I am writing this note to demystifying the concepts we have about the brain such as neural networks, computation and so on, whereby it is ignored that the brain is, fundamentally, a conglomerate of biochemical processes elaborated by its neurons to act as signals of a complex and mysterious nocturnal and diurnal synchrony, among themselves and with the rest of the body. Also, I try to make them understand that by going out, staying up late, eating late, not living a life according to a schedule, we are attacking the central clock that resides in the brain.
The body's health and longevity depend on the precise performance of daily tissue functions, which are governed by a molecular oscillatory system and our genes present in every cell. Circadian clocks are active 24 hours a day, commanded from a command centre located in the hypothalamus, where this region of the brain also commands the thyroid and other hormones and other functions, mainly through chemical messages.
This oscillatory centre is located in what we call the suprachiasmatic nucleus (SCN) of the brain, which receives daily light and dark signals, as well as receiving and integrating external signals about whether we are sedentary or active, our breakfast-feeding rhythms or circadian fluctuations in body temperature, and from there transmits this information to the rest of the body (see Figure 1). 6 - 8 ).
It communicates back and forth with the physiological functions of the liver, pancreas, stomach and stem cells in muscle and skin, reprogramming their daily functions, probably to cope with stressors and disruptions to the sleep-wake cycle.
The muscle clock directly controls functions essential for muscle mass, commanding genes involved in the proliferation and differentiation of myogenic cells to build muscle, as well as the autophagy pathways of aged or damaged cells and immune responses (e.g., the immune response). 34 , 72 ). This control mechanism ensures that genes are expressed appropriately throughout the day to support the specific metabolic requirements and physiology of muscle tissue.
The circadian rhythm ensures the synchrony of all these functions, which is why when we have slept very well we are in a state of well-being and health (2, 3). Communication and coordination between tissue clocks are crucial for maintaining physical and mental health and critical homeostatic processes, such as mitochondrial activity (giving us energy) and lipid metabolism (cholesterols). Similarly, for responses to metabolic signals such as insulin and glucose.
It is important to be in accordance with our circadian rhythms, so it is important to it is better to eat in the morning. And by exercising in the afternoon, you lose more fat, especially trunk-abdominal fat, and build muscle. Because the light, physical activity and nutrition are the three synchronisers of the internal clock.
We attack this wonderful synchrony that works to keep us alive and we break it with the circadian rhythm disturbances caused by lifestyles. The functioning of the human body, its organs and tissues, like all other living things (animals and plants), has its own timetable and performance. On this basis, as our central clock of the hypothalamus has to be synchronised with the outside world, it is in its interest that, when we get up, we have plenty of light, physical activity and that we eat a hearty breakfast.
Short or insufficient sleep can lead to alterations in appetite hormones, such as ghrelin and leptin. It can also lead to a decrease in the individual's immunity, cardiovascular disorders (such as high blood pressure) and problems with memory and mood.
These discoveries will enable us to develop treatments for age-related diseases. We will accelerate our ageing and deterioration as we introduce lifestyles contrary to this brain-driven synchrony.
Another example of intercommunication between our biological systems
After acute liver damage, liver cells, called hepatocytes, produce glutamate and release it into the bloodstream. The glutamate travels through the blood to the bone marrow - inside the bones - where it activates monocytes, a type of immune system cell. The monocytes then travel to the liver and along the way become macrophages, also immune cells. The presence of glutamate reprograms the macrophage metabolism and the macrophages then begin to secrete a growth factor that causes the hepatocytes to proliferate to repair the damage.
In other words, a rapid chain of events allows glutamate to trigger liver regeneration within minutes, through changes in macrophage metabolism.
*José Antonio Rodríguez Piedrabuena is a specialist in Psychiatry and Psychoanalysis, and in management training, group and couple therapies..