Receptors

   The other night found us with some friends and perhaps because of all that has happened --our dog becoming paralyzed, our moms showing a bit more dementia, the heat, who knows-- we got a bit more giddy than usual.  So by the time I went to bed my head was swirling, not like Robin Williams used to describe (you being so drunk or loaded that he said that the room was spinning like a massive roulette wheel with the dealer yelling "place your bets, place your bets" -- heavens no, although I had been there before in my younger days; with age came, one hopes, the knowledge that that wasn't a very good place to visit) but inhibitions down enough that my mind seemed to be going in several directions; all of which got me to thinking about how our brains operate at such a point, a point when functions and reactions are dulled but awareness apparently is not.  Then I happened to remember a piece on the different receptors in our brain and how different drugs, from sugar to opiates (much as with different diseases) affect entirely different areas of the brain.  Think of it this way, your brain is a control tower at an airport, one which has to handle everything from small crop dusters to fighter jets to large cargo planes.  Some will arrive at a rather slow speed, refill and exit quite quickly, while others will come in with heavier loads or need more runway to both land and take off; but all need to be accommodated.

Illustration by Serge Seidlitz as featured in Popular Science

  In an article in Popular Science, a summary of these allocated areas was shown and described.  In just the compartmentalized section on cocaine, here's what the article said: PREFRONTAL CORTEX.  Normally dopamine carries signals between neurons, binding to cell receptors until a transporter removes it.  But cocaine keeps the Neurotransmitter latched in place.  Dopamine then floods the brain, causing an addictive euphoria.  Continued use alters this decision-making center, making it even harder to resist using the stimulant.  Or this on marijuana: AMYGDALA + NUCLEUS ACCUMBENS.  THC binds to cannabinoid receptors on nerve cells, altering communications all over the brain.  It can cause contentment in the nucleus accumbens, a reward center, and paranoia via the amygdala, which regulates fear and emotion.  THC curbs pain and nausea by hindering signals from sensory nerves.  But there's a catch because many of these drug and chemicals are much more complex than it would seem; marijuana alone has 483 known chemical compounds each of which has a different effect on our brains (and there are over 700 strains of marijuana).

   What struck me most about that simple illustration of our brain receptors (which were based on current studies from research on brain scans) was the original design or perhaps the end result of today's brain.  An engineering student might know to scatter the receptors throughout the brain so that if one center is knocked out, others might continue.  But it was something which I had never thought about; getting a bit inebriated or loose just seemed to happen in my head in general and wasn't something that I pictured as relegated to specific and unique parts of my brain, sort of like getting a headache; it made sense, of course, but I just didn't picture it that way.  But then look at that diagram and there's that puzzling stretch labelled opiates heading down the spine (from the article: BRAIN STEM.  Drugs like morphine and codeine block pain messages sent from the body to the brain.  They work by dulling neural activity and hijacking opioid receptors to dump dopamine into the brain.  The resulting pleasant feelings overwhelm any pain signals, creating an intense sense of well-being.  But opiates are also highly addictive.)  Key words there..."brain stem" and "highly addictive."  The problem of opioid abuse and addiction is now large enough to have entire states such as Ohio declaring opioid usage a problem; said one report, "Opioid overdoses are the leading killer of Americans under 50 – more than car crashes or gun deaths."  What??  But then later came the cover story in the AARP (American Association of Retired People) Bulletin: Modern factory-produced opioids are only slightly different in chemical makeup from opiates derived from opium poppy flowers...Prescription opioids were initially administered primarily for short-term bouts of pain.  But starting in the 1990s, doctors began to prescribe them more to treat chronic pain.  Long-term use led to higher levels of addiction and overdoses among wide swaths of the population: Since 1999, the number of overdose deaths that were attributed to opioid misuse has quadrupled.  About half of those deaths in 2015 were from prescription opioid drugs...Almost one-third of all Medicare patients --nearly 12 million people--were prescribed opioid painkillers by their physicians. Wait, this was a whole new population now getting addicted...senior citizens.

Graph by Nicolas Rapp for AARP Bulletin

    My mother has her own order from her physician for an opioid for pain, but her taking it is monitored and charted in the facility where she stays.  But in the outside world where self-medication is the norm and where pain is a real and sometimes persistent happening, some seniors are not only heading to the streets to buy illegal painkillers once their prescriptions run out, but to become dealers that sell  (my community newsletter said that the going rate for a single hydrocodone pill in high school was $60).  And it's not only prescription drugs that senior citizens are buying and selling, it's bumping up to another drug of choice, heroin: Heroin is an opioid that is two to three times more powerful than morphine.  Because opioid users tend to build up a tolerance to their prescription drug, they seek more potent forms to feed their addiction.  In some cases, this has led addicts to heroin; the illegal recreational drug is a relatively cheap source of an opioid high, especially as prescription drugs become harder to obtain.  And the mass addiction is fueling more dangerous forms of heroin.  In a recent trend, heroin has been laced with carfentanil, a drug that is 100 times stronger than the opioid fentanyl; the primary use of carfentanil is to sedate elephants...Nearly 14,000 people age 45-plus died from an opioid overdose in 2015 -- 42 percent of all such deaths in the U.S., according to the Centers for Disease Control and Prevention (CDC).  

    It's strange for me to read about another age group entering the fray of becoming addicted, or to read that some seniors are taking heroin; it's like finding your grandmother shooting up, the picture just doesn't make sense.  Admittedly, many such things in today's world are changing from cough syrups being used as the new way to get high (read about the promethazine craze in Bloomberg Businessweek) to the party usage of ketamine; there's even the office trend of microdosing and Canada's quest to become the world's largest producer of legal marijuana.  But senior citizens overdosing?  Said National Geographic, "Seven out of 10 Americans take a prescription drug; of these, one in four women in their 40s or 50s takes an antidepressant, though studies show that for some of them, anything from therapy to a short walk in the woods can do as much good."   I'm  officially a senior now; and while I giddily partied with friends and later tried to fall asleep with my brain a bit fuzzy, I still had to marvel at our bodies and our brains, the intricacy and the complexity of it all.  Earlier in the day I had received this email from the sequencing going on with the genome kit I mentioned in a recent post: We just started reading the millions of letters that make up your entire exome: the part of your DNA that makes you, you.  Just how much data are we talking about? Well, if you started typing 60 letters per minute—for eight hours a day—it would take about a decade to capture it all.  While we do it a lot faster, it still takes some time.   Such things are difficult to comprehend. 

    I won't pretend to understand what it must be like to live with constant pain, physical or mental, just as I won't pretend to understand what it is like to be addicted* to something.  Give up cigarettes or coffee, alcohol or drugs?  It'd be tough but not impossible, right?  Not so to an addict.  Judging from the statistics, more and more ordinary people seem to want to escape reality in some form, be it via taking drugs or wearing headsets of "virtual" reality displays.  Maybe it is because of pain they have or feeling that their or the world's problems have become too much to bear; or maybe it's as simple as wanting a break from the routine.  But in this changing world of ours, a little taste or hit of something can sometimes tease our receptors into wanting more; and all along the way our brains have to make sense of it all.  Concluded the piece by National Geographic on our changing bodies: Our cars are our feet, our calculators are our minds, and Google is our memory.  Our lives now are only partly biological, with no clear split between the organic and the technological, the carbon and the silicon.  We may not know yet where we’re going, but we’ve already left where we’ve been.

*Earlier I examined the growing rate of drug addiction with a four-part series of posts...