Medical Aspiring author looking for theories

[Kitmin1246]

Aspiring author looking for theories...

Hi :)
I'm looking for some information / theories for a sci-fi book I'm working on.
I have no medical or biology background so I'm kind of starting from scratch with this.

I'm specifically looking for theories regarding parasites, virus's, things of that nature that would effect the brain.
Some questions I'm trying to work out are:

1. Is there any factors that could theoretically cause a virus/parasite-host relationship to change from an antagonistic relationship to a mutualistic one?
2. Plausibility of parasite/virus causing neurological phenomenons.
3. Could a naturally occurring parasite/virus theoretically mutate quickly (perhaps spontaneously) as opposed to over thousands of years, without using external stimulus like radiation?

I'm very new to writing and researching so any thoughts, idea, resources would be greatly appreciated!

Thanks!

 

[Cincinnatus]

Toxoplasma gondii!

This is a really weird one, they can only complete their lifecycle and reproduce when they have infected cats. However, they can infect many other organisms (including people) as well.

The really weird thing: There have been reports that when toxoplasma gondii infects rats then these rats become less afraid of cats than they would otherwise be. They are also not repelled by the smell of cat urine (as rats normally would be). The tantalizing interpretation is that toxoplasma gondii wants to be infecting cats so when it is in some other organism then it exerts some neurological effect that makes this organisms (e.g. the rat) more likely to be eaten by a cat. Thereby allowing T. gondii to transfer to its favored host!

Even more speculative: There is some epidemiological evidence (Mortensen et al 2007) that the mothers of schizophrenic people are more likely to have antibodies to T. gondii. the possible interpretation is that maternal T. gondii infection has some connection to the causes of schizophrenia! (this of course, is extremely speculative). It is a fascinating hypothesis though, especially considering the (more or less accepted) results on T. gondii changing rat behavior. See the Torrey and Yolken 1995 paper for details.

I should also note that T. gondii infection is normally harmless (except perhaps viza viz pregnancy complications). A pretty high percentage of people are infected and don't know it... There is no obvious effect of these benign infections, but they haven't been much studied either...

I happen to have collected a bunch of references on this hypothesis. I think my literature search was pretty complete at the time. Though there isn't too much out there on it... I did this a couple years ago so there may be something more recent. Here are a few references to get you started. These are all scientific articles... I recall there being a new york times popular science article on this subject a few years ago also (you should be able to find that in their online archives).

Yolken RH, Bachmann S, Rouslanova I, Lillehoj E, Ford G, Torrey EF, et al. Antibodies to Toxoplasma gondii in individuals with firstepisode schizophrenia. Clin Infect Dis 2001;32:842–4.

Wittig, P. A. (1979). "Learning capacity and memory of normal and Toxoplasma-infected laboratory rats and mice." Zeit. Parasit. 61: 29-51.

Werner H, M. K., Senk U (1981). "Latent toxoplasma-infection as a possible risk factor for CNS disorders." Zentr. Bakteriol. Mikrobiol. Hyg 250(3): 368-75.

Wende S. Die Bedeutung der Toxoplasmose für die Neurologie und Psychiatrie. Archiv für Psychiatrie und Zeitschrift Neurologie 1956;194:179–99.

Webster, J. P. (2001). "Rats, cats, people and parasites: the impact of latent toxoplasmosis on behaviour." Microbes Infect 3(12): 1037-45.

Webster JP, B. C., MacDonlald DW (1994). "Effect of Toxoplasma gondii upon neophobic behaviour in wild brown rats, Rattus norvegicus." Parasitology(109): 37-43.

Wastling J, Heap S, Ferguson D. Toxoplasma gondii—keeping our guests under control. Biologist (London) 2000;47:234–8.

Vyas A, Kim SK, Giacomini N, Boothroyd JC, Sapolsky RM (2007). “Behavioral changes induced by Toxoplasma infection of rodents are highly specific to aversion of cat odors.” Proc. Natl. Academy of Sciences. 104(15): 6442-7.

Vojtechovská M, Vojtechovsky M, Petru M. Nekteré parasitologické problémy u duševne nemocných. Cas Lek Ces 1956;95:559–66.

Torrey EF,and Robert H. Yolken. “Toxoplasma gondii and Schizophrenia.” Emerging Infectious Diseases, November 2003: 1375-1380.

Torrey EF, Robert H. Yolken. Could schizophrenia be a viral zoonosis transmitted from house cats? Schizophr Bull 1995;21:167–71.

Tenter Astrid, H. A., Weiss Louis (2000). "Toxoplasma gondii: from animals to humans." International Journal of Parasitology(30): 1217-1258.

Suzuki Y. Host resistance in the brain against Toxoplasma gondii. J Infect Dis 2002;185(suppl 1):S58–S65.

Roch E, Varela G. Diversos aspectos de la investigación sobre toxoplasmosis en México. Resultados obtenidos en 29 883 reacciones de Sabin y Feldman efectuadas de 1953 a 1965. Rev Invest Salud Púb. (Méx) 1966;26:31–49.

Qiuying L, Xiaonian L, Li L, et al. [The control study of schizophrenia and affective disorders and Toxoplasma infections.] Acta Academiae Medicinae Hubei 1999;20:223–5.

Mortensen PB, Pedersen BN, Waltoft BL, et al. Toxoplasma gondii as a risk factor for schizophrenia: analysis of filter paper blood samples obtained at birth. Biol Psychiatry. In press. 2007

Mortensen, P. B., B. Norgaard-Pedersen, et al. (2007). "Early Infections of Toxoplasma gondii and the Later Development of Schizophrenia." Schizophr Bull.

Minto A, Roberts FJ. The psychiatric complications of toxoplasmosis. Lancet 1959;1:1180–2.

Leweke FM, Gerth CW, Koethe D, Klosterkötter J, Ruslanova I, Krivogorsky B, et al. Antibodies to infectious agents in individuals with recent onset schizophrenia. In press, Eur Arch Psychiatry Clin Neurosci 2003.

Kramer W. Frontiers of neurological diagnosis in acquired toxoplasmosis. Psychiatria, Neurologia, Neurochirurgia 1966;69:43–64.

Kankova S, Sulc J, Nouzova K, Fajfrlik K, Frynta D, Flegr J. “Women infected with parasite Toxoplasma have more sons.” Naturwissenschaften. 2007 Feb;94(2):122-7. Epub 2006 Sep 30.

Is insanity due to a microbe? [editorial] Sci Am 1896;75:303

Hay J. Aitken P.P, H. W. M. G. D. I. (1983). "The effect of congenital and adult acquired Toxoplasma infections on activity and responsiveness to novel stimulation in mice." Ann. Trop. Med. Parasitol. 77: 483-495.

Gu H, Yolken RH, Phillips M, Yang F, Bilder RM, Gilmore JH, et al. Evidence of Toxoplasma gondii infection in recent-onset schizophrenia [abstract]. Schizophr Res 2001;49:53.

Flegr,J. “Effects of Toxoplasma on Human Behavior.” Schizophr Bull. 2007 Jan 11; [Epub ahead of print]
Garcia GD. Toxoplasmosis y enfermedades mentales. Rev Cub Med Trop 1979;31:127–31.

Cook I, Derrick EH. The incidence of Toxoplasma antibodies in mental hospital patients. Australas Ann Med 1961;10:137–41.

Brown AS, Schaefer CA, Quesenberry CP Jr, Liu L, Babulas VP, Susser ES. Maternal exposure to toxoplasmosis and risk of schizophrenia in adult offspring. Am J Psychiatry. 2005;162:767–773.

Buentello E. Comunicación preliminar sobre las relaciones entre toxoplasmosis, acido lisérgico y esquizofrenia. Gac Méd Méx 1958;88:693–708.

Boronow J, Dickerson F, Stallings C, Lee B, Origoni A, Yolken R. HSV-1, CMV and Toxoplasma serology predict cognitive deficits in schizophrenia. Schizophr Res 2002;53:85.

Brando JL, Torrey EF, Yolken R. Drugs used in treatment of schizophrenia and bipolar disorder inhibit the replication of Toxoplasma gondii.

Berdoy M, Webster JP, Macdonald DW. Fatal attraction in Toxoplasma-infected rats: a case of parasite manipulation of its mammalian host. Proc R Soc (Lond) 2000;B267:1591–4.

Aparicio Garrido J, Paniagua Redondo V. Toxoplasmosis y enfermedades mentales. Archivos de Neurobiología 1968;31:161–72.

 

[zoobyshoe]

Toxoplasma gondii!

That's fricking fascinating. Never ran into that before.

3. Could a naturally occurring parasite/virus theoretically mutate quickly (perhaps spontaneously) as opposed to over thousands of years, without using external stimulus like radiation?

Theoretically, yes. In his work on fractals, Benoit Mandelbrot observed two dynamics that apply to any and all change: The Job Effect, whereby, once a pattern is established it tends to persist, and, The Noah Effect, whereby, once a pattern that has persisted begins to change it changes very suddenly and drastically. Evolutionary biologists are changing their thinking on the notion of slow, gradual change, considering more and more the idea that populations might evolve, instead, in sudden, fast leaps and bounds. Any Chaotic Reversal might, also, serve the same function as a mutation for science fiction purposes.

In general the field of Chaos (in reference to Mandelbrot) is rife with outside-the-box notions just waiting to be misinterpreted and corrupted into science fictions premises. I'm surprised it didn't already explode into that genre years ago.

(Also: Normally I don't bother mentioning this sort of thing, but if you want to be a writer you must greatly tighten up on your English. You wrote effect when you meant affect, and the singular form of the verb to be: is, disagrees with the plural noun: factors in your first question. In question three you have a similar problem: "...without using external stimulus like radiation?" It should be: "...without using an external stimulus..." or " ...without using external stimuli...". [Decide if you want it to be singular or plural and then be consistent with the use of articles.] And the much more widely used plural of phenomenon, phenomena is preferable to the naive sounding phenomenons. )

 

[Kitmin1246]

Thanks Cincinnatus. :)
Appreciate all the references!
I was actually just starting to research Toxoplasma gondii!

 

[Kitmin1246]

Theoretically, yes. In his work on fractals, Benoit Mandelbrot observed two dynamics that apply to any and all change: The Job Effect, whereby, once a pattern is established it tends to persist, and, The Noah Effect, whereby, once a pattern that has persisted begins to change it changes very suddenly and drastically. Evolutionary biologists are changing their thinking on the notion of slow, gradual change, considering more and more the idea that populations might evolve, instead, in sudden, fast leaps and bounds. Any Chaotic Reversal might, also, serve the same function as a mutation for science fiction purposes.

Okay, riddle me this:

Would it be conceivable for the "Toxoplasma gondii" parasite to undergo a sudden evolution/mutation?
If so, would there be limitations on the result? (theoretically)?

Looking at it from a science fiction standpoint, I'm interested in knowing what's plausible and what's laughable. :)

Btw, my apologies on my loose English ;) I don't bother editing myself when posting.

 

[Tsu]

http://images.google.com/images?hl=en&q=CT images of Toxoplasmosis&um=1&ie=UTF-8&sa=N&tab=wi

This google page shows some CT images of patients w/ toxoplasmosis. We saw quite a lot of it when I lived and scanned in So. California.

 

[Proton Soup]

also just read something that says T. gondii raises libido in women.

 

[Cincinnatus]

Yeah, "mind controlling" parasites are more common than you think! Especially in the insect world. There are fascinating discussions of how these parasites could have evolved in some some of Richard Dawkins' books.

T. gondii gets a lot of attention because it seems to be the one that could most plausibly be affecting humans in this manner...

 

[Andy Resnick]

I'd add Gordian worms to the list.

http://other-invertebrates.suite101.com/article.cfm/horsehair_snakes

The article also mentions Toxoplasma and Dicrocoelium dendriticum.

 

[adrenaline]

2. Plausibility of parasite/virus causing neurological phenomenons.

Subacute sclerosing panencephalitis (SSPE) may develop many years after measles comes to mind, it develops 2-10 years after the measles infection. Of course it is nearly fatal.

I had not read about toxo and shizophrenia ( so thanks for the info!) but I have read literature regarding flu infection in pregnancy and its possible association with producing an offspring with schizophrenia.

 

[Proton Soup]

a bit off the parasite path, but my favorite schizophrenia theory is that it's caused by shoes with heels.

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&cmd=search&term=schizophrenia+footwear

 

[adrenaline]

a bit off the parasite path, but my favorite schizophrenia theory is that it's caused by shoes with heels.

http://www.ncbi.nlm.nih.gov/sites/entrez?db=pubmed&cmd=search&term=schizophrenia+footwear

How funny, almost all my schizophrenic patients smoke, wonder if we find a similar correlation with invention of cigarettes...
(although i think the nicotine soothes the schizophrenic brain, sort of a self medication..)

 

[jwlm88]

About the mutation or adaptation...

Adaptation is more a viral and bacterial. The biological agent if not completely removed may adapt to be more resistant to the anti-biotic, anti-viral, or antigen. Case and point T.B is a bacterial infection, however there are drug resistant forms of T.B. T.B is a bacteria however not necessarily what I would call a parasite.

Parasite vs Symbiote

There is a slight difference... possibly only semantic. A parasite may cause little to no outward symptoms however, do nothing of any benefit to the host. Usually these parasites cause harmful, sometimes deadly side effects, especially when the development of the parasite is done in an abnormal area. A certain parasites (can't remember name) usually develop in the lungs, however there has been many cases when the parasite develops in the hosts brain causing a large sist. A symbiotic life form usually does no harm to the host and benefits the host. Sometimes, as in the case with cows the symbiote is necessary for life...(that information is based on memory alone, it would be best to research that on your own).

Affecting the function of a host

As mentioned in an earlier post a parasite can influence the hosts brain function. There is a particular parasite that moves to the brain of a slug, and completely controls the slug. It causes the slug to move into the high branches of a tree (or out in the open). Where it will wait to be eaten by a predator (again based on memory, do research on your own).

If you consider a virus as a parasite.

A virus will attach itself to a cell and inject genetic material and mutate the cell to produce more of the virus. And many viral infections can affect mental stability, and in fiction can cause "rage" (A.K.A zombies).