Propagating waves of calcium suggest that networks of astrocytes constitute a long-range signaling system within the brain. ~ American neurobiologist Ann Cornell-Bell et al
Like sodium and potassium, calcium is a prevalent oceanic ion. All 3 chemicals had critical roles in the origination of life.
Calcium is essential for an organism to be multicellular. Cell interaction and division are calcium dependent. Calcium is the 5th most abundant element in Earth’s crust, and in the human body.
Stabilized calcium serves as a base material for bones. But it is the reactive nature of calcium that makes it especially prized for biological application. Calcium highly reacts with the organically significant elements nitrogen and oxygen, as well as spontaneously reacting with water.
The universe is fundamentally comprised of coherent energy waves. Apprehending and using information are also wave functions.
Calcium waves are the standard biological means for intelligence processing. Calcium signaling facilitated intercellular cell communication in early multicellular organisms.
Plants employ calcium waves for their rapid long-distance communication network. Root-to-shoot communiqués travel this way. Plant root growth depends on calcium. Flowers bloom based upon calcium signaling.
The significance of sodium and potassium in nerve cell transmission was long known. It was not until 1883 that English clinician and pharmacologist Sydney Ringer discovered, via frog dissection, the significance of calcium in neural communication.
Calcium is a cellular regulator in all bodily organs and is critical to proper development in both plants and animals.
When an egg is fertilized, the ovum initiates conception via a calcium wave. Mother’s milk is calcium rich.
Almost all cortical astrocytes are interconnected. The end feet of different astrocytes wrap around each other, forming junctions through which receptors bind cells. Gap junctions are fused together via intercellular channels.
About 230 gap junctions connect a pair of astrocytes in the brain. The control of myelination that facilitates neural conductance occurs via gap junctions between astrocytes and oligodendrocytes. Gap junctions are employed between neurons and astrocytes during nerve cell construction. Other organs also employ gap junctions, including the liver and heart. All such gaps are bridged by calcium waves.
Neurotransmitters stimulate astrocytes to produce a calcium influx, transmitted as a calcium puff: a calcium-based wave to other networked astrocytes. Calcium is the cell regulator of neural communication: necessary at nerve cell synapses to release transmitters.
Neural signals come in from the senses. If the strength of the neural firing is over a threshold, astrocyte calcium waves propagate to other astrocytes at frequencies harmonious to the firing of the neuron.
There is a feedback dynamic to sensory processing. Strong neural firing at the synapse is indicative of a strong sensory stimulus. Strong firing increases the capacity of an axon to fire. Astrocyte calcium waves become more frequent, and are more readily initiated, from previous strong neural signaling.
Glutamate level corresponds with glial activity. A shot of glutamate is released from an astrocyte as part of a calcium wave firing. An increase in glutamate release corresponds with an increase in calcium wave propagation.
Astrocytes don’t just signal neurons at their synapse. An astrocyte can signal a neuron anywhere along its body. As a calcium wave spreads, glutamate release stimulates more neurons.
Calcium waves affect astrocytes within milliseconds. This is relatively slow compared to neural electrical signal transmission, but that extra duration is essential. Calcium waves spreading more slowly than neuronal communication allows time to integrate and process information.
Besides inter-glial communication by calcium wave, calcium also acts on astrocyte genes and proteins: affecting long-term changes in an astrocyte’s reaction to calcium stimulus. This suggests memory storage.