Neurotoxins, Poisons, and Pesticides

Neurotoxins and Cell Signaling

Definitions

Black Widow

Poisons

• Neurotoxin: a poison that acts on the nervous system
• Poison: a substance capable of causing illness or death of a living organism
• Pesticide: substance used to destroy insects or organisms harmful to cultivated plants

Neurotoxins inhibit neuron control over ion concentrations across the cell membrane which block the signals from being able to move across a synapse. This can alter an organism's ability to react to stimuli by inhibiting the signal and blocking it from getting to its destination

• Poisons are generally chemicals that affect the nervous system resulting in harmful neurological effects
• Poisons can affect the nervous system both directly and indirectly
• One form of directly altering the nervous system is targeting the neural signaling pathways
• Poisons additionally affect the nervous system indirectly in forms such as metabolic substances

The black widow's neurotoxin alpha latrotoxin targets the central nervous system by changing the structure and function of nerve terminals. This triggers rapid exocytosis where the nerve cells eject calcium and can no longer communicate.

Example

Example

An example of a direct influence poisons have on the nervous system is through nerve agents which can trigger unconsciousness and seizures

An example of a poisons indirect affect is a metabolic poison disrupting cellular respiration, preventing the brain from getting oxygen and the whole body from getting an adequate amount of energy.

Hexachlorophene

Effects of neurotoxins

• Neurotoxins either disrupt the chemical balance and functioning of nerve cells or degenerate the cell completely causing problems in the CNS (Central Nervous System) in humans.

• Hexachlorophene is commonly found in anti-septic products.

• Acts as a neurotoxin by causing swelling in organs associated with the nervous system including the spine, brain stem, and optic nerves.

• Hexachlorophene does this by inhibiting the portion of the ETC that is bound to the cell membrane known as respiratory D-lactate dehydrogenase found in nerves of teh respiratiry system.

• Inhibition of this part of the ETC initiates respiratory failure if hexachlorophene is present in copious amounts.

Neurotoxins, Poisons, and Pesticides

Pesticides

Pesticides' effect on Parkinson's Disease

• Exposure to Pesticides can greatly impact humans.
• even low levels can have large effects.
• Active and Inert Ingredients are present in pesticides.
• Active: What kills the pest.
• Inert: help the active ingredients.
• solvents may be absorbed by the skin and can be toxic if inhaled.

• Many pesticides inhibit ALDH, an enzyme that converts aldehydes(toxic compounds) into less harmful compounds.
• Aldehydes impede brain cells that produce dopamine.
• This lack of dopamine causes limb stiffness and loss of balance, which are experienced by those with Parkinson's.

Examples

Effects of Pesticides

Ingredients in pesticides that affect the human nervous system include organophosphates and carbamates while others may be carcinogens and cause cancer.

• Pesticide exposure can cause memory loss, loss of coordination, reduced visual ability, and uncontrolled mood and general behavior.
• Fetuses can exhibit growth issues.
• Fewer nerve cells and a low birth weight are also common to those exposed to pesticides.
• Those exposed to pesticides are at a 70% increase for Parkinson's disease.

Organophosphates

Works Cited

Commonly found in agricultural pesticides.

Acts as a neurotoxin by inhibiting enzymes that produce vital neurotransmitters

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• Katz, Kenneth D. "Organophosphate Toxicity." Medscape. WebMD LLC., 12 Oct. 2014. Web. 4 Dec. 2014. <http%3A%2F%2Femedicine.medscape.com%2Farticle%2F167726-overview%23a0104>.
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