Sahasrar Chakra and Brahmarandhra-Centers of Divine Powers
The human body (Microcosm) is said to be a small  sample of the cosmos (Macrocosm).  The entire body of a big tree is  hidden in a tiny seed.  In a small sperm lies the cast of the entire  human body.  The manner in which the mutual attraction and activities of  the planets of the solar system are executed, can be seen albeit at a  microlevel within the atomic family represented by electrons, neutrons  etc.  In the same way the entire cosmos can be seen in a microform  within this small human body.  Whatever is visible / invisible in this  gigantic cosmos is present within this tiny human body.  All the special  characteristics of earth too are found in the human body.
All  the energies, special qualities and glories of earth are found in the  point of balance i.e. the North and South Poles.  From here all  movements /activities of earth are controlled.  As a result this earth  is an active ball and a playground for all creatures.  If the North /  South Poles lose their balance or they undergo some change, the entire  earth will look like something totally different.  It is said that even  if a minor fist blow is executed on the point of center of balance in  the 2 Poles, the earth will change its orbit by leaps and bounds.  As a  result this very nature of days, nights, seasons etc. will change and  take up a new extreme form.  Further this minor fist blow can induce  earth to dash into other stars, galaxies etc. and thus get powdered to  pulp.  The cause is very clear.  In that the 2 Poles control all the  movements of earth.  It is their energy centers that induce our earth to  dance to its tunes like a puppet.  All earthly activities are given the  necessary capacity and inspiration to function aptly.  The 2 Poles are  the central points of earth's activities and energy centers.
Just  as the planet earth attains energy and activities from the 2 Poles, so  too the human body has 2 Poles.  The North Pole is Sahasrar Kamal in the  Brahmarandhra (center of the brain).  The South Pole is the Mooladahr  Chakra of Kundalini or Divine Serpent Power center at the base of  Sushumna (near the genitals). According to Indian Mythology, Lord Vishnu  sleeps on Lord Shesha (1000 hooded serpent) in the Ksheersagar (ocean  of nectar).  This Ksheersagar is nothing but the intense white ocean of  love in our brain.  Sahasrar Kamal is that atom which instead of being  round like other sheaths is like serrated teeth of a cog-wheel.  These  teeth are compared to the petals of a lotus.  The central point of  energy lies in this atomic Pole.   This Vishnu Pole or Sahasrar Kamal  (1000 petalled lotus in the brain) is the very basis of attainment of  sensory and extrasensory knowledge pertaining to the innumerable  conscious and unconscious units of the brain.  This region is the  central point of all spiritual practices like meditation / trance /  self-reflection / Yoga of devotion alongwith will power, soul power and  Sidhis attained due to a strong power of resolve (Sankalps).
The  North Pole lies in the central point of the head called Sahasrar Chakra.   In the center of the head is a subtle 1000 petalled lotus and is  called the Sahasrar Chakra. Within it dwells divine energy or Shiva.  It  is over here that Kundalini or Divine Serpent Power rises from the  South Pole to merge into Shiva in the North Pole.  From this area all  bodily movements are controlled just as a puppeteer seated behind a  curtain, controls his puppets via mere finger movements.  It is also  called the region of the soul etc.  All energies and its sub-categories  that create movements in this gigantic cosmos are found situated around  the Sahasrar.
Sacred scriptures say that Kundalini is the very  life force of all energies and Sidhis.  A person who activates the  otherwise latent (sleeping) Divine Serpent Power becomes the Lord of  infinite grandeur of this world.  In India this has been discovered  right since ancient times.  There is no end or limit to the potency of  Kundalini Shakti or Divine Serpent Power.
But activating the  Kundalini is not the ultimate goal of a living being.  The ultimate goal  of all creatures is to attain salvation (Moksha) i.e. merging the  individual ego into the cosmic soul (God).  The aim of any human life is  to merge into Brahman / God/ cosmic soul.  Yoga and other spiritual  practices are meant exactly for this purpose.  The same holds true for  Kundalini too.  This has been commented upon in Hathayoga Pradeepika as  follows –
"Just as a person tries to open the lock of a bolt, so  too a Yogi finds the path of Sushumna via Kundalini based practices.  He  then enters Brahmaloka so as to attain salvation (Moksha)."
Only  when a spiritual aspirant enters this Sahasrar Chakra, can he  experience the joy of immortality, vision of the cosmos, control of  cosmic powers and Samadhi or trance.  The Brahmaloka mentioned in the  above lines is nothing but the Sahasrar Chakra.  It is very difficult to  reach this Chakra.  Majority of spiritual seekers get stuck in the  lower Chakras and merge into the lower type of bliss that they get in  that region.  Hence Sidhis (extraordinary powers) attained during  preliminary Kundalini awakening are said to be obstacles.  Just as a man  thinks the material world to be the ultimate goal of life because of  having immense wealth, grandeur and a beautiful wife, so too a person  who activates his Divine Serpent Power thinks that Sidhis like hearing  far off words, seeing far off objects, knowing other people's thoughts,  predicting the future accurately etc. attained while activating the  lower Chakras, is the be all and end all of life.  Thus he totally loses  sight of the supreme goal of rising upto the last Chakra i.e. Sahasrar  and merging into it.
Even if a person reaches the Sahasrar  Chakra, he cannot dwell in this region for a great length of time.  How  long can a spiritual seeker dwell in the Sahasrar Chakra?  This depends  on the nature of spiritual practice which he follows and how much inner  spiritual energy he possesses.  Many spiritual seekers dwell in the  Sahasrar Chakra for a certain length of time and then get demoted into  lower Chakras and their levels of lower bliss.  But he, who steadfastly  "ripens" his Sahasrar Chakra, attains the omnipotent Lord and thus  experiences infinite bliss eternally.
The Sahasrar Chakra lies 2  inches within the ears and 3 inches within the eyebrows.  Its form is  that of a ball of light in the hollow portion of the upper region of an  opening called "Mahavivar" of the brain area.  Via the process of Divine  Serpent Power awakening, this Mahavivar opening has to be widened so as  to enter the state of divinity.   Hence it is called the "10th door" or  Brahmarandhra too.  In the Dhyanbindupanishad it is said that –
"A  Yogi is one who knows the light akin to a jewel in the brain.  That  jewel akin to 7 golds that is lit up by an electrical like stream, is  found in the lower region of Meru and 4 fingers above the fire region.   It seeks shelter in the Svadhishthan Chakra and is subtle sound  manifest"
The scriptures while describing the powers attained in reaching this region say –
"Such  a person knows the ultimate knowledge, he becomes omniscient (i.e.  knower of past, present and future) and can do anything he wishes.  He  may perform any action, yet no sin accrues.  None can gain victory over  such a person."
In one way Brahmarandhra is the head office of a  creature.  It is a laboratory which helps us attain whatever we see in  this visible world and all those things which are beyond our knowledge.  According to Indian philosophy over here there are such rare auras of  light made up of 17 principles which cannot be seen in the visible world  with our gross eyes. All nervous elements and air tubicles come out  from this area and spread out into the entire body.  The Creator seated  in this white lotus, sends and receives orders and messages from any  part of the body via any nerve.  He can create movements in any area.   He can clean and create a rain of vital force in any area without any  technological paraphernalia which we limited creatures can never even  dream of doing.  All this takes place because of emission, contraction  and relaxation of auras of light.  It is this ball of light that induces  the nose to smell, the ears to hear, the eyes to see, the tongue to  taste and speak.  This ball of light is under the direct jurisdiction of  Almighty God dwelling in the Sahasrar Chakra.  In the initial stages of  meditation, this light is seen either as glow-worms, twinkling stars,  shining petals or half/ full moon. Slowly and steadily its divine nature  is experienced.  As a result the gross sense organs become lax and the  working arena of the soul shines brilliantly in the entire world.  An  ordinary individual can worry only about his immediate family members.   But a Yogi enfolds the entire world in the embrace of his soul and  extends upto other Lokas (worlds) too.  He also has to ascertain whether  there is any imbalance in the movements of planets, galaxies etc.  In a  gross manner denizens of our planet earth too are influenced by these  activities.  Hence even unknowingly such a spiritual seeker, who enters  the state of Godhood, can work only for the well-being of all creatures  of the cosmos.  Whatever rights and omnipotency is attained by such a  great soul is taken up as a gigantic responsibility by him.  He may seem  to be having a human body yet he has no body consciousness at all.  He  knows everything.  He sees and hears everything and can predict future  events very accurately.
The substratums of the Intellectual  Sheath and Mental Sheath viz. the intellect and mind dwell in this  region. They unearth news of objects lying far away or those beyond the  ken of the sense organs of knowledge.  When one's soul resolve  progresses into the intellectual arena after leaving the mental arena,  one attains divine wisdom.  It comes out from the Ajna Chakra so as to  unite with the different types of rays of the cosmos and thus attains  its knowledge.  Just as with the help pf electrical waves, space  shuttles can be directed to the right or left of planet earth (called  traversing), just as with the help of a television you can see scenes of  far off places so too man can see scenes in my part of the world or  obstruct one's cosmic movement with the help of the rays of his resolve  (Sankalpa).  In the Mundak Upanishad (Chapter 2) and Chandogya Upanishad  (Chapter 9) details of this self-realization have been given as follows  –
"A self realized saint subtly experiences that God without  Kalas (divisions) in the form of a light that is whiter than white and  is present in the Golden Sheath."
Many forms of Sahasrar based  spiritual practices like Pratyahar (disallowing sense organs to contact  their respective objects), Dharana (focusing of mind), Dhyan  (meditation) and Samadhi (trance) have been put forth as studies.  A  description has been given about the good results attained due to their  successful execution.  The deep import of the success of that region has  been given in the form of material and spiritual progress.
Today  even modern scientists accept that there are extraordinary energy  centers in the brain.  According to research studies conducted by the  brain specialist Smithy, a pure intellect is controlled by different  centres of the human brain.  It is a production of a cooperative  endeavour of all of them.  This is the gist (region) which creates a  human character and nourishes it.  A mental level is created by memory,  analysis, synthesis, selectivity etc.   Where does its admixture and  production take place?  This has not been aptly deduced yet it is clear  that this area should be in the cerebellum part of the brain.  This is  that very sensitive spot which if undergoes ripening, can induce  advancement of one's inner personality.  Spiritual seers of yore had  discovered this center and had named it Sahasrar.
While deeply  analyzing the brain so many layers are discovered which not only help us  think but also creates our very character.  This region of special  capabilities is the "Frontal lobe".  In it one discovers man's  personality, imagination power, ambitions, social behaviour,  experiences, sensations and other important functions.  It is not  possible to influence this area by medicines or surgery. Only those  spiritual practices like Dhyan (meditation), Dharana (Concentration)  etc. can be made use of which is a part of Kundalini i.e Divine Serpent  Power awakening.
In the above paragraphs we have merely made a  minor reference of only one center of the brain.  Yet it is well-known  that the brain abounds with infinite mysterious powers.  The conclusions  drawn by today's modern scientists specializing in brain research, is  very much in tandem with the discoveries of ancient Indian seers.
From  a grosser type of classification, the brain can be categorized into 5  parts 1) Cerebrum 2) Cerebellum 3) Mid-brain 4) Pons 5) Medulla  Oblongata.  The last three parts that is mid-brain, pons and medulla  oblongata together form a single unit called the "brain stem."
According  to Spiritual Sciences, 0.33 billion demigods dwell in heaven  represented by the brain.  But 5 of them are chief representatives.  All  of these control various divine centers.  The 5 regions of the brain  listed above can be said to be the region of the 5 demi-gods.  With  their help the 5 energies of the 5 sheaths are produced and controlled.   The 5-fold spiritual practices of Gayatri help evolve these 5 in  unison.  As a result a creature dwelling in Brahmaloka or heaven,  experiences a heavenly atmosphere.
So far our discussion revolved  around a certain type of classification.  Many scholars right since  ancient times have been describing this very fact albeit in various  ways.  Even today this type of discussion continues.  This one single  precept pertaining to the classification of the brain and Sahasrar  Chakra are described in various ways.
The Sahasrar Chakra is also called the "pot of nectar".  It is  said that Som juice emanates from it.  The demi-gods drink this nectar  and become immortal.
According to modern brain anatomy, the brain  is filled with a special "Cerebro-spinal fluid." This fluid nourishes  and protects the various centers of the brain. It drips from the brain's  membrane and is absorbed by various centers of the brain and the  Sushumna (subtle spinal nerve).
The "pot of nectar" has 16  coverings.  In the same way at certain places the Sahasrar is said to  have 16 petals.  These are nothing but 16 important centers of the  brain.  The Shiva Samhita too says that the Sahasrar Kamal has petals.  
"One  should meditate on the Sahasrar Chakra made of 16 Kalas situated in the  centre of the brain and which shines like the moon."
-YOGA MANJUSHA
These  16 Kalas of the Sahasrar are the 16 points of the brain related to the  cerebrospinal fluid.  If the previously 5 grossly classified parts of  the brain are classified more minutely, they will add upto 16 in number  as follows –
1) Cerebrum 2) Cerebellum 3) Medula Oblongata 4)  Pons 5) Mid brain 6) Corpus Colosum 7) Corpus Stratum 8) Pituitary Gland  9) Pineal gland 10) Thalamus 11) Hypothalamus 12) Subthalamus 13)  Metathalamus 14) Epithalamus 15) Corad plexuses 16) Ventrilces.
All  these above parts have centers full of ESP (Extra Sensory Potential)  that control the body.  By activating the pot of nectar of Sahasrar, we  can make the brain more active and thus attain extraordinary benefits.   The scriptures have clearly said –
"Due to activation  of the Sahasrar Kamal, a Yogi's psyche becomes equipoised and thus  merges into his soul.  He overcomes bondage of the material world.  He  is full of all-round potential.  He moves freely everywhere and his  speech becomes nectarine."
- SHATCHAKRA NIRUPANA
"One must  meditate on the Ksheersagar ocean in the core of the forehead and on  the moon-like light in the Sahasrar Kamal (1000 petalled lotus)."
- SHIV SAMHITA
"That  Yogi who continuously drinks the nectar emitted by the Sahasrar Kamal  can bring in a law to 'kill death'.  Meaning death is no longer death  for him because he lives a life that has gone beyond death.  It is in  the Sahasrar region that Kundalini merges itself.  At that time the 4  types of creation merge into God and everything becomes Godlike."
- SHIV SAMHITA
"That Soma juice of Sahasrar Kamal which purifies Richas, Samveda, Yajurved, Brahmanas, may it purify me too."
- YAJURVED
What  exactly is the Sahasrar? This answer according to anatomists is that  the electrical onrush from the center of the brain which controls bodily  movement does not get emitted from a substratum but that a special  center is responsible for it.  This is not man's own creation but is a  divine blessing.  The liver, heart and other organs function as a result  of this energy attained from a divine center.  The blood nourishes  various bodily organs and it is a fact.  It is also true that the lungs  are responsible for respiration and the stomach for digestion.  Yet the  question arises that when these organs carry out various tasks, where do  they get the necessary energy to do so?  It is not correct to say that  respiration, digestion etc. give us the energy to survive because if  this were to be true, man could only die because of hunger or choking of  breath.
This electrical onrush continuously gets emitted in  spurts in the central region of the brain.  It can be said to be an  extraordinary electrical spring.  From there a fire-worklike light is  emitted in spurts.  The heart experiences such rests in between  heart-beats.  There is a rise and fall even in wave-flows of heat, sound  etc.  The same holds true for the activities of the fount of energy in  the central point of the brain.  Scientists opine that the energy spurts  are the main basis of the activities of various centers of the brain.   This very principle has been elucidated by Indian Yogic scriptures in  their own way.
"In the center of the brain is a jewel-like light.   From that, electrical streams are emitted akin to heated gold.  He is a  true Yogi who understands this mystery."
- DHYANBINDU UPANISHAD.
"The  light of Brahman (God) dwells in the Brahmarandhra as fire.  It  purifies our spiritual practice.  This it self is fire of Yoga."
- MATSYA PURANA
This  brain dwelling energy fount can be called Sahasrar Chakra according to  anatomical sciences.  "Sahastra" means 1000 but here it means infinite.   The Lord is said to have 1000 heads, 1000 legs etc.  The sparks of  energy emitted from the brain fount are not 1000 in number but are  infinite in number.  The number of drops of that shower is not 1000 only  but connotes infinite number of drops.  On the basis of this  description this "1000" is the fount of energy called Sahasrar.
Today's  modern science accepts that infinite streams of electricity flow from  the brain.  As per requirements those streams flow in infinite special  nerves in infinite directions.  Based on each one's function, scientists  have classified these nerves into various categories. For example,  Ascending Reticular Activating System, Descending Reticular Activating  System, Specific Thalamic Projection, Defused Thalamic Projection and  Brain Stem Reticular Formation.  From the standpoint of Yoga, the  combined influence of the above systems can be seen in the form of  thousands of streams of electrical onrushes in the brain.
This is  the very basis of the Sahasrar Kamal (1000 petalled lotus) and Lord  Shesha (1000 hooded serpent).   The form of Lord Vishnu sleeping on Lord  Shesha abounding with Kundalini Shakti in the midst of the Ksheersagar  or Brahmaloka, is meant for understanding the state of Sahasrar.   Ksheersagar means marrow of the brain.  The coiled 1000 hooded serpent  means the teeth of the axle of Sahasrar Chakra.  A wheel of a cart too  has an axle.  The Lord's Sudershan Chakra (disc weapon) too has teeth.   Thus Sahasrar can be correlated to the abovementioned details.
The  Sahasrar has been compared to the sun (1000 rays) too.  It is the  energy that lights up the solar system and induces various activities in  them.  Every unit of human existence is influenced by the brain energy.   Hence if the sun is said to be the presiding deity of the ball called  Bhuloka (earth), it definitely is apt.  The divine existence of Sahasrar  has been compared to the sun –
"O Deveshi! Within the stalk of  the great lotus Sahasrar dwells the soul akin to Mercury.  Although it  radiates likes crores of suns, yet during emotions it is comparable to  crores of moons.  This supreme material is extremely grand and oozes  with the Divine Serpent Power."
- SKAND PURANA
"This sun is nothing but the divine principle and its material symbol is the material sun."
- YAJURVEDA (23/48)
"Your  indwelling nectar is one who is the indweller in the sun whom the sun  does not know, whose body is the sun and who controls the sun by  dwelling within the sun."
- BRIHADARANYAK UPANISHAD
Just  as our solar system gets energy from the sun, in the same way the brain  gets the necessary capacity for various functions from the energy source  of Sahasrar Kamal.  Many machines are used in mills, factories etc.    These machines are attached to motors, transmitting electricity.  When  the motor functions, it transmits energy to the machine.  But the  electricity does not belong to the motor.  It comes from another source.   The brain is our motor and the bodily organs are small / big machines.   The energy required for smooth functioning of mills, factories etc.  comes from somewhere else.  It is akin to the flow of grace attained by  earth from its polar regions.  This is a gift of interplanetary energy.   A man is free and the author of his own destiny.  Yet the energy that  creates man's inner personality is said to be divine grace.  The moment  this stream of energy is obstructed, man dies instantly.  Even if the  heartbeats have stopped completely yet via artificial means it can be  re-activated.  But the moment the electrical onrush of Sahasrar stops,  know for sure that this is ultimate death.  Despite the fittings of a  bulb being appropriate, if the electrical connection is cut off, we face  darkness.  Despite the bodily organs being healthy, if the brain energy  flow stops, we cannot remain alive.
Grossly we may describe  birth and death of creatures in a certain manner, yet according to  subtle sciences like Yoga, birth and death are totally dependent on the  activities of Sahasrar Chakra.  This is not the end of the discussion  because a lot more follows hereafter.  Sahasrar is not merely the source  of life but it is from here that the nature of one's character and  level is charted out and determined.  Even a little extra tilt, will  change the course of flow of rain.  When a particular form of slant that  induces rain water to enter a particular river is changed, this rain  water will enter another totally different river.  At the beginning of  the slant there was a difference of only a few inches yet when the rain  water enters a totally new river, the difference in number of miles of  area covered amounts to thousands.  Many trains standing in queue at a  railway junction travel in different directions because of change of  levers.  The changed levers are separated by the few inches only yet the  trains that travel in different directions are separated by thousands  of miles.  The same holds true for the Sahasrar Chakra.  In that, even  an infinitesimal change in the Sahasrar, can induce amazing  transformations; both within and without.
For a modern scientist  even to think of reduction / addition in the grants given by  interplanetary space to earth, means facing fearful worries and turmoil.   Even a mere thought of taking one step in this direction, induces  jitters in their minds.  Even a slight bit of topsy-turvying can induce  massive destruction.  As against this if some conducive solutions are  found it will greatly benefit all denizens of earth.  Thus we can become  lords of unimaginable comforts.  Today scientists refuse to take big  steps in this direction because of lack of knowledge.  They have merely  taken minor steps in conducting research on the earth's polar region.   They have yet not found the earth's axis and nor have they made serious  efforts in this direction.
But no such danger is encountered when  we talk of the Sahasrar which is the axis of the brain situated in the  polar region of the human body.  Material / worldly energy is like a  demon.  Even minor misuse of electricity, fire etc. can kill many  people.  As against this no major calamity comes in the way in the  relationship of a body and its doting mother.  This is the material  difference between soul consciousness and material consciousness.   Sahasrar is a center of union of the individual soul and cosmic soul  i.e. God.  This is a consciousness based give and take.  Within it  overflow high leveled sentiments.  The nature of spiritual practices has  been conjoined to the wealth of good-will.  This divine grace of  greatness overflows from it.
The Sahasrar Chakra is related to  the Brahmarandhra.  Brahmarandhra is the 10th door.  The 9 doors are the  2 nostrils, 2 ears, 2 eyes, 1 mouth and 2 openings of faeces and urine.   The 10th door is Brahmarandhra.  Great Yogis give up their life by  passing through this 10th door.  The very reason behind which the "Kapal  Kriya' (rite) is carries out after death, is that even if a bit of  vital force has remained behind, it should pass out from this 10th door  and thus induced go to a higher state.
A newborn baby has a bit  of a hollow space in the center of the scalp.  In it there is a tissue  instead of bone.  It is situated between the parietal and acivital  bones. As the body grows the bones too augment in size and cover the  above mentioned hollow region.  The Yogic scriptures say that divinity  or cosmic consciousness enters the human body through this hollow  region.
From the standpoint of bodily design, this region is not  merely made up of bones because below its frontal area there are other  principles.  There is also the cerebral cortex beneath the bones of our  forehead that covers the brain region.  Within it are carvings akin to  those seen when a farmer ploughs his field.  Thus it categorizes the  brain into various parts.  These parts are called sulks.  The cortex is  partitioned lengthwise by the longitudinal fissure and breadthwise it is  called central cortex.  The crossing or point of union of both these  corresponds to the Brahmarandhra of Indian Yogic scriptures.  In front  of this Brahmarandhra, lies the most mysterious gland in the upper  region of the brain called the Pineal Gland.
This Brahmarandhra  is a very special doorway for the individual's bodily soul to establish a  bond with the cosmic soul (God).  Great Yogis give up their life force  through this very doorway at the time of death.  Thus they merge into  the cosmic soul or God.  It is very clear that while their bodies are  alive the Brahmarandhra of great Yogis execute tasks of give and take of  divine experiences and divine powers via the medium of Sahasrar Chakra  of the brain.  The Sahasrar Chakra and Brahmarandhra work in tandem like  a unit.  Thus in Yogic practices they are influenced and utilized in  unison.