The brain is a truly fascinating organ. It operates at lightning speed,
controlling every aspect of our lives, keeping all activities under a strict
watch. All of that in a 1.3 kilograms of highly functioning jelly. How it comes
to be such a construct is a story of everybody's lifetime!
This article leans heavily on previous knowledge gathered
in preceeding articles about neurons, astrocytes, oligodendrocytes and
microglia. It is highly recommended to
explore them first, for a better reading pleasure. Due to the complexity and volume of the topic, it will
be covered in two articles.
The brain matter indeed is very similar in both texture and density to a
block of jelly, locked away behind the skull like a criminal, in a location
superior to other organs. The skull, in some more dense than in others,
provides ample protection to our jelly block from outside hazards. Contrary to
popular beliefs, the brain isn't attached to the skull almost anywhere. Rather,
it floats in a thin layer of liquid that functions as both insulation and
buoyantic fluid, working 24/7, scheming to keep us alive. And, for the most
part, doing it rather well, with the help of all other organs. Or, to be more
precise, because all other organs, who were all developed to either prolong
the life of the brain, or to replicate and enhance it. There is a thought to
How can we do that? How can we – think? How can we form thoughts, remember,
plan and solve complex mathematical problems, write articles and research the
very organ we research with? How is a thought birthed, how is a decision being
Any individual claiming to know the definite answer to these questions
might want to contact https://www.nobelprize.org/ for further inquiries. You might be eligible!
It all starts with a bang
To discuss the birth of thoughts is to discuss brain development, both
through biological and personal history. The secret to it lies somewhere in the
very beginnings of human development, several hours after successful
sex, right at the time of fertilization.
Every human life starts from a single unified cell when a sperm cell
fertilizes an egg cell. The union of the two is called a zygote, and it starts
rapidly dividing, with not much differences between it and a tumor. After a
period of time, the conglomerate of cells forms a partially hollow sphere the
size of a pin head called gastrula. From there, three distinct cell lines can
be seen: endodem, ectoderm and mesoderm. The endoderm gives rise to most of the
internal organs such as lungs and liver. The mesoderm evolves into the skeletal
system, muscles and the vascular system, while the ectoderm forms the skin, and
both the central and the peripheral nervous systems.
of a zygote into a gastrula, with its three distinct layers.
At this stage, our brain
is the equivalent of a LED light equipped with a power source and a switch.
Further cell division
gives rise to more complex forms, and a critical mass of cells in a part of the
ectoderm called the neural plate prompts the formation of the neural tube. This
is the precursor of our brain and the spinal cord.
of the neural tube.
The formation of the tube
from the neural plate most probably arises due to the critical mass of cells
who were displeased to live in a two-dimensional plate instead of in a
three-dimensional tube. It might not sound scientific, but most of the primal
stimuli and incentives for change occur due to physical limitations of space.
Neural tube formation is a good example of a sheet of paper being cramped
together into folds.
The formation of our
brain has always fascinated humans, especially the field of research. We are
still far from having penetrated all the mysteries of this block of jelly
locked behind bone bars. And yet, we are slowly learning and discovering its
history: wiring like a computer, the discovery of the first sensations, the
birth and finally the exploration. All of it is a story to follow!
Dekaban, A.S. and Sadowsky, D., Changes in
brain weights during the span of human life: relation of brain weights to body
heights and body weights, Ann. Neurology, 4:345-356, 1978
Hepper, P., "Unraveling our
beginnings", The Psychologist, 18:474-477, 2005.
Huttenlocher PR, Dabholkar AS. Regional
differences in synaptogenesis in human cerebral cortex. The Journal of
Comparative Neurology. 1997; 387:167–178. [PubMed: 9336221]
Saladin, K (2011). Anatomy &
physiology : the unity of form and function (6th ed.). McGraw-Hill. p. 541.
Kandel, Eric R. (2006). Principles of
neural science (5. ed.). Appleton and Lange: McGraw Hill. ISBN 978-0071390118.
Tierney A. L., Nelson C. A. Brain
Development and the Role of Experience in the Early Years. Zero Three. 2009 November
1; 30(2): 9–13.
BrainConnection.com [no longer in