My Life in Brain Injuries

.

There are so many ways to break a brain, but in case one’s imagination flags, the NIH has created a graphic to help one consider the options. (OK, I doubt that was the motivation for the creation of the chart.) I’ve added “hormonal disorders” and “environmental exposures”. I’ll give some examples of these as my blog progresses.

In spite being encased in the skull, the brain is vulnerable – in fact, the skull can be part of the problem, but we’ll address that later.

If you have been lucky enough to handle a brain in a lab setting – perhaps a mouse brain in 8^th grade science – you probably noted it felt dense and rubbery, like the eraser on the end of your pencil. That consistency is the result of the preservation process – the brain was soaked in formaldehyde or some other preservative in order to make it durable for handling.

The consistency of a living brain is more like a soft-boiled egg or a pudding than a Pink Pearl eraser. Inside that “pudding” is an architecture that ranges from micro to macro.

The brain likes to think it’s the only show in town, the master of all it surveys, but it can’t do much without the spinal cord. Together the brain and spinal cord comprise the central nervous system (CNS). On the microscopic level, the CNS is neurons (nerve cells) and a variety of glial cells.

This is how old I am: When I took my first neuroanatomy class in the 1980s the glia were considered to be simply “nurse cells” that insulated the neurons. When I retook neuroanatomy in the mid-90s, however, there were “new” glia cells.

• astroglia (or astrocytes)
• oligodendroglia (or oligodendrocytes)
• microglia

Where did they come from? I happened to have the same instructor for both classes, so I asked, “Dr. Brons, where did the new glia come from?” He explained that further differentiation of the cells was facilitated by the development of new staining techniques (metal impregnation) in light-microscopy. My eyes glazed over, but the point was the “new” glia weren’t new, they had simply been revealed.  

On the macro level there are multiple structures within the brain and we’ll touch on some of them as time goes by.

I wish I could find an analogy that does the complexity of the brain justice. You’ll find references to it being like the motherboard of a computer or an intricate highway system, but the brain is so much more than any one image can capture. And it is fragile.

If the human brain were so simple
That we could understand it,
We would be so simple
That we couldn’t.

Emerson M. Pugh­­