Wednesday, November 16, 2005

Eyes Part Two

It was not until the middle of the nineteenth century, as the subcontinent of Australia and its surrounding territory came to be explored, that a flurry of interest centered upon a lizard native to the area, the tuatara (Sphenodon punctatum). This animal possessed, in addition to two perfectly ordinary eyes located on either side of its head, a third eye buried in the skull which was revealed through an aperture in the bone, covered by a transparent membrane, and surrounded by a rosette of scales. It was unmistakably a third eye but upon dissection it proved to be non-functional.

Though this eye still possessed the structure of a lens and a retina, these were found to be no longer in good working order: also lacking were the appropriate neural connections to the brain. The presence of this eye in the tuatara still posses a puzzle to present-day evolutionists, for almost all vertebrates possess a homologous structure in the center of their skull. It is present in many fish, all reptiles, birds, and mammals (including man). This structure is known in literature today as the pineal gland.

The gland is shaped like a tine pine cone situated deep in the middle of the brain between the two hemispheres. Studies then began to determine whether this organ was a true functioning gland or merely a vestigial sight organ, a relic from our reptilian past. In 1959 Dr. Aaron Lerner and his associates at Yale University found that meletonin (1), a hormone manufactured by the pineal gland, was created through the action of certain enzymes on a precursor chemical which must pre-exist in the pineal in order for it to be transformed into melatonin. This precursor chemical turned out to be serotonin (2).

It was E.J. Gaddum, a professor of pharmacology at the University of Edinburgh, who was the first to note a connection between serotonin and mental states of being. In a paper published in 1953, he pointed out the fact that LSD-25 was a potent antagonist to serotonin. Serotonin is not an unusual chemical in nature; it is found in many places - some of them odd, like the salivary glands of octopuses, others ordinary; it abounds in plants such as bananas, figs, and plums. What then is its function in the human brain?

The Biological Function of the Third Eye

In other eyeball news...this is pretty horrible so I thought I'd bury it way down here at the've been warned...

Ants Eat Woman's Eyeball

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