Brains & Neurons
“There is nothing about a brain, studied at any scale, that even suggests that it might harbor consciousness.” ~ American neurobiologist Sam Harris
The religious error of positing the physical as the penultimate of existence is compounded by neurobiologists, who wrongly identify neurons, not glia, as the cells associated with cognition.
“As long as our brain is a mystery, the universe, the reflection of the structure of the brain, will also be a mystery.” ~ Santiago Ramón y Cajal
In the late 19th century, Spanish neurologist Santiago Ramón y Cajal elucidated and fiercely defended what became known as the neuron doctrine: neurons were the cells of intelligence. Cajal shared the 1906 Nobel prize in physiology and medicine with Italian physician and pathologist Camillo Golgi, who had identified astrocytes, a glial cell type, as important in thought processing.
Despite Golgi’s findings, Cajal’s thoroughly neuron-centric influence prevailed, becoming the mainstream school of modern neuro-pseudoscience. Because of Cajal and his followers, glia went unstudied for 6 decades.
“Until recently, our understanding of the brain was based on a century-old idea: the neuron doctrine. This theory holds that all information in the nervous system is transmitted by electrical impulses over networks of neurons linked through synaptic connections. But this bedrock theorem is deeply flawed.” ~ American neurobiologist Douglas Fields
Misattribution is made by facilely mistaking coincidence for cause. One cannot see what is not looked at, or gain insight from what is looked at with a predetermined perspective. In academic disciplines, only economics has proceeded with as much built-in bias as neurobiology.
Neurobiologists long assumed that neurons were the governors of consciousness, particularly the transition between sleep and the awake state. Instead, that physiological transition occurs through ion flows regulated by glia.
Hunger is monitored and its response controlled by glia, not neurons. This is done by regulating the release of the hormones which control the sensation of hunger and adjust energy expenditure. The effects of metabolic hormones come by commanding neural circuits, which are mere communicators, not controllers.
In all degenerative brain diseases, the first symptom, even before the loss of mental faculty, is losing the sense of smell. Smell receptor cells actively lock onto ambient molecules for detection, which occurs via discrimination of molecular energy vibrations. The coupling of cells with their scent targets requires frequent replacement of these receptors. Hence, the sense of smell is constantly changing, and is an apt indicator of holistic health.
The olfactory bulb, locally responsible for smell, has the highest turnover of cells in the brain. Glia are the stem cells for this turnover.
Neural processing cannot explain the pattern matching that predominates mentation. After extensive study of nerve cells for well over a century, neurobiologists still cannot explain memory via neurons. That’s because mentation physiologically transpires in glia, not nerves.
Cognitive diseases, such as epilepsy and autism, result from defective glia, not neurons. In old age, Alzheimer’s disease comes via crippled glia, not worn-out neurons.
A long-known fact is that brain tumors are almost always glial cells. These tumors would not be so devastating if neurons were running the show.
Glia are the adult stem cells in the brain. They reproduce themselves, and produce neurons only upon need.
Glia manage nerve cells. Glia guide developing neurons in their growth and connectivity, sop up chemicals used in cell-to-cell communication, and generally contribute to the health and well-being of nerve cells and their environment. But glia do much more.
Glia regenerate and grow locally in order to store more data. Via intercellular calcium waves, glia distribute and process information. Neurons have no memory capacity beyond those of other cell types. That’s because mentation has its physical correlate in glia, not nerves.
The explosive growth of the human brain in the first year after birth owes to astrocyte propagation. Meantime, nerve cell growth is fractional.
Children begin to experience dreams and are able to retain long-term memories by around age 4, after glia grow and establish themselves postnatally. If neurons held memories, people could recall being in the womb.
Nerve cells predominate in the cortex, which is gray matter. Cortex development increases to about age 8, then the brain becomes more streamlined. An adult cortex is considerably smaller than that of an 8-year old.
Learning results in a temporary increase in neurons in the affected area. As the learning takes hold and becomes rote, neural pathways streamline, with neurons atrophying and lessening in number. Conversely, more glia grow and remain robust with learning.
The cortex thinning that occurs from childhood is mostly neuron loss. Autism arises with a failure to prune neurons. Contrastingly, smarter children experience accelerated neural thinning.
“More is not better when it comes to synapses, for sure, and pruning is absolutely essential.” ~ American molecular biologist Lisa Boulanger
An evolutionary perspective highlights the importance of glia. If glia function as the cerebral library, then species with greater cognitive facility should have proportionally more glia. The ratio of glia to neurons increases with what is broadly considered cognitive capacity.* 3% of a leech’s intelligence cells are glial. The rest are neurons. In an earthworm, glia make up 16% of the nervous system. That ratio rises to 20% in flies; 60% in rodents; 80% in apes; and 90% in humans.
We know little of the mental lives of other organisms, so a sweeping conclusion about cognitive capabilities based upon cell types should be taken skeptically; but the evolutionary point about glial versus neural cell percentages remains.
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“Glia are the conductors.” ~ Douglas Fields
Actually, glia are not the conductors. They may rule the roost with regard to intelligence physiology, giving a deceptive appearance of conducting. But the material ruse frays when trying to explain how cogent mentation could possibly arise from disparate electro-chemical reactions.
“We can’t even begin to explain how consciousness, how sensation, arises out of electric chemistry.” ~ English neurosurgeon Henry Marsh
This difficulty may be glossed over when massive tissue is involved: simply hand-wave that so much meat matters. But when brains become tiny and cognitive skills stay sharp, the jig is up.