Reptile & Amphibian Forums

First off, thanks for all the support I got when I first started posting. Since then I have read everything about venomous reptiles I can, and I've learned a lot.
I am, however, confused about the effects of neurotoxin...does it affect the actual neurons themselves, or the synapse? Also, does this cause automatic body functions (breathing, pumping blood, etc.) to quit? Finally, what venomous snakes is this toxin most prominent in?
Thanks again, sorry to ask newbie questions....
-Ryan
2.0 Miniature collies
1.0 Chilean Rose Hair Tarantula
0.1 Ball Python
3.1 Sugar gliders
0.0.1 Veiled chameleon
2.0 Leopard Geckos
1.1 Finches
1.0 Green Tree Python

If I'm not too terribly mistaken, the neurotoxic compments that snakes carry mainly affect the space between the neuron and synapse, disrupting the messages between them. This is why autonomic bodily functions like breathing tend to shut down. There are numerous people on the board who are well-versed in this, so they could probably answer you more fully.

As for snakes who prominantly display neurotoxins, I would have to say that Dendroaspis takes the cake. Other snakes do display some impressive toxic collages though, including Oxyuranus and Pseudonaja of Aus/NG. Funny thing is that many people tend to generalize venoms as hemo or neurotoxic, and give the classic examples of vipers and cobras, but in reality most cobras (both true Najas and others) have a large amount of cyto or hemotoxic components to their venom, as evidenced by the massive tissue destruction they can cause. Go to venomousreptiles.org and take a look at the snake bite section of the photo gallery for some impressive...and disturbing...bite pictures from monocled cobras.

Anyway, I'm sure other more knowledgable people will add onto this thread, but this is my take on it.
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Chance Duncan
www.rivervalleyexotics.com

Neurotoxins tend to be classed as pre-synaptic or post-synaptic (before and after) The synaptic cleft refares to the space between the neuron(pre) and the receptor site on the muscle(post). The brain will send a message down the neuron and at the end a neuro transmitter will be released and "swim" across the synaptic cleft(space) to the muscle telling it to contract. Those that affect the pre synaptic region tend to take longer to cause affect but are more damaging, they can cause necrosis of the affected neuron. Not only can they stop the neurotransmitter from being released they can do the opposite and cause a mass release, this can be seen as muscle twitching. Antivenom has little affect against this type of venom once it has reached its target area. The venoms that affect post synapticly are quicker at reaching their target area and just tend to block the receptor site and there by stopping the signal from getting to the muscle. Antivenom is affective at removing these types of venoms. Hope that was simple enough to understand?

John
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"Its no help to hide behind the statement that snake bite accidents are a rarity and that the average Dr seldom or never will treat one. For the bitten patient, it is a matter of life or death, and the rarity of the event is of no interest to him."

An easy way to remember it is to call them the ABC neurotoxins. Alpha, beta, and cleft. Some snakes have more then others, but Dendroaspis is strong in this trio. Just an easy way to remember it. Peace, Tim Friede