Multifunctional Merkel cells: Their roles in electromagnetic reception, finger-print formation, Reiki, epigenetic inheritance and hair form
Introduction
Merkel cells are neuroendocrine cells found in hairy skin, glabrous skin, and ectoderm-derived mucosa such as mouth, lips and nose [1]. In glabrous skin, Merkel cells are always located on the epidermal ridges in close contact with myelinated nerve fibers [2]. In hair follicles, Merkel cells are located in the bulge, an area that corresponds to the reservoir of stem cells, and are rarely associated with nerve endings [3]. In hairy skin, Merkel cells are found in thickened parts of the epidermis between hair follicles, the so-called “touch dome” [4]. Various nerve fibers innervate Merkel cells within the touch dome, but stimulation of touch domes housing Merkel cells does not produce a conscious sensation [5]. Merkel cells also exist in the epithelia of oral and nasal mucosa but some of them are not connected to nerve fibers and play a role within the epithelium as isolated cells [6]. Merkel cells are linked to adjacent keratinocytes by desmosomes and attached to the basement membrane by hemidesmosomes [3]. Microvilli are present on the cell surface and interdigitate with the surrounding epidermal cells [2]. Furthermore, melanosomes have been described inside the cytoplasm of Merkel cells [7]. Their cytoplasm also contains a cytoskeleton of intermediate filaments (cytokeratin CK20) that are more loosely distributed than in keratinocytes and extend into spine-like protrusions [8].
Merkel cells synthesize numerous neuropeptides contained in dense-core secretory granules located in the cytoplasm apposed to the nerve terminals [1]. After stimulation of the Merkel cells, dense-core granules release their neuropeptides by classical exocytosis, but the stimulation required for this phenomenon has not been clearly identified [9]. The peptides presumably act as neurotransmitters, neuromodulators, or mediators, acting on sensory nerve endings and serving either a trophic role on keratinocytes or some unknown endocrine function [1]. Both Merkel cells and neurons are excitable cells, but the information that may be transmitted has not been clearly elucidated [10]. Merkel cell–neurite complexes and their localization in touch-sensitive areas led to the suggestion that they are mechanoreceptors [11], but studies disagree about the dependence of epidermal touch sensitivity on Merkel cells [12]. While the structure of the Merkel cell is well established, their function is still unclear. The numerous peptides they synthesize and release may allow them to communicate with many cells other than neurons, and they may play an important role in human physiology and biology. The purpose of the present review is to shed light on the possible functions of these least-known cells of the skin.
Section snippets
Role of Merkel cells in electromagnetic reception
Many animals have a magnetic sense which they may use in navigation, but almost nothing is known of the detailed cellular structures and processes by which magnetic fields are detected and encoded by receptor cells for transmission to the brain [13]. The discovery that crystals of the mineral magnetite (Fe3O4) underlie the ability of magnetotactic bacteria to swim along magnetic field lines [14] inspired searches for magnetite in diverse animals. Magnetite particles suitable for use in magnetic
Role of Merkel cells in finger-print formation
On the palmar surfaces of the hands and plantar surfaces of the feet there are numerous fine epidermal ridges which form regular but complex patterns called fingerprints. Finger-print patterns are encoded at the interface between dermis and epidermis, therefore the pattern cannot be destroyed by superficial skin injuries [40]. Although most fingerprints can be classified as one of three types – arches, loops, or whorls – there is great individual variation in detail, so great indeed that no two
Role of Merkel cells in biofield modalities such as Reiki, therapeutic touch and telekinesis
While specific frequencies of electromagnetic radiation can be absorbed by the body, electromagnetic fields are also produced in the body due to movement or rotation of charged particles such as protons, electrons and ions [45]. So the humans not only absorb but also radiate the electromagnetic frequencies [46]. Biofield therapies such as therapeutic touch (hands-off) and Reiki (hands-on therapies) which have been used to reduce pain, facilitate healing and promote health claim to base their
In utero functions of Merkel cells
Human fetal adrenal development is characterized by rapid growth, high steroidogenic activity, and a distinct morphology, including a unique cortical compartment known as the fetal adrenal cortex. For most of gestation, the predominant fetal zone accounts for 80–90% of the cortical volume and is the primary site of growth and steroidogenesis, producing 100–200 mg/day of the androgenic steroid, dehydroepiandrosterone sulfate (DHEA-S) [57]. We previously published our hypothesis about dependence
Role of Merkel cells in epigenetic inheritance and biological adaptation
All human groups of present-day are adapted to their ecological niche in various ways. As a result of adaptation, there is a great deal of variation from one geographic region to another in skin color, hair form, craniofacial morphology, stature, body proportions, and a host of less immediately obvious traits [65]. The term adaptation is therefore interpreted to encompass those responses in the phenotype, which are produced by the action of the environment upon a given gene system, and is
Role of Merkel cells in hair form and skin biology
Hair form is an important structure that has enabled man to adapt to life in diverse environmental conditions [69]. Humans who reside in cold climates tend to have straight hair; inhabitants of more moderate climates have wavy hair, and those from hot humid climates have tightly coiled, spiraled, wool-like hair. Tightly coiled spiraled hair tends to facilitate the removal of the heat from the scalp and cooling of the brain while straight hair promotes conservation of heat and warming of the
Conflicts of interest statement
None declared.
Acknowledgments
I dedicate this work to my parents Fatma and Ferhat Irmak and to my wife Zisan Irmak.
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