Propagating calcium wave
1. RHYTHMS IN HUMAN NATURE
Of the ultradian frequency clusters, I consider the following the most important in our study of human virtues and passions.
o The 90-minute rest/activation cycle, coordinated in the pontine reticular activating system in the brain, identified by Nathan Kleitman in the sixties, a cycle that runs continuously through the day and shapes the sleep stages and enters into REM sleep and dream life and so touches on the resources of human imagination. The same period is found in the somite deposition in vertebrate embryology.13
o The 20-minute cell division cycle conserved from prokaryotes and carried into more complex eukaryotic cell cycles as the M phase in mitosis. Rossi and Lippincott see this as a trigger or a latency period for the basic rest/activation cycle. According to their literature search, “A 20 minute building up period of mediating factors (maturation pro-moting factor and H1 kinase) is required to trigger the 90-120 minute process of genetic replication in the complete 24 hour circadian cell cycle in eukaryotes.”14 Murray, Solomon and Kirschner, quoted in Rossi and Lippincott tie the biology to behavior this way: “The neuroendocrine system is now well recognized as having prominent ultradian and circadian components related to a variety of psychobiological behaviors associated with mental and physical activity, nutrition, metabolism and reproduction. There are experimentally verifiable 20-minute couplings between peaks of associated hormones that are released in approximately 90-120 minute ultradian rhythms: luteinizing hormones peaks lead prolactin and testosterone peaks by 10-20 minutes (Veldhuis et al. 1987. Veldhuis and Johnson, 1988, Veldhuis, this volume); Glucose leads insulin by 15-20 minutes (van Cauter et al, 1989); cortisol leads B-endorphin by 20-30 minutes (Iranmanesh et al, 1989). These associations that extend from the molecular-genetic generation of these hormones at the cellular level to their expression at the neuroendocrinal level and their interaction with the mind-brain processes of memory, learning and behavior described below can hardly be accidental.”
o The interaction of heart and breath, rhythmically driven by the respiratory sinus arrhythmia (RSA) organized in the medulla of the brain. Though it shows a good deal of cycle to cycle variability, heart rate variability is important to our study because it feeds and drives emotional states, paces relaxation, pushes anxiety, and contributes enormously to a moment to moment sense of ourselves. It entrains other body rhythms related to blood flow, blood pressure, fluid shifts, vasomotor and kidney functions. A power spectrum analysis of heart rate variability shows the presence of all of these systems. Jerome Kagan treats these conditioned cardiac cycle patterns as formative factors in a child’s temperament.
o Calcium oscillations conserved across many phyla carry coded signals across cell membranes and bear instructions that start or stop or change the rate of reactions. Spontaneous calcium oscillations have been discovered in the astrocytes of human brain cells. Astrocytes respond to chemical, electrical and mechanical stimuli with transient increases in intracellular calcium concentration ([Ca2+](i)).15 Parri et al write that “astrocytes in situ display intrinsic [Ca2+](i) oscillations that are not driven by neuronal activity. These spontaneous astrocytic oscillations can propagate as waves to neighboring astrocytes and trigger slowly decaying NMDA receptor-mediated inward currents in neurons located along the wave path. These findings show that astrocytes in situ can act as a primary source for generating neuronal activity in the mammalian central nervous system." These rate-determining factors play a role in synaptic neurotransmitter release and reuptake and in the balances between the neurotransmitters themselves, and these balances have distinct emotional and behavioral consequences.
Fast calcium oscillations are found across all kingdoms of life. Jaffe and Creton, 1998, have been collecting and analyzing calcium wave traffic at a variety of frequencies.
Jaffe (1994)16 provides a good review of the possible rates and rhythms divided into four frequency bands. These closely fit the ultradian frequency bands we have been describing.
o Rhythm based motility. Organisms do not stay still. Their gliding, flying, twitching, swimming, walking and galloping gaits function rhythmically. The muscle contractions and relaxations behind them move rhythmically. Motility has been studied in organisms of many phyla. The rhythms of flagellated and ciliated locomotion in single celled organisms have been found in our own human bodies. The villi in our intestines and the cilia in our airways beat in tempos that are conserved across species. The molecular biology of actin-myosin is shared everywhere. So too with the biochemistry of the “movement molecules” actin, dynein, kinesin and others. The 9:2 rotors of flagellae and the coordinated movements of cilia of single-celled protista continue to function in the physiology of multicellular or-ganisms. The 9:2 flagellar motor drives our sperm cells.
o Many 8-12 Hz rhythms appear in human physiology, and may link together such divergent functions as theta brain waves, flagellar movements and the rhythm of muscle tone related to essential tremor. These frequencies recur all through the tree of life. We observe them in embryonic development. Rudolpho LLinas discuss these frequencies in primitive sea animal embryos, and notes “that intrinsic tremor in the musculature itself leads, via electrotonic coupling, to rhythmic, oscillatory movement, thus allowing water to flow through the gills and oxygen exchange with the external world and, so vital to life, throughout the egg sack. This form of motricity is “myogenic,” for it represents movement born purely from the intrinsic properties of the muscle cells.”17
Molecular biologists understand these intrinsic properties to involve the ratcheting movements in the actin and myosin motor molecules found even in primitive single celled organisms.
o Micromotion can sometimes entrain rhythms of the near environment. They are transmitted to the movement of air, to slight temperature changes, electrical potentials, to the wafting of pheromones and other chemotactic communications. These tremulous dance-like movements, small as they are, produce big changes when they are timed right. They move into resonant relationships with other body oscillators and to the rhythms in the near environment, including the micromotion of other persons. There is some evidence that mother/infant bonding works this way. With current digital video motion analysis technology, we will very likely view these rhythmic interactions in all kinds of social exchanges.