Related Experiment Video
Updated: Aug 12, 2026

Functional Evaluation of Biological Neurotoxins in Networked Cultures of Stem Cell-derived Central Nervous System Neurons
Published on: February 5, 2015
The effect of the scorpion venom, tityustoxin, on high-affinity choline uptake in rat brain cortical slices
Abstract:
Tityustoxin (TsTx) inhibited high affinity choline uptake (HAChU) in cortical slices of the rat brain. The effect was dependent on the concentration of tityustoxin, energy source, incubation time, temperature, and the pH of the incubation medium. The inhibitory effect was dependent upon the presence of sodium and calcium ions in the incubation medium; barium ions could not replace calcium. Both tetrodotoxin and ethyleneglycol-tetra-acetic acid (EGTA) blocked the inhibitory effect of tityustoxin on high affinity choline uptake. On this evidence, it is suggested that the effect of tityustoxin might be related to its action on cell depolarization, causing an increase in the release of acetylcholine (ACh).
Related Concept Videos
Neurochemical Transmission: Sites of Drug Action
Direct-Acting Cholinergic Agonists: Pharmacokinetics
Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Anticholinesterase Agents: Poisoning and Treatment
Irreversible agents form a strong bond with the cholinesterase enzyme, making it inactive. The breakdown of the phosphorylated enzyme is slower than the...
Depolarizing Blockers: Pharmocokinetics

