Neurons transmit to each other through synapses using glutamine and dopamine as chemical controls:

https://medicalxpress.com/news/2017-08-discovery-neuron

"Neurons communicate with one another by releasing chemicals called neurotransmitters, such as dopamine and glutamate, into the small space between two neurons that is known as a synapse. Inside neurons, neurotransmitters awaiting release are housed in small sacs called synaptic vesicles.

"'Our findings demonstrate, for the first time, that neurons can change how much dopamine they release as a function of their overall activity. When this mechanism doesn't work properly, it could lead to profound effects on health," explained the study's senior author Zachary Freyberg, M.D., Ph.D., who recently joined Pitt as an assistant professor of psychiatry and cell biology. Freyberg initiated the research while at Columbia University.

"When the researchers triggered the dopamine neurons to fire, the neurons' vesicles began to release dopamine as expected. But then the team noticed something surprising: additional content was loaded into the vesicles before they had the opportunity to empty. Subsequent experiments showed that this activity-induced vesicle loading was due to an increase in acidity levels inside the vesicles.

***

"The team then demonstrated that the increase in acidity was driven by a transport channel in the cell's surface, which allowed an influx of negatively charged glutamate ions to enter the neuron, thus increasing its acidity. Genetically removing the transporter in fruit flies and mice made the animals less responsive to amphetamine, a drug that exerts its effect by stimulating dopamine release from neurons.

"'In this case, glutamate is not acting as a neurotransmitter. Instead it is functioning primarily as a source of negative charge, which is being used by these vesicles in a really clever way to manipulate vesicle acidity and therefore change their dopamine content," Freyberg said. "This calls into question the whole textbook model of vesicles as having fixed amounts of single neurotransmitters. It appears that these vesicles contain both dopamine and glutamate, and dynamically modify their content to match the conditions of the cell as needed.'"

Comment: This is a typical biological setup, with balancing chemicals controlling the levels of signal, much like feedback loops, which may be eventually found here. This cannot develop by chance but must be developed by design all at once.

Advanced research has found that the brain contains many different types of neurons. No two may be the same increasing the possible complexity many, many times:

http://www.the-scientist.com/?articles.view/articleNo/50700/title/Advancing-Techniques-...

"For years, neurons in the brain were assumed to all carry the same genome, with differences in cell type stemming from epigenetic, transcriptional, and posttranscriptional differences in how that genome was expressed. But in the past decade, researchers have recognized an incredible amount of genomic diversity, in addition to other types of cellular variation that can affect function. Indeed, the human brain contains approximately 100 billion neurons, and we now know that there may be almost as many unique cell types.

***

"Recent technological advances have enabled a highly resolved characterization of the extent of cellular diversity in the brain, showing that there is far more heterogeneity within a given cell type than previously appreciated.

"Research has also begun to examine how somatic mosaicism might drive functional differences in individual neurons. Such neuronal diversity may help explain the origin of personality in humans and interindividual behavioral variations in other animals. Anecdotally, siblings, even monozygotic twins, often have remarkably different personalities even at young ages, despite sharing genes and environments. Diversification of neurons arising from somatic gene mutations or subtle molecular and environmental differences may help explain the origin of cognitive and behavioral individuality. The findings thus far highlight the importance of moving away from a blanket definition of “cell types” that are assumed to behave in a stereotyped manner toward a more nuanced view of neurons that includes the multidimensional combination of transcriptome, epigenome, and genome when attempting to understand the impact of a given cell state.

***

"Of the 100 billion or so neurons in the human brain, there may be no two that are alike. Recent advances in single-cell omics and other techniques are revealing variation at genomic, epigenomic, transcriptomic, and posttranscriptomic levels. Such diversity can arise at all stages of development and into adulthood. In the case of genetic changes that are passed on to daughter cells, the stage at which mutations occur will dictate their frequency in the brain. Researchers are now working hard to catalog every cell type within the human brain, and understand how differences among them may underlie variation in neuronal function. There are early hints that this mosaicism may contribute to personality and behavioral differences among individuals, as well as to various neurological or psychiatric disorders.

***

"While it was traditionally believed that every cell in the body contained identical genetic material, recent evidence has revealed that individual neurons actually differ significantly due to somatic DNA mutations and rearrangements, including those caused by the movement of L1 and other retrotransposons. Somatic mutations can occur both during development and in adulthood. Early progenitor cells that accumulate somatic mutations may give rise to many progeny, which also carry the same mutation, whereas a later progenitor, like an NPC in a neurogenic niche of the adult brain, may only give rise to a few progeny, limiting the spread of that particular mutation. This process could represent a lifelong flexibility of the brain, potentially making it more adaptable to changing demands.

***

"The brain is capable of remarkable remodeling in response to experience. Signals originating from the environment can cause both widespread and localized adaptations. At the level of individual cells, structure and function are continually changing with the environment in a dance of lifelong brain plasticity, and some experiences, such as stress or physical exercise, affect the growth, survival, and fate of newborn neurons in neurogenic regions of the brain.15  Considering that each neuron in the human brain makes 5,000 to 200,000 connections with other neurons, changes at the synapse level could have effects on multiple brain circuits and downstream behavioral or cognitive phenotypes.

***

"Once we begin to consider all of the subtle cell-to-cell variations, it becomes clear that the number of cell types is much greater than ever imagined. In fact, it may be more appropriate to place some cells along a continuum rather than into categories at all.

"Brain cells in particular may be as unique as the people to which they belong. This genetic, molecular, and morphological diversity of the brain leads to functional variation that is likely necessary for the higher-order cognitive processes that are unique to humans."

Comment: This helps explain why we can think the way we do and how the brain can adapt to individual usage creating each unique person.

dhw: I had two objections to your original post. Firstly, there is nothing special about homo sapiens having to learn to use his brain. You now agree. Second was the idea that the soul/self starts “from zero to learn every function of self/soul/consciousness/brain activity”. I may have misunderstood this, but if all you meant was that a newborn baby knows nothing about life outside the womb, I shan’t argue. And yes indeed, they are born with different genomes, which a materialist will tell you explains their different characters/selves and hence their different responses to whatever early life throws at them. But if they have a dualist soul, according to your beliefs (most of the time), it is the soul that has to learn to use the brain, not the other way round. The twins did not start at zero, because the way in which they used their brain right from the first “WAH!” was dictated by their already existing (materialist) genome or (dualist) soul. The only zero was their knowledge of life outside the womb.

DAVID: Please see my entry from Cosmos today. It covers all of this.

dhw: Please see my reply. The experiment is with six-month old and not new born babies and tells us that babies learn in bursts, which vary from one individual to another (confirming my observations of my twin grandsons from birth). It does not tell us that newborn babies start from zero, or that the brain learns to use the soul, and it does not even discuss what dictates the individuality of the responses.

Despite your comments, the newborn is on autmatic pilot at birth. The cortex is very underdeveloped and only finishes its developmentc at +/- 25 years 0f age. From birth:

http://www.urbanchildinstitute.org/why-0-3/baby-and-brain

"Between conception and age three, a child’s brain undergoes an impressive amount of change. At birth, it already has about all of the neurons it will ever have. It doubles in size in the first year, and by age three it has reached 80 percent of its adult volume.

"Even more importantly, synapses are formed at a faster rate during these years than at any other time. In fact, the brain creates many more of them than it needs: at age two or three, the brain has up to twice as many synapses as it will have in adulthood. These surplus connections are gradually eliminated throughout childhood and adolescence, a process sometimes referred to as blooming and pruning.

***

"The early stages of development are strongly affected by genetic factors; for example, genes direct newly formed neurons to their correct locations in the brain and play a role in how they interact. However, although they arrange the basic wiring of the brain, genes do not design the brain completely.

"Instead, genes allow the brain to fine-tune itself according to the input it receives from the environment. A child’s senses report to the brain about her environment and experiences, and this input stimulates neural activity. Speech sounds, for example, stimulate activity in language-related brain regions. If the amount of input increases (if more speech is heard) synapses between neurons in that area will be activated more often.

"Repeated use strengthens a synapse. Synapses that are rarely used remain weak and are more likely to be eliminated in the pruning process. Synapse strength contributes to the connectivity and efficiency of the networks that support learning, memory, and other cognitive abilities. Therefore, a child’s experiences not only determine what information enters her brain, but also influence how her brain processes information.

***

"The early weeks of the third trimester are a transitional period during which the cerebral cortex begins to assume many duties formerly carried out by the more primitive brainstem. For example, reflexes such as fetal breathing and responses to external stimuli become more regular. The cerebral cortex also supports early learning which develops around this time.

***

"At birth, a baby knows her mother’s voice and may be able to recognize the sounds of stories her mother read to her while she was still in the womb.

"The brain continues to develop at an amazing rate throughout the first year. The cerebellum triples in size, which appears to be related to the rapid development of motor skills that occurs during this period. As the visual areas of the cortex grow, the infant’s initially dim and limited sight develops into full binocular vision.

"At about three months, an infant’s power of recognition improves dramatically; this coincides with significant growth in the hippocampus, the limbic structure related to recognition memory. Language circuits in the frontal and temporal lobes become consolidated in the first year, influenced strongly by the language an infant hears."

Comment: The newborn has to learn to use what it is given. It's self is a blank slate as it starts out in life.