.  I’ve had a lot of bad research luck lately, and this leaves me with a thoroughly isolated vision of a thoroughly frustrating task.  My guess is that I am not the only scientist in this position.  This situation is good for no one.  So, I stepped back, took a look at the work, and realized, well this is really interesting.  And people I talk to about it think so, too.  At the clinical level, this is a question that affects many, many people.   This is what I forget until my work happens to come up in a social conversation.

The funniest thing about working on medically-related research is that strangers will often talk to you like you’re a physician.  I’ve heard a lot of weird details about the health of strangers, completely unbidden.  It happened when I did my PhD research on bladder function (awkward) and it happens now when I mention that I study the potential role of estrogen in pain.  It starts casually, “Oh, what brings you to Montreal?  What are you doing at the University?...”  If they keep pressing for details, I tell them, “I’m looking at the effect  of estrogen on pain, specifically abdominal pain.”  Once this happens, I know I’ll either get a funny look, plus complete silence thereafter, or way too much information that I’m not even remotely prepared to comment on.  I’ve heard about the veterinarian’s monthly pain experiences, and the estrogen treatments that were given to a new acquaintance I met at a friend’s wedding.  Yep, people share these things with me just as soon as I meet them. 

I’ve got more coming, just wait!  To be continued soon. J

Charlie Murphy Says

Charlie Murphy says, "I'm ready for St. Patty's Day.  Are you ready for St. Patty's Day?"

The View From Here (Part One)

There’s a few great things about my Montreal life.  One of them is simply the view I have from my front room.  I know lots of people in this city and in the whole world have way better views than me.  But, I have been enjoying the heck out of mine for a few years now.  From here, I can see the shiny buildings of downtown, have a clear view of Mont Royal and the St. Joseph’s Observatory.  There is the added bonus of the highway just outside, providing hours of vehicle-watching, seeing accidents nearly happen on the highway just outside.  Haha.  I sit out on my front balcony for 3 seasons, watch my plants grow, listen to my pot-head neighbors as they party a few balconies over, pull up my head from my book to the sound of cars honking.  In summer, I can see the fireworks from the International Fireworks Competition (but only the ones that go really high).  I can see Mont Royal turn from brown/grey to that baby-bright green in spring, to full dark green in summer, over to yellow and red in the fall.  And then when winter hits, I sit inside and watch the snow fall, looking out at the highway, glad to not be driving one of those cars I see out on the road.  I snuggle under a blanket with the purring cat, and feel grateful.  (Yes, you might have noticed, I am easily pleased.)

However, now, it is March.  The only month of the year that I regularly wonder: “WHY didn’t I move further south?  Why oh why oh why?”  I’m ready to head out to the balcony again.  Cabin fever is setting in, and the wacky weather has begun.  Single-digit (Fahrenheit) cold one day, things are melting the next day for a few hours, then whatever melted turns back into ice.  Then they predict a snowstorm, and it’s back to winter with 20 cm of snow.  Two days later, it’s a sunny day.  The sunlight lasts until after you leave work (miraculous!) and you begin to notice that the days, in fact, are actually getting longer.  And now that the U.S. government decided in 2007 to extend Daylight Savings time, this modern miracle of screwing with time happens even sooner.  (In fact, we’re almost there!)  By the way:  thank you to the Canadian government for also adapting the new Daylight Savings time. 

However, this is still March.  To me, the month of eternal torture.  The temperatures hover around the freezing point, above and below, above and below, rarely shooting high enough to give actual hope.  March.  It’s supposed to ‘come in like a lion and go out like a lamb,’ but I’ve noticed that ever since I moved to various northern locations near or north of the Canadian border ten years ago, that this isn’t really true.  Where is the lamb?  Somewhere in April, the lamb shows up.  Until then, it’s simply daydreams of sitting out on the front porch, quietly plotting my new container garden, literally dreaming of soil and basil plants.  At least we have St. Patrick’s Day to look forward to.  Green beer, anyone?

Charlie Murphy Says

Charlie Murphy says, "Don't let the bastards get ya down."

Ants Marching (Ant-plications)

I am thinking of the mountain again, and this time, I'm thinking about ants! J  So, how about heading back there with me?!  Here goes: early summer day, not too hot, everything including the grass, so green, trees decked out in their fullest leaves, heavy swish of the wind through their branches, a plethora of chirping birds.  The screen door bangs as a little, young version of you leaves the house to head to the backyard by yourself and visit your ant trail and check on the doings of your ants (yeah, I really was always so nerdy).  There is occasional kitchen clatter and chatter from the cabin, but you don’t notice.  The mountain was plentiful in carpenter ants, the big black ones, about the size of a grown-up thumbnail.  Here’s what you’re wondering, if you’re me:  how and why are they wearing a trail in the grass so well that the grass is worn down to dirt, so clear that you can see it from standing.  You’d spend some time watching them walk along, enjoying the day, observing the way the ants meet and greet each other with their little antennae as they pass in different directions. 

And then the questions would begin.  What sort of information they are passing to each other, if anything, and how might they be doing it?  How awesome is it that they walk along the same path enough to wear the grass down?  And how do they find the path?  Do they find it by smell?  They don’t have eyes do they?  How big is an ant brain?  Does an ant have a brain?  So, I’m all grown up now, and I still want to look into what was going on here.  I realize that even after all this neurobiology training, I still don’t know much about ant brains, after all! 

So, I have now done my research and I’ve learned a few neat things.  A lot of neat things, actually, but here are some of my favorite bits. 

Ants are actually incredibly interesting and the study of ant behavior has applications to neuroscience, engineering, ecosystems, and stock markets (whoah!).  As for foraging and trail-making, ants make trails using pheromones.  The pheromones, depending on the species of ant, are secreted from a variety of gland locations, including glands on the feet, thorax, anus and abdomen.  They even release different pheromones for ‘to’ a food source as opposed to ‘away from’ a food source.  Ants will leave a pheromone trail behind them as they are leaving a food source, indicating to other ants that the trail had been successful.  As the food source is used up, the ants cease leaving this ‘success’ pheromone behind, and the trail scent slowly dissipates.  Carpenter ants can make well-worn trails that they use for years, probably guiding them to an area commonly good for food (perhaps towards our camp, for example). 

Argentine ant trails - Latty et al., 2011

While doing my present-day ant exploration (reading, no ant progressions to follow here in the apartment in Montreal that I’ve found, very grateful for THAT), I also found that ant path-making is an area of current active research.  In particular, researchers are interested in the way individual ants find the shortest route to a food source or other location with no central influence. Latty et al. arranged a colony of Argentine ants in separate nests and then recorded and studied how they form paths between the nests.  They also wanted to know if the number of individual ants made a difference in the way the ants organized network pathways.  Here’s what happened:  the ants made networks of paths with lengths that increased to a maximum, and then were trimmed down to a final length.  At first, individual ants made redundant paths, but overall, through trial and error, the colony of ants produced more efficient pathways.  With more ants in the colony, the networks formed were less precise in the end, and the extra total length traveled per ant increased.  With too few ants, no paths were created at all. 

This fits in interestingly with something else I found.  An ant brain has about 250,000 neurons.  A human brain has about 100 billion neurons (of course, this is a bit debatable).  Some ant researchers liken an ant colony to a single human brain, where each ant could represent a neuron, all of them signaling to each other in various ways.  Together they are accomplishing great feats where one neuron in a brain or one ant in a colony could accomplish so very little.

This is also interesting because the authors compare the ant networking situation with, for one, mammalian vasculature development.  It’s funny, because little ant paths and networks really do resemble vascular networks in a visual sense.  Just like ants don’t always follow the straightest path from A to B, so endothelial cells (the cells that form the inner lining of blood vessels) do not form blood vessels that make straight lines through the human body.  And I remember this from anatomy class:  not everyone’s vasculature is the same.  And most do not look exactly like those diagrams in the textbooks.  It’s all just a bit haphazard, organic.  And worthy of a lot more study.  Perhaps the same principles that guide an individual ant on its journey to find food, is in some global way related to the workings of neurons in a human brain or the relation of individuals to a stock market.  This is cool.

Now, I am only scratching the surface of ant science and am certainly not giving it due justice, but that was fun!!  Check out the references if you’d like to know more.  There are plenty of ant books out there also. 

References:

Delgado J, Sole, R (2000) Self-synchronization and task fulfillment in ant colonies.  Journal of Theoretical Biology.  205: 433-441.

Jackson DE, Ratnieks FLW (2006)  Communication in ants.  Current Biology.  16:570-574.

Latty T, Ramsch K, Ito K, Nakagaki T, Sumpter D, Middendorf M, Beekman M (2011)  Structure and formation of ant transportation networks.  Journal of the Royal Society Interface. Published online 2 February 2011.

Robinson EJH, Ratnieks FLW, Holcombe M (2008)  An agent-based model to investigate the roles of attractive and repellent pheromones in ant decision making during foraging.  Journal of Theoretical Biology. 255:250-258. 

By the way, I am a big fan of old-school Dave Matthews Band.  I hope you will enjoy this video as much as I did!!