Mama Glia [poem]

by Greg Crowther

This was originally written as a Mother's Day poem ... but it has also occasionally proven useful in physiology classes.

I am a neuron -- a nerve cell.
I sense and respond to stimuli.
I am electric; I am excitable.
Charges flow in and out, in and out, in and out.
I ping my neighbors
With terse, transient messages --
A never-ending stream of micro-updates:
Cold, cold, COLD-COLD-COLD-COLD-COLD...
OK, all clear now.

How do I keep this up?
Who sends me nutrients
And sequesters my waste?
Who protects my axon
With a blanket of insulation?

How did I get here in the first place?
Who provided scaffolding to follow?

And that one time when I was badly cut,
Who nursed me with growth factors
Until I was, once again, whole?

My glia, that’s who --
The Greek word for “glue.”

Songs like this one can be used during class meetings and/or in homework assignments. Either way, the song will be most impactful if students DO something with it, as opposed to just listening.

An initial, simple follow-up activity could be to answer the study questions below. A more extensive interaction with the song might entail (A) learning to sing it, using an audio file and/or sheet music as a guide, and/or (B) illustrating it with pictures, bodily poses, and/or bodily movements. The latter activity could begin with students identifying the most important or most challenging content of the song, and deciding how to illustrate that particular content.

(1) Based on the poem, write down several distinct functions played by glial cells.

(2) Not all of these functions are executed by the same cells. List the different subtypes of glial cells within the central nervous system (CNS), and within the peripheral nervous system (PNS).

(3) Do you think the "narrator neuron" of the poem is located in the CNS or the PNS? Why?

(4) How, physiologically speaking, does a given neuron communicate different levels of a stimulus (e.g., mere "cold" versus "COLD-COLD-COLD-COLD-COLD")?

(5) Is the "narrator neuron" myelinated? How do you know?

(6) The original definition of glia -- as the "glue" of the nervous system -- is now considered misleading by neuroscientists. Why?