1. The Virtual Museum of Natural History Presents

2. Third Eyes, Saurians, and

3. Third Eyes, Saurians, and Scandinavian Suicide! By Dr. Robert Sprackland

4. A long time ago, in a galaxy… well, right here.

5. It was a time of civil strife, war, and peace protestors, but they have nothing to do with our story. In the mid 1960s three herpetologists decided to set out to discover the function, if any, of the third eye in lizards.

6. The lizard they chose to study was one of the Galapagos lava lizards. Running an Imperial blockade with their data…

7. A Field Study of the Lava Lizard ( Tropidurus albemarlensis ) in the Galapagos Islands by Robert C. Stebbins, Jerold M. Lowenstein, and Nathan W. Cohen Ecology: 1967. Vol. 48, No. 5, pp. 839–851. The species is now known as Microlophus albemarlensis

8. Findings : The third eye is a real eye: Cornea Lens Retina Optic nerve

9. Of course, we’d long known that tuatara and many lizards had such structures. We just didn’t know what – if anything – those third eyes did.

10. The Anatomy of the Third Eye and Related Structures

11. But – “ Behavior, activity, body temperature, and Iodine—131 uptake by the thyroid gland were studied.” “ Parietalectomy had no detectable effect on any of the parameters investigated.”

12. 1976: Study of collared lizards. Parietal eye is active in light; sends afferent signal to pineal gland. Does the same thing if third eye is doused with 5-hydroxytryptamine (serotonin).

13. Conclusion: Some hormones require light if they are to function. Well, DUH, genius!

14. 1989: Pinealectomized collared lizards selected significantly lower temperatures than normal lizards, especially at night. However, pinetalectomy had no effect on the temperatures selected by chuckwallas. B. T. Firth , J. S. Turner, and C. L. Ralph, in : Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology Volume 159, Number 1 / January, 1989

17. During those same two decades, physiologists were discovering a host of new neurotransmitters in humans. It seemed that our emotions had a strong link to the chemicals related to the third eye…

18. Questions about a variety of mental disorders were bringing herpetologists and neurophysiologists on an intersecting course.

19. One question seemed to run through many discussions… … why was the suicide rate in Scandinavian countries statistically so high? Is light exposure related to HUMAN behaviour???

21. Did the pineal gland and third eye effect any nocturnal lizard species? In 1999, researchers reported that the parietal eyes of nocturnal desert night lizards ( Xantusia vigilis ) do indeed fire nerve impulses in response to light! E. SOLESSIO and G. ENGBRETSON Visual Neuroscience (1999), 16: 895-907.

22. Most nocturnal reptiles have no visible third eye. Not snakes, diurnal geckos, or the vast majority of burrowing lizards.

23. Melatonin level in two humans. Gray = night; white = daytime.

31. Scandinavians live in places where the winters are long, dark, and gloomy. “ Yo, Sven; how are you feeling?” “ So-so, Ole; a bit dark and gloomy.”

32. In the prolonged absence of full-spectrum light, people living at higher latitudes fail to produce adequate serotonin and melatonin.

33. Low UV also limits activation of vitamin D3, which in turn makes the body’s calcium levels drop.

34. Calcium is essential in making nerves work, including those in the brain that produce and respond to chemicals such as serotonin. Serotonin, in turn, regulates moods. Melatonin controls sleep and appetite.

35. Those long Arctic Circle winters were literally depressing people into suicidal tendencies! We call this seasonal affective disorder .

36. Therapies to fight the gloom include the simple use of special full-spectrum lamps during the winter months…

37. … and medications that complement the normal role of neurotransmitters.

38. That’s why some of us take Prozac, Effexor, or Citalopram. Side effects may cause drowsiness, hyperactivity, diarrhea, constipation, sexual dysfunction, egg impaction, moodiness, cramps, headaches, euphoria, increased appetite, anorexia, gout, trench foot, hoof-and-mouth disease, anemia, and death. Symptoms generally temporary, except for gout.

39. Much of what we know about depression we gleaned from observing sun-loving lizards.

40. But there are still many unanswered questions: Ultraviolet light governs production of behaviour-modifying Chemicals and vitamin D3; does vitamin D3 also affect behaviour? How much UV exposure is adequate/necessary for an animal? Excess UV has been linked to melanomas; does hyervitaminosis D3 or excess serotonin/melatonin adversely affect health? How do nocturnal reptiles conduct vitamin D3 and serotonin metabolism?

41. THE NEXT STEP Observation of lizards under controlled conditions, in which the amount of UV exposure and intake of calcium are strictly regulated. Differences in behaviour, reproductive output or growth could provide insights to the effects of these factors.

42. THE NEXT STEP Include nocturnal lizards in the study, including species with and without parietal eyes. Understanding how animals produce adequate behaviour-regulating chemicals in the absence of sunlight could lead to an understanding of how to effectively treat humans with seasonal affective disorder and other forms of depression.