The Virtual Museum of Natural History at curator Presents

1. The Virtual Museum of Natural History at www.curator.orgPresents

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 Islandsby 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: CorneaLensRetinaOptic 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, pinealectomy 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 PhysiologyVolume 159, Number 1 / January, 1989

15. Meanwhile, in 1988: • Herpetologists found that if the third eye of a submissive male curly-tailed lizard was covered, it would become more aggressive and dominant. • “The results suggest that the responses are hormonally-controlled .” J. A. Phillips and K. Howe, in: Physiol Behav. 42(1):103-8

16. Considerable supporting data followed: ·Opiates influence behavioral thermoregulation in the curly-tailed lizard, Leiocephalus carinatus. [Physiol Behav. 1984] Serotonin reverses dominant social status. [Behav Brain Res. 2001] Activation of central biogenic amines following aggressive interaction in male lizards, Anolis carolinensis. [Brain Behav. Evol. 1995] • Independent effects of the pineal and a bacterial pyrogen in behavioural thermoregulation in lizards. [Nature. 1980] • Cytophysiological responses of the pineal gland to intermale aggression in a wild rat. [Endokrinologie. 1982]

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???

20. Suicide Rates (per 100,000), by country, year, and gender. Most recent year available. As of May 2003. COUNTRY YEAR MALES FEMALES TOTAL Denmark 1998 20.9 8.1 29.0 Finland 1999 34.610.9 45.5 Japan 1999 36.514.1 50.6 Norway 1999 19.5 6.8 26.3 Sweden 1999 19.7 8.0 27.7 Kazakhstan 1999 46.4 8.6 55.0 Australia 1999 21.2 5.1 26.3 Italy 2000 11.1 3.4 14.5 Britain 1999 11.8 3.3 15.1 U.S.A. 2000 17.6 4.1 21.7 Canada 1999 19.5 5.1 24.6

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

22. Most nocturnal reptiles have no visible third eye. Neither do snakes, diurnal geckos, or the vast majority of burrowing lizards.

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

24. Serotonin is produced from the amino acid tryptophan in retinal cells. During daylight hours serotonin is sent to the thalamus, and finally to the pineal. There, it is converted into melatonin.

25. What was learned? • Light, especially ultraviolet, has profound effect on retinal cell activity. • Retinal cells fire off nerve impulses, which jump from nerve to nerve as chemical neurotransmitters.

26. What was learned? • Light, especially ultraviolet, has profound effect on retinal cell activity. • Retinal cells are found in all eyes, including parietal eyes. • The neurotransmitter they secrete is serotonin.

27. What was learned? • Light, especially ultraviolet, has profound effect on retinal cell activity. • Retinal cells are found in all eyes, including parietal eye. • In daylight, some retinal cells send serotonin to the pineal gland, then convert it into melatonin. It remains stored there until daylight dims at dusk.

28. What was learned? • Light, especially ultraviolet, has profound effect on retinal cell activity. • Retinal cells are found in all eyes, including parietal eye. • In daylight, some retinal cells send serotonin to the pineal gland, then convert it into melatonin. • At night, the pineal releases melatonin into the bloodstream. From there, it goes to the brain’s limbic system.

29. What was learned? • Melatonin regulates most biorhythms: • sleep • mood • activity level • sex drive • emotional stability, and • control of gastrointestinal muscles

30. What was learned? • Melatonin therefore helps keep us sane. • Too little melatonin, and we can become depressed. • Less than that and depression can turn to personality disorders and suicide.

31. Scandinavians live in places where the winters are long, dark, and gloomy. Turn on the light, Helga. It IS on, Sven!

32. In the prolonged absence of full-spectrum light, they fail to produce adequate serotonin and melatonin.

33. Low UV also limits activation of vitamin D3, making the body’s calcium levels drop. Hey, look! I’ve got a new joint between my elbow and my wrist!! You idiot! Your bones are Turning into rubber!

34. Calcium is essential in making nerves work. Serotonin 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. It’s so S.A.D.

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

38. That’s why some of us take Prozac, Effexor, or Citalopram.

39. For all this, we can thank sun-loving lizards.

41. Coming in the fall of 2007: GIANT LIZARDS Completely revised and expanded second edition.

42. LIZARDS AND TUATARA Also for Fall 2007: 400+ essential-to-know species for the ecotourist and terrarium keeper By Robert George Sprackland, Ph.D.

43. Good night, and thank you.

44. “Okay! Pizza time, right?” Visit us at www.curator.org