Neuroscience and Karma: 04. Birth, Growth, Aging, Death

0. Programed Sequence

What determines the life-span of a living organism? According to the doctrine of karman, āyuṣya karman is the chief determinant and the decision is made in the previous life, that is, an organism is born with a predetermined life-span. It may run the full course or die a premature death, depending upon whether it meets with an upakrama (cause of untimely death e.g. fire, drowning, accident) or not, when the bondage of āyuṣya karman is sopakrama - subject to upkrama. Death, however is inevitable and no organism can live a single instant more than its determined life-span (āyuṣya). The time duration or length of the life-span is characteristic of the species of the organism which is determined by the nāma karman^[1] which is, thus, the auxiliary determinant of the life-span. The death is usually preceded by aging and senescence.

Biologically, the life of a human, from conception to death, may be viewed as a series of events that follow one another in a programed sequence.^[2] The sequence of human development, early helplessness, long childhood, late and short adolescence and long adult life is designed to allow the brain to develop and to acquire and use a set of programs of an essentially social life.

1. Reproduction

Living organisms perpetuate their species from one generation to another through reproduction. It is a precise duplication and transmission of characteristics from parent to offspring. In lower organisms, reproduction is often a simple matter of division of cells. In human and higher organisms, sex comes into operation; reproduction requires two parents: a male and a female. Reproductive cells, called gametes, which ate produced in the reproductive organs of both sexes, are a special variant of cell. The female gamete is called ovum or egg and the male gamete is called sperm. Meiosis is a special process of cell-division and takes place in the reproductive organs. It is a sequence of two divisions. In thirst division, each daughter cell receives only one of each pair of homologous chromosomes. Thus, in meiosis, daughter cells differ in their sets of genetic information both from each other and from the original cell.

A. Conception

The incredible sequence of events that occur before birth, resulting in the formation of a perfect human being, is one of the most amazing parts of the human story. Fertilization is union of the ovum with the sperm which takes place in the mother's womb. In humans, a mature viable ovum is surrounded by a barrier (tough membrane). An estimated 35 million sperms are needed to break a large enough hole in the barrier for a single sperm to enter the ovum. As soon as this is accomplished, the ovum fuses with the sperm and prevents the entry of additional sperms. Now the male pronucleus with 23 chromosomes unites with its counterpart - the female pronucleus - and the full complement of 46 chromosomes align themselves in 23 pairs in the fertilized ovum. The single cell is now ready to receive a soul.

Precisely at this instant, a transmigrating soul, which is conscious substance enveloped in microbody - karmana śarīra - arrives in the womb (from its previous life) and animates the fertilized ovum which becomes its physical body through a stage-by-stage biological process.^[3] A new human being has been conceived. The new human is thus, endowed with

1. the genetic code contained in the 23 chromosomes from the mother
2. the genetic code contained in the 23 chronosomes from the father and
3. the code contained in the karmana śarīra appended to his soul from his previous life/lives.

All these begin and continue to interact and integrate into various programs which would control the life of the new human. Its existence and development is totally dependent on karmic and hereditary programmed instructions. Those for remaining alive come from DNA and āyuṣya karman.

B. Prenatal Development

Now the single cell with a full set of 46 chromosomes, (23 from the mother and 23 from the father) divides into two duplicates of itself. This is the first in a series of divisions and the cells divide again and again in a long process of development in which many changes occur in a precise sequence. The nucleus of the fertilized and animated cell contains full instructions needed to make all the different proteins of all the different types of cells in the body (a liver cell, a nerve cell and so on). Using these instructions, the embryo produces all the different organs in a precise sequence following a harmoniously regulated time-schedule and spelled out in DNA blue-prints contained in the nuclei of the fertilized ovum. The growing embryo is attached, first by a stalk and then by a rope-like umbilical cord, to the placenta. It receives nourishment from the placenta via its umbilical life-line.

When a human baby is born, it is already about nine months old. It has spent these nine months of life, since conception, living as a parasite within the body of its mother. During this period it increases from a microscopic single cell to 3 to 4 kg. mass of protoplasm composed of nearly 10 trillion cells, integrated into various functional systems.

C. Birth

Birth inevitably, brings a certain amount of trauma for the infant. For nine months it has rested in gently supporting fluids. The sheltering environment is suddenly replaced by air. The oxygen supply from the mother is cut off. With a convulsive gasp the newborn draws in air and fills its lungs for the first time.^[4] A baby's existence and growth is partly dependent on hereditary programmed instructions 'contained in his DNA and partly on the instructions from the fruition of the body-making (nāma) karman. Organ building, joint building, structure building and such other functions of remaining alive and growth would be the outcome of the joint action of the DNA and various sub-species of the body making (nāma) karman.

2. Childhood

After birth, the child begins to learn by virtue of the neural equipment provided by heredity. But this equipment is not a static machine; it is not complete and in final form at birth. The full number of nerve-cells is already laid down at the time of birth but they are far from their final form either in structure or in function. Each of them has the capacity to develop and mature with a wide margin of possibilities by suitable experience. The nervous system continues to change and matures for many years after birth, with the help of suitable inputs, at appropriate time. Simultaneously, the body grows in size and weight. Cell-division - increasing the total number of cells - is the main process of growth.

Development of Skills

A child is born with an ability to perform well some actions including those that it needs to maintain its life such as sucking, swallowing and breathing. This implies that programs for such actions are 'hard wired'^[5] and cannot be varied. Within the first two years, it acquires other skills - feeding, attending, perceiving, manipulating and inter-acting with others. Each of these has a background of species - types genetic instructions - but are also capable of adaptational changes. They form the very center and core of all subsequent behavior and personality, that is, form the center of brain-program of actions. Thus, these skills become generative and can be combined and recombined and lead on to the use of tools and language.

As the child brain develops further, the skills that ate acquired include language and the capacity to understand conservation of quantity, cause and effect and much else. These later developments are accompanied by physical changes in the brain. For example, if a child, up to at least 10 years old, unfortunately loses the usually dominant left cerebral hemisphere, it will, none the less be able to acquire language in the right hemisphere, which would normally not possess this facility. So evidently the use to which the brain is put fundamentally influences its later development.

In the pre-operational age (2-7 years), the child's thinking is like a slow motion film representing one static frame after another but lacking a simultaneous encompassing view of all the frames.

Later, however, there is unification of previously distinct processes, either by the overall interaction of the parts or by a dominating superior control. At this time, the child is becoming more socialized and less egocentric. The interaction with others may be a requirement for the maturation. The child begins to pass from personal forms of representations to socialized forms with more general meaning.

Emotional Development

It is obvious from the crying of a child's first day that

1. he is a communicating creature, and that
2. he experiences something that can be called emotion or feeling, viz. discomfort or pain.

The expressions of emotion do not all appear from the beginning but gradually, following a hereditary program. One of the earliest is smile. At first, the baby smiles mainly when he is drowsy but later on it becomes an important part of the communicating system. Laughter seems to develop gradually, later, in response to tickling and much later in social situations. Anger develops later than smiling but full temper tantrums come much later. Surely a child cannot have learned to throw tantrums from his elders. The capacity to do so was inborn and then developed and matured. It involves specific actions of the brain and we shall see later that it comes from the limbic system. Blushing develops later still and more readily in girls. All these obvious facts show us that humans are born with certain capacities for communication of emotional and even moral attitudes.

The human pattern of a long childhood is genetically determined. Other mammals become mature, immediately they have stopped growing. Only in man and apes is there a long period of immaturity followed by rapid pre-adolescent growth spurt. It seems likely that extension of the period of childhood is related to the acquisition of social skills, which will be only learned if the child is obedient to his elders. During childhood the child is mostly concerned with its own life in the immediate present. His own homeostasis is his primary interest in these early years and for long after and meeting his own emotional and physical needs may be a requirement for maturation. Here cognition and emotion are never wholly separate, because of the interaction of brain processes.

3. The Programs for Adolescence

To emphasize the place that emotion plays in the unfolding of the programs, consider what happens at adolescence. An internal biological clock, that has been ticking, begins to send signals to the pineal gland which had been producing a hormone, melatonin, which inhibited the maturity of the sex glands. Now the pineal begins to remove the inhibition and allows maturation to start. Simultaneously, the hypothalamus sends chemical signals to the pituitary to release gonadotropic hormones. We have no control over the clock and there is ample evidence that factors such as climate or food have little effect also. Sex hormones, now released from the ovary or testis, produce a dramatic change in her or his physical and emotional condition. A sudden growth spurt is sparked adding as much as 15 to 18 cms in a year. The brain also continues to develop some of the human characteristics with appropriate inputs at series of critical or sensitive periods. Learning consists both by selection among the many possible pathways in the brain as well as instruction. It may well be that the emergence of new potentialities, requiring new stimuli, continues far on into the adult life. Growth in height stops entirely by the age of 18 to 21 in boys and 16 to 18 in girls.

4. Aging and Death

During the long adult life, active growth ceases; cells that wear out or are destroyed by accident or disease are replaced and a dynamic equilibrium is maintained. But ultimately, the repair processes become less efficient and cannot adequately replace the day-to-day losses. Various body-functions gradually begin to deteriorate and senescence (aging) sets in and ultimately results in death.

The end of the life is by a definite process of senescence, which should be distinguished from disease (even though some of its manifestations lead to disease). It has been recently shown that cells from older men are capable of fewer divisions than those from younger ones. This proves that senescence itself is a programmed terminus and death is a part of the program of life. Actually, death occurs at each moment throughout life - thousands of blood cells and cells of the intestine die every second, but they are replaced and repaired by programmed mechanisms that allow the attainment of the predetermined age. There are enzymatic mechanisms by which even DNA can be repaired. If a piece of one of the double chains of DNA dysfunctions, it is removed and a new stretch of DNA is synthesized. Specific enzymes - the ligases - then join the new pieces into the old chain and more and more such repairs have to be made in older organisms. The problem is that repair mechanisms themselves need repairing and the regress of what repairs the repairer and the repairer of the repairer cannot be indefinitely avoided. Thus, there is a limit on the possible length of survival of any individual homeostatic device. This fact is, sometimes, expressed in a different way in terms of cell-division. There is an upper maximum limit to the number of divisions of a cell called 'Hayflick limit' after which they cease dividing and die. In a life time of 100 years, the number of divisions is about 50. Thus senescence or aging is a complex process with many contributing factors not necessarily exclusive. "Hayflick limit" of cell division agrees with the concept of an inherently programmed finite life-span of about 110 or 120 years. This does not mean that there is no possibility of improving repair processes. Though the actual life-span could never be exceeded, and the idea of much longer life is not altogether pleasing, particularly to those of us who are already very old, knowledge of some of the factors, would not only reduce the possibility of dying in younger age, but also some of the miseries of old age.