Robin P. ZanderSnafu

Category: Random

Jonah Lehrer on Neuroscience and Humanity

On Tuesday night I went to the Herbst theatre in San Francisco to hear neuro-scientist and writer Jonah Lehrer in conversation with Roy Eisenhardt.  While I grew up listening to City Arts and Lecturs, this was my first live discussion and a much needed return to academic discourse (not to be confused with discussion, debate, or dialogue).  As an alumnus of Columbia and Oxford Universities, Lehrer is now a contributor to Scientific American,  National Public Radio, and Wired Magazine, among others.  He has published articles in The New Yorker, Nature, Seed, The Washington Post and The Boston Globe and maintains the blog The Frontal Cortex.

Lehrer’s talk was especially interesting personally because of his combination of academic affiliations and real-world application.  As a scientific correspondent Lehrer straddles disciplines with which I myself struggle: the balance of academic research and real-world application.  Lehrer speaks and writes with the ease of a well-read academic.  In discussing one of his two books – Proust Was a Neuroscientist – Lehrer cited Plato to confirm his thesis that some fundamental ideas currently espoused by popular neuroscience were conceptualized by the Greeks.   (I grow bored with the use of the classics merely for the edification of ones argument though this trend is by no means exclusive to Lehrer.  In my opinion, references should be accessible to the audience to which they are cited.)  However, I heartily concur with Lehrer’s argument that the humanities use different methods to answer fundamentally human questions about thought, cognition, existence, humanity… .  What artist, writer, poet, dancer – who?! – does not seek to answer such questions through whatever medium their profession employs?
Jonah Lehrer’s most recent book, How We Decide, encompasses decision making throughout the development of research psychology all the way to recent publications in neuroscience.  I have a pretty thorough grounding in classic Behaviorism (B. F. Skinner, etc.) and Cognitive Psychology.   It was interesting, then, to hear studies with which I am very familiar (the classic example of Pavlov’s dogs trained to salivate at the sound of a bell which ques food) in the context of neuroscience.  Lehrer discussed Chimpanzees being fed squirts of apple juice and conditioned to respond to a bell just as Skinner’s dogs were, with the important difference that these Chimps were also undergoing brain scanners.  The brain scans showed anticipation of food as clearly as did Skinner’s dog’s saliva.  My cognitive psychology profession Dan Reisberg used to argue that neuroscience would not replace cognitive psychology but merely confirm what we (as cognitive psychologists) had already learned.  I saw echos of this throughout Lehrer’s discussion.

In all, I very much enjoyed Lehrer for his wit, humor, and melding of neuroscience with the news.  I am critical of academic’s trend to use lofty references to establish credibility but I see this everywhere that academics publish.  And truly, Plato had some interesting things to say.   I will be adding The Frontal Cortex to my blogroll and will certainly be posting about Lehrer in the future.

As an aside I am also amused by Lehrer’s public image:

This rumpled look is awfully reminiscent of the graduate students I know in the sciences at UCSF.

CNS (Central Nervous System is Sexy)

A couple of clarifying notes as relate to my most recent post on Neurons and Excitability…

Often, when one hears Central Nervous System the inclination is to think of the brain.  This is accurate but not a complete picture.  The CNS also includes a region of the spine down to about the waist line – the spinal cord.  It is important to note that the spinal cord does not extend the full length of the spinal column.

Sensory information may arrive at a wide variety of points along the spinal cord or reach the brain itself.  Information that is processed along the spinal cord without reaching the brain results in what we call reflexes.  This is why reflexive actions occur so quickly: they need not travel the length of the spine and into the brain.

Muscle Fibers and Nerve Excitability

I have spent a great deal of time dissecting cadavers this year.  This has been an amazing opportunity to learn in person about human anatomy and physiology and is deeply informative for my continuing work with clients seeking to overcome pain.  In examining these bodies, generously donated to UCSF/SFSU, I have spent a great deal of time isolating muscles as well as bony landmarks and nerve bundles.  A muscle cell, technically called a muscle fiber, is composed of interconnected proteins which contract and release.  The first part of my revelation was that each of these fibers is the full length of the muscle of which it is part.  This means that a fiber (remember, that means a muscle cell) which makes up a small part of the Rectus Femoris (the outermost of the quadriceps muscles, it runs from the pelvis down to the knee cap) also runs the full length from the pelvis to the knee.  My second breakthrough was in connecting this fact to a similar detail about nerve cells.  A nerve cell is called a neuron and the aspect of the cell responsible for transmitting electrical impulses from the body of the cell to the outputting ends is called the axon.   Note the axon of the neuron below, covered in a myelin sheath.

Nerve

When I bump my toe everything happens so fast that it is nearly impossible to tell what is going on.  The sensory neurons in my toe send a signal to my spinal cord or my brain for processing, which then facilitates either a reflex or a processed reaction to the stimulus.  Perhaps, I withdraw my toe and cradle it in pain.  The signal, as it travels in both directions, is traveling from neuron to neuron or along the axon of many neurons, from extremity to the central nervous system (CNS, see following post for further discussion of this system) and back out again.  Some of the axons responsible for conducting the impulse to and from the toe are the length of the distance from toe to CNS!  Once the signal reaches the injured extremity it excites muscles fibers which contract (too late) to bring the toe out of harm’s way.  In these contractions, remember, fibers the length of the muscle are contracting.

Given two facts – that muscle fibers run the length of a muscle and that axons may run the distance between an extremity and the central nervous system – we can begin to understand why we can experience pain in parts of the body distant from a specific injury.  Neurons begin to respond when other neurons in their vicinity are excited.  Thus a wave of signals traveling away from the CNS may excite offshoots and facilitate muscle contraction in an area not directly impacted by the original stimulus.  As part of the healing process, this interconnectivity may be utilized by subtly adjusting areas peripheral to the site of injury.

I was recently working with a client, a professional dancer, who suffered injury to his ankle some years ago.  Since that time his career has been successful but he reports always having noticed less mobility at the site of injury.  He had seen physical therapists and massage practitioners about the issue with little or no success.  He reported that these practitioners had spent considerable time working directly on his foot and ankle and wondered aloud why I was dedicating so much attention elsewhere on his body.  But consider: if muscle fibers systematically run the length of a muscle and the axons of nerves may run from an extremity to the CNS, what impact might working elsewhere i.e. on the same leg have on the point of injury?  Muscle cells that directly connect to the area may be as far away as the knee.  Neurons that directly relate the the area may end as far as the upper spine or head.  Conceivably – just given these two facts – we could have worked on his head and seen results in his foot.  Certainly, my clients saw results!

That muscle fibers and neurons can be the lengths discussed should not be taken to completely explain interconnection throughout the body.  How neurons communicate is a very active field of research.  How axons come to be a certain length is not thoroughly understood.  Nor should the story of my client be an incentive to start poking at a friend’s head in hopes of provoking a response in her foot.  It probably will only serve to get you a good swift kick.  Of course, none of this changes the two tenants of the discussion.

Next time you stub your toe, consider: where did your responses originate?

The Lives of a Cell: Notes of A Biology Watcher

The Lives of a Cell by Lewis Thomas does not contain of the exclusive scientific vocabulary one might expect from a Doctor of Medicine who was professor, chairman, and dean at some of the most prestigious hospitals and medical universities in the United States. Thomas writes not as a scientist but as a scientifically-minded poet.  The book is a slim volume which covers a great deal of territory: each of the ten chapters takes a different perspective on issues relating to micro-biology, human evolution, the natural world, the pursuit of science.  The consistent humor and delicacy with which Thomas delves into difficult issues is a primary connection between the essays’ diverse topics.

Before properly beginning the book properly I turned to a random page and read:

Watching television, you’d think we lived at bay, in total jeopardy, surrounded on all sides by human-seeking germs, shielded against infection and death only by a chemical technology that enables us to keep killing them off.

These descriptions of our fearful actions continue for a lengthy paragraph and it is only at the end of the page that Thomas begins an outright discussion of the chapter’s topics of disease and the micro-organisms held responsible.  He sheds light on human behavior as relates to germs, behavior based not on knowledge of the cells themselves but rather on our own immune responses.  Thomas elaborates on several cases in which changing our approach could achieve more productive outcomes.

Lives of a Cell covers much more than just a discussion of micro-biology, even as relates to human behavior.  In “Some Biomythology” Thomas seriously discusses mythical beasts from a diversity of cultures and casually compares what these have to teach us about the animal kingdom with what recently-discovered micro-organisms can reveal of biology to the public.

In “Ceti” Thomas discusses Tau Ceti – a nearby start which resembles our sun, the CETI (Conference on Communication with Extraterrestrial Intelligence), and the logistics of communicating with intelligent life beyond our solar system.  He revels in the potential miscommunication. What of ourselves would we choose to share with newly-found intelligent life if the beginning of our conversation spanned hundreds of years?  Our recent discoveries in science would be an embarrassment 300 years later.  He draws the reader into the realization of how quickly human society is changing, and proposes that perhaps music – Thomas favors Bach, specifically – could be our greatest ally.

Lewis Thomas’ prose are not what one might expect from the highest echelons of academia.  He is far too human and humble in his stringing together of abstract ideas; too good at reaching a broad audience.  I cannot wait to get my hands on his earlier book The Medusa and the Snail, on his many published articles, maybe even articles published by his colleagues, to discover whether the beauty of his thoughts and writing extend beyond these pages.  I hope they do.