This series is reprinted with permission from my friend and fellow mental health nurse Felicity Stockwell. Her complete writings can be found on her website at http://www.felicitystockwell.com/

I’m grateful to Felicity for agreeing to let me publish her work here.

The bonding process arises from an extremely complex neuro-chemical system within the more primitive parts of the brain. It is incorporated into the autonomic nervous system, and is linked to the endocrine system, which monitor and maintain physiological ‘balance’ (homeostasis), and it is an extension of it, in that it monitors and motivates psycho-social ‘balance’ (sociability)

At birth, the baby’s physiology is fully functional to sustain life, but he needs nurturing and protection. The main function of all the physiology is to ensure that the tissue fluid throughout the body is maintained at its optimum consistency. This is monitored and controlled by specialised nerve centres and pathways and the interconnected endocrine system, and the process is called ‘maintaining homeostasis’.

Because this process is fundamental to Bonding, a brief account is given below.

The anatomy of the midbrain and autonomic nervous system

Figure 1: a sagitial section of the brain                                  

 Figure 2: A diagram of the limbic system

The Thalamus

This is a collection of nucleii, situated in the midbrain.  It acts as a relay station for all the sensory information from inside and outside the body and transmits it to all the effector ‘visceral’ muscle and glands within the body, and to relevant areas of the brain.

The hypothalamus, the amygdala and the hippocampus.

These nucleii have direct neural links from the thalamus, and have close interconnections and specialised areas that monitor all the sensory information that is relayed from the thalamus. This information determines the impulses that are passed to the autonomic nervous system and to the pituitary gland and endocrine system, ensuring that internal homeostasis is maintained at all times. For most of the time this ‘fine-tuning’, with its many ‘feed back’ systems carries on, day and night, without conscious awareness.

The Frontal Lobes

The frontal lobes are the control and communication centre for emotional experience and behavior.

The autonomic nervous system The function of the Auto NS is to maintain the  level of physiological homeostasis and to respond to physical threats with alacrity.

It is made up of efferent (motor) nerves that supply visceral muscle and glands throughout the body, which are divided, anatomically and physiologically into two branches :-

The sympathetic branch (Symp NS) mainly has adrenalin as the neuro-transmitter and, when physiological lacks or threats are detected’ it initiates the increase in heart and respiration rates, and re-distributes the blood in the body by controlling the diameter of arterioles. This, and the effects on other smooth muscle and glands, generate sensations that can reach conscious awareness when action of the whole body is needed, and these are experienced as hunger, thirst etc. or as anxiety when deficits or threats are serious. When fully aroused the ‘fight or flight’ response results.

The parasympathetic branch (Para NS) mainly has acetylcholine as its neuro-transmitter and its function is restorative in maintaining internal equilibrium and ensuring rest and repair. It also causes the release of endorphins in the brain which engender conscious awareness of pleasurable feelings.

When babies are born this physiological monitoring system is fully functional, but because humans can only survive through communal living, an elaboration of this system of special nerve cells and pathways is laid down in the midbrain. These are inert until specific sensory information passes along them, within a specific ‘window’ of time, which is from birth and for twelve to twenty four months. It is the activation of these pathways and their linking with the physiological monitoring process that is called ‘Bonding’

From the moment of birth the infant is bombarded with sensations and is programmed to learn from constant repetitions of essential stimuli that arise from the nurturing behaviour of the mother.

It is now understood that the hormone ‘oxytocin’ plays a vital part in initiating and sustaining the neurological bonding process in the baby, and in influencing the mother’s specific bonding behaviours with the baby. (see the link to ‘skin to skin touch’ in side panel.)

There is a close association between the Auto NS and the endocrine system by way of the pituitary gland. The endocrine system, through ‘feedback systems’ maintains the optimal function of the myriad chemical processes in the body. One of the effects of this process is the release of cortisol, which plays its part in the body’s response to threats and lacks, and there are likely to be many others to be discovered.