Monday, April 15, 2013

Gee, I'm Nervous! Or, I'm Feelin' that Excitation! - Week 2


Merriam-Webster - Nervous
1
archaic : sinewystrong
2
: marked by strength of thought, feeling, or style : spirited<a vibrant tight-packed nervous style of writing>
3
: of, relating to, or composed of neurons
As the text states, "...the cerebral cortex...made up of ten billion neurons...", and that's just the cerebral cortex. The cerebellum is rich with neuronal activity, featuring tall Purkinje fiber ladders and all the various parts of the brain communicate with each other either directly or indirectly.   The startling origin of all these neurons begins as the period of the zygote transitions into the period of the embryo. In the space of ten days the neural plate(how did that form?) is transformed into a tube, that is closed on both ends eleven days later, providing the rudimentary brain/spinal cord structures. All happening from day nineteen to day thirty (http://bit.ly/139xSKZ). The maternal intake of folic acid in the pre/peri natal periods is crucial for proper neural tube development. I'd sure like a journal article or two on that relationship. 
Another fascinating aspect of the brain is the ratio of neurons to the glial cells. Glial cells, sometimes referred as neuroglia, are a family of helper cells, without which neurons function only marginally. There are four distinct types of glial cells, astrocytes, oligodendrocytes,  microglia and ependymal cells. Wikipedia provides a nice summary here: http://bit.ly/139zbK9. I mention them here for two reasons:1) I wrote an anatomy/physiology paper on them several years ago; 2) they outnumber neurons five-ten to one, forming about half or more of the cranial parenchyma. The astrocytes and oligodendrocytes are crucial to neural communication and networks. They not only assist the neurons to to chat with one another, they also chat with each other and determine when a neural circuit needs to expand, new ones are needed or when a network needs to be pruned - the synaptic pruning  mentioned in the text. 
Now consider the low birth weight neonates and the study showing these kids at three years old are cognitively impaired. The complexity of the developmental processes involved requires adequate nutritional building blocks (and perhaps less environmental stressors) to provide optimal neural physiology. Consider that oligodendrocytes are especially important in myelination of cerebral cortex neurons, which enables fast transmission and are facilitators of neural networks. Associate that with the increased maternal fat intake required in the third trimester which enables completion of myelination of the entire nervous system. It is not difficult to link inadequate nutrition with poor neural network formation and myelination, leading to the impaired functioning of the study group. 

Some loose thoughts about self-identity. Let's go back to the moment just before the two gametes fuse. Were either of those me? What were they made of - just materials from nature via the origins of the universe. Are those me? Are they mine? Am I them? So, if the sum of my physiological processes/substances aren't really mine, aren't really me (always being exchanged for new stuff), and if the "me" is not the stardust (would that be twinkle, twinkle?) I think of as me, then who am I?

Interesting journal article - Neural correlates of cognitive ability: http://bit.ly/12hgYLR.

3 comments:

  1. Hello Rebekah,
    It was a pleasure reading your blog. In addition, the impairment of the central nervous system of low birth weight of neonates is not the only complication these children often undergo. At birth, they often face challenges such as an inability to maintain body temperature due to the lack of insulating tissue and neurological problems. Furthermore, there are many factors that can contribute to low birth weight. Thanks for sharing. I am looking forward to next week’s blog and what you have to say.
    P.S I thought your Haiku was brilliant.
    Dawna Evans

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  2. Hey Rebekah,

    I absolutely loved reading your blog. Especially the little links that you put in there. I really found those to be really helpful. I also really liked how at the end you kind of asked questions that really get you thinking. It's so fasinating how all these cells we have are different yet without a single one of them we would not function the same and without one of these cells we would grow up having more of a struggle. Thank you for getting me thinking more in depth.

    Brandie

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  3. Love your blogs!!There is always so much information. My middle child was born premature and of course of low birth weight. Learning has always been more difficult for her, she always has to work longer and harder than others. It gets her down but she always succeeds!

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