What Matters? Week 4

Gray and white matter,

Matter connecting to world;

Nutrition matters

That Brainy Feeling or I’m Feeling All Sparkly Upstairs - Week 4

Relax and brreeeeathhhe; no big long crammed-too-full posting this week. But there were a couple of things in the instructor’s notes concerning brain development and cognitive change.

First: a LOT of myelination occurs postpartum; Babinski’s reflex (an upside ‘J’ stroke on the plantar surface of the foot) is normally elucidated in infants up to about a year of age. The reason is myelination of the spinal cord not complete at birth, resulting in a spinal cord reflex action rather than being suppressed by the cerebral cortex (http://bit.ly/UFnyKY). If Babinski’s reflex is noted in adults, it is a sign of spinal cord damage, lesions, tumors, etc. and signals pathology. Also, recall from the text that the human brain is not fully mature until about 30 years of age, especially the executive functions. That’s the stuff Leah mentioned in her notes about frontal/prefrontal lobe development. 

My interest here focuses on nutrition; myelination requires lipids (fatty acids) to occur properly. If the mother’s contains insufficient fatty acids, myelination will slow, placing constraints on developmental milestones. In a rat study, researchers found that dietary fat regulated how well myelination proceeded (abstract here: http://1.usa.gov/ZSicfE). A separate study found that maternal diets (both pre/postpartum) high in these fatty acids, actually accelerated myelination. (They used the term “precocious appearance”; in other words, the reflexes of the baby rats matured earlier and stronger than the control group.) I like words/phrases like that; they are so rich in depth and meaning – like up or down regulation of gene expression. It is clear that proper nutrition pre/postpartum is essential in both mother and baby to achieve proper neural system development. The transfats of French fries, potato chips and snack foods are not the kind of fatty acids that promote myelination.

Here’s a great little synopsis of myelination both in the peripheral/central  nervous systems: http://bit.ly/ZSjZkT.

Gee, the words are starting to pile up :-}

Ok here’s the second: on the pruning part in the notes, I think most of us get the concept: use it or lose it. So, if a neural circuit is busy all day long doing its little job of polarizing/depolarizing it gets to stay. Sort of like a quiet but regularly used side street, say the ‘road’ to your tongue. At first there’s not a lot of traffic, but as time goes by a lot of road construction is underway connecting distant towns like Wernickeville, Brocaville and Middleearville (road map: http://bit.ly/ZSkSKc). 

Pretty soon that first little neuron can’t handle all the traffic, so those glial cells I wrote about last week commence turning the single lane road into a multilane complex to make all the connections. The oligodendrocytes are chatting with the neurons which advise things could go a lot faster with a little blacktop (myelin), and so the oligos punch the clock and get to work. And the more the circuits to various organs/functions are used, the more complex and multilayered the system becomes. And when they’re all done (well, they’re never done), you are able to go talking and walking and looking and turning and listening (no texting pls) to nature’s wonderful world – all at the same time and without hardly a thought about all the processes involved. Well, except if bite your tongue while chewing gum!

And putting that whole complex system together is the result of synaptogenesis, the capacity and efficiency mentioned in Leah’s notes.