Section I: Significance of the Pineal Gland and Its Hormone Melatonin.- 1 Some Historical Remarks Concerning Research on the Pineal Gland and Cancer.- References.- 2 Biology of the Pineal Gland and Melatonin in Humans.- 2.1 Introduction.- 2.2 The Pineal Gland in Animal Species.- 2.2.1 Structural Aspects, Innervation, and Pinealocyte Receptors.- 2.2.2 Melatonin (MEL) Synthesis and the Regulation of Its Day/Night Rhythm.- 2.2.3 The Influence of Light and Darkness on MEL Formation.- 2.2.4 The Function of MEL in Non-Human Mammals.- 2.2.5 Influence of Magnetic and Electromagnetic Fields on the Pineal Gland.- 2.3 The Human Pineal Gland and MEL.- 2.3.1 General Aspects.- 2.3.2 Release and Fate of MEL.- 2.3.3 Interindividual Variation of MEL Secretion.- 2.3.4 Day/Night Rhythm of MEL Formation in Humans.- 2.3.5 Influence of Light and Dark on MEL Secretion.- 2.3.6 Seasonal Differences in MEL Secretion.- 2.3.7 MEL Secretion in Old Age and Pineal Calcification.- 2.3.8 Various Factors Influencing MEL Secretion.- 2.3.9 MEL and Seasonal Affective Disorder.- 2.3.10 Electromagnetic and Magnetic Fields.- 2.3.11 Function of MEL in Humans.- 2.4 Conclusions.- References.- 3 The Role of Melatonin in the Neuroendocrine System: Multiplicity of Sites and Mechanisms of Action.- 3.1 Melatonin Is a Universal Time-Related Signal.- 3.2 Sites of Melatonin Action Are Multiple.- 3.3 Melatonin Promotes GABAergic Responses in SCN and the Brain.- 3.4 Melatonin Acts on Cells Through cAMP- and Non-cAMP-Signal Transduction Pathways.- 3.5 Melatonin Interacts with Cytoskeletal Proteins.- 3.6 Melatonin Exerts Antioxidant Effects.- 3.7 Melatonin Restores Amplitude of Circadian Rhythm in Chronic Inflammation or Aging.- 3.8 Concluding Remarks.- References.- 4 The Pineal Gland and Chronobiologic History: Mind and Spirit as Feedsidewards in Time Structures for Prehabilitation.- 4.1 Introduction.- 4.2 Render Measurable What as Yet Is Not: Emotion, Mind, and Spirit.- 4.3 Let Us Learn That We Do Not Know Even What Wl“