The Brain–Quaggas of Creativity 1

Zebras Grazing

hmm…just when we least expected it, our first quagga of creativity has been sighted on the horizon. This one may look a little dusty at first, even off-putting, but, as it turns out, is rather important: this Quagga is the brain, which is more flexible (and older) than many might imagine. And what a story it has to tell!

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Putting aside our understandable pride in having the largest brain/body ratio of any animal, brains have been around for a ridiculously long time. 500 million years, to be precise (more or a less). And the first animal to develop a brain was none other than the humble flatworm. In fact, only a few invertebrates today lack a brain; all other animals possess one.

So what makes a brain so important?

Brain of a Malagasy Mongoose

A brain is the part of an animal that controls all the other parts. It is the center of the nervous system and is composed of two different kinds of cells: neurons and glial cells. While glial cells are important (providing structural and metabolic support, among other roles), the neuron constitutes the business end of the brain, processing and transmitting information by electronic and chemical signalling. The human cerebral cortex (the largest part of our brain) contains 15-33 billion neurons.

Chew them beans!

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Vertebrate Brain Regions

And the next time you have a great thought, ponder this: almost all animal species are believed to have developed from a tube worm, the celebrated common ancestor, which lived about 575 million years ago. One reason that scientists believe this is the bilateral body shape most living species share with tube worms. And this bilaterality is reflected in the brain structure.

Skipping ahead a few hundred million years or so, let’s look at the brain components that comprise the brains of advanced vertebrates: 1) the medulla, located along the spinal cord, is involved in motor and sensory functions; 2) the pons, located directly above the medulla, regulates (among other things) sleep, respiration, swallowing, and equilibrium; 3) the hypothalamus controls sleep cycles, eating and drinking, and hormone release; 4) the thalamus is involved with motivation and information transmission; 5) the cerebellum modulates other brains systems, coordinating their activity to  make their output more precise–this precision is learned, say, for instance, as when we learn to ride a bike; 6) the optic tectum, which allows actions to be directed to specific points in space; 7) the pallium, which in reptiles and mammals is known as the cerebral cortex–it regulates smell and spatial memory (in mammals, the CC dominates the rest of the brain); 8) the basal ganglia, which control action, either inhibiting or activating the parts of the brain directly involved with action; and 9) the olfactory bulb, which process olfactory signals; in primates, the OB is greatly reduced in importance.

Whew! And we haven’t even gotten to dolphins yet!

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Mammals: the brains of mammals are much larger than those of other vertebrates, twice as large as birds of comparable size and 10 times as large as reptiles of the same size.

Other differences in mammalian brains: the principle difference is the size of the cerebral cortex, which has developed into a six-layer structure. Mammalian brains also contain the hippocampus, which is involved in memory and spatial navigation.

Primates: the main difference here once again is in size: the encephalization quotient (EQ) for rats is .4; for elephants, up to 2.36; for, chimpanzees, up to 2.35; for bottlenose dolphins, 4.14, and for people, up to 7.8.

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Neurotransmitters. These are the chemicals that neurons emit and receive when transmitting information. A partial list includes serotonin (involved in pleasure); norepinephrine (involved in arousal); acetylcholine; and dopamine.

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OK, so that’s our first look at the brain, the mise-en-scene of creativity’s elaborate dramas. Certainly an elaborate stage, especially when we consider that we have yet to look at the human brain and its peculiarities. Something tells RT that this may be the next quagga to come galloping over the horizon.      RT

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All Images: WikiCmns, Public Domain.

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  1. July 29, 2012 at 7:11 pm

    You know I love it when you find a new passion! There is so much coming out on the brain that this will keep you occupied and happy for quite a while.

    margo

    • August 2, 2012 at 9:50 pm

      margo: passion’s flower blooms at unexpected moments…so much the better! eric

  2. August 13, 2012 at 12:21 pm

    Reblogged this on ram0ram note book.

    • August 13, 2012 at 2:33 pm

      R0R: thanks for the reblog! Always appreciated! RT

  1. September 22, 2013 at 3:52 am

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