Thousands of years that separate us from Eastern spiritualism did not bring further clarification to the Medical Science, which cannot identify in its methods any evidence of the existence of the chakras. Even so, we should consider a hypothesis to try to correlate chakras to brain activity.

It's typical to study the brain in its modular aspects highlighting the motor, sensory functions, language, memory, calculation, and emotions among others. Circuits limited to a particular brain area process these activities. But there is another functional arrangement that neurology emphasizes as a set of neural groups that exert their action in a diffuse way, including multiple neural pathways and their areas of influence. This is the case, for example, of ascending activation systems that has the property of keeping us alert or in full sleep.

In simple terms, we can consider at least three systems of global operations, usually labeled "diffuse modulatory systems" (DMS): hypothalamic-secretion system, the autonomic nervous system and relationship with neurotransmitters such as dopamine system, serotonergic and noradrenergic, being the three strongly related to various mental disorders. These are the ones that we are suggesting in this article, as hypothetically related to frontal and crown chakras.

Considering the chakras that display their effects in the brain, we can note their coincidence with the "fuzzy systems performance." On the frontal chakra, predominates the dopaminergic system responsible for the expression of abstract thoughts and inclusion in the physical reality. Diseases such as epilepsy and frontal dementias lead to deterioration of the patients’ mind, who become completely detached from the physical world in which we live. In the crown chakra region, we observed the significance of the endocrine control performed by diencephalon-pituitary axis. This orchestrated glandular activity is essential for the maintenance of our metabolism, without which life would be impossible for us. 

The bloodstream and the vital energy - is very easy to accept the idea that our life is closely connected to the heart. Aristotle said that the soul is located there because any injury there immediately leads to death.

Nowadays, the elementary school students already learn that the heart beats propel the blood through the arteries, which then distributes through the capillaries and returns through the veins. In this return, the blood passes through the lungs, from which takes oxygen that breathing provides. We have about six liters  (1.58 gallons) of blood circulating in our body and about twenty percent of that goes to the brain. As it enters and exits through the arteries veins, blood circulates within the brain in just six seconds.

Once death occurs, the arteries of the body are empty since the last beat drives all blood to the veins. This observation led Galen to suggest that the arteries would always be filled with air. He also proposed that blood circulated along with an ethereal element called pneuma. This fluid would originate in the heart, distributed throughout the body and turning into animal pneuma at the brain, allowing us to perceive the world through the senses and react to our movements to their stimuli. The idea of an "animal spirit" producing our reflexes was also adopted by René Descartes and Thomas Williams, having medical acceptance for centuries. To Williams, the corpuscles of the "animal spirit" would travel up the nerve to put into action our movements.

Nowadays, we know the importance of blood circulation supplying throughout the body not only the oxygen that sustains our lives but also a number of unsuspected substances linked to the maintenance of cellular metabolism and the entire immune system.

André Luiz brings us new knowledge in this area too. This known spirit said that along with the bloodstream circulates the "vital principle" essential for sustaining life. Kardec teaches that it is the vital principle that gives life to the organic matter. Each of us has available while incarnate, consuming our share throughout the years. It comes from the "universal cosmic fluid" that fuels us according to our actions in life commitments. Meditation, prayer and the compulsion that inclines us to love others provide the ingredient and the renewal of the vital principle. It penetrates us through breathing, which reminds us of one of the most beautiful verses of the Bible - And God made man out of the clay of the earth and breathed into his nostrils the breath of life.

Anaxagoras believed that air was the primitive substance from which originates everything that exists. The relationship between air and life has widely been accepted in many cultures. In the books of Galen, the spirits and pneumas (air) are equivalent expressions.

We learned from André Luiz that the vital principle is absorbed by breathing and travels throughout the body following the bloodstream. 

The pineal gland and its spiritual physiology - This gland, located in the center of the brain, has been known for over two thousand years, and yet we know so little about it that in the classical treaties of neurology, it has not motivated interest to deserve more than short quotations of some lines on the hormone it secretes - melatonin.

The pineal is the biological clock that signals one of the most important moments of life, the beginning of sexuality. During puberty the pineal gland reduces production of melatonin, when it starts the development of external organs related to sexual activity.

Even today we can observe, in some animals, that the pineal gland may behave functionally as a third eye. In these animals the pineal gland is located above the skull, functioning as a periscope works as a surveillance device for the animal. Therefore, we should not be surprised by the strong sensitivity that our pineal has to light. The entry of light reaching the pineal gland through nerve fibers that conduct our optic nerve reduces the production of melatonin. In dark environment, it significantly increases production of that hormone. We all know that bears hibernate in caves during months of darkness, and this time, the increase in melatonin produces the numbness of its sexual interest, which then returns to unfold at the dawn of spring.

The pineal hormone has a direct connection with the deposit of melanin in our skin. It has a whitening effect of reducing skin pigmentation. This explains, for example, the whitish color of catfish that live in the depths of dark water.

Melatonin has been used as a tranquilizer producing relaxation and sleepiness. Was also tried in the treatment of headaches and epilepsy, but in all these scenarios the effect of melatonin is quite poor.

André Luiz via Chico Xavier brought us unprecedented and surprising information about the role of the pineal gland when viewed from the spiritual plane.

Sensitive to electromagnetic radiation, our pineal is a tuner of the mental communication phenomena, keeping us in constant contact with all those who share the same range of vibration.

In the mediumistic practices, the spiritual approach relies on the pineal gland to transmit its message to several brain areas that resonate the transmission.

During incarnations, that God's mercy has allowed us to be on earth, we got involved into situations where we had the opportunity to cultivate deep emotional relationships at the same time foster rivalries and conflicts of the most various consequences. As the Divine law does not exempt anyone form the necessary readjustments, it will be through the pineal gland that we will find, sooner or later, those with sincere love that will encourage us towards progress and past enemies that will demand us to pay off our debts and commitments.

Despite brain’s anatomy advancements, it does not recognize from the pathways that emerge from the pineal gland any indication of its extraordinary participation in our mental life. Then, how can we explain the teaching from André Luiz? I assume that you will need to know what is the mechanism of action of the spirit on the brain. Hence, our purpose to gather this set of phenomena that we suggest to be "spirit-somatic".

Under this notable "spiritual physiology" that André Luiz highlights, I believe that the key to its understanding is the involvement of so-called "universal fluid", as known in Spiritism.

Spirits who teach the faith developed with Allan Kardec that fluids serve as vehicles for the transmission of thought. Derived from the universal cosmic fluid, it floods the universe, involving us and allowing us to share the "Divine Breath" that feeds us.

In physical life, we operate by the nerve pathways organized by neurons, their huge communication networks and their extraordinary chemistry that combines and synthesizes neurotransmitters.  In the spiritual dimension we will be using this subtle, fluid element, which obeys the will directed by the mind, allowing us to create, through spiritual physiology, a much wider dispersion in their physiological effects.

When Louis Pasteur unveiled the immense field of microbiology, this new knowledge has enabled us to clarify the dynamics of the etiology of infectious diseases. The discovery of DNA has opened up new areas for explanation of the so-called diseases of genetic origin. However, the study of fluids and their properties may reveal a new physiology and, as a result, diseases that cause abnormalities. The presence of these fluids is closely related to our regular mental activity. The spiritist literature emphatically states that we are an image of the mental life we choose to build and that we reflect the fluidic composition selected on our appearance.

Neurobiology today understand mental imbalances as arising from changes in neurotransmitters that surely begin their disturbance from the fluids we allow our mind to project on the brain, bypassing the chemistry that presides in the balance of thought. 

The ectoplasm - From the phenomena of turning tables, mediumship has provided researchers of the nineteenth century an immense variety of physical manifestations, including the materialization of spiritual entities. In this phenomenology is mobilized a lot of ectoplasm allowing the study of their preparation and chemical constitution. All people that are present in the experimental environment will be donating a larger or smaller share of fluids, but it is from the medium that leaves through all pores and canals of excretion, more or less dense material that will allow the presence of silhouettes that will embody in the environment where the audience waits.

Within the study we are addressing, it is interesting to note that [in the physical realm] the biochemical content of ectoplasm comes from the cytoplasm of cells of the medium/psychic apparatus. In conjunction with the fluids of the two planes of life is that the phenomenon acquires the properties of transition that allow spirits to step into our dimension. 

The healing breathing - the air, as an irreplaceable source of life, is the perception of a usual sense to any of us. The act of breathing is closely linked to our survival. Anaxagoras attributed to air the origin of everything. The Bible records that we receive life from the breath of God. In the texts of Galen, as already noted, the spirit and pneuma (air) expressions were equivalent. To him the vital pneumas were absorbed by the lungs and circulate from the heart to the brain to keep us alive. In Eastern culture the breathing exercises are suggested to be more important than work out exercises.

One of the foundations of Spiritism is that life arises from the presence of the vital principle that animates the organic matter giving it the properties of responding.

The constant activity of our organs is done at the expense of this vital principle and its depletion causes the body to death. On the other hand, our mental activity allows us to absorb from the spirituality the fluids that contain elements that support the vital principle. More activity equals more life, from physical and spiritual perspectives.

André Luiz points out in his writings that breathing is the healing doorway to refuel our vital energies.