Use the following information to answer the next set of ques

Use the following information to answer the next set of questions:

One of the most feared venomous spiders is the black widow. Most illustrations portray the female who bears a red hourglass-shaped marking on her spherical black abdomen. The black widow’s venom, known as latrotoxin, is injected through its fangs. Symptoms of latrotoxin poisoning include rashes, elevated blood pressure, respiratory problems and nausea.

The table below illustrates the responses by guinea pigs to the injection of latrotoxin plus four other different neurotoxins (each injected separately into a different guinea pig with latrotoxin) compared to the injection of each toxin individually into separate guinea pigs.

Saxitoxin

Botulin

Physostigmine

Atropine

Effect of Neurotoxin alone

Paralysis

Paralysis

Seizures, spasms

Paralysis

Effect with Latrotoxin

Less paralysis

Less paralysis

More spasms

Less paralysis

Which hypothesis is best supported by the data in the table? Latrotoxin ...

Solution

A. Enhance the Exocytosis of acetylcholine.

Latrotoxin effects the neuromuscular junction which causes the release of acetylcholine from the pre-synapse. It bbinds to receptor and activate the IP3/DAG pathway and release intracellular calcium. Increased calcium at pre-synapse leads to release of synaptic vesicles of acetylcholine.