2.2. Protection generates action

exploring homeostasis [1]. It should be noted that homeostasis may evidently produce both

Although homeostasis is present in all living systems and relates to large numbers of different biochemical and physiological mechanisms, it reveals amazingly similar features and behavior. Such universality is not unique in the physical world. For example, physical systems, from crystals to large biomolecules, demonstrate universal behavior near critical points in spite of considerable differences in its structures and intermolecular interactions. This occurs due to the critical behavior of the systems being determined by the analytical properties of free energy near critical points, while the peculiarities of system structure and intermolecular interactions

We assume that the universality of homeostasis is a consequence of the analytical properties of the S-Lagrangian, which determines the dynamic equation associated with homeostasis, while peculiarities of the biochemical and physiological mechanisms determine phenomenological parameters of the Lagrangian. We show in Section 2 that plausible assumptions about S-Lagrangian properties lead to good agreement between theoretical descriptions and observed

Living beings actively oppose their degradation in continuously changing environments by means of homeostasis [3] that supports the intrinsic bodily constants within acceptable limits. Maintenance of individual life requires evaluating and regulating its inner state. Homeostatic regularities can be traced to the level of particular cellular parameters, cells, in general, physiological systems of an organism, and an organism as a whole. In this study, we primarily focus on homeostasis of neurons and the nervous system. A cell, as a body, manifests complete homeostasis. This occurs not only to maintain biological constants but also to regulate physiological functions and motivational behavior. The behaving animal is sensitive to single neuronal spikes and even to their temporal patterning [4]. Moreover, a neuronal spike can serve as a tool of reaction for the whole animal [1]. Individual neurons act in concert to govern

At first glance, homeostatic mechanisms are not complicated. In theoretical research, the problem is often evaluated by the introduction of positive- and negative-feedback loops between the sensor and the metabolic flaw (e.g., [6, 7]). Attempts to model homeostatic regulation consider only simple homeostasis, with regulation of each variable described by the introduction of specific individual controllers. However, when homeostatic protection begins to work against a permanent environmental factor or severe injure, these mechanisms become ineffective and living systems utilize indirect paths to assign optimal parameters,

Homeostatic function depends on sensors, which register deviations from the norm. Appearance of a metabolic flaw triggers the homeostatic device to compensate for the shortage.

are "hidden" within the phenomenological parameters of the free energy.

maintenance of life and the will to act [2].

homeostatic features.

148 Lagrangian Mechanics

2.1. Homeostasis levels

behavior [5].

depending on the situation.

2. Biological background

Misalignment of homeostasis leads to damage, the increase in the activity, and leads to further aggravation of injury. As a rule, the response of neurons is proportional to the coming stimulation. However, superfluous stimulation and neuronal injury are intimately connected (excitotoxicity) [9]. Thus, the injured neurons generate spikes.

It should be noted that extensive damage of nerve tissue reduces excitability and violates its function, while protection temporarily restores excitability. Therefore, there is a region of the paradoxical states of excitable tissues, where excitation is reduced due to damage, but irreversible deterioration of the tissue has not yet occurred. In such a case, inhibition (or decreased excitation) counteracts the damage, paradoxically recovers the normal excitability, and promotes the generation of action (parabiosis, in accordance with N.E. Vedensky) [10]. Properties of homeostatic protection make it tempting to consider homeostasis as a driving force that induces actions directed against actual or anticipated damage. However, in cases where the damage cannot be completely compensated for by available resources, metabolic problems may be solved through actions directed at the environment.

To outside observers, the resulting behavior will resemble the emergence of motivation, will to live, and be match with conscious decision. The optimal state corresponds to such conditions that do not threaten the lives and do not evoke attempts to change structure and functioning of

<sup>1</sup> We do not consider this complicated form of homeostasis in this study; however, our approach is extendable to this case, as well.

the brain. A minimum of homeostatic load will serve as a criterion for this state. Joint behavior of a huge variety of such systems generates to complex forms of awareness. The neural tissue concentrates within itself the ability to evaluate its own state and endeavor to survive. A single cell, neurons in particular, can live, learn, want, suffer, delight, and try to survive [1]. Exertion of neuronal metabolism, leading to protection and goal-directed behavior, is rather appropriate for the description of conscious actions. Purposeful behavior corresponds to conscious decision and resembles a kind of generalized "pursuit of life." To the outside observer, this is reminiscent of intentional action and a manifestation of will.

## 2.3. Emergence of the feeling of a death threat

The essence of subjective feeling, goals, and will is still the amazing mysteries. The establishment of the theory of systems regulating optimal constants of their own state gives hope for understanding the problem of subjectivity, as homeostasis is the key tool that supports the system alive. The emergence of self as a state separated from the external environment is probably a direct consequence of the vitality of living systems. Alive system should assess its own vitality, and the phenomenon of maintaining its life is impossible to distinguish from instrumental actions. Probably, life appears along with the ability of an individual to evaluate its own integrity and health, and the homeostatic protection is a material manifestation of the pursuit of life.

Maintenance of vital activity resembles a manifestation of the mystical "vital force," which prevents disorder and violates the laws of thermodynamics. Homeostatic activities are so rational that their discoverer, W. Cannon, described them as "Wisdom of the body."

The appearance of self-dissatisfaction plays a crucial role in triggering homeostatic protection, especially in the emergence of aware decisions. Nevertheless, it is difficult to provide a formal definition for the subjective feelings of discomfort that coincide with the appearance of damage. The assessment of general parameters is qualitative and is guided by the "injure-repair" scale. Living systems somehow regulate the avoidance of injury and the aspiration to life as it shifts toward death or life, that is, behaves as an object possessing minimum awareness. This mysterious variable may not be a function of the state and should depend on the previous history of the system, since homeostasis, as well as behavior, improves after exercise [1].

We have no possibility of determining how a neuron evaluates its own state, but we know that injury decreases positive feelings, while protection decreases distress. In any case, the approach of death increases cellular efforts to operate. A living system reacts to damage as if it is having a negative sensation. Homeostasis entails a relationship between physiology and mind. The problems of consciousness and the problem of life self-maintenance are inseparable. It is likely that the origin of life necessarily leads to the emergence of consciousness.

#### 2.4. Homeostatic regulation

Theoretically, there are two explanations for homeostatic operation:


If it is algorithmically predetermined by the Genetics, the body needs to recognize its own current state and select a genetically pre-tuned course of recovery. However, the number of possible optima can be as high as the number of non-lethal states of external environment and this would create invalid load on the genome. Besides, genetic defects often have limited impact on the relevant functional paths, since homeostasis is capable of compensating for many such defects [11, 12]. Therefore, it is reasonable to assume that spontaneous recovery to a sustained state is the main mechanism of homeostasis.

In general, a living system is open and its dynamics is irreversible. Living beings are somehow able to evaluate their remoteness or closeness to death. While this is beyond doubt, we cannot specify the exact mechanism of evaluation. Movement of a living being within the space of its parameters should minimize this global parameter, that is, proximity to death.
