In the animal kingdom, bigger is better right? Well, not always.
What the video to the right and pay close attention to the salamander.
The Salamander secretes a poisonous substance from its skin, killing the frog within seconds.
Poisons can work in a number of different ways; what we are going to focus on here are how specific poisons, drugs and diseases can affect neurotransmission in the body.
Before we start you should have an understanding of how neurons communicate (click here). You also need to understand two key terms, Agonists and Antagonists.
Observe the animation to the left. The orange chemical introduced into the system, binds to the receptor on the post synaptic cell. This causes the channels to remain open, setting the neuron into a constant state of excitement.
Other agonists block the enzyme from breaking down neurotransmitters, causing the cell to constantly remain excited.
Drugs such as cocaine actually prevent the re-
Agonist
Antagonist
Observe the animation to the right. The chemical added binds to the receptors, preventing the neurotransmitters from binding to the receptors and exciting the neuron.
These chemicals do not excite the neuron.
An example of this is Curare. This is a poison binds to achetylcholine receptors located on muscle cells. This causes muscle paralysis.
Poisons Animals
Red back spider
The Red back spider is one of the most poisonous spiders in the world. Closely related to the black widow spider, it has the ability to take down a full grown adult with one bite.
The Red back spiders venom works in a number of ways, however one of its effects is to stimulate the production of Atacetylcholine and norephinephrine. This causes paralysis of the entire nervous system.
Brown Snake
The brown snake has one of the most potent snake venoms in the world. Its not just the venom that makes this snake dangerous, but its aggressive nature.
The venom produced by this snake, can easily take down a full grown human, causing muscle paralysis and weakness.
The venom affects both the pre-
The neurotoxin released is Textilotoxin, this prevents the release of neurotransmitters from the axon endings, and blocks the acetylcholine receptors on the post-
Drugs
Cocaine
Cocaine enters the blood stream, making its way to the brain. It interferes with the communication of neurons, by blocking the re uptake of neurotransmitters.
Norepinephrine, Serotonin, Dopamine, and other neurotransmitters are blocked from being re-
The physiological effects of cocaine are devastating on the body. They constrict the blood vessels, while increasing the heart rate. This results in strokes (image to the right), seizures, abnormal behaviour and heart attacks.
Ecstasy
MDMA is the chemical name for Ecstasy. Ecstasy causes a release of serotonin, dopamine, and norepinephrine. However what distinguishes this drug from other amphetamines is the amount of serotonin released.
Ecstasy instructs the neuron to release large amounts of serotin.
This causes the user a sense of happiness and deep connections with those around.
Side effects of this drug include:
- Brain damage
- Memory Damage
- Sleep and emotion issues
- Depression
- Anxiety
- Kidney failure
- Hemorrhaging
- Psychosis
- Cardiovascular collapse
Disorders
Parkinsons Disease (PD)
Parkinson’s disease is a neurodegenerative disease, which attacks dopamine releasing neurons.
Individuals with Parkinson’s have low amounts dopamine in their brain.
Individuals with Parkinson’s have:
- Tremor of the hands, arms, legs, jaw and face
- Slow reactions
- Stiffness of the limbs
- Impaired balance and coordination
