“action potentials.” Action potentials also carry information pertaining to sensory input from the body to the brain.
As the physiological techniques developed to study electrical communication in nerves, scientists began to use these techniques on glial cells in the late 1950s and early 1960s. As scientists stuck electrodes into the cells, they initially believed glia had no electrical potential. They were just sitting there like a piece of wood—something to knock on for good luck. However, these studies were performed inaccurately and were more designed as a confirmation of Cajal’s conclusion—the platitudes of yes-men trying to please their revered ancestors.
In 1955, Paul Glees (1909–1999) broke from the neuron religion—and was the first to suspect a noninsulating role for astrocytes. Glees wrote a book titled
Neuroglia: Morphology and Function
and stated, “Apart from a protective, insulating and supporting function, could neuroglia have a metabolic activity exceeding its own requirements, which would influence directly neuronal metabolism or synaptic activity? Until this dynamic concept has been proved, neuroglia will remain largely a domain of morphology and the artistic delight of neurohistologists.”
The first studies of the physiology of glial cells in vertebrates were performed on the frog and mud puppy and published in 1966 out of Steven W. Kuffler’s (1913–1980) lab at Harvard. Ironically, in the same year, he founded the Harvard neurobiology department. The name of the department demonstrates the influence of the neuron doctrine through the twentieth century. If he were more democratic and more aware of his research, he would have called it the “Brain Biology Department.” Of course, this doesn’t sound as fancy. Kuffler’s groundbreaking studies were also performed with the intent to provide evidence for Pedro’s theory, but he inadvertently discovered an electrical potential in astrocytes along the way. At the time, it might have been more appropriate for him to call the department “The Neuro and Check Out ThisRandom Interesting Stuff We Found Out About This Previously Thought to Be Functionless Cell Department.”
He starts the mud puppy paper with the line, “Little is known about the physiological properties of glial cells in the vertebrate central nervous system.” In fact, in 1966, absolutely nothing was known about glial cells, the most abundant cell in the brain by a large magnitude.
The studies that Kuffler and his students Nicholls and Orkand performed on the leech encouraged the idea that glia were functioning cells. In science, however, since humans are vertebrates and not octopi, a paper on a leech matters less than one on a vertebrate. In the frog, as in the leech, they found astrocytes exhibited an electrical potential that could be changed dramatically in the presence of potassium. Kuffler was interested in potassium as it flows out of neurons during an electrical potential. He wanted to test (or confirm) the theory that glia absorbs neuronal electrical firing, and the idea that astrocytes respond to potassium might lead credence to the theory.
The finding that astrocytes respond to an ion had long-range implications and inspired scientists to consider them more closely. Electrical stimulation of astrocytes was unable to create an action potential, however, and because this was believed to be the only worthy brain cell communication (the preferred method of the neuron) scientists could not yet grasp the importance of glia.
In an adjoining paper, when Kuffler and colleagues stimulated neurons, they found that glia also depolarized. They assumed that potassium influx in glial cells was the main constituent of this depolarization. However, scientists now know that many factors contribute, with calcium taking the most prominent role.
In 1986, Sean Murphy and colleagues at the Open University discovered that transmitters released from neurons stimulate astrocytes in
As the physiological techniques developed to study electrical communication in nerves, scientists began to use these techniques on glial cells in the late 1950s and early 1960s. As scientists stuck electrodes into the cells, they initially believed glia had no electrical potential. They were just sitting there like a piece of wood—something to knock on for good luck. However, these studies were performed inaccurately and were more designed as a confirmation of Cajal’s conclusion—the platitudes of yes-men trying to please their revered ancestors.
In 1955, Paul Glees (1909–1999) broke from the neuron religion—and was the first to suspect a noninsulating role for astrocytes. Glees wrote a book titled
Neuroglia: Morphology and Function
and stated, “Apart from a protective, insulating and supporting function, could neuroglia have a metabolic activity exceeding its own requirements, which would influence directly neuronal metabolism or synaptic activity? Until this dynamic concept has been proved, neuroglia will remain largely a domain of morphology and the artistic delight of neurohistologists.”
The first studies of the physiology of glial cells in vertebrates were performed on the frog and mud puppy and published in 1966 out of Steven W. Kuffler’s (1913–1980) lab at Harvard. Ironically, in the same year, he founded the Harvard neurobiology department. The name of the department demonstrates the influence of the neuron doctrine through the twentieth century. If he were more democratic and more aware of his research, he would have called it the “Brain Biology Department.” Of course, this doesn’t sound as fancy. Kuffler’s groundbreaking studies were also performed with the intent to provide evidence for Pedro’s theory, but he inadvertently discovered an electrical potential in astrocytes along the way. At the time, it might have been more appropriate for him to call the department “The Neuro and Check Out ThisRandom Interesting Stuff We Found Out About This Previously Thought to Be Functionless Cell Department.”
He starts the mud puppy paper with the line, “Little is known about the physiological properties of glial cells in the vertebrate central nervous system.” In fact, in 1966, absolutely nothing was known about glial cells, the most abundant cell in the brain by a large magnitude.
The studies that Kuffler and his students Nicholls and Orkand performed on the leech encouraged the idea that glia were functioning cells. In science, however, since humans are vertebrates and not octopi, a paper on a leech matters less than one on a vertebrate. In the frog, as in the leech, they found astrocytes exhibited an electrical potential that could be changed dramatically in the presence of potassium. Kuffler was interested in potassium as it flows out of neurons during an electrical potential. He wanted to test (or confirm) the theory that glia absorbs neuronal electrical firing, and the idea that astrocytes respond to potassium might lead credence to the theory.
The finding that astrocytes respond to an ion had long-range implications and inspired scientists to consider them more closely. Electrical stimulation of astrocytes was unable to create an action potential, however, and because this was believed to be the only worthy brain cell communication (the preferred method of the neuron) scientists could not yet grasp the importance of glia.
In an adjoining paper, when Kuffler and colleagues stimulated neurons, they found that glia also depolarized. They assumed that potassium influx in glial cells was the main constituent of this depolarization. However, scientists now know that many factors contribute, with calcium taking the most prominent role.
In 1986, Sean Murphy and colleagues at the Open University discovered that transmitters released from neurons stimulate astrocytes in
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