[Marks Man]

Marks Man  asked the Naked Scientists:
   
This is Michael from South Africa.

Can you please explain to me how the human brain develops and also how does a persons memory improve. Lastly is it true that a person's brain develops fast when in puberty than in adult stages and if true why is that? and how can one train his/her memory.
 
I eagerly wait in anticipation thanks.
 
Sincerely yours from
Michael

What do you think?

[Chemistry4me]

It could take quite a while to explain! []

[Chemistry4me]

This is citing from a book:

Three to four weeks after conception, one of the two cell layers of the embryo starts to thicken and build up along the middle. As this flat neural plate grows, parallel ridges, similar to the creases in a paper airplane, rise across its surface. Within a few days, the ridges fold in toward each other and fuse to form the hollow neural tube. The top of the tube thickens into three bulges that form the hindbrain, midbrain, and forebrain. The first signs of the eyes and then the hemispheres of the brain appear later.

Many initial steps in brain development are similar across species, although later steps are different. Neurons are initially produced along the central canal in the neural tube. These neurons then migrate from their birthplace to a final destination in the brain. They collect together to form each of the various brain structures and acquire specific ways of transmitting nerve messages. Their axons grow long distances to find and connect with appropriate partners, forming elaborate and specific circuits. Finally, sculpting action eliminates redundant or improper connections, honing the specific purposes of the circuits that remain. The result is a precisely elaborated adult network of 100 billion neurons capable of body movement, perception, emotion, and thought.

[Chemistry4me]

The embryo has three layers that undergo many interactions in order to grow into organ, bone, muscle, skin, or neural tissue. Skin and neural tissue arise from one layer, the ectoderm, in response to signals provided by the next layer, the mesoderm. A number of molecules interact to determine whether the ectoderm becomes neural tissue or develops in another way to become skin. Studies of spinal cord development in frogs show that one major mechanism depends on specific molecules that inhibit the activity of various proteins. If nothing interrupts the activity of such proteins, the tissue becomes skin. If other molecules, which are secreted from the mesoderm, block protein signaling, then the tissue becomes neural. Once the ectodermal tissue has acquired its neural fate, more signaling interactions determine the type of neural cell to which it gives rise. The mature nervous system contains a vast array of cell types, which can be divided into two main categories: the neurons, responsible primarily for signaling, and supporting cells called glial cells.

[Chemistry4me]

Researchers are finding that the destiny of neural tissue depends on a number of factors, including position, that define the environmental signals to which the cells are exposed. For example, a key factor in spinal cord development is a secreted protein called sonic hedgehog that is similar to a signaling protein found in flies. The protein, initially secreted from mesodermal tissue lying beneath the developing spinal cord, marks young neural cells that are directly adjacent to become a specialized class of glial cells. Cells farther away are exposed to lower concentrations of sonic hedgehog, and they become the motor neurons that control muscles. An even lower concentration promotes the formation of interneurons that relay messages to other neurons, not muscles.

A combination of signals also determines the type of chemical messages, or neurotransmitters, that a neuron will use to communicate with other cells. For some, such as motor neurons, the type of neurotransmitter is fixed, but for others it is a matter of choice. Scientists found that when certain neurons are maintained in a dish with no other cell type, they produce the neurotransmitter norepinephrine. In contrast, if the same neurons are maintained with other cells, such as cardiac or heart tissue cells, they produce the neurotransmitter acetylcholine. Since all neurons have genes containing the information for the production of these molecules, it is the turning on of a particular set of genes that begins the production of specific neurotransmitters. Many researchers believe that the signal to engage the gene and, therefore, the final determination of the chemical messengers that a neuron produces, is influenced by factors coming from the targets themselves.